import { db } from '../db/index.js';
import { matchChatTimeline } from './chat.js';
import {
    MIN_RECORDED_ROUND,
    type MatchDetail,
    type MatchPlayer,
    type MatchHistoryResponse,
    type ServerMatch
} from '../../match-history.js';

import { readMatchQuery, type MatchHistoryQuery } from '../../match-history-query.js';

const matchSummary = `m.id, m.game, m.highest_round AS observedRound, m.server, m.server_deleted_at, m.map_name AS map, m.started_at AS startedAt, m.status,
        CASE WHEN m.status = 'completed' THEN m.ended_at END AS endedAt,
        m.start_players AS startPlayers,
        (SELECT COUNT(*) FROM leaderboard_match_players p WHERE p.match_id = m.id) AS uniquePlayers,
        CASE WHEN m.status = 'completed' THEN
            (SELECT COUNT(*) FROM leaderboard_match_players p WHERE p.match_id = m.id AND p.present = 1)
        END AS endPlayers,
        CASE WHEN m.status = 'completed' AND m.start_observed = 1 THEN
            MAX(0, ROUND((julianday(m.ended_at) - julianday(m.started_at)) * 86400000)) END AS durationMs,
        CASE WHEN m.status = 'completed' THEN m.highest_round END AS finalRound`;

export function serverMatchHistory(
    server?: string,
    limit = 25,
    query: MatchHistoryQuery = readMatchQuery(new URLSearchParams()),
    now = Date.now()
): MatchHistoryResponse {
    const handle = db();
    const clauses = [`m.highest_round >= ${MIN_RECORDED_ROUND}`];
    const parameters: Array<string | number> = [];
    if (server !== undefined) {
        clauses.push('m.server = ?');
        parameters.push(server);
    }
    if (query.game) {
        clauses.push('m.game = ?');
        parameters.push(query.game);
    }
    const maps = handle
        .prepare(
            `SELECT m.map_key AS key, MAX(m.map_name) AS name, m.game
        FROM leaderboard_matches m WHERE ${clauses.join(' AND ')} GROUP BY m.map_key, m.game ORDER BY name COLLATE NOCASE, game`
        )
        .all(...parameters) as MatchHistoryResponse['maps'];
    if (query.map) {
        clauses.push('m.map_key = ?');
        parameters.push(query.map);
    }
    if (query.status) {
        clauses.push('m.status = ?');
        parameters.push(query.status);
    }
    if (query.days) {
        clauses.push('julianday(m.started_at) >= julianday(?)');
        parameters.push(new Date(now - query.days * 86400000).toISOString());
    }
    // Search readable instance names as well as their stored identifiers. Tokens allow "Town Lobby 1".
    for (const token of query.q
        .toLowerCase()
        .replace(/\blobby\s+(?=\d+\b)/g, '')
        .split(/[\s_]+/)
        .filter(Boolean)) {
        clauses.push("instr(lower(m.server || ' ' || m.map_name), ?) > 0");
        parameters.push(token);
    }
    const where = `WHERE ${clauses.join(' AND ')}`;
    const total = (
        handle
            .prepare(`SELECT COUNT(*) AS total FROM leaderboard_matches m ${where}`)
            .get(...parameters) as { total: number }
    ).total;
    const page = Math.min(query.page, Math.max(1, Math.ceil(total / limit)));
    const column = {
        started: 'startedAt',
        round: 'observedRound',
        duration: 'durationMs',
        players: 'uniquePlayers'
    }[query.sort];
    const direction = query.direction === 'asc' ? 'ASC' : 'DESC';
    const matches = handle
        .prepare(
            `SELECT ${matchSummary} FROM leaderboard_matches m
        ${where} ORDER BY ${column} IS NULL ASC, ${column} ${direction}, m.id DESC LIMIT ? OFFSET ?`
        )
        .all(...parameters, limit, (page - 1) * limit) as ServerMatch[];
    return { matches, total, page, limit, maps };
}

/** Read durable match records without depending on a current server or scoreboard. */
export function getMatchDetail(id: number): MatchDetail | null {
    if (!Number.isSafeInteger(id) || id < 1) return null;
    const handle = db();
    const match = handle
        .prepare(
            `SELECT ${matchSummary}, m.start_observed AS startObserved
        FROM leaderboard_matches m WHERE m.id = ? AND m.status = 'completed'
            AND m.highest_round >= ${MIN_RECORDED_ROUND}`
        )
        .get(id) as
        | (Omit<MatchDetail, 'players' | 'chat' | 'startObserved'> & { startObserved: number })
        | undefined;
    if (!match) return null;

    const players = handle
        .prepare(
            `SELECT p.guid,
        COALESCE((SELECT identity.name FROM leaderboard_players identity
            WHERE identity.guid = p.guid AND identity.game IN ('t5', 't6')
            ORDER BY identity.last_seen_at DESC, identity.game LIMIT 1),
            (SELECT identity.name FROM leaderboard_players identity
                WHERE identity.guid = p.guid AND identity.game = ?), p.guid) AS name,
        p.has_stats AS hasStats, p.present AS presentAtEnd,
        p.first_seen_at AS firstSeenAt, p.last_seen_at AS lastSeenAt,
        CASE WHEN p.has_stats = 1 THEN p.highest_round END AS highestRound,
        CASE WHEN p.has_stats = 1 THEN p.rounds_survived END AS roundsSurvived,
        CASE WHEN p.has_stats = 1 THEN p.kills END AS kills,
        CASE WHEN p.has_stats = 1 THEN p.headshots END AS headshots,
        CASE WHEN p.has_stats = 1 THEN p.downs END AS downs,
        CASE WHEN p.has_stats = 1 THEN p.revives END AS revives,
        CASE WHEN p.has_stats = 1 THEN p.best_score END AS bestScore,
        EXISTS (SELECT 1 FROM leaderboard_players identity
            WHERE identity.guid = p.guid AND identity.game IN ('t5', 't6')) AS canViewProfile
        FROM leaderboard_match_players p WHERE p.match_id = ?
        ORDER BY hasStats DESC, kills DESC, highestRound DESC, name COLLATE NOCASE, p.guid`
        )
        .all(match.game, id) as Array<
        Omit<MatchPlayer, 'hasStats' | 'presentAtEnd' | 'canViewProfile'> & {
            hasStats: number;
            presentAtEnd: number;
            canViewProfile: number;
        }
    >;
    return {
        ...match,
        chat: matchChatTimeline(id),
        startObserved: Boolean(match.startObserved),
        players: players.map((player) => ({
            ...player,
            hasStats: Boolean(player.hasStats),
            presentAtEnd: Boolean(player.presentAtEnd),
            canViewProfile: Boolean(player.canViewProfile)
        }))
    };
}