const { GameEngine } = require('../game/GameEngine');
const { buildStarterDeck, STARTER_DECKS, ALL_CARDS, CARD_DB } = require('../cards');

class GameManager {
  constructor() {
    this.rooms = new Map();
    this.playerRooms = new Map();
    this.games = new Map();
  }

  createRoom(hostId, hostName, roomName) {
    const roomId = `room_${Date.now()}_${Math.random().toString(36).slice(2, 6)}`;
    const room = {
      id: roomId,
      name: roomName || `${hostName}'s Game`,
      hostId,
      players: [{ id: hostId, name: hostName, deck: null, ready: false }],
      status: 'waiting',
      gameId: null,
      maxPlayers: 2,
    };
    this.rooms.set(roomId, room);
    this.playerRooms.set(hostId, roomId);
    return room;
  }

  joinRoom(roomId, playerId, playerName) {
    const room = this.rooms.get(roomId);
    if (!room) return { error: 'Room not found' };
    if (room.status !== 'waiting') return { error: 'Game already in progress' };
    if (room.players.length >= room.maxPlayers) return { error: 'Room is full' };
    if (room.players.find((p) => p.id === playerId)) return { error: 'Already in room' };

    room.players.push({ id: playerId, name: playerName, deck: null, ready: false });
    this.playerRooms.set(playerId, roomId);
    return { success: true, room };
  }

  leaveRoom(playerId) {
    const roomId = this.playerRooms.get(playerId);
    if (!roomId) return { error: 'Not in a room' };

    const room = this.rooms.get(roomId);
    if (!room) {
      this.playerRooms.delete(playerId);
      return { error: 'Room not found' };
    }

    room.players = room.players.filter((p) => p.id !== playerId);
    this.playerRooms.delete(playerId);

    if (room.players.length === 0) {
      this.rooms.delete(roomId);
      if (room.gameId) this.games.delete(room.gameId);
      return { success: true, roomDeleted: true, roomId };
    }

    if (room.hostId === playerId) {
      room.hostId = room.players[0].id;
    }

    return { success: true, room };
  }

  selectDeck(playerId, deckColor) {
    const roomId = this.playerRooms.get(playerId);
    if (!roomId) return { error: 'Not in a room' };

    const room = this.rooms.get(roomId);
    if (!room) return { error: 'Room not found' };

    const player = room.players.find((p) => p.id === playerId);
    if (!player) return { error: 'Player not in room' };

    if (!STARTER_DECKS[deckColor]) return { error: 'Invalid deck color' };

    player.deck = deckColor;
    player.ready = true;
    return { success: true, room };
  }

  selectCustomDeck(playerId, cardIds) {
    const roomId = this.playerRooms.get(playerId);
    if (!roomId) return { error: 'Not in a room' };

    const room = this.rooms.get(roomId);
    if (!room) return { error: 'Room not found' };

    const player = room.players.find((p) => p.id === playerId);
    if (!player) return { error: 'Player not in room' };

    if (cardIds.length < 40) return { error: 'Deck must have at least 40 cards' };
    if (cardIds.length > 60) return { error: 'Deck cannot exceed 60 cards' };

    for (const cid of cardIds) {
      if (!CARD_DB[cid]) return { error: `Invalid card id: ${cid}` };
    }

    const nonLandCounts = {};
    for (const cid of cardIds) {
      const card = CARD_DB[cid];
      if (card.type !== 'land' || card.subtype !== 'basic') {
        nonLandCounts[cid] = (nonLandCounts[cid] || 0) + 1;
        if (nonLandCounts[cid] > 4) {
          return { error: `Cannot have more than 4 copies of ${card.name}` };
        }
      }
    }

    player.deck = cardIds;
    player.customDeck = true;
    player.ready = true;
    return { success: true, room };
  }

  startGame(roomId) {
    const room = this.rooms.get(roomId);
    if (!room) return { error: 'Room not found' };
    if (room.players.length < 2) return { error: 'Need at least 2 players' };
    if (!room.players.every((p) => p.ready)) return { error: 'Not all players are ready' };

    const p1 = room.players[0];
    const p2 = room.players[1];

    const deck1 = p1.customDeck ? p1.deck : buildStarterDeck(p1.deck);
    const deck2 = p2.customDeck ? p2.deck : buildStarterDeck(p2.deck);

    const engine = new GameEngine(p1.id, p2.id, deck1, deck2);
    const initialState = engine.startGame();

    room.status = 'playing';
    room.gameId = engine.id;
    this.games.set(engine.id, engine);

    return { success: true, gameId: engine.id, state: initialState };
  }

  getGame(gameId) {
    return this.games.get(gameId);
  }

  handleGameAction(gameId, playerId, action) {
    const engine = this.games.get(gameId);
    if (!engine) return { error: 'Game not found' };
    return engine.handleAction(playerId, action);
  }

  getGameState(gameId, playerId) {
    const engine = this.games.get(gameId);
    if (!engine) return null;
    return engine.getState(playerId);
  }

  getRooms() {
    const roomList = [];
    for (const room of this.rooms.values()) {
      roomList.push({
        id: room.id,
        name: room.name,
        playerCount: room.players.length,
        maxPlayers: room.maxPlayers,
        status: room.status,
        host: room.players.find((p) => p.id === room.hostId)?.name || 'Unknown',
      });
    }
    return roomList;
  }

  getRoomDetails(roomId) {
    return this.rooms.get(roomId) || null;
  }

  getCardList() {
    return ALL_CARDS;
  }

  getStarterDecks() {
    return STARTER_DECKS;
  }
}

module.exports = { GameManager };