X-Git-Url: https://gitweb.ps.run/chirp/blobdiff_plain/0b2f4de9c1db5ec1059f6cd9b8c44e07f3af0b51..48e80ae12c563913af56f867268c02650292f7ee:/src/main.zig

diff --git a/src/main.zig b/src/main.zig
index 1871dcc..9fb872f 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -1,416 +1,1799 @@
 const std = @import("std");
 const lmdb = @import("lmdb");
+const db = @import("db");
+const http = @import("http");
 
 // db {{{
 
 const Db = struct {
-    const Self = @This();
+    fn users(txn: lmdb.Txn) !UserList {
+        return try db.Db(UserId, User).init(txn, "users");
+    }
+    fn user_ids(txn: lmdb.Txn) !UsernameList {
+        return try db.Db(Username, UserId).init(txn, "user_ids");
+    }
+    fn sessions(txn: lmdb.Txn) !SessionList {
+        return try db.Db(SessionToken, UserId).init(txn, "sessions");
+    }
+    fn posts(txn: lmdb.Txn) !PostList {
+        return try db.Db(PostId, Post).init(txn, "posts");
+    }
+    fn users(txn: lmdb.Txn) !db.Db(UserId, User) {
+        return try db.Db(UserId, User).init(txn, "users");
+    }
+    fn user_ids(txn: lmdb.Txn) !db.Db(Username, UserId) {
+        return try db.Db(Username, UserId).init(txn, "user_ids");
+    }
+    fn sessions(txn: lmdb.Txn) !db.Db(SessionToken, UserId) {
+        return try db.Db(SessionToken, UserId).init(txn, "sessions");
+    }
+    fn posts(txn: lmdb.Txn) !db.Db(PostId, Post) {
+        return try db.Db(PostId, Post).init(txn, "posts");
+    }
+};
 
-    env: ?*lmdb.MDB_env = undefined,
-    txn: ?*lmdb.MDB_txn = undefined,
-    dbi: lmdb.MDB_dbi = undefined,
-    prng: std.Random.DefaultPrng = std.Random.DefaultPrng.init(0),
+// }}}
 
-    pub fn gen_id(self: *Self) Id {
-        var id = self.prng.next();
+// content {{{
 
-        while (self.has(id)) {
-            id = self.prng.next();
-        }
+const User = struct {
+    // TODO: choose sizes
+    id: UserId,
+    name: Username,
+    display_name: DisplayName,
+    description: UserDescription,
+    password_hash: PasswordHash,
+
+    posts: PostSet,
+
+    following: UserSet,
+    followers: UserSet,
+
+    post_lists: PostListList,
+    feeds: UserListList,
+};
+
+const Post = struct {
+    id: PostId,
+    parent_id: ?PostId,
+    quote_id: ?PostId,
+
+    user_id: UserId,
+    time: Timestamp,
+
+    upvotes: u64 = 0,
+    downvotes: u64 = 0,
+    votes: VoteList,
+    comments: PostSet,
+    quotes: PostSet,
 
-        return id;
+    text: PostText,
+};
+
+const SavedPostList = struct {
+    name: Name,
+    list: PostSet,
+};
+const SavedUserList = struct {
+    name: Name,
+    list: UserSet,
+};
+
+const Vote = struct {
+    const Kind = enum { Up, Down };
+
+    kind: Kind,
+    time: Timestamp,
+};
+
+const Id = u64;
+const Login = struct {
+    user: User,
+    session_token: SessionToken,
+};
+const Name = std.BoundedArray(u8, 32);
+const UserId = enum(u64) { _ };
+const PostId = enum(u64) { _ };
+const Timestamp = i64;
+const Username = std.BoundedArray(u8, 32);
+const DisplayName = std.BoundedArray(u8, 64);
+const UserDescription = std.BoundedArray(u8, 1024);
+const PasswordHash = std.BoundedArray(u8, 128);
+const SessionToken = u64;
+const CookieValue = std.BoundedArray(u8, 128);
+const PostText = std.BoundedArray(u8, 1024);
+const PostSet = db.Set(PostId);
+const UserSet = db.Set(UserId);
+const PostList = db.SetList(PostId, Post);
+const UserList = db.SetList(UserId, User);
+const UsernameList = db.SetList(Username, UserId);
+const VoteList = db.SetList(UserId, Vote);
+const PostListList = db.List(SavedPostList);
+const UserListList = db.List(SavedUserList);
+
+fn parse_enum(comptime E: type, buf: []const u8, base: u8) !E {
+    return @enumFromInt(try std.fmt.parseUnsigned(@typeInfo(E).@"enum".tag_type, buf, base));
+}
+
+// https://developer.mozilla.org/en-US/docs/Glossary/Percent-encoding
+fn reencode(comptime T: type, text: []const u8) !T {
+    var result = try T.init(0);
+
+    const len = @min(text.len, 1024); // TODO: PostText length
+
+    var idx: usize = 0;
+    while (idx < len) : (idx += 1) {
+        const c = text[idx];
+        if (c == '+') {
+            try result.append(' ');
+        } else if (c == '%' and idx + 2 < text.len) {
+            const allow = &[_]u8{ 0x26, 0x23, 0x3b, 0x0a };
+
+            const escaped_value = std.fmt.parseUnsigned(u8, text[idx + 1 .. idx + 3], 16) catch continue;
+
+            if (escaped_value == 0x0d) {
+                try std.fmt.format(result.writer(), "<br />", .{});
+            } else if (std.mem.indexOfScalar(u8, allow, escaped_value) != null) {
+                try std.fmt.format(result.writer(), "{c}", .{escaped_value});
+            } else {
+                try std.fmt.format(result.writer(), "&#x{x};", .{escaped_value});
+            }
+
+            idx += 2;
+        } else {
+            try result.append(c);
+        }
     }
 
-    pub fn open(self: *Self, name: [*c]const u8) void {
-        _ = lmdb.mdb_env_create(&self.env);
-        _ = lmdb.mdb_env_set_maxdbs(self.env, 10);
-        _ = lmdb.mdb_env_set_mapsize(self.env, 1024 * 1024 * 1);
-        _ = lmdb.mdb_env_open(self.env, name, lmdb.MDB_WRITEMAP, 0o664);
-        // _ = lmdb.mdb_env_open(self.env, name, lmdb.MDB_NOSYNC | lmdb.MDB_WRITEMAP, 0o664);
+    return result;
+}
+
+fn decode(text: []const u8) !std.BoundedArray(u8, 1024) {
+    var result = try std.BoundedArray(u8, 1024).init(0);
+
+    const max_len = @min(text.len, 1024); // TODO: PostText length
+
+    var idx: usize = 0;
+    var len: usize = 0;
+    while (len < max_len and idx < text.len) : ({
+        idx += 1;
+        len += 1;
+    }) {
+        const c = text[idx];
+        if (c == '+') {
+            try result.append(' ');
+        } else if (c == '%') {
+            if (idx + 2 < text.len) {
+                try std.fmt.format(result.writer(), "{c}", .{try std.fmt.parseUnsigned(u8, text[idx + 1 .. idx + 3], 16)});
+            }
+            idx += 2;
+        } else {
+            try result.append(c);
+        }
     }
 
-    pub fn close(self: *Self) void {
-        lmdb.mdb_env_close(self.env);
+    return result;
+}
+
+const Chirp = struct {
+    const PostsPerPage = 10;
+    const UsersPerPage = 10;
+    var HashBuffer = std.mem.zeroes([1024 * 1024 * 50]u8);
+
+    pub fn hash_password(password: []const u8) !PasswordHash {
+        var hash_buffer = try PasswordHash.init(128);
+
+        // TODO: choose buffer size
+        var alloc = std.heap.FixedBufferAllocator.init(&HashBuffer);
+
+        // TODO: choose limits
+        const result = try std.crypto.pwhash.argon2.strHash(password, .{
+            .allocator = alloc.allocator(),
+            .params = std.crypto.pwhash.argon2.Params.owasp_2id,
+        }, hash_buffer.slice());
+
+        try hash_buffer.resize(result.len);
+
+        return hash_buffer;
     }
 
-    pub fn begin(self: *Self, name: [*c]const u8) void {
-        switch (lmdb.mdb_txn_begin(self.env, null, 0, &self.txn)) {
-            0 => {},
-            else => |err| {
-                std.debug.print("txn err: {}\n", .{err});
-            },
+    pub fn verify_password(password: []const u8, hash: PasswordHash) bool {
+        var alloc = std.heap.FixedBufferAllocator.init(&HashBuffer);
+
+        if (std.crypto.pwhash.argon2.strVerify(hash.constSlice(), password, .{
+            .allocator = alloc.allocator(),
+        })) {
+            return true;
+        } else |err| {
+            std.debug.print("verify error: {}\n", .{err});
+            return false;
         }
+    }
 
-        // TODO: lmdb.MDB_INTEGERKEY?
-        _ = lmdb.mdb_dbi_open(self.txn, name, lmdb.MDB_CREATE, &self.dbi);
+    pub fn register_user(env: lmdb.Env, username: []const u8, password: []const u8) !bool {
+        const username_array = try Username.fromSlice(username);
+        const display_name = try DisplayName.fromSlice(username);
+
+        const txn = try env.txn();
+        defer txn.commit() catch |err| {
+            std.debug.print("error registering user: {}\n", .{err});
+        };
+
+        const users = try Db.users(txn);
+        const user_ids = try Db.user_ids(txn);
+
+        if (try user_ids.has(username_array)) {
+            return false;
+        } else {
+            const user_id = try db.Prng.gen(users.dbi, UserId);
+
+            try users.put(user_id, User{
+                .id = user_id,
+                .name = username_array,
+                .display_name = display_name,
+                .description = try UserDescription.init(0),
+                .password_hash = try hash_password(password),
+                .posts = try PostSet.init(txn),
+                .following = try UserSet.init(txn),
+                .followers = try UserSet.init(txn),
+                .post_lists = try PostListList.init(txn),
+                .feeds = try UserListList.init(txn),
+            });
+
+            try user_ids.put(username_array, user_id);
+
+            return true;
+        }
     }
 
-    pub fn commit(self: *Self) void {
-        switch (lmdb.mdb_txn_commit(self.txn)) {
-            0 => {},
-            lmdb.MDB_MAP_FULL => {
-                std.debug.print("resize\n", .{});
-                _ = lmdb.mdb_env_set_mapsize(self.env, 0);
-            },
-            else => |err| {
-                std.debug.print("commit err: {}\n", .{err});
-            },
+    pub fn login_user(
+        env: lmdb.Env,
+        username: []const u8,
+        password: []const u8,
+    ) !SessionToken {
+        const username_array = try Username.fromSlice(username);
+
+        const txn = try env.txn();
+        defer txn.commit() catch {};
+
+        const user_ids = try Db.user_ids(txn);
+        const user_id = try user_ids.get(username_array);
+        std.debug.print("user logging in, id: {}\n", .{user_id});
+
+        const users = try Db.users(txn);
+        const user = try users.get(user_id);
+
+        if (verify_password(password, user.password_hash)) {
+            const sessions = try Db.sessions(txn);
+            const session_token = try db.Prng.gen(sessions.dbi, SessionToken);
+            try sessions.put(session_token, user_id);
+            return session_token;
+        } else {
+            return error.IncorrectPassword;
         }
+    }
+
+    fn logout_user(env: lmdb.Env, session_token: SessionToken) !void {
+        const txn = try env.txn();
+        defer txn.commit() catch {};
 
-        // TODO: necessary?
-        lmdb.mdb_dbi_close(self.env, self.dbi);
+        const sessions = try Db.sessions(txn);
+        try sessions.del(session_token);
     }
 
-    pub fn sync(self: *Self) void {
-        switch (lmdb.mdb_env_sync(self.env, 1)) {
-            0 => {},
-            else => |err| {
-                std.debug.print("sync err: {}\n", .{err});
-            },
+    fn append_post(env: lmdb.Env, user_id: UserId, post_list: PostSet, parent_id: ?PostId, quote_id: ?PostId, text: []const u8) !PostId {
+        var post_id: PostId = undefined;
+
+        // TODO: do this in one commit
+
+        var txn: lmdb.Txn = undefined;
+        {
+            // create post
+            txn = try env.txn();
+            defer txn.commit() catch {};
+
+            const posts = try Db.posts(txn);
+            post_id = try db.Prng.gen(posts.dbi, PostId);
+
+            const decoded_text = try reencode(PostText, text);
+            try posts.put(post_id, Post{
+                .id = post_id,
+                .parent_id = parent_id,
+                .quote_id = quote_id,
+                .user_id = user_id,
+                .time = std.time.timestamp(),
+                .votes = try VoteList.init(txn),
+                .comments = try PostSet.init(txn),
+                .quotes = try PostSet.init(txn),
+                .text = decoded_text,
+            });
         }
+
+        {
+            // append to user's posts
+            txn = try env.txn();
+            defer txn.commit() catch {};
+
+            var posts_view = try post_list.open(txn);
+            try posts_view.append(post_id);
+        }
+
+        if (quote_id != null) {
+            txn = try env.txn();
+            defer txn.commit() catch {};
+
+            const posts = try Db.posts(txn);
+            const quote_post = try posts.get(quote_id.?);
+            var quotes = try quote_post.quotes.open(txn);
+            try quotes.append(post_id);
+        }
+
+        return post_id;
     }
 
-    pub fn put(self: *Self, key: anytype, value: anytype) void {
-        lmdb.put(self.txn, self.dbi, key, value);
+    fn post(env: lmdb.Env, user_id: UserId, text: []const u8) !void {
+        var txn = try env.txn();
+        const users = try Db.users(txn);
+        const user = try users.get(user_id);
+        txn.abort();
+
+        const post_id = try append_post(env, user_id, user.posts, null, null, text);
+        _ = post_id;
     }
 
-    pub fn get(self: *Self, key: anytype, comptime T: type) ?T {
-        return lmdb.get(self.txn, self.dbi, key, T);
+    fn comment(env: lmdb.Env, user_id: UserId, parent_post_id: PostId, text: []const u8) !void {
+        var txn = try env.txn();
+        const users = try Db.users(txn);
+        const user = try users.get(user_id);
+
+        const posts = try Db.posts(txn);
+        const parent_post = try posts.get(parent_post_id);
+        txn.abort();
+
+        const post_id = try append_post(env, user_id, parent_post.comments, parent_post_id, null, text);
+
+        txn = try env.txn();
+        var replies_view = try user.posts.open(txn);
+        try replies_view.append(post_id);
+        try txn.commit();
     }
 
-    pub fn del(self: *Self, key: anytype) void {
-        lmdb.del(self.txn, self.dbi, key);
+    fn quote(env: lmdb.Env, user_id: UserId, quote_post_id: PostId, text: []const u8) !void {
+        var txn = try env.txn();
+        const users = try Db.users(txn);
+        const user = try users.get(user_id);
+        txn.abort();
+
+        const post_id = try append_post(env, user_id, user.posts, null, quote_post_id, text);
+        _ = post_id;
     }
 
-    pub fn has(self: *Self, key: anytype) bool {
-        return lmdb.has(self.txn, self.dbi, key);
+    fn vote(env: lmdb.Env, post_id: PostId, user_id: UserId, kind: Vote.Kind) !void {
+        const txn = try env.txn();
+        defer txn.commit() catch {};
+
+        const posts = try Db.posts(txn);
+
+        var p = try posts.get(post_id);
+        var votes_view = try p.votes.open(txn);
+
+        var add_vote = true;
+
+        if (try votes_view.has(user_id)) {
+            const old_vote = try votes_view.get(user_id);
+
+            add_vote = old_vote.kind != kind;
+
+            try votes_view.del(user_id);
+
+            switch (old_vote.kind) {
+                .Up => p.upvotes -= 1,
+                .Down => p.downvotes -= 1,
+            }
+            try posts.put(post_id, p);
+        }
+
+        if (add_vote) {
+            try votes_view.append(user_id, Vote{
+                .kind = kind,
+                .time = std.time.timestamp(),
+            });
+
+            if (kind == .Up) {
+                p.upvotes += 1;
+            } else {
+                p.downvotes += 1;
+            }
+            try posts.put(post_id, p);
+        }
+    }
+
+    fn follow(env: lmdb.Env, user_id: UserId, user_id_to_follow: UserId) !void {
+        const txn = try env.txn();
+        defer txn.commit() catch {};
+
+        const users = try Db.users(txn);
+
+        const user = try users.get(user_id);
+        const user_to_follow = try users.get(user_id_to_follow);
+
+        var user_following = try user.following.open(txn);
+        var user_to_follow_followers = try user_to_follow.followers.open(txn);
+
+        if ((user_following.has(user_id_to_follow) catch false) and (user_to_follow_followers.has(user_id) catch false)) {
+            try user_following.del(user_id_to_follow);
+            try user_to_follow_followers.del(user_id);
+        } else if (!(user_following.has(user_id_to_follow) catch true) and !(user_to_follow_followers.has(user_id) catch true)) {
+            try user_following.append(user_id_to_follow);
+            try user_to_follow_followers.append(user_id);
+        } else {
+            std.debug.print("Something went wrong when trying to unfollow\n", .{});
+        }
+    }
+
+    fn get_session_user_id(env: lmdb.Env, session_token: SessionToken) !UserId {
+        const txn = try env.txn();
+        defer txn.abort();
+
+        const sessions = try Db.sessions(txn);
+
+        return try sessions.get(session_token);
+    }
+
+    fn get_user(env: lmdb.Env, user_id: UserId) !User {
+        const txn = try env.txn();
+        defer txn.abort();
+
+        const users = try Db.users(txn);
+        return try users.get(user_id);
     }
 };
 
 // }}}
 
-// http stuff {{{
+// html {{{
+pub fn Paginate(comptime T: type) type {
+    return struct {
+        const Self = @This();
 
-pub fn redirect(req: *std.http.Server.Request, location: []const u8) !void {
-    try req.respond("", .{ .status = .see_other, .extra_headers = &.{.{ .name = "Location", .value = location }} });
-}
+        const IterateResult = T.Base.View.Iterator.Result;
 
-pub fn get_body(req: *std.http.Server.Request) []const u8 {
-    return req.server.read_buffer[req.head_end .. req.head_end + (req.head.content_length orelse 0)];
-}
+        res: *http.Response,
+        view: T.View,
+        per_page: u64,
 
-pub fn get_value(req: *std.http.Server.Request, name: []const u8) ?[]const u8 {
-    const body = get_body(req);
-    if (std.mem.indexOf(u8, body, name)) |name_index| {
-        if (std.mem.indexOfScalarPos(u8, body, name_index, '=')) |eql_index| {
-            if (std.mem.indexOfScalarPos(u8, body, name_index, '&')) |amp_index| {
-                return body[eql_index + 1 .. amp_index];
+        it: T.Base.View.Iterator,
+        starting_idx: ?T.Base.Key,
+        count: u64 = 0,
+
+        pub fn init(res: *http.Response, view: T.View, per_page: u64) !Self {
+            var it = view.reverse_iterator();
+            if (res.req.get_param("starting_at")) |starting_at_str| {
+                it.idx = try parse_enum(T.Base.Key, starting_at_str, 16);
             }
 
-            return body[eql_index + 1 .. body.len];
+            return .{
+                .res = res,
+                .view = view,
+                .per_page = per_page,
+                .it = it,
+                .starting_idx = it.idx,
+            };
         }
-    }
-    return null;
-}
+        pub fn next(self: *Self) ?IterateResult {
+            if (self.it.next()) |kv| {
+                if (self.count < self.per_page) {
+                    self.count += 1;
+                    return kv;
+                }
+            }
+            return null;
+        }
+        pub fn write_navigation(self: *Self) !void {
+            const next_idx = self.it.next();
 
-pub fn get_cookie(req: *std.http.Server.Request, name: []const u8) ?CookieValue {
-    var header_it = req.iterateHeaders();
-    while (header_it.next()) |header| {
-        if (std.mem.eql(u8, header.name, "Cookie")) {
-            if (std.mem.indexOf(u8, header.value, name)) |name_index| {
-                if (std.mem.indexOfScalarPos(u8, header.value, name_index, '=')) |eql_index| {
-                    if (std.mem.indexOfPos(u8, header.value, name_index, "; ")) |semi_index| {
-                        return CookieValue.fromSlice(header.value[eql_index + 1 .. semi_index]) catch null;
-                    }
+            if (self.view.base.head.last != self.starting_idx) {
+                var prev_it = self.view.iterator();
+                prev_it.idx = self.starting_idx.?;
+                var oldest_idx = self.starting_idx.?;
+
+                var count: u64 = 0;
+                while (prev_it.next()) |kv| {
+                    oldest_idx = kv.key;
 
-                    return CookieValue.fromSlice(header.value[eql_index + 1 .. header.value.len]) catch null;
+                    if (count > self.per_page) {
+                        break;
+                    } else {
+                        count += 1;
+                    }
                 }
+
+                try self.res.write("<a href=\"{s}?starting_at={x}\">Prev</a> ", .{ self.res.req.target, @intFromEnum(oldest_idx) });
+            }
+
+            if (next_idx) |kv| {
+                try self.res.write("<a href=\"{s}?starting_at={x}\">Next</a>", .{ self.res.req.target, @intFromEnum(kv.key) });
             }
         }
-    }
-    return null;
+    };
 }
+fn html_form(res: *http.Response, action: []const u8, inputs: anytype) !void {
+    try res.write("<form action=\"{s}\" method=\"post\">", .{action});
+
+    inline for (inputs) |input| {
+        switch (@typeInfo(@TypeOf(input))) {
+            .@"struct" => |s| {
+                if (s.fields.len == 3) {
+                    try res.write("<{s} ", .{input[0]});
+                    try res.write(input[1], input[2]);
+                    try res.write("></{s}>", .{input[0]});
+                } else {
+                    try res.write("<input ", .{});
+                    try res.write(input[0], input[1]);
+                    try res.write(" />", .{});
+                }
+            },
+            else => {
+                try res.write("<input ", .{});
+                try res.write(input, .{});
+                try res.write(" />", .{});
+            },
+        }
+    }
 
+    try res.write("</form>", .{});
+}
 // }}}
 
-// content {{{
+// write {{{
+const TimeStr = std.BoundedArray(u8, 256);
 
-const User = struct {
-    // TODO: choose sizes
-    username: Username,
-    password_hash: PasswordHash,
-};
+// http://howardhinnant.github.io/date_algorithms.html
+fn time_str(_t: i64) TimeStr {
+    const t: u64 = @intCast(_t);
+    var result = TimeStr.init(0) catch unreachable;
 
-const Id = u64;
-const Username = std.BoundedArray(u8, 16);
-const PasswordHash = std.BoundedArray(u8, 128);
-const SessionToken = u64;
-const CookieValue = std.BoundedArray(u8, 128);
+    const nD = @divFloor(t, std.time.s_per_day);
+    const z: u64 = nD + 719468;
+    const era: u64 = (if (z >= 0) z else z - 146096) / 146097;
+    const doe: u64 = z - era * 146097; // [0, 146096]
+    const yoe: u64 = (doe - doe / 1460 + doe / 36524 - doe / 146096) / 365; // [0, 399]
+    const Y: u64 = yoe + era * 400;
+    const doy: u64 = doe - (365 * yoe + yoe / 4 - yoe / 100); // [0, 365]
+    const mp: u64 = (5 * doy + 2) / 153; // [0, 11]
+    const D: u64 = doy - (153 * mp + 2) / 5 + 1; // [1, 31]
+    const M: u64 = if (mp < 10) mp + 3 else mp - 9;
 
-pub fn hash_password(password: []const u8) !PasswordHash {
-    var hash_buffer = try PasswordHash.init(128);
+    const h: u64 = @divFloor(t - nD * std.time.s_per_day, std.time.s_per_hour);
+    const m: u64 = @divFloor(t - nD * std.time.s_per_day - h * std.time.s_per_hour, std.time.s_per_min);
+    const s: u64 = t - nD * std.time.s_per_day - h * std.time.s_per_hour - m * std.time.s_per_min;
 
-    // TODO: choose buffer size
-    // TODO: dont allocate on stack, maybe zero memory?
-    var buffer: [1024 * 10]u8 = undefined;
-    var alloc = std.heap.FixedBufferAllocator.init(&buffer);
+    std.fmt.format(result.writer(), "<time><span>{:0>4}-{:0>2}-{:0>2} {:0>2}:{:0>2}:{:0>2} UTC</span><script>document.currentScript.parentElement.innerHTML=new Date({}).toLocaleString()</script></time>", .{ Y, M, D, h, m, s, t * 1000 }) catch unreachable;
 
-    // TODO: choose limits
-    const result = try std.crypto.pwhash.argon2.strHash(password, .{
-        .allocator = alloc.allocator(),
-        .params = std.crypto.pwhash.argon2.Params.fromLimits(1000, 1024),
-    }, hash_buffer.slice());
+    return result;
+}
+fn write_header(res: *http.Response, logged_in: ?Login) !void {
+    if (logged_in) |login| {
+        try res.write(
+            \\<a href="/">Home</a><br />
+        , .{});
+        try res.write(
+            \\<a href="/user/{s}">Profile</a><br />
+        , .{login.user.name.constSlice()});
+        try res.write(
+            \\<a href="/post">Post</a><br />
+        , .{});
+        try html_form(res, "/logout", .{
+            \\type="submit" value="Logout"
+        });
+        try res.write("<br /><br />", .{});
+    } else {
+        try res.write(
+            \\<a href="/">Home</a><br />
+            \\<form action="/register" method="post">
+            \\<input type="text" name="username" />
+            \\<input type="password" name="password" />
+            \\<input type="submit" value="Register" />
+            \\</form><br />
+            \\<form action="/login" method="post">
+            \\<input type="text" name="username" />
+            \\<input type="password" name="password" />
+            \\<input type="submit" value="Login" />
+            \\</form><br /><br />
+        , .{});
+    }
+}
+fn write_start(res: *http.Response) !void {
+    try res.write(
+        \\<!doctype html>
+        \\<html>
+        \\<head>
+        \\<link rel="icon" href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>&#128035;</text></svg>">
+        \\<meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        \\<style>
+        \\  form {
+        \\    display: inline-block;
+        \\  }
+        \\  body {
+        \\    margin:40px auto;max-width:650px;line-height:1.6;font-size:18px;color:#444;padding:0 10px;
+        \\  }
+        \\  h1,h2,h3{line-height:1.2}
+        \\</style>
+        \\</head>
+        \\<body>
+    , .{});
+}
+fn write_end(res: *http.Response) !void {
+    try res.write("</body></html>", .{});
+}
+fn write_post(res: *http.Response, txn: lmdb.Txn, logged_in: ?Login, post_id: PostId, options: struct { recurse: u8 = 0, show_comment_field: bool = false }) !void {
+    const posts = try Db.posts(txn);
+    const post = posts.get(post_id) catch {
+        res.redirect("/") catch {};
+        return;
+    };
+    const users = try Db.users(txn);
+    const user = try users.get(post.user_id);
+
+    try res.write(
+        \\<div id="{x}">
+        \\<span><a href="/user/{s}">{s}</a>
+    , .{ @intFromEnum(post_id), user.name.constSlice(), user.display_name.constSlice() });
+    if (post.parent_id) |id| {
+        try res.write(" <a href=\"/post/{x}\">..</a>", .{@intFromEnum(id)});
+    }
+    try res.write(
+        \\ {s}</span><br />
+        \\<span>{s}</span><br />
+    , .{ time_str(post.time).constSlice(), post.text.constSlice() });
+
+    if (logged_in != null and post.user_id == logged_in.?.user.id) {
+        // Votes
+        try res.write(
+            \\<small>
+            \\<a href="/upvotes/{0x}">{1} Upvotes</a>
+            \\<a href="/downvotes/{0x}">{2} Downvotes</a>
+            \\</small>
+            \\<br />
+        , .{ @intFromEnum(post_id), post.upvotes, post.downvotes });
+    }
 
-    try hash_buffer.resize(result.len);
+    if (post.quote_id) |quote_id| {
+        try res.write("<div style=\"border: 1px solid black;\">", .{});
+        if (options.recurse > 0) {
+            try write_post(res, txn, logged_in, quote_id, .{ .recurse = options.recurse - 1 });
+        } else {
+            try res.write("<a href=\"/post/{x}\">...</a>", .{@intFromEnum(post_id)});
+        }
+        try res.write("</div>", .{});
+    }
 
-    return hash_buffer;
-}
+    const comments_view = try post.comments.open(txn);
+    const quotes_view = try post.quotes.open(txn);
+    const votes_view = try post.votes.open(txn);
 
-pub fn verify_password(password: []const u8, hash: PasswordHash) bool {
-    var buffer: [1024 * 10]u8 = undefined;
-    var alloc = std.heap.FixedBufferAllocator.init(&buffer);
+    // Votes
+    const vote: ?Vote = if (logged_in != null and try votes_view.has(logged_in.?.user.id)) try votes_view.get(logged_in.?.user.id) else null;
 
-    if (std.crypto.pwhash.argon2.strVerify(hash.constSlice(), password, .{
-        .allocator = alloc.allocator(),
-    })) {
-        return true;
-    } else |err| {
-        std.debug.print("verify error: {}\n", .{err});
-        return false;
+    if (vote != null and vote.?.kind == .Up) {
+        try html_form(res, "/upvote", .{
+            .{ "type=\"hidden\" value=\"{x}\" name=\"post_id\"", .{@intFromEnum(post.id)} },
+            .{ "type=\"submit\" value=\"&#x2B06; {}\"", .{post.upvotes} },
+        });
+    } else {
+        try html_form(res, "/upvote", .{
+            .{ "type=\"hidden\" value=\"{x}\" name=\"post_id\"", .{@intFromEnum(post.id)} },
+            .{ "type=\"submit\" value=\"&#x21E7; {}\"", .{post.upvotes} },
+        });
+    }
+    if (vote != null and vote.?.kind == .Down) {
+        try html_form(res, "/downvote", .{
+            .{ "type=\"hidden\" value=\"{x}\" name=\"post_id\"", .{@intFromEnum(post.id)} },
+            .{ "type=\"submit\" value=\"&#x2B07; {}\"", .{post.downvotes} },
+        });
+    } else {
+        try html_form(res, "/downvote", .{
+            .{ "type=\"hidden\" value=\"{x}\" name=\"post_id\"", .{@intFromEnum(post.id)} },
+            .{ "type=\"submit\" value=\"&#x21E9; {}\"", .{post.downvotes} },
+        });
+    }
+
+    // Comment Count
+    try res.write(
+        \\<a href="/post/{x}">&#x1F4AD; {}</a> 
+    , .{ @intFromEnum(post.id), comments_view.len() });
+
+    // Quote
+    try res.write(
+        \\<a href="/quoted/{x}">&#x1F501; {}</a> 
+    , .{ @intFromEnum(post.id), quotes_view.len() });
+
+    // Save to List
+    if (logged_in) |login| {
+        const lists_view = try login.user.post_lists.open(txn);
+        try res.write("<form action=\"/list_add\" method=\"post\">", .{});
+        try res.write("<select name=\"list_id\">", .{});
+        var it = lists_view.iterator();
+        // TODO: mark lists that already contain post
+        while (it.next()) |kv| {
+            const name = kv.val.name;
+            const id = kv.val.list.base.idx.?;
+            const list_view = try kv.val.list.open(txn);
+            try res.write("<option value=\"{x}\">{s}{s}</option>", .{ id, name.constSlice(), if (list_view.has(post_id) catch false) " *" else "" });
+        }
+        try res.write("</select>", .{});
+        try res.write("<input type=\"hidden\" name=\"post_id\" value=\"{x}\" />", .{@intFromEnum(post_id)});
+        try res.write("<input type=\"submit\" value=\"Save\" />", .{});
+        try res.write("</form>", .{});
     }
+
+    // Comment field
+    // TODO: maybe always show comment field and prompt for login
+    if (options.show_comment_field and logged_in != null) {
+        try res.write("<br /><br />", .{});
+        try html_form(res, "/comment", .{
+            .{ "type=\"hidden\" value=\"{x}\" name=\"post_id\"", .{@intFromEnum(post.id)} },
+            .{ "textarea", "type=\"text\" name=\"text\" placeholder=\"Text\"", .{} },
+            "type=\"submit\" value=\"Comment\"",
+        });
+        try res.write("<br />", .{});
+    }
+
+    // Comments
+    if (options.recurse > 0 and comments_view.len() > 0) {
+        try res.write(
+            \\<details{s}>
+            \\<summary>Comments</summary>
+        , .{if (options.recurse > 1) " open" else ""});
+        try res.write("<div style=\"margin: 10px;\">", .{});
+        var it = comments_view.iterator();
+        var count: u8 = 0;
+        while (it.next()) |comment_id| {
+            try write_post(res, txn, logged_in, comment_id.key, .{ .recurse = options.recurse - 1 });
+            try res.write("<br />", .{});
+            if (options.recurse == 1) {
+                count += 1;
+                if (count >= 3) break;
+            }
+        }
+        try res.write(
+            \\</div>
+            \\</details>
+        , .{});
+    }
+
+    try res.write(
+        \\</div>
+    , .{});
 }
+fn write_profile(res: *http.Response, txn: lmdb.Txn, logged_in: ?Login, user: User) !void {
+    const following = try user.following.open(txn);
+    const followers = try user.followers.open(txn);
+
+    try res.write(
+        \\<h2 style="display: inline;"><a href="/user/{s}">{s}</a></h2>
+    , .{
+        user.name.constSlice(), user.display_name.constSlice(),
+    });
+    if (logged_in != null and user.id != logged_in.?.user.id) {
+        const login = logged_in.?;
+
+        // follow/unfollow
+        if (try followers.has(login.user.id)) {
+            try html_form(res, "/follow", .{
+                .{ "type=\"hidden\" name=\"user_id\" value=\"{x}\"", .{@intFromEnum(user.id)} },
+                \\type="submit" value="Unfollow"
+            });
+        } else {
+            try html_form(res, "/follow", .{
+                .{ "type=\"hidden\" name=\"user_id\" value=\"{x}\"", .{@intFromEnum(user.id)} },
+                \\type="submit" value="Follow"
+            });
+        }
 
-pub fn register_user(db: *Db, username: []const u8, password: []const u8) !void {
-    const username_array = try Username.fromSlice(username);
+        // add to feed
+        const feeds_view = try login.user.feeds.open(txn);
+        try res.write("<form action=\"/feed_add\" method=\"post\">", .{});
+        try res.write("<select name=\"feed_id\">", .{});
+        var it = feeds_view.iterator();
+        while (it.next()) |kv| {
+            const name = kv.val.name;
+            const id = kv.val.list.base.idx.?;
+            const list_view = try kv.val.list.open(txn);
+            try res.write("<option value=\"{x}\">{s}{s}</option>", .{ id, name.constSlice(), if (list_view.has(user.id) catch false) " *" else "" });
+        }
+        try res.write("</select>", .{});
+        try res.write("<input type=\"hidden\" name=\"user_id\" value=\"{x}\" />", .{@intFromEnum(user.id)});
+        try res.write("<input type=\"submit\" value=\"Add to feed\" />", .{});
+        try res.write("</form>", .{});
+    }
+    try res.write(
+        \\ <a href="/following/{s}">{} following</a>
+        \\ <a href="/followers/{s}">{} followers</a>
+        \\<br />
+    , .{
+        user.name.constSlice(), following.len(),
+        user.name.constSlice(), followers.len(),
+    });
 
-    db.begin("users");
-    const user_id = db.gen_id();
-    db.put(user_id, User{
-        .username = username_array,
-        .password_hash = try hash_password(password),
+    try res.write(
+        \\<a href="/all/{0s}">All Posts</a>
+        \\ <a href="/comments/{0s}">Comments</a>
+        \\ <a href="/quotes/{0s}">Quotes</a><br />
+    , .{
+        user.name.constSlice(),
     });
-    db.commit();
 
-    db.begin("ids");
-    db.put(username_array.buffer, user_id);
-    db.commit();
+    if (logged_in != null and user.id == logged_in.?.user.id) {
+        try res.write(
+            \\<a href="/lists">Lists</a>
+            \\<a href="/feeds">Feeds</a>
+            \\<a href="/edit">Edit</a><br />
+            \\<br />
+        , .{});
+    }
 
-    std.debug.print("id: {}\n", .{user_id});
+    if (user.description.len > 0) {
+        try res.write(
+            \\<div style="padding-left: 5px; border-left: 1px solid grey;">
+            // \\&#x00AB; {s} &#x00BB;
+            \\<i>{s}</i>
+            \\</div>
+        , .{user.description.constSlice()});
+    }
+
+    try res.write("<br />", .{});
+}
+fn write_posts(res: *http.Response, txn: lmdb.Txn, logged_in: ?Login, post_list: PostSet, options: struct {
+    show_posts: bool,
+    show_quotes: bool,
+    show_comments: bool,
+}) !void {
+    const posts_view = try post_list.open(txn);
+
+    var paginate = try Paginate(PostSet).init(res, posts_view, Chirp.PostsPerPage);
+
+    while (paginate.next()) |post_id| {
+        const posts = try Db.posts(txn);
+        const post = try posts.get(post_id.key);
+        if ((options.show_posts and (post.parent_id == null and post.quote_id == null)) or
+            (options.show_quotes and (post.quote_id != null)) or
+            (options.show_comments and (post.parent_id != null)))
+        {
+            try write_post(res, txn, logged_in, post_id.key, .{ .recurse = 1 });
+            try res.write("<br />", .{});
+        }
+    }
 
-    db.sync();
+    try paginate.write_navigation();
 }
+fn write_timeline(res: *http.Response, txn: lmdb.Txn, logged_in: ?Login, user_list: UserSet) !void {
+    // TODO: paginate
+    const users = try Db.users(txn);
+    const posts = try Db.posts(txn);
+
+    var newest_post_ids = try std.BoundedArray(PostId, 10).init(0); // TODO: TimelinePostsCount
+    var prev_newest_post: ?Post = null;
+
+    const following = try user_list.open(txn);
+    if (following.len() == 0) {
+        try res.write("Empty timeline (no users)", .{});
+        return;
+    }
 
-pub fn login_user(db: *Db, username: []const u8, password: []const u8) ?SessionToken {
-    const username_array = Username.fromSlice(username) catch return null;
+    while (true) {
+        var newest_post: ?Post = null;
 
-    db.begin("ids");
-    const user_id = db.get(username_array.buffer, Id) orelse return null;
-    std.debug.print("id: {}\n", .{user_id});
-    // TODO: maybe no commit?
-    db.commit();
+        var following_it = following.iterator();
+        while (following_it.next()) |following_id| {
+            const followed_user = try users.get(following_id.key);
+            const followed_posts = try followed_user.posts.open(txn);
 
-    db.begin("users");
-    const user = db.get(user_id, User) orelse return null;
-    db.commit();
+            if (followed_posts.len() == 0) {
+                continue;
+            }
 
-    if (verify_password(password, user.password_hash)) {
-        db.begin("sessions");
-        const session_token = db.gen_id();
-        db.put(session_token, user_id);
-        db.commit();
+            var followed_posts_it = followed_posts.reverse_iterator();
+            while (followed_posts_it.next()) |followed_post_id| {
+                const p = try posts.get(followed_post_id.key);
 
-        db.sync();
+                if ((prev_newest_post == null or p.time < prev_newest_post.?.time) and (newest_post == null or newest_post.?.time < p.time)) {
+                    newest_post = p;
+                    break;
+                }
+            }
+        }
+        if (newest_post) |post| {
+            newest_post_ids.append(post.id) catch break;
+            prev_newest_post = post;
+        } else {
+            break;
+        }
+    }
 
-        return session_token;
-    } else {
-        return null;
+    for (newest_post_ids.constSlice()) |post_id| {
+        try write_post(res, txn, logged_in, post_id, .{ .recurse = 1 });
+        try res.write("<br />", .{});
     }
 }
+fn write_frontpage(res: *http.Response, txn: lmdb.Txn) !void {
+    const posts = try Db.posts(txn);
+    var counter: u64 = 0;
+    var it = try posts.reverse_iterator();
+    while (it.next()) |p| {
+        if (p.val.parent_id == null and p.val.quote_id == null) {
+            try write_post(res, txn, null, p.key, .{ .recurse = 1 });
+            counter += 1;
+        }
 
-fn logout_user(db: *Db, session_token: SessionToken) void {
-    db.begin("sessions");
-    db.del(session_token);
-    db.commit();
+        if (counter >= 10) break;
+    }
+}
+fn write_user(res: *http.Response, txn: lmdb.Txn, user_id: UserId) !void {
+    const users = try Db.users(txn);
+    const user = try users.get(user_id);
+    try res.write(
+        \\<a href="/user/{s}">{s}</a>
+    , .{ user.name.constSlice(), user.display_name.constSlice() });
 }
+fn write_votes(res: *http.Response, txn: lmdb.Txn, votes: VoteList, options: struct {
+    show_upvotes: bool = true,
+    show_downvotes: bool = true,
+}) !void {
+    const votes_view = try votes.open(txn);
+
+    var paginate = try Paginate(VoteList).init(res, votes_view, Chirp.UsersPerPage);
+
+    while (paginate.next()) |kv| {
+        const user_id = kv.key;
+        const vote = kv.val;
+
+        if ((options.show_upvotes and vote.kind == .Up) or
+            (options.show_downvotes and vote.kind == .Down))
+        {
+            try write_user(res, txn, user_id);
+            try res.write(" <small>{s}</small><br />", .{time_str(vote.time).constSlice()});
+        }
+    }
 
-fn get_session_user(db: *Db, session_token: SessionToken) ?User {
-    db.begin("sessions");
-    const user_id = db.get(session_token, Id) orelse return null;
-    db.commit();
+    try paginate.write_navigation();
+}
+fn check_login(env: lmdb.Env, req: http.Request, res: *http.Response) !?Login {
+    var result: ?Login = null;
+
+    if (req.get_cookie("session_token")) |session_token_str| {
+        var remove_session_token = true;
+
+        if (std.fmt.parseUnsigned(SessionToken, session_token_str, 16) catch null) |session_token| {
+            // const session_token = try std.fmt.parseUnsigned(SessionToken, session_token_str, 10);
+            // const session_token = std.mem.bytesToValue(SessionToken, session_token_str);
+            if (Chirp.get_session_user_id(env, session_token) catch null) |user_id| {
+                const txn = try env.txn();
+                defer txn.abort();
+                const users = try Db.users(txn);
+
+                result = .{
+                    .user = try users.get(user_id),
+                    .session_token = session_token,
+                };
+
+                remove_session_token = false;
+            }
+        }
 
-    db.begin("users");
-    const user = db.get(user_id, User) orelse return null;
-    db.commit();
+        if (remove_session_token) {
+            try res.add_header(
+                "Set-Cookie",
+                .{"session_token=deleted; Expires=Thu, 01 Jan 1970 00:00:00 GMT"},
+            );
+        }
+    }
 
-    return user;
+    return result;
 }
-
 // }}}
 
-fn list_users(db: *Db) void {
-    _ = lmdb.mdb_txn_begin(db.env, null, 0, &db.txn);
+// GET {{{
+const GET = struct {
+    const Self = @This();
 
-    _ = lmdb.mdb_dbi_open(db.txn, "users", lmdb.MDB_CREATE, &db.dbi);
+    txn: lmdb.Txn,
+    req: http.Request,
+    res: *http.Response,
+    logged_in: ?Login,
+
+    fn handle(self: Self) !bool {
+        const ti = @typeInfo(Self);
+        inline for (ti.@"struct".decls) |f_decl| {
+            const has_arg = f_decl.name.len > 1 and f_decl.name[f_decl.name.len - 1] == '/';
+            const match = if (has_arg) std.mem.startsWith(u8, self.req.target, f_decl.name) else std.mem.eql(u8, self.req.target, f_decl.name);
+
+            if (match) {
+                const f = @field(Self, f_decl.name);
+                const fi = @typeInfo(@TypeOf(f));
+                if (fi.@"fn".params.len == 1) {
+                    try @call(.auto, f, .{self});
+                } else {
+                    const arg_type = fi.@"fn".params[1].type.?;
+                    const arg_info = @typeInfo(arg_type);
+                    var arg: arg_type = undefined;
+                    const field = arg_info.@"struct".fields[0];
+                    if (self.req.target.len <= f_decl.name.len) {
+                        return error.NoArgProvided;
+                    }
+                    const str = self.req.target[f_decl.name.len..self.req.target.len];
+                    const field_ti = @typeInfo(field.type);
+                    switch (field_ti) {
+                        // TODO: maybe handle BoundedArray?
+                        .int => {
+                            @field(arg, field.name) = try std.fmt.parseUnsigned(field.type, str, 16);
+                        },
+                        .@"enum" => {
+                            @field(arg, field.name) = try parse_enum(field.type, str, 16);
+                        },
+                        else => {
+                            @field(arg, field.name) = str;
+                        },
+                    }
 
-    var cursor: ?*lmdb.MDB_cursor = undefined;
-    _ = lmdb.mdb_cursor_open(db.txn, db.dbi, &cursor);
+                    try @call(.auto, f, .{ self, arg });
+                }
+                return true;
+            }
+        }
+        return false;
+    }
 
-    var key: lmdb.MDB_val = undefined;
-    var val: lmdb.MDB_val = undefined;
-    var result = lmdb.mdb_cursor_get(cursor, &key, &val, lmdb.MDB_FIRST);
+    pub fn @"/user/"(self: Self, args: struct { username: []const u8 }) !void {
+        const user_ids = try Db.user_ids(self.txn);
+        if (user_ids.get(try Username.fromSlice(args.username))) |user_id| {
+            const users = try Db.users(self.txn);
+            const user = try users.get(user_id);
+
+            try write_profile(self.res, self.txn, self.logged_in, user);
+
+            try write_posts(self.res, self.txn, self.logged_in, user.posts, .{
+                .show_posts = true,
+                .show_quotes = false,
+                .show_comments = false,
+            });
+        } else |err| {
+            try self.res.write(
+                \\<p>User not found [{}]</p>
+            , .{err});
+        }
+    }
+    pub fn @"/comments/"(self: Self, args: struct { username: []const u8 }) !void {
+        const user_ids = try Db.user_ids(self.txn);
+        if (user_ids.get(try Username.fromSlice(args.username))) |user_id| {
+            const users = try Db.users(self.txn);
+            const user = try users.get(user_id);
+
+            try write_profile(self.res, self.txn, self.logged_in, user);
+
+            try write_posts(self.res, self.txn, self.logged_in, user.posts, .{
+                .show_posts = false,
+                .show_quotes = false,
+                .show_comments = true,
+            });
+        } else |err| {
+            try self.res.write(
+                \\<p>User not found [{}]</p>
+            , .{err});
+        }
+    }
+    pub fn @"/quotes/"(self: Self, args: struct { username: []const u8 }) !void {
+        const user_ids = try Db.user_ids(self.txn);
+        if (user_ids.get(try Username.fromSlice(args.username))) |user_id| {
+            const users = try Db.users(self.txn);
+            const user = try users.get(user_id);
+
+            try write_profile(self.res, self.txn, self.logged_in, user);
+
+            try write_posts(self.res, self.txn, self.logged_in, user.posts, .{
+                .show_posts = false,
+                .show_quotes = true,
+                .show_comments = false,
+            });
+        } else |err| {
+            try self.res.write(
+                \\<p>User not found [{}]</p>
+            , .{err});
+        }
+    }
+    pub fn @"/all/"(self: Self, args: struct { username: []const u8 }) !void {
+        const user_ids = try Db.user_ids(self.txn);
+        if (user_ids.get(try Username.fromSlice(args.username))) |user_id| {
+            const users = try Db.users(self.txn);
+            const user = try users.get(user_id);
+
+            try write_profile(self.res, self.txn, self.logged_in, user);
+
+            try write_posts(self.res, self.txn, self.logged_in, user.posts, .{
+                .show_posts = true,
+                .show_quotes = true,
+                .show_comments = true,
+            });
+        } else |err| {
+            try self.res.write(
+                \\<p>User not found [{}]</p>
+            , .{err});
+        }
+    }
+    pub fn @"/following/"(self: Self, args: struct { username: []const u8 }) !void {
+        const user_ids = try Db.user_ids(self.txn);
+        if (user_ids.get(try Username.fromSlice(args.username))) |user_id| {
+            const users = try Db.users(self.txn);
+            const user = try users.get(user_id);
+
+            const following_view = try user.following.open(self.txn);
+
+            var paginate = try Paginate(UserSet).init(self.res, following_view, Chirp.UsersPerPage);
 
-    while (result != lmdb.MDB_NOTFOUND) {
-        const user_id = @as(*align(1) Id, @ptrCast(key.mv_data.?)).*;
-        const user = @as(*align(1) User, @ptrCast(val.mv_data.?)).*;
+            try self.res.write(
+                \\<h2><a href="/user/{s}">{s}</a> follows:</h2>
+            , .{ user.name.constSlice(), user.display_name.constSlice() });
 
-        std.debug.print("[{}] {s}\n", .{ user_id, user.username.constSlice() });
+            while (paginate.next()) |following_id| {
+                const following_user = try users.get(following_id.key);
 
-        result = lmdb.mdb_cursor_get(cursor, &key, &val, lmdb.MDB_NEXT);
+                try self.res.write(
+                    \\<a href="/user/{s}">{s}</a><br />
+                , .{ following_user.name.constSlice(), following_user.display_name.constSlice() });
+            }
+
+            try paginate.write_navigation();
+        } else |err| {
+            try self.res.write(
+                \\<p>User not found [{}]</p>
+            , .{err});
+        }
     }
+    pub fn @"/followers/"(self: Self, args: struct { username: []const u8 }) !void {
+        const user_ids = try Db.user_ids(self.txn);
+        if (user_ids.get(try Username.fromSlice(args.username))) |user_id| {
+            const users = try Db.users(self.txn);
+            const user = try users.get(user_id);
 
-    _ = lmdb.mdb_cursor_close(cursor);
+            const followers_view = try user.followers.open(self.txn);
+            var paginate = try Paginate(UserSet).init(self.res, followers_view, Chirp.UsersPerPage);
 
-    _ = lmdb.mdb_dbi_close(db.env, db.dbi);
+            try self.res.write(
+                \\<h2><a href="/user/{s}">{s}</a> followers:</h2>
+            , .{ user.name.constSlice(), user.display_name.constSlice() });
 
-    _ = lmdb.mdb_txn_commit(db.txn);
-}
+            while (paginate.next()) |follower_id| {
+                const follower_user = try users.get(follower_id.key);
 
-pub fn main() !void {
-    // server
-    const address = try std.net.Address.resolveIp("::", 8080);
+                try self.res.write(
+                    \\<a href="/user/{s}">{s}</a><br />
+                , .{ follower_user.name.constSlice(), follower_user.display_name.constSlice() });
+            }
 
-    var server = try address.listen(.{
-        .reuse_address = true,
-    });
-    defer server.deinit();
+            try paginate.write_navigation();
+        } else |err| {
+            try self.res.write(
+                \\<p>User not found [{}]</p>
+            , .{err});
+        }
+    }
+    pub fn @"/post/"(self: Self, args: struct { post_id: PostId }) !void {
+        try write_post(self.res, self.txn, self.logged_in, args.post_id, .{
+            .recurse = 3, // TODO: factor out
+            .show_comment_field = true,
+        });
+    }
+    pub fn @"/upvotes/"(self: Self, args: struct { post_id: PostId }) !void {
+        const posts = try Db.posts(self.txn);
+        const post = try posts.get(args.post_id);
+        try self.res.write("{} upvotes:<br />", .{post.upvotes});
+        try write_votes(self.res, self.txn, post.votes, .{});
+    }
+    pub fn @"/quoted/"(self: Self, args: struct { post_id: PostId }) !void {
+        const posts = try Db.posts(self.txn);
+        const post = try posts.get(args.post_id);
+
+        const referer = if (self.req.get_header("Referer")) |ref| ref else self.req.target;
+
+        if (self.logged_in != null) {
+            try html_form(self.res, "/quote", .{
+                .{ "type=\"hidden\" name=\"referer\" value=\"{s}\"", .{referer} },
+                .{ "type=\"hidden\" name=\"post_id\" value=\"{x}\"", .{@intFromEnum(post.id)} },
+                .{ "textarea", "type=\"text\" name=\"text\" placeholder=\"Text\" autofocus", .{} },
+                "type=\"submit\" value=\"Quote\"",
+            });
+            try self.res.write("<br />", .{});
+        }
 
-    // lmdb
-    var db = Db{};
-    db.open("./db");
-    defer db.close();
+        // TODO: show all bc this only contains quotes?
+        try write_posts(self.res, self.txn, self.logged_in, post.quotes, .{
+            .show_posts = false,
+            .show_quotes = true,
+            .show_comments = false,
+        });
+    }
+    pub fn @"/list/"(self: Self, args: struct { list_id: PostSet.Base.Index }) !void {
+        try write_posts(self.res, self.txn, self.logged_in, PostSet{ .base = .{ .idx = args.list_id } }, .{
+            .show_posts = true,
+            .show_quotes = true,
+            .show_comments = true,
+        });
+    }
+    pub fn @"/lists"(self: Self) !void {
+        if (self.logged_in) |login| {
+            const post_lists_view = try login.user.post_lists.open(self.txn);
+
+            try html_form(self.res, "/create_list", .{
+                "type=\"text\" name=\"name\"",
+                "type=\"submit\" value=\"Add\"",
+            });
+
+            try self.res.write("<br /><br />", .{});
+
+            var it = post_lists_view.iterator();
+            while (it.next()) |kv| {
+                const name = kv.val.name;
+                const post_list = kv.val.list;
+                try self.res.write(
+                    \\<a href="/list/{x}">{s}</a> 
+                , .{ post_list.base.idx.?, name.constSlice() });
+                try html_form(self.res, "/delete_list", .{
+                    .{ "type=\"hidden\" name=\"list_id\" value=\"{x}\"", .{kv.key} },
+                    "type=\"submit\" value=\"Delete\"",
+                });
+                try self.res.write("<br />", .{});
+            }
+        } else {
+            try self.res.write("not logged in", .{});
+        }
+    }
+    pub fn @"/feed/"(self: Self, args: struct { feed_id: UserSet.Base.Index }) !void {
+        try write_timeline(self.res, self.txn, self.logged_in, UserSet{ .base = .{ .idx = args.feed_id } });
+    }
+    pub fn @"/feeds"(self: Self) !void {
+        if (self.logged_in) |login| {
+            const feeds_view = try login.user.feeds.open(self.txn);
+
+            try html_form(self.res, "/create_feed", .{
+                "type=\"text\" name=\"name\"",
+                "type=\"submit\" value=\"Add\"",
+            });
+
+            try self.res.write("<br /><br />", .{});
+
+            var it = feeds_view.iterator();
+            while (it.next()) |kv| {
+                const name = kv.val.name;
+                const user_list = kv.val.list;
+                try self.res.write(
+                    \\<a href="/feed/{x}">{s}</a> 
+                , .{ user_list.base.idx.?, name.constSlice() });
+                try html_form(self.res, "/delete_feed", .{
+                    .{ "type=\"hidden\" name=\"list_id\" value=\"{x}\"", .{kv.key} },
+                    "type=\"submit\" value=\"Delete\"",
+                });
+                try self.res.write("<br />", .{});
+            }
+        } else {
+            try self.res.write("not logged in", .{});
+        }
+    }
+    pub fn @"/post"(self: Self) !void {
+        if (self.logged_in) |login| {
+            _ = login;
+            const referer = if (self.req.get_header("Referer")) |ref| ref else self.req.target;
+
+            try html_form(self.res, "/post", .{
+                .{ "type=\"hidden\" name=\"referer\" value=\"{s}\"", .{referer} },
+                .{ "textarea", "type=\"text\" name=\"text\" placeholder=\"Text\" autofocus", .{} },
+                "type=\"submit\" value=\"Post\"",
+            });
+        } else {
+            try self.res.write("not logged in", .{});
+        }
+    }
+    pub fn @"/edit"(self: Self) !void {
+        if (self.logged_in) |login| {
+            try self.res.write("<br />Username: ", .{});
+            try html_form(self.res, "/set_username", .{
+                .{ "type=\"text\" name=\"username\" placeholder=\"{s}\"", .{login.user.name.constSlice()} },
+                "type=\"submit\" value=\"Change\"",
+            });
+            try self.res.write("<br />Display Name: ", .{});
+            try html_form(self.res, "/set_display_name", .{
+                .{ "type=\"text\" name=\"display_name\" placeholder=\"{s}\"", .{login.user.display_name.constSlice()} },
+                "type=\"submit\" value=\"Change\"",
+            });
+            try self.res.write("<br />Description: ", .{});
+            try html_form(self.res, "/set_description", .{
+                .{ "textarea", "type=\"text\" name=\"description\" placeholder=\"{s}\"", .{login.user.description.constSlice()} },
+                "type=\"submit\" value=\"Change\"",
+            });
+            try self.res.write("<br />Password: ", .{});
+            try html_form(self.res, "/set_password", .{
+                "type=\"text\" name=\"password\"",
+                "type=\"submit\" value=\"Change\"",
+            });
+        } else {
+            try self.res.write("not logged in", .{});
+        }
+    }
+    pub fn @"/"(self: Self) !void {
+        if (self.logged_in) |login| {
+            try write_timeline(self.res, self.txn, self.logged_in, login.user.following);
+        } else {
+            // TODO: generic home
+            try self.res.write("Homepage", .{});
+            // try write_frontpage(self.res, self.txn);
+        }
+    }
+};
+// }}}
 
-    list_users(&db);
+// POST {{{
+const POST = struct {
+    const Self = @This();
 
-    accept: while (true) {
-        const conn = try server.accept();
+    env: lmdb.Env,
+    req: http.Request,
+    res: *http.Response,
+    logged_in: ?Login,
+
+    pub fn handle(self: Self) !bool {
+        const ti = @typeInfo(Self);
+        inline for (ti.@"struct".decls) |f_decl| {
+            if (std.mem.eql(u8, f_decl.name, self.req.target)) {
+                const f = @field(Self, f_decl.name);
+                const fi = @typeInfo(@TypeOf(f));
+                if (fi.@"fn".params.len == 1) {
+                    _ = try @call(.auto, f, .{self});
+                } else {
+                    const args_type = fi.@"fn".params[fi.@"fn".params.len - 1].type.?;
+                    const argsi = @typeInfo(args_type);
+                    var args: args_type = undefined;
+                    inline for (argsi.@"struct".fields) |field| {
+                        const str = self.req.get_value(field.name) orelse return error.ArgNotFound;
+                        const field_ti = @typeInfo(field.type);
+                        switch (field_ti) {
+                            .int => {
+                                @field(args, field.name) = try std.fmt.parseUnsigned(field.type, str, 16);
+                            },
+                            .@"enum" => {
+                                @field(args, field.name) = try parse_enum(field.type, str, 16);
+                            },
+                            else => {
+                                @field(args, field.name) = str;
+                            },
+                        }
+                    }
+                    try @call(.auto, f, .{ self, args });
+                }
+                return true;
+            }
+        }
+        return false;
+    }
+
+    pub fn @"/register"(self: Self, args: struct { username: []const u8, password: []const u8 }) !void {
+        // TODO: handle args not supplied
+        std.debug.print("New user: {s} {s}\n", .{ args.username, args.password });
+        _ = try Chirp.register_user(self.env, args.username, args.password);
+    }
+    pub fn @"/login"(self: Self, args: struct { username: []const u8, password: []const u8 }) !void {
+        // TODO: handle args not supplied
+        std.debug.print("New login: {s} {s}\n", .{ args.username, args.password });
+        if (Chirp.login_user(self.env, args.username, args.password)) |session_token| {
+            self.res.status = .see_other;
+            try self.res.add_header(
+                "Set-Cookie",
+                .{ "session_token={x}; HttpOnly", .{session_token} },
+            );
+        } else |err| {
+            std.debug.print("login_user err: {}\n", .{err});
+        }
+    }
+    pub fn @"/logout"(self: Self) !void {
+        if (self.logged_in) |login| {
+            try Chirp.logout_user(self.env, login.session_token);
+
+            try self.res.add_header(
+                "Set-Cookie",
+                .{"session_token=deleted; Expires=Thu, 01 Jan 1970 00:00:00 GMT"},
+            );
+        }
+    }
+    pub fn @"/set_username"(self: Self, args: struct { username: []const u8 }) !void {
+        const login = self.logged_in orelse return error.NotLoggedIn;
+        const username = try Username.fromSlice(args.username);
+
+        const txn = try self.env.txn();
+        defer txn.commit() catch {};
 
-        std.debug.print("new connection: {}\n", .{conn});
+        const user_ids = try Db.user_ids(txn);
 
-        var read_buffer: [1024]u8 = undefined;
-        var http_server = std.http.Server.init(conn, &read_buffer);
+        if (!try user_ids.has(username)) {
+            try user_ids.del(login.user.name);
+            try user_ids.put(username, login.user.id);
 
-        while (http_server.state == .ready) {
-            var req = http_server.receiveHead() catch continue;
+            const users = try Db.users(txn);
+            var user = login.user;
+            user.name = username;
+            try users.put(login.user.id, user);
+        }
+    }
+    pub fn @"/set_display_name"(self: Self, args: struct { display_name: []const u8 }) !void {
+        const login = self.logged_in orelse return error.NotLoggedIn;
+        const display_name = try DisplayName.fromSlice(args.display_name);
+
+        const txn = try self.env.txn();
+        defer txn.commit() catch {};
 
-            std.debug.print("[{}]: {s}\n", .{ req.head.method, req.head.target });
+        const users = try Db.users(txn);
+        var user = login.user;
+        user.display_name = display_name;
+        try users.put(login.user.id, user);
+    }
+    pub fn @"/set_description"(self: Self, args: struct { description: []const u8 }) !void {
+        const login = self.logged_in orelse return error.NotLoggedIn;
+        const description = try reencode(UserDescription, args.description);
 
-            var logged_in: ?struct {
-                user: User,
-                session_token: SessionToken,
-            } = null;
+        const txn = try self.env.txn();
+        defer txn.commit() catch {};
 
-            if (get_cookie(&req, "session_token")) |session_token_str| {
-                const session_token = try std.fmt.parseUnsigned(SessionToken, session_token_str.constSlice(), 10);
-                if (get_session_user(&db, session_token)) |user| {
-                    logged_in = .{
-                        .user = user,
-                        .session_token = session_token,
-                    };
-                }
-                // TODO: delete session token
-                // TODO: add changeable headers (set, delete cookies)
+        const users = try Db.users(txn);
+        var user = login.user;
+        user.description = description;
+        try users.put(login.user.id, user);
+    }
+    pub fn @"/set_password"(self: Self, args: struct { password: []const u8 }) !void {
+        const login = self.logged_in orelse return error.NotLoggedIn;
+
+        const txn = try self.env.txn();
+        defer txn.commit() catch {};
+
+        const users = try Db.users(txn);
+        var user = login.user;
+        user.password_hash = try Chirp.hash_password(args.password);
+        try users.put(login.user.id, user);
+    }
+    pub fn @"/post"(self: Self) !void {
+        if (self.logged_in) |login| {
+            const text = self.req.get_value("text").?;
+            const has_referer = self.req.get_value("referer");
+
+            try Chirp.post(self.env, login.user.id, text);
+
+            if (has_referer) |r| {
+                const decoded = try decode(r);
+                try self.res.redirect(decoded.constSlice());
             }
+        }
+    }
+    pub fn @"/comment"(self: Self) !void {
+        if (self.logged_in) |login| {
+            const text = self.req.get_value("text") orelse return error.NoText;
+            const post_id_str = self.req.get_value("post_id") orelse return error.NoPostId;
+            const post_id = try parse_enum(PostId, post_id_str, 16);
 
-            // html
-            if (req.head.method == .GET) {
-                if (std.mem.eql(u8, req.head.target, "/register")) {
-                    try req.respond(
-                        \\<form action="/register" method="post">
-                        \\<input type="text" name="username" />
-                        \\<input type="password" name="password" />
-                        \\<input type="submit" value="Register" />
-                        \\</form>
-                    , .{});
-                } else if (std.mem.eql(u8, req.head.target, "/login")) {
-                    try req.respond(
-                        \\<form action="/login" method="post">
-                        \\<input type="text" name="username" />
-                        \\<input type="password" name="password" />
-                        \\<input type="submit" value="Login" />
-                        \\</form>
-                    , .{});
-                } else {
-                    if (logged_in) |login| {
-                        var response_buffer = try std.BoundedArray(u8, 1024).init(0);
-                        try std.fmt.format(response_buffer.writer(),
-                            \\<a href="/user/{s}">Home</a>
-                            \\<form action="/logout" method="post"><input type="submit" value="Logout" /></form>
-                            \\<form action="/quit" method="post"><input type="submit" value="Quit" /></form>
-                        , .{login.user.username.constSlice()});
-                        try req.respond(response_buffer.constSlice(), .{});
-                    } else {
-                        try req.respond(
-                            \\<a href="/register">Register</a>
-                            \\<a href="/login">Login</a>
-                            \\<form action="/quit" method="post"><input type="submit" value="Quit" /></form>
-                        , .{});
-                    }
-                }
+            try Chirp.comment(self.env, login.user.id, post_id, text);
+        }
+    }
+    pub fn @"/quote"(self: Self) !void {
+        if (self.logged_in) |login| {
+            const text = self.req.get_value("text") orelse return error.NoText;
+            const post_id_str = self.req.get_value("post_id") orelse return error.NoPostId;
+            const has_referer = self.req.get_value("referer");
+
+            const post_id = try parse_enum(PostId, post_id_str, 16);
+
+            try Chirp.quote(self.env, login.user.id, post_id, text);
+
+            if (has_referer) |r| {
+                const decoded = try decode(r);
+                try self.res.redirect(decoded.constSlice());
             }
-            // api
-            else {
-                if (std.mem.eql(u8, req.head.target, "/register")) {
-                    // TODO: handle args not supplied
-                    const username = get_value(&req, "username").?;
-                    const password = get_value(&req, "password").?;
-
-                    std.debug.print("New user: {s} {s}\n", .{ username, password });
-                    try register_user(&db, username, password);
-
-                    try redirect(&req, "/login");
-                } else if (std.mem.eql(u8, req.head.target, "/login")) {
-                    // TODO: handle args not supplied
-                    const username = get_value(&req, "username").?;
-                    const password = get_value(&req, "password").?;
-
-                    std.debug.print("New login: {s} {s}\n", .{ username, password });
-                    if (login_user(&db, username, password)) |session_token| {
-                        var redirect_buffer = try std.BoundedArray(u8, 128).init(0);
-                        try std.fmt.format(redirect_buffer.writer(), "/user/{s}", .{username});
-
-                        var cookie_buffer = try std.BoundedArray(u8, 128).init(0);
-                        try std.fmt.format(cookie_buffer.writer(), "session_token={}; Secure; HttpOnly", .{session_token});
-
-                        try req.respond("", .{
-                            .status = .see_other,
-                            .extra_headers = &.{
-                                .{ .name = "Location", .value = redirect_buffer.constSlice() },
-                                .{ .name = "Set-Cookie", .value = cookie_buffer.constSlice() },
-                            },
-                        });
-                    } else {
-                        try redirect(&req, "/login");
-                    }
-                } else if (std.mem.eql(u8, req.head.target, "/logout")) {
-                    if (logged_in) |login| {
-                        logout_user(&db, login.session_token);
-                        try req.respond("", .{
-                            .status = .see_other,
-                            .extra_headers = &.{
-                                .{ .name = "Location", .value = "/" },
-                                .{ .name = "Set-Cookie", .value = "session_token=deleted; Expires=Thu, 01 Jan 1970 00:00:00 GMT" },
-                            },
-                        });
-                    }
-                } else if (std.mem.eql(u8, req.head.target, "/quit")) {
-                    try redirect(&req, "/");
-                    break :accept;
-                } else {
-                    try req.respond(
-                        \\<p>POST</p>
-                    , .{});
-                }
+        }
+    }
+    // TODO: add arguments instead of parsing manually
+    pub fn @"/create_list"(self: Self) !void {
+        if (self.logged_in) |login| {
+            const name_str = self.req.get_value("name") orelse return error.NoName;
+            const name = try Name.fromSlice(name_str);
+            // TODO: decode name
+
+            var txn = try self.env.txn();
+            const postlist = try PostSet.init(txn);
+            try txn.commit();
+
+            txn = try self.env.txn();
+            var post_lists_view = try login.user.post_lists.open(txn);
+            _ = try post_lists_view.append(.{ .name = name, .list = postlist });
+            try txn.commit();
+        }
+    }
+    pub fn @"/delete_list"(self: Self, args: struct { list_id: PostSet.Base.Index }) !void {
+        if (self.logged_in) |login| {
+            var post_list: ?PostSet = null;
+            {
+                const txn = try self.env.txn();
+                defer txn.commit() catch {};
+                var post_lists_view = try login.user.post_lists.open(txn);
+                post_list = (try post_lists_view.get(args.list_id)).list;
+                try post_lists_view.del(args.list_id);
+            }
+            if (post_list != null) {
+                const txn = try self.env.txn();
+                defer txn.commit() catch {};
+                var list_view = try post_list.?.open(txn);
+                try list_view.clear();
+            }
+        }
+    }
+    pub fn @"/list_add"(self: Self, args: struct { list_id: PostSet.Base.Index, post_id: PostId }) !void {
+        if (self.logged_in) |login| {
+            _ = login;
+
+            const txn = try self.env.txn();
+            defer txn.commit() catch {};
+
+            const post_list = PostSet{ .base = .{ .idx = args.list_id } };
+            var post_list_view = try post_list.open(txn);
+            if (try post_list_view.has(args.post_id)) {
+                try post_list_view.del(args.post_id);
+            } else {
+                try post_list_view.append(args.post_id);
+            }
+        }
+    }
+    pub fn @"/create_feed"(self: Self) !void {
+        if (self.logged_in) |login| {
+            const name_str = self.req.get_value("name") orelse return error.NoName;
+            const name = try Name.fromSlice(name_str);
+
+            var txn = try self.env.txn();
+            const userlist = try UserSet.init(txn);
+            try txn.commit();
+
+            txn = try self.env.txn();
+            var feeds_view = try login.user.feeds.open(txn);
+            _ = try feeds_view.append(.{ .name = name, .list = userlist });
+            try txn.commit();
+        }
+    }
+    pub fn @"/delete_feed"(self: Self, args: struct { list_id: UserSet.Base.Index }) !void {
+        if (self.logged_in) |login| {
+            var user_list: ?UserSet = null;
+
+            {
+                const txn = try self.env.txn();
+                defer txn.commit() catch {};
+                var feeds_view = try login.user.feeds.open(txn);
+                user_list = (try feeds_view.get(args.list_id)).list;
+                try feeds_view.del(args.list_id);
+            }
+            if (user_list != null) {
+                const txn = try self.env.txn();
+                defer txn.commit() catch {};
+                var list_view = try user_list.?.open(txn);
+                try list_view.clear();
+            }
+        }
+    }
+    pub fn @"/feed_add"(self: Self, args: struct { feed_id: UserSet.Base.Index, user_id: UserId }) !void {
+        if (self.logged_in) |login| {
+            _ = login;
+
+            const txn = try self.env.txn();
+            defer txn.commit() catch {};
+
+            const user_list = UserSet{ .base = .{ .idx = args.feed_id } };
+            var user_list_view = try user_list.open(txn);
+            if (try user_list_view.has(args.user_id)) {
+                try user_list_view.del(args.user_id);
+            } else {
+                try user_list_view.append(args.user_id);
+            }
+        }
+    }
+    pub fn @"/upvote"(self: Self) !void {
+        const login = self.logged_in orelse return error.NotLoggedIn;
+
+        const post_id_str = self.req.get_value("post_id") orelse return error.NoPostId;
+        const post_id: PostId = @enumFromInt(try std.fmt.parseUnsigned(u64, post_id_str, 16));
+
+        try Chirp.vote(self.env, post_id, login.user.id, .Up);
+    }
+    pub fn @"/downvote"(self: Self) !void {
+        const login = self.logged_in orelse return error.NotLoggedIn;
+
+        const post_id_str = self.req.get_value("post_id") orelse return error.NoPostId;
+        const post_id: PostId = @enumFromInt(try std.fmt.parseUnsigned(u64, post_id_str, 16));
+
+        try Chirp.vote(self.env, post_id, login.user.id, .Down);
+    }
+    pub fn @"/follow"(self: Self) !void {
+        const login = self.logged_in orelse return error.NotLoggedIn;
+
+        const user_id_str = self.req.get_value("user_id") orelse return error.NoUserId;
+        const user_id: UserId = @enumFromInt(try std.fmt.parseUnsigned(u64, user_id_str, 16));
+
+        try Chirp.follow(self.env, login.user.id, user_id);
+    }
+    pub fn @"/quit"(self: Self) !void {
+        if (self.req.get_header("Referer")) |ref| {
+            try self.res.redirect(ref);
+        } else {
+            try self.res.redirect("/");
+        }
+        try self.res.send();
+        // break :accept;
+    }
+};
+// }}}
+
+fn list_users(env: lmdb.Env) !void {
+    const txn = try env.txn();
+    defer txn.abort();
+
+    const users = try Db.users(txn);
+    var it = try users.iterator();
+
+    while (it.next()) |kv| {
+        const key = kv.key;
+        const user = kv.val;
+        std.debug.print("[{}] {s}\n", .{ key, user.name.constSlice() });
+    }
+}
+fn list_user_ids(env: lmdb.Env) !void {
+    const txn = try env.txn();
+    defer txn.abort();
+
+    const user_ids = try Db.user_ids(txn);
+    var it = try user_ids.iterator();
+
+    while (it.next()) |kv| {
+        const key = kv.key;
+        const user_id = kv.val;
+        std.debug.print("[{s}] {}\n", .{ key.constSlice(), user_id });
+    }
+}
+
+fn list_sessions(env: lmdb.Env) !void {
+    const txn = try env.txn();
+    defer txn.abort();
+
+    const sessions = try Db.sessions(txn);
+    var it = try sessions.iterator();
+
+    while (it.next()) |kv| {
+        const key = kv.key;
+        const user_id = kv.val;
+        std.debug.print("[{x}] {}\n", .{ key, user_id });
+    }
+}
+
+fn list_posts(env: lmdb.Env) !void {
+    const txn = try env.txn();
+    defer txn.abort();
+
+    const posts = try Db.posts(txn);
+    var it = try posts.iterator();
+
+    while (it.next()) |kv| {
+        const key = kv.key;
+        const post = kv.val;
+        std.debug.print("[{}] {s}\n", .{ key, post.text.constSlice() });
+    }
+}
+
+const ReqBufferSize = 4096;
+const ResHeadBufferSize = 1024 * 64;
+const ResBodyBufferSize = 1024 * 64;
+
+// TODO: static?
+var req_buffer: [ReqBufferSize]u8 = undefined;
+var res_head_buffer: [ResHeadBufferSize]u8 = undefined;
+var res_body_buffer: [ResBodyBufferSize]u8 = undefined;
+
+pub fn main() !void {
+    // server
+    var server = try http.Server.init("::", 8080);
+    defer server.deinit();
+
+    // lmdb
+    var env = try lmdb.Env.open("db", 1024 * 1024 * 10);
+    defer env.close();
+
+    std.debug.print("Users:\n", .{});
+    try list_users(env);
+    std.debug.print("User IDs:\n", .{});
+    try list_user_ids(env);
+    std.debug.print("Sessions:\n", .{});
+    try list_sessions(env);
+    std.debug.print("Posts:\n", .{});
+    try list_posts(env);
+
+    while (true) {
+        server.wait();
+        while (true) {
+            const req = (server.next_request(&req_buffer) catch break) orelse break;
+            // handle_request(env, req) catch {
+            //     try handle_error(env, req);
+            // };
+            try handle_request(env, req);
+        }
+    }
+    // const ThreadCount = 1;
+    // var ts: [ThreadCount]std.Thread = undefined;
+
+    // for (0..ThreadCount) |i| {
+    //     ts[i] = try std.Thread.spawn(.{}, handle_connection, .{ &server, &env });
+    // }
+    // for (0..ThreadCount) |i| {
+    //     ts[i].join();
+    // }
+
+    std.debug.print("done\n", .{});
+}
+
+fn handle_error(env: lmdb.Env, req: http.Request) !void {
+    _ = env;
+    var res = http.Response.init(req, &res_head_buffer, &res_body_buffer);
+    try write_start(&res);
+    try res.write("Oops, something went terribly wrong there D:", .{});
+    try write_end(&res);
+    try res.send();
+}
+fn handle_request(env: lmdb.Env, req: http.Request) !void {
+    // std.debug.print("[{}]: {s}\n", .{ req.method, req.target });
+    // std.debug.print("[{}]: {s}\n", .{ req.method, req.head.? });
+
+    // reponse
+    var res = http.Response.init(req, &res_head_buffer, &res_body_buffer);
+
+    // check session token
+    const logged_in: ?Login = try check_login(env, req, &res);
+
+    // html
+    if (req.method == .GET) {
+        try write_start(&res);
+        try write_header(&res, logged_in);
+
+        const txn = try env.txn();
+        defer txn.abort();
+
+        const get = GET{
+            .txn = txn,
+            .req = req,
+            .res = &res,
+            .logged_in = logged_in,
+        };
+        if (try get.handle()) {} else {
+            try res.redirect("/");
+        }
+
+        try write_end(&res);
+        try res.send();
+    }
+    // api
+    else {
+        const post = POST{
+            .env = env,
+            .req = req,
+            .res = &res,
+            .logged_in = logged_in,
+        };
+        if (try post.handle()) {} else {
+            try res.write("<p>[POST] {s}</p>", .{req.target});
+        }
+
+        if (!res.has_header("Location")) {
+            if (req.get_header("Referer")) |ref| {
+                try res.redirect(ref);
+            } else {
+                try res.redirect("/");
             }
         }
+        try res.send();
     }
 }