import { expose } from "comlink";
import initDb from "../db/db";
import scoresRepository from "../db/repository/scores";
import rankedsRepository from "../db/repository/rankeds";
import eventBus from "../utils/broadcast-channel-pubsub";
import { convertArrayToObjectByKey } from "../utils/js";
import { diffColors } from "../utils/scoresaber/format";
import { getAccFromScore } from "../utils/scoresaber/song";
import {
  getTotalPpFromSortedPps,
  WEIGHT_COEFFICIENT,
} from "../utils/scoresaber/pp";
import makePendingPromisePool from "../utils/pending-promises";
import produce, { setAutoFreeze } from "immer";
import beatmapsEnhancer from "../stores/http/enhancers/common/beatmaps";
import accEnhancer from "../stores/http/enhancers/scores/acc";

let db = null;

let rankeds = null;

const resolvePromiseOrWaitForPending = makePendingPromisePool();

const getPlayerScores = async (playerId) =>
  scoresRepository().getAllFromIndex("scores-playerId", playerId, true);
const getRankedsFromDb = async (refreshCache = false) => {
  const dbRankeds = await rankedsRepository().getAll(refreshCache);

  return dbRankeds ? convertArrayToObjectByKey(dbRankeds, "leaderboardId") : {};
};

const getRankeds = async (refreshCache = false) =>
  resolvePromiseOrWaitForPending(`rankeds/${refreshCache}`, () =>
    getRankedsFromDb(),
  );

async function init() {
  if (db) return;

  db = await initDb();

  // setup immer.js
  // WORKAROUND for immer.js esm (see https://github.com/immerjs/immer/issues/557)
  self.process = { env: { NODE_ENV: "production" } };
  setAutoFreeze(false);

  rankeds = getRankeds();

  eventBus.on("rankeds-changed", () => (rankeds = getRankeds(true)));
}

const getRankedScores = async (playerId, withStars = false) => {
  const scores = await getPlayerScores(playerId);

  if (!scores || !scores.length) return null;

  let allRankeds = null;
  if (withStars) {
    allRankeds = await rankeds;
  }

  return withStars
    ? (
        await Promise.all(
          scores
            .filter((score) => score?.score?.pp)
            .map(async (score) => {
              score = await produce(
                await produce(score, (draft) => beatmapsEnhancer(draft, true)),
                (draft) => accEnhancer(draft),
              );

              return {
                ...score,
                stars: allRankeds[score?.leaderboardId]?.stars ?? null,
              };
            }),
        )
      ).filter((s) => s.stars)
    : scores.filter((score) => score?.score?.pp);
};

const getPlayerRankedScoresWithStars = async (playerId) =>
  getRankedScores(playerId, true);

const calcPlayerStats = async (playerId) => {
  await init();

  const rankedScores = await getRankedScores(playerId);
  if (!rankedScores) return null;

  const stats = rankedScores
    .filter(
      (score) =>
        (score?.score?.score && score?.score?.maxScore) || score?.score?.acc,
    )
    .reduce(
      (cum, s) => {
        const leaderboardId = s?.leaderboard?.leaderboardId;
        const pp = s?.score?.pp;
        const score = s?.score?.unmodifiedScore ?? s?.score?.score ?? 0;
        const accFromScore = getAccFromScore({ ...s.score, leaderboardId });
        const scoreAcc = s?.score?.acc;

        if (!accFromScore && !scoreAcc) return cum;

        let acc = accFromScore ? accFromScore : scoreAcc;
        if (!acc || isNaN(acc)) return cum;

        s.score.acc = acc;
        cum.totalScore += score;
        cum.totalAcc += acc;

        if (cum.topAcc < acc) cum.topAcc = acc;
        if (cum.topPp < pp) cum.topPp = pp;

        cum.badges.forEach((badge) => {
          if (
            (!badge.min || badge.min <= acc) &&
            (!badge.max || badge.max > acc)
          )
            badge.value++;
        });

        return cum;
      },
      {
        playerId,
        badges: [
          {
            label: "SS+",
            min: 95,
            max: null,
            value: 0,
            bgColor: diffColors.expertPlus,
          },
          {
            label: "SS",
            min: 90,
            max: 95,
            value: 0,
            bgColor: diffColors.expert,
          },
          { label: "S+", min: 85, max: 90, value: 0, bgColor: diffColors.hard },
          {
            label: "S",
            min: 80,
            max: 85,
            value: 0,
            bgColor: diffColors.normal,
          },
          {
            label: "A",
            min: null,
            max: 80,
            value: 0,
            bgColor: diffColors.easy,
          },
        ],
        topAcc: 0,
        topPp: 0,
        totalAcc: 0,
        totalScore: 0,
        avgAcc: 0,
        playCount: rankedScores.length,
        medianAcc: 0,
        stdDeviation: 0,
      },
    );

  stats.medianAcc =
    rankedScores.length > 1
      ? rankedScores.sort((a, b) => a.score.acc - b.score.acc)[
          Math.ceil(rankedScores.length / 2)
        ].score.acc
      : stats.totalAcc;
  stats.avgAcc = stats.totalAcc / rankedScores.length;
  stats.stdDeviation = Math.sqrt(
    rankedScores.reduce(
      (sum, s) => sum + Math.pow(stats.avgAcc - s.score.acc, 2),
      0,
    ) / rankedScores.length,
  );

  delete stats.totalAcc;

  eventBus.publish("player-stats-calculated", stats);

  return stats;
};

const calcPpBoundary = async (playerId, expectedPp = 1) => {
  const rankedScores = await getRankedScores(playerId);
  if (!rankedScores) return null;

  const calcRawPpAtIdx = (bottomScores, idx, expected) => {
    const oldBottomPp = getTotalPpFromSortedPps(bottomScores, idx);
    const newBottomPp = getTotalPpFromSortedPps(bottomScores, idx + 1);

    // 0.965^idx * rawPpToFind = expected + oldBottomPp - newBottomPp;
    // rawPpToFind = (expected + oldBottomPp - newBottomPp) / 0.965^idx;
    return (
      (expected + oldBottomPp - newBottomPp) / Math.pow(WEIGHT_COEFFICIENT, idx)
    );
  };

  const rankedScorePps = rankedScores.map((s) => s.pp).sort((a, b) => b - a);

  let idx = rankedScorePps.length - 1;

  while (idx >= 0) {
    const bottomSlice = rankedScorePps.slice(idx);
    const bottomPp = getTotalPpFromSortedPps(bottomSlice, idx);

    bottomSlice.unshift(rankedScorePps[idx]);
    const modifiedBottomPp = getTotalPpFromSortedPps(bottomSlice, idx);
    const diff = modifiedBottomPp - bottomPp;

    if (diff > expectedPp) {
      const ppBoundary = calcRawPpAtIdx(
        rankedScorePps.slice(idx + 1),
        idx + 1,
        expectedPp,
      );

      eventBus.publish("player-pp-boundary-calculated", {
        playerId,
        expectedPp,
        ppBoundary,
      });

      return ppBoundary;
    }

    idx--;
  }

  const ppBoundary = calcRawPpAtIdx(rankedScorePps, 0, expectedPp);

  eventBus.publish("player-pp-boundary-calculated", {
    playerId,
    expectedPp,
    ppBoundary,
  });

  return ppBoundary;
};

const worker = {
  init,
  calcPlayerStats,
  calcPpBoundary,
  getPlayerRankedScoresWithStars,
};

expose(worker);