const fs = require("fs")
const request = require("request-promise-native")
const sleep = require("util").promisify(setTimeout)
const low = require("lowdb")
const FileAsync = require("lowdb/adapters/FileAsync")

const express = require("express")
const app = express()
const port = 3000

const patch = "8.24.1";
const key = "RGAPI-dce1850a-0954-4b1e-8072-77a26739f076";

let appRateLimit1;
let appRateLimit120;
let appRateLimitCount1;
let appRateLimitCount120;

// Express routing
// ---------------
let rules = [
  ["/lol", "index.html"],
  ["/lol/script.js", "script.js"],
  ["/lol/style.css", "style.css"],
];

for (i in rules) {
  let path = rules[i][0];
  let file = rules[i][1];
  app.get(path, (req, res) => {
    res.sendFile(__dirname + "/html/" + file);
  });
}
// ---------------

// Riot API request
// ----------------
const regions = {
  "BR": "br1.api.riotgames.com",
  "EUNE": "eun1.api.riotgames.com",
  "EUW": "euw1.api.riotgames.com",
  "JP": "jp1.api.riotgames.com",
  "KR": "kr.api.riotgames.com",
  "LAN": "la1.api.riotgames.com",
  "LAS": "la2.api.riotgames.com",
  "NA": "na1.api.riotgames.com",
  "OCE": "oc1.api.riotgames.com",
  "TR": "tr1.api.riotgames.com",
  "RU": "ru.api.riotgames.com",
  "PBE": "pbe1.api.riotgames.com",
};

async function riotRequest(region, url, params, retries) {
  if (retries < 1) throw "Error too many tries";

  let req = "https://" + regions[region] + url + "?api_key=" + key;
  for (p in params) {
    req += "&" + p + "=" + params[p];
  }

  try {
    console.log("[Info] request: " + req);
    let result = await request({uri: req, resolveWithFullResponse: true, json: true});

    let appRateLimit = result.headers["x-app-rate-limit"];
    let appRateLimitCount = result.headers["x-app-rate-limit-count"];
    appRateLimit1 = appRateLimit.split(",")[0].split(":")[0];
    appRateLimit120 = appRateLimit.split(",")[1].split(":")[0];
    appRateLimitCount1 = appRateLimitCount.split(",")[0].split(":")[0];
    appRateLimitCount120 = appRateLimitCount.split(",")[1].split(":")[0];

    let delay1 = 1000 / (appRateLimit1 - 1);
    let delay120 = 120000 / (appRateLimit120 - 1);
    await sleep(Math.max(delay1, delay120));

    if (typeof result.body == "object") return result.body;
    return JSON.parse(result.body);
  } catch (err) {
    console.log("[Error] riotRequest: " + err.message);
    return await riotRequest(region, url, params, retries - 1);
  }
}
// ----------------

// User functionality
// ------------------
let users = {};
let nameLookup = {};

async function loadUserDb(region, accountId) {
  if (!users[region]) users[region] = {};
  if (users[region][accountId]) return;
  let adapter = new FileAsync(region + "/" + accountId + ".json");
  let db = await low(adapter);
  await db.defaults({ games: [], gameSummaries: [], account: {} })
    .write();
  users[region][accountId] = db;
}

async function loadUserInfo(region, summonerName) {
  if (!nameLookup[region]) nameLookup[region] = {};
  if (nameLookup[region][summonerName]) return;
  let user = await riotRequest(region, "/lol/summoner/v4/summoners/by-name/" + summonerName, {}, 5);
  let accountId = user.accountId;
  await loadUserDb(region, accountId);
  users[region][accountId].set("account", user);
  nameLookup[region][summonerName] = accountId;
}

async function loadGameSummaries(region, accountId) {
  let totalGames;
  let bI = 0, eI = 100;

  loop1:
  do {
    let matchlist = await riotRequest(region, "/lol/match/v4/matchlists/by-account/" + accountId, { beginIndex: bI, endIndex: eI }, 5);
    totalGames = matchlist.totalGames;
    for (m in matchlist.matches) {
      let match = matchlist.matches[m];
      if (users[region][accountId].get("gameSummaries").find({ gameId: match.gameId }).value()) {
        break loop1;
      }
      users[region][accountId].get("gameSummaries").push(match).write();
    }
    bI = eI;
    eI += 100;
  } while (bI <= totalGames);
  users[region][accountId].write();
  users[region][accountId].set("gameSummaries",
    users[region][accountId].get("gameSummaries").sortBy("timestamp").sortedUniqBy((x) => x.gameId).value()).write();
}

app.get("/lol/matches", async (req, res) => {
  let region = req.query.region;
  let summoner = req.query.summoner;
  console.log("[Info] getting game summaries for " + summoner + " from " + region);
  try {
    await loadUserInfo(region, summoner);
    let accountId = nameLookup[region][summoner];
    await loadGameSummaries(region, accountId);
    let matches = users[region][accountId].get("gameSummaries").value();
    console.log(matches.length);
    res.send(JSON.stringify(matches));
  } catch (err) {
    console.log("[Error] GET /lol/matches: " + err);
    res.send("error");
  }
});
// ------------------

// Static Data
// -----------
let champions;
let champLookup = {};
function loadChampions() {
  request("http://ddragon.leagueoflegends.com/cdn/" + patch + "/data/en_US/champion.json", (err, res, body) => {
    if (err) console.log("[Error] loadChampions: " + err);
    champions = JSON.parse(body).data;
    for (c in champions) {
      champLookup[champions[c].key] = c;
    }
  });
}

app.get("/lol/champions", (req, res) => {
  res.send(JSON.stringify(Object.keys(champions)));
});

app.get("/lol/champlookup", (req, res) => {
  res.send(JSON.stringify(champLookup));
});
// -----------

loadChampions();
app.listen(port, () => {
  console.log("Listening on port %d", port)
});