import msgpack from '@msgpack/msgpack'
import fs from 'fs'
import { execMany } from './helper.js'

import { sqlite } from './init.js'

/**
 * This module parses the msgpack provided by DDNet...
 * @module db/decodeMsgpack
 */
export function decodeMsgpack() {
    const data = fs.readFileSync('players.msgpack')
    const decoded = msgpack.decodeMulti(data, { wrap: true })
    const order = ['categories', 'maps', 'totalPoints', 'pointsRanks', 'pointsThisWeek', 'pointsThisMonth', 'teamRankPoints', 'rankPoints', 'serverRanks']
    let final = {}

    let i = 0
    for (const part of decoded) {
        final[order[i]] = part
        ++i
    }
    return final
}

/**
 * This generates rankings for each map...
 * @module db/processRankings
 */
export function processRankings() {
    const maps = sqlite.prepare(`SELECT map FROM maps`);

    for (const map of maps.iterate())
        sqlite
            .prepare(`
                INSERT INTO rankings
                (
                    map, name, time, timestamp, rank, server
                )
                SELECT   map, name, time, timestamp, rank, server
                FROM     (
                        SELECT   rank() OVER w AS rank,
                                map,
                                timestamp,
                                NAME,
                                min(time) AS time,
                                server
                        FROM     race
                        WHERE    map = ?
                        GROUP BY NAME window w AS (ORDER BY time) ) AS a
                ORDER BY rank
            `)
            .run(map.Map)
}

/**
 * This generates teamrankings for each map...
 * @module db/processTeamRankings
 */
export function processTeamRankings() {
    const maps = sqlite.prepare(`SELECT map FROM maps`);

    for (const map of maps.iterate())
        sqlite
            .prepare(`
                INSERT INTO teamrankings
                (
                    name, map, id, time, timestamp, server, teamrank
                )
                SELECT DISTINCT(r.NAME),
                                r.map, r.id, r.time, r.timestamp,
                                Substring(n.server, 1, 3),
                                dense_rank() OVER w AS rank
                FROM            ((
                                    SELECT DISTINCT id
                                    FROM            teamrace
                                    WHERE           map = ?
                                    ORDER BY        time) AS l
                                )
                LEFT JOIN       teamrace AS r
                ON              l.id = r.id
                INNER JOIN      race AS n
                ON              r.map = n.map
                AND             r.NAME = n.NAME
                AND             r.time = n.time window w AS (ORDER BY r.time)
            `)
            .run(map.Map)
}

/**
 * This inserts all types of points into a table...
 * @module db/processAllPoints
 */
export function processAllPoints() {
    const msgpack = decodeMsgpack()

    const types = {
        points: msgpack.pointsRanks,
        pointsThisWeek: msgpack.pointsThisWeek,
        pointsThisMonth: msgpack.pointsThisMonth,
        pointsTeam: msgpack.teamRankPoints,
        pointsRank: msgpack.rankPoints,
    }

    /* Generate tables */
    sqlite.exec(`
        CREATE TABLE IF NOT EXISTS "points"
        (
            "type" varchar(16) NOT NULL,
            "rank" INTEGER NOT NULL,
            "name" varchar(16) NOT NULL,
            "points" INTEGER NOT NULL
        );
    `)

    /* Insert data */
    for(const type in types) {
        let rank = 1

        for (const entry of types[type]) {
            sqlite
                .prepare(`
                    INSERT INTO "points"
                    (
                        type, rank, name, points
                    ) VALUES (?, ?, ?, ?)
                `)
                .run(
                    type,
                    rank,
                    entry[0],
                    entry[1]
                )

            ++rank
        }
    }

    /* Generate indexes */
    execMany([
        `CREATE INDEX IF NOT EXISTS "idx_points_type" ON "points" ("type")`,
        `CREATE INDEX IF NOT EXISTS "Idx_points_rank" on "points" ("rank")`,
        `CREATE INDEX IF NOT EXISTS "Idx_points_name" on "points" ("name")`
    ])
}

export default {
    processAllPoints,
    processRankings,
    processTeamRankings
}