import { ref } from 'vue'

export const DEFAULT_MAX_PLAYERS = 4
export type RoomStatus = 'waiting' | 'playing' | 'finished'

export interface RoomPlayerState {
  index: number
  playerId: string
  displayName?: string
  ready: boolean
  handCount?: number
  melds?: string[]
  outTiles?: string[]
  hasHu?: boolean
  missingSuit?: string | null
}

export interface RuleState {
  name: string
  isBloodFlow: boolean
  hasHongZhong: boolean
}

export interface GamePlayerState {
  playerId: string
  index: number
  ready: boolean
}

export interface EngineState {
  phase: string
  dealerIndex: number
  currentTurn: number
  needDraw: boolean
  players: GamePlayerState[]
  wall: string[]
  lastDiscardTile: string | null
  lastDiscardBy: string
  pendingClaim: Record<string, unknown> | null
  winners: string[]
  scores: Record<string, number>
  lastDrawPlayerId: string
  lastDrawFromGang: boolean
  lastDrawIsLastTile: boolean
  huWay: string
}

export interface GameState {
  rule: RuleState | null
  state: EngineState | null
}

export interface RoomState {
  id: string
  name: string
  gameType: string
  ownerId: string
  maxPlayers: number
  playerCount: number
  status: RoomStatus | string
  createdAt: string
  updatedAt: string
  game: GameState | null
  players: RoomPlayerState[]
  currentTurnIndex: number | null
  myHand: string[]
}

function createInitialRoomState(): RoomState {
  return {
    id: '',
    name: '',
    gameType: 'chengdu',
    ownerId: '',
    maxPlayers: DEFAULT_MAX_PLAYERS,
    playerCount: 0,
    status: 'waiting',
    createdAt: '',
    updatedAt: '',
    game: null,
    players: [],
    currentTurnIndex: null,
    myHand: [],
  }
}

export const activeRoomState = ref<RoomState>(createInitialRoomState())

export function destroyActiveRoomState(): void {
  activeRoomState.value = createInitialRoomState()
}

export function resetActiveRoomState(seed?: Partial<RoomState>): void {
  destroyActiveRoomState()
  if (!seed) {
    return
  }

  activeRoomState.value = {
    ...activeRoomState.value,
    ...seed,
    players: seed.players ?? [],
    myHand: seed.myHand ?? [],
  }
}

export function mergeActiveRoomState(next: RoomState): void {
  if (activeRoomState.value.id && next.id && next.id !== activeRoomState.value.id) {
    return
  }

  activeRoomState.value = {
    ...activeRoomState.value,
    ...next,
    name: next.name || activeRoomState.value.name,
    gameType: next.gameType || activeRoomState.value.gameType,
    ownerId: next.ownerId || activeRoomState.value.ownerId,
    status: next.status || activeRoomState.value.status,
    createdAt: next.createdAt || activeRoomState.value.createdAt,
    updatedAt: next.updatedAt || activeRoomState.value.updatedAt,
    game: next.game ?? activeRoomState.value.game,
    players: next.players.length > 0 ? next.players : activeRoomState.value.players,
    currentTurnIndex:
      next.currentTurnIndex !== null ? next.currentTurnIndex : activeRoomState.value.currentTurnIndex,
    myHand: next.myHand.length > 0 ? next.myHand : activeRoomState.value.myHand,
  }
}

export function hydrateActiveRoomFromSelection(input: {
  roomId: string
  roomName?: string
  gameType?: string
  ownerId?: string
  maxPlayers?: number
  playerCount?: number
  status?: string
  createdAt?: string
  updatedAt?: string
  players?: RoomPlayerState[]
  currentTurnIndex?: number | null
  myHand?: string[]
}): void {
  resetActiveRoomState({
    id: input.roomId,
    name: input.roomName ?? '',
    gameType: input.gameType ?? 'chengdu',
    ownerId: input.ownerId ?? '',
    maxPlayers: input.maxPlayers ?? DEFAULT_MAX_PLAYERS,
    playerCount: input.playerCount ?? 0,
    status: input.status ?? 'waiting',
    createdAt: input.createdAt ?? '',
    updatedAt: input.updatedAt ?? '',
    players: input.players ?? [],
    currentTurnIndex: input.currentTurnIndex ?? null,
    myHand: input.myHand ?? [],
  })
}