import { buildMapCommands, sanitizeConsoleText } from './cs2Config.js';
import { DemoMatchSimulator } from './demoMatchSimulator.js';
import { backupPrefix, describeBackup, isValidBackupFile, pointsForMap } from '../rounds.js';
import { HttpError, CLOSED_STATUSES } from '../matchService.js';
import { randomPassword } from '../security.js';

export const SERVER_STATUS = {
  starting: 'Server startet',
  ready: 'Server bereit – wartet auf Veto',
  configuring: 'Server wird konfiguriert',
  configured: 'Server konfiguriert',
  start_failed: 'Serverstart fehlgeschlagen',
  config_failed: 'Konfiguration fehlgeschlagen',
  failed: 'Server ausgefallen',
  stopped: 'Server gestoppt',
};

const ACTIVE = ['starting', 'ready', 'configuring', 'configured', 'config_failed', 'failed'];
const SLOW_POLL_MS = 30_000;

/**
 * Steuert den Lebenszyklus der Match-Server. Kennt nur die Adapter-Schnittstelle
 * (start/status/configure/stop) und speichert alle Zugangsdaten ausschließlich in der Datenbank.
 */
export class ServerManager {
  constructor({ db, service, adapter, config, logger = console }) {
    Object.assign(this, { db, service, adapter, config, logger });
    this.busy = new Set();
    this.simulator = new DemoMatchSimulator();
    this.autoAdvance = new Map();
    this.lastPoll = new Map();
    this.timers = [];
  }

  init() {
    this.service.on('created', (id) => this.provision(id).catch((err) => this.logger.error(err)));
    this.service.on('vetoFinished', (id) => this.maybeConfigure(id));
    this.service.on('closed', (id) => this.stop(id, 'Match beendet').catch((err) => this.logger.error(err)));
    this.service.on('mapEnded', (e) => this.onMapEnded(e));
  }

  /**
   * Nach Map-Ende: ist die Serie entschieden, wird das Match abgeschlossen, sonst die nächste Map geladen.
   * Die Wartezeit lässt Spielern und Stream Zeit für den Endstand. Lädt der Organisator vorher selbst, entfällt es.
   */
  onMapEnded({ matchId, number, decided, hasNext }) {
    const seconds = this.config.autoAdvanceSeconds;
    if (seconds < 0) return;
    clearTimeout(this.autoAdvance.get(matchId));
    const finish = Boolean(decided) || !hasNext;
    this.service.log(matchId, 'series', finish
      ? `Serie entschieden – das Match wird in ${seconds} s automatisch abgeschlossen`
      : `Map ${number + 1} wird in ${seconds} s automatisch geladen`);
    this.service.changed(matchId);
    this.autoAdvance.set(matchId, setTimeout(() => {
      this.autoAdvance.delete(matchId);
      const match = this.service.getMatch(matchId);
      if (CLOSED_STATUSES.includes(match.status) || match.current_map_number !== number) return;
      try {
        if (finish) {
          this.service.closeMatch(matchId, 'finished', 'Match automatisch abgeschlossen – Serie entschieden');
        } else if (this.row(matchId)?.status === 'configured') {
          this.service.advanceSeriesFor(matchId);
          this.configure(matchId).catch((err) => this.logger.error(err));
        }
      } catch (err) {
        this.logger.warn(`[serie] Automatischer Wechsel für ${matchId} fehlgeschlagen: ${err.message}`);
      }
    }, seconds * 1000));
  }

  /** Nach einem Neustart des Backends: unterbrochene Vorgänge aufräumen und fortsetzen. */
  async resume() {
    const rows = this.db.prepare(`SELECT * FROM servers WHERE status IN ('starting','configuring')`).all();
    for (const row of rows) {
      if (row.status === 'starting' && !row.handle) {
        this.update(row.match_id, { status: 'start_failed', message: 'Start wurde durch einen Neustart des Backends unterbrochen' });
      } else if (row.status === 'configuring') {
        this.update(row.match_id, { status: 'ready', message: 'Konfiguration wurde unterbrochen und wird wiederholt' });
        this.maybeConfigure(row.match_id);
      }
    }
  }

  startLoops() {
    this.timers.push(setInterval(() => this.poll().catch((e) => this.logger.error(e)), this.config.statusPollSeconds * 1000));
    this.timers.push(setInterval(() => this.reap().catch((e) => this.logger.error(e)), this.config.reaperIntervalSeconds * 1000));
  }

  /** Admin: Rücksprungpunkte der aktuellen Map, neueste Runde zuerst. */
  async rollbackPoints(viewer) {
    this.service.require(viewer, 'organizer');
    const { match, seriesMap, handle } = this.rollbackContext(viewer.matchId);
    const all = await this.adapter.listRoundBackups(handle, match.id, seriesMap.map);
    return pointsForMap(all, seriesMap.map);
  }

  /** Admin: Match auf den Stand nach einer Runde zurückspielen. */
  async rollback(viewer, file) {
    this.service.require(viewer, 'organizer');
    const { match, handle, seriesMap } = this.rollbackContext(viewer.matchId);
    if (!isValidBackupFile(file, match.id)) throw new HttpError(400, 'Ungültige Sicherungsdatei', 'invalid_input');
    const point = describeBackup(file, match.id);
    if (point.map !== seriesMap.map) throw new HttpError(409, 'Die Sicherung gehört zu einer anderen Map', 'wrong_map');
    if (this.busy.has(match.id)) throw new HttpError(409, 'Für diesen Server läuft bereits eine Aktion', 'busy');
    this.busy.add(match.id);
    try {
      await this.adapter.loadRoundBackup(handle, file);
    } catch (err) {
      throw new HttpError(502, `Zurückspielen fehlgeschlagen: ${err.message}`, 'server_error');
    } finally {
      this.busy.delete(match.id);
    }
    this.service.rewindLiveScore(match.id, point.round, file);
  }

  rollbackContext(matchId) {
    const match = this.service.getMatch(matchId);
    const row = this.row(matchId);
    if (!row?.handle || row.status !== 'configured' || match.status !== 'live') {
      throw new HttpError(409, 'Zurückspielen ist nur bei einem laufenden Match mit bereitem Server möglich', 'wrong_state');
    }
    const seriesMap = this.service.seriesMaps(matchId).find((m) => m.number === match.current_map_number);
    return { match, row, seriesMap, handle: JSON.parse(row.handle) };
  }

  /** Löscht ein Match samt Server-Datensatz. Ein laufender Server wird vorher freigegeben. */
  async deleteMatch(matchId) {
    this.service.getMatch(matchId);
    clearTimeout(this.autoAdvance.get(matchId));
    this.autoAdvance.delete(matchId);
    this.simulator.stop(matchId);
    await this.stop(matchId, 'Match vom Admin gelöscht');
    this.db.prepare('DELETE FROM matches WHERE id = ?').run(matchId);
    this.service.emit('changed', matchId);
  }

  /** Wartet, bis keine Server-Aktion mehr läuft (höchstens timeoutMs). */
  async idle(timeoutMs = 5000) {
    const deadline = Date.now() + timeoutMs;
    while (this.busy.size > 0 && Date.now() < deadline) await new Promise((r) => setTimeout(r, 50));
  }

  stopLoops() {
    this.simulator.stopAll();
    for (const t of this.autoAdvance.values()) clearTimeout(t);
    this.autoAdvance.clear();
    this.timers.forEach(clearInterval);
    this.timers = [];
  }

  row(matchId) {
    return this.db.prepare('SELECT * FROM servers WHERE match_id = ?').get(matchId) ?? null;
  }

  update(matchId, fields) {
    const entries = { ...fields, updated_at: Date.now() };
    const sets = Object.keys(entries).map((k) => `${k} = @${k}`).join(', ');
    this.db.prepare(`UPDATE servers SET ${sets} WHERE match_id = @match_id`).run({ ...entries, match_id: matchId });
    this.service.changed(matchId);
  }

  usedPorts() {
    const used = new Set();
    for (const r of this.db.prepare(`SELECT host, port, tv_port FROM servers WHERE status != 'stopped' AND port IS NOT NULL`).all()) {
      used.add(r.port);
      used.add(r.tv_port);
      used.add(`${r.host}:${r.port}`);
    }
    return used;
  }

  // ---------- Start ----------

  async provision(matchId) {
    if (this.busy.has(matchId)) throw new HttpError(409, 'Für diesen Server läuft bereits eine Aktion', 'busy');
    this.busy.add(matchId);
    try {
      const previous = this.row(matchId);
      const secrets = {
        rconPassword: randomPassword(24),
        serverPassword: randomPassword(10),
        tvPassword: randomPassword(10),
      };
      const now = Date.now();
      this.db
        .prepare(
          `INSERT INTO servers (match_id, adapter, simulated, status, message, handle, host, port, tv_port,
             rcon_password, server_password, tv_password, config_key, attempts, started_at, updated_at)
           VALUES (@match_id, @adapter, @simulated, 'starting', @message, NULL, NULL, NULL, NULL,
             @rcon, @server, @tv, @key, @attempts, @now, @now)
           ON CONFLICT(match_id) DO UPDATE SET adapter = excluded.adapter, simulated = excluded.simulated,
             status = 'starting', message = excluded.message, handle = NULL, host = NULL, port = NULL, tv_port = NULL,
             rcon_password = excluded.rcon_password, server_password = excluded.server_password,
             tv_password = excluded.tv_password, config_key = excluded.config_key, attempts = excluded.attempts,
             started_at = excluded.started_at, ready_at = NULL, configured_at = NULL, stopped_at = NULL,
             player_count = NULL, last_player_seen_at = NULL, updated_at = excluded.updated_at`,
        )
        .run({
          match_id: matchId,
          adapter: this.adapter.name,
          simulated: this.adapter.simulated ? 1 : 0,
          message: this.adapter.simulated ? 'Demo-Modus: es wird kein echter Server gestartet' : 'Server wird angefordert',
          rcon: secrets.rconPassword,
          server: secrets.serverPassword,
          tv: secrets.tvPassword,
          key: randomPassword(24),
          attempts: (previous?.attempts ?? 0) + 1,
          now,
        });
      this.service.changed(matchId);
      this.service.log(matchId, 'server', this.adapter.simulated ? 'Demo-Server (Simulation) wird vorbereitet' : 'Server wird gestartet');

      const match = this.service.getMatch(matchId);
      try {
        const result = await this.adapter.start({ matchId, mode: match.mode, secrets });
        this.update(matchId, {
          handle: JSON.stringify(result.handle),
          host: result.host,
          port: result.port,
          tv_port: result.tvPort,
          message: this.adapter.simulated ? 'Simulierter Start läuft' : 'Server fährt hoch',
        });
      } catch (err) {
        this.update(matchId, { status: 'start_failed', message: err.message });
        this.service.log(matchId, 'server', `Serverstart fehlgeschlagen: ${err.message}`);
      }
    } finally {
      this.busy.delete(matchId);
    }
  }

  // ---------- Status ----------

  async poll() {
    const rows = this.db
      .prepare(`SELECT * FROM servers WHERE status IN ('starting','ready','configured','config_failed') AND handle IS NOT NULL`)
      .all();
    await Promise.all(rows.map((row) => this.pollOne(row)));
  }

  async pollOne(row) {
    const matchId = row.match_id;
    if (this.busy.has(matchId)) return;
    const last = this.lastPoll.get(matchId) ?? 0;
    if (row.status !== 'starting' && Date.now() - last < SLOW_POLL_MS) return;
    this.lastPoll.set(matchId, Date.now());

    let status;
    try {
      status = await this.adapter.status(JSON.parse(row.handle));
    } catch (err) {
      status = { state: row.status === 'starting' ? 'starting' : 'running', message: `Statusabfrage fehlgeschlagen: ${err.message}` };
    }
    const current = this.row(matchId);
    if (!current || current.status !== row.status) return; // zwischenzeitlich geändert

    const fields = {};
    if (status.playerCount !== undefined && status.playerCount !== current.player_count) fields.player_count = status.playerCount;
    if (status.playerCount > 0) fields.last_player_seen_at = Date.now();

    if (status.state === 'running' && current.status === 'starting') {
      Object.assign(fields, { status: 'ready', ready_at: Date.now(), message: status.message ?? 'Server ist erreichbar' });
      this.service.log(matchId, 'server', this.adapter.simulated ? 'Demo-Server (Simulation) bereit' : 'Server ist hochgefahren');
    } else if (status.state === 'failed') {
      Object.assign(fields, { status: current.status === 'starting' ? 'start_failed' : 'failed', message: status.message });
      this.service.log(matchId, 'server', `Server-Fehler: ${status.message}`);
    } else if (status.state === 'stopped') {
      Object.assign(fields, { status: 'stopped', stopped_at: Date.now(), message: status.message ?? 'Server wurde extern beendet' });
      this.service.log(matchId, 'server', 'Server wurde außerhalb der Anwendung beendet');
    } else if (status.message && status.message !== current.message && current.status === 'starting') {
      fields.message = status.message;
    }

    if (Object.keys(fields).length) this.update(matchId, fields);
    if (fields.status === 'ready') this.maybeConfigure(matchId);
  }

  // ---------- Konfiguration ----------

  maybeConfigure(matchId) {
    const match = this.service.getMatch(matchId);
    const row = this.row(matchId);
    if (match.status === 'server_setup' && row?.status === 'ready') {
      this.configure(matchId).catch((err) => this.logger.error(err));
    }
  }

  async configure(matchId) {
    const row = this.row(matchId);
    if (!row?.handle) throw new HttpError(409, 'Es gibt noch keinen gestarteten Server', 'no_server');
    if (!['ready', 'configured', 'config_failed'].includes(row.status)) {
      throw new HttpError(409, `Server kann im Zustand „${SERVER_STATUS[row.status]}" nicht konfiguriert werden`, 'wrong_state');
    }
    if (this.busy.has(matchId)) throw new HttpError(409, 'Für diesen Server läuft bereits eine Aktion', 'busy');
    this.busy.add(matchId);
    try {
      const match = this.service.getMatch(matchId);
      const pool = this.service.poolFor(match);
      const seriesMap = this.service
        .seriesMaps(matchId)
        .find((m) => m.number === match.current_map_number);
      if (!seriesMap) throw new HttpError(409, 'Das Veto ist noch nicht abgeschlossen', 'veto_pending');

      const mapName = pool.maps.find((m) => m.id === seriesMap.map)?.name ?? seriesMap.map;
      this.update(matchId, { status: 'configuring', message: `Lade Map ${seriesMap.number}: ${mapName}` });
      this.service.log(matchId, 'server', `Konfiguration für Map ${seriesMap.number} (${mapName}) gestartet`);

      const plan = buildMapCommands({
        match,
        pool,
        seriesMap: { map: seriesMap.map, ctTeam: seriesMap.ct_team },
        secrets: { serverPassword: row.server_password, tvPassword: row.tv_password },
        settings: this.config.match,
        logUrl: `${this.config.logReceiverUrl}/api/logs/${matchId}/${row.config_key}`,
        backupPrefix: backupPrefix(matchId),
      });
      this.simulator.stop(matchId);
      this.service.resetLiveScore(matchId, seriesMap.number);
      try {
        await this.adapter.configure(JSON.parse(row.handle), { map: seriesMap.map, ...plan });
      } catch (err) {
        this.update(matchId, { status: 'config_failed', message: err.message });
        this.service.log(matchId, 'server', `Konfiguration fehlgeschlagen: ${err.message}`);
        return;
      }
      this.update(matchId, {
        status: 'configured',
        configured_at: Date.now(),
        message: this.adapter.simulated
          ? `Simuliert: ${mapName} wäre jetzt geladen – kein echter Server`
          : `${mapName} geladen – Aufwärmphase läuft`,
      });
      this.service.markCurrentMapLive(matchId);
      if (this.service.getMatch(matchId).status === 'server_setup') this.service.setStatus(matchId, 'live');
      this.service.log(matchId, 'server', `Map ${seriesMap.number} (${mapName}) ist eingerichtet`);
    } finally {
      this.busy.delete(matchId);
    }
  }

  // ---------- Aktionen des Organisators ----------

  async retry(viewer) {
    this.service.require(viewer, 'organizer');
    const matchId = viewer.matchId;
    const match = this.service.getMatch(matchId);
    if (CLOSED_STATUSES.includes(match.status)) throw new HttpError(409, 'Das Match ist bereits beendet', 'match_closed');
    const row = this.row(matchId);
    if (this.busy.has(matchId)) throw new HttpError(409, 'Für diesen Server läuft bereits eine Aktion', 'busy');

    if (!row || ['start_failed', 'failed', 'stopped'].includes(row.status)) {
      if (row?.handle) await this.safeStop(row);
      this.service.log(matchId, 'server', 'Organisator startet den Server neu');
      await this.provision(matchId);
      return;
    }
    if (row.status === 'config_failed' || (row.status === 'ready' && match.status === 'server_setup')) {
      this.service.log(matchId, 'server', 'Organisator wiederholt die Konfiguration');
      this.configure(matchId).catch((err) => this.logger.error(err));
      return;
    }
    throw new HttpError(409, `Im Zustand „${SERVER_STATUS[row.status]}" ist kein erneuter Versuch nötig`, 'wrong_state');
  }

  async loadNextMap(viewer) {
    this.service.require(viewer, 'organizer');
    const row = this.row(viewer.matchId);
    if (row?.status !== 'configured') throw new HttpError(409, 'Der Server ist nicht bereit für die nächste Map', 'wrong_state');
    clearTimeout(this.autoAdvance.get(viewer.matchId));
    this.autoAdvance.delete(viewer.matchId);
    this.service.advanceSeries(viewer);
    this.configure(viewer.matchId).catch((err) => this.logger.error(err));
  }

  async endWarmup(viewer) {
    this.service.require(viewer, 'organizer');
    const row = this.row(viewer.matchId);
    if (row?.status !== 'configured') throw new HttpError(409, 'Der Server ist noch nicht konfiguriert', 'wrong_state');
    if (!this.adapter.sendCommands) throw new HttpError(501, 'Dieser Adapter unterstützt keine Befehle', 'unsupported');
    // Vor dem Befehl markieren: CS2 schickt Match_Start sofort nach mp_warmup_end, oft bevor RCON antwortet.
    this.service.markWarmupEnded(viewer.matchId, true);
    try {
      await this.adapter.sendCommands(JSON.parse(row.handle), ['mp_warmup_pausetimer 0', 'mp_warmup_end']);
    } catch (err) {
      this.service.markWarmupEnded(viewer.matchId, false);
      throw new HttpError(502, `Befehl konnte nicht gesendet werden: ${err.message}`, 'server_error');
    }
    this.service.log(viewer.matchId, 'server', this.adapter.simulated ? 'Aufwärmphase beendet (simuliert)' : 'Aufwärmphase beendet – Match startet');
    if (this.adapter.simulated) this.startDemoSimulation(viewer.matchId);
    this.service.changed(viewer.matchId);
  }

  /** Demo-Modus: simuliert einen Matchverlauf, indem echte CS2-Logzeilen erzeugt und ausgewertet werden. */
  startDemoSimulation(matchId) {
    const match = this.service.getMatch(matchId);
    const seriesMap = this.service.seriesMaps(matchId).find((m) => m.number === match.current_map_number);
    if (!seriesMap) return;
    this.service.log(matchId, 'server', 'Demo: simulierter Spielverlauf startet (keine echten Ergebnisse)');
    this.simulator.start(matchId, {
      map: seriesMap.map,
      teamNames: { A: sanitizeConsoleText(match.team_a_name), B: sanitizeConsoleText(match.team_b_name) },
      ctTeam: seriesMap.ct_team ?? 'A',
      maxRounds: match.mode === 'wingman' ? this.config.match.maxRoundsWingman : this.config.match.maxRoundsCompetitive,
      roundMs: this.config.demo.roundSeconds * 1000,
      onLines: (lines) => {
        try {
          this.service.applyLiveLog(matchId, lines);
        } catch (err) {
          this.logger.warn(`[demo] Simulation für ${matchId}: ${err.message}`);
          this.simulator.stop(matchId);
        }
      },
    });
  }

  async stopByOrganizer(viewer) {
    this.service.require(viewer, 'organizer');
    await this.stop(viewer.matchId, 'Vom Organisator gestoppt');
  }

  async safeStop(row) {
    try {
      await this.adapter.stop(JSON.parse(row.handle), { resetPassword: randomPassword(16) });
    } catch (err) {
      this.logger.warn(`[server] Stopp für ${row.match_id} fehlgeschlagen: ${err.message}`);
    }
  }

  async stop(matchId, reason) {
    this.simulator.stop(matchId);
    const row = this.row(matchId);
    if (!row || row.status === 'stopped') return;
    if (row.handle) await this.safeStop(row);
    this.update(matchId, { status: 'stopped', stopped_at: Date.now(), message: reason, player_count: null });
    this.service.log(matchId, 'server', `Server gestoppt: ${reason}`);
  }

  // ---------- Automatisches Herunterfahren ----------

  async reap(now = Date.now()) {
    const timeoutMs = this.config.idleTimeoutMinutes * 60_000;
    const rows = this.db.prepare(`SELECT * FROM servers WHERE status IN (${ACTIVE.map(() => '?').join(',')})`).all(...ACTIVE);
    for (const row of rows) {
      if (this.busy.has(row.match_id)) continue;
      const match = this.service.getMatch(row.match_id);
      if (CLOSED_STATUSES.includes(match.status)) {
        await this.stop(row.match_id, 'Match beendet');
        continue;
      }
      if (row.started_at && now - row.started_at > this.config.maxLifetimeHours * 3_600_000) {
        await this.stop(row.match_id, `Maximale Laufzeit von ${this.config.maxLifetimeHours} h erreicht`);
        continue;
      }
      const webActive = this.service.presence(row.match_id).size > 0;
      let lastUse = match.last_activity_at;
      if (row.status === 'configured' && row.player_count !== null) {
        // Echter Server mit bekannter Spielerzahl: entscheidend ist, ob jemand auf dem Server ist.
        if (row.player_count > 0) continue;
        lastUse = Math.max(row.configured_at ?? 0, row.last_player_seen_at ?? 0);
      } else if (webActive) {
        continue;
      }
      if (now - lastUse > timeoutMs) {
        await this.stop(row.match_id, `Automatisch heruntergefahren – ${this.config.idleTimeoutMinutes} Minuten ungenutzt`);
      }
    }
  }
}