import { v7 as uuidv7 } from 'uuid';
import type {
  WsRequest,
  WsResponse,
  WsEvent,
  WsInMessage,
  WsAction,
  WsRequestParams,
  WsResponseData,
  RoomMessagePayload,
  AiStreamChunkPayload,
  ProjectEventPayload,
  RoomResponse,
  RoomCategoryResponse,
  RoomMessageResponse,
  RoomMessageListResponse,
  RoomMemberResponse,
  PinResponseData,
  RoomThreadResponse,
  ReactionListData,
  ReactionItem,
  SearchResultData,
  EditHistoryEntry,
  AiConfigData,
  NotificationListData,
  MentionListData,
  MessageEditHistoryResponse,
  SubscribeData,
  UserInfo,
  RoomReactionUpdatedPayload,
} from './ws-protocol';

export type {
  RoomMessagePayload,
  AiStreamChunkPayload,
  ProjectEventPayload,
  RoomResponse,
  RoomCategoryResponse,
  RoomMessageResponse,
  RoomMessageListResponse,
  RoomMemberResponse,
  PinResponseData,
  RoomThreadResponse,
  ReactionListData,
  ReactionItem,
  SearchResultData,
  EditHistoryEntry,
  AiConfigData,
  NotificationListData,
  MentionListData,
  MessageEditHistoryResponse,
  UserInfo,
  RoomReactionUpdatedPayload,
};

export interface WsTokenResponse {
  token: string;
  expires_in_seconds: number;
}

export type RoomWsStatus = 'idle' | 'connecting' | 'open' | 'closing' | 'closed' | 'error';

interface PendingRequest<T = WsResponseData> {
  resolve: (value: T) => void;
  reject: (error: Error) => void;
  timeout: ReturnType<typeof setTimeout>;
}

export interface RoomWsCallbacks {
  onRoomMessage?: (payload: RoomMessagePayload) => void;
  onProjectEvent?: (payload: ProjectEventPayload) => void;
  onAiStreamChunk?: (chunk: AiStreamChunkPayload) => void;
  onRoomReactionUpdated?: (payload: import('./ws-protocol').RoomReactionUpdatedPayload) => void;
  onMessageEdited?: (payload: import('./ws-protocol').MessageEditedPayload) => void;
  onMessageRevoked?: (payload: import('./ws-protocol').MessageRevokedPayload) => void;
  onMessagePinned?: (payload: import('./ws-protocol').MessagePinnedPayload) => void;
  onMessageUnpinned?: (payload: import('./ws-protocol').MessageUnpinnedPayload) => void;
  onStatusChange?: (status: RoomWsStatus) => void;
  onError?: (error: Error) => void;
}

export class RoomWsClient {
  private ws: WebSocket | null = null;
  private status: RoomWsStatus = 'idle';
  private baseUrl: string;
  private callbacks: RoomWsCallbacks;
  private pendingRequests = new Map<string, PendingRequest>();
  private reconnectAttempt = 0;
  private reconnectTimer: ReturnType<typeof setTimeout> | null = null;
  private shouldReconnect = true;
  private subscribedRooms = new Set<string>();
  private subscribedProjects = new Set<string>();
  private readonly reconnectBaseDelay: number;
  private readonly reconnectMaxDelay: number;
  private readonly requestTimeout: number;
  private wsToken: string | null = null;

  constructor(
    baseUrl: string,
    callbacks: RoomWsCallbacks = {},
    options: {
      reconnectBaseDelay?: number;
      reconnectMaxDelay?: number;
      requestTimeout?: number;
      wsToken?: string;
    } = {},
  ) {
    this.baseUrl = baseUrl;
    this.callbacks = callbacks;
    this.reconnectBaseDelay = options.reconnectBaseDelay ?? 1000;
    this.reconnectMaxDelay = options.reconnectMaxDelay ?? 15000;
    this.requestTimeout = options.requestTimeout ?? 30_000;
    this.wsToken = options.wsToken ?? null;
  }

  setWsToken(token: string | null): void {
    this.wsToken = token;
  }

  getWsToken(): string | null {
    return this.wsToken;
  }

  getStatus(): RoomWsStatus {
    return this.status;
  }

  getSubscribedRooms(): Set<string> {
    return new Set(this.subscribedRooms);
  }

  getSubscribedProjects(): Set<string> {
    return new Set(this.subscribedProjects);
  }

  async connect(forceNewToken = false): Promise<void> {
    if (this.ws && this.status === 'open') {
      return;
    }

    this.shouldReconnect = true;
    this.setStatus('connecting');

    // Fetch a fresh token unless we have a valid existing one and not forcing.
    // When forceNewToken=false (reconnect path), try existing token first.
    if (forceNewToken || !this.wsToken) {
      try {
        const tokenResp = await fetch(`${this.baseUrl}/api/ws/token`, {
          method: 'POST',
          credentials: 'include',
        });
        if (!tokenResp.ok) {
          const text = await tokenResp.text().catch(() => '');
          console.error(`[RoomWs] Token fetch failed: ${tokenResp.status} ${tokenResp.statusText} — ${text}`);
          throw new Error(`Token fetch failed: ${tokenResp.status}`);
        }
        const tokenData = await tokenResp.json();
        this.wsToken = tokenData.data?.token || null;
        if (!this.wsToken) {
          console.error('[RoomWs] Token is empty — not logged in?');
          throw new Error('No WS token received');
        }
      } catch (err) {
        console.error('[RoomWs] Failed to fetch WS token:', err);
        this.setStatus('error');
        this.callbacks.onError?.(err instanceof Error ? err : new Error(String(err)));
        throw err;
      }
    }

    const wsUrl = this.buildWsUrl();
    console.debug('[RoomWs] Connecting to:', wsUrl);
    this.ws = new WebSocket(wsUrl);

    // Guard: if ws is closed before handlers are set, skip
    if (this.ws.readyState === WebSocket.CLOSED || this.ws.readyState === WebSocket.CLOSING) {
      console.warn('[RoomWs] WebSocket closed immediately');
      // If we used an existing token and it was immediately rejected, retry with a new token
      if (!forceNewToken && this.wsToken) {
        console.debug('[RoomWs] Existing token rejected — fetching new token and retrying');
        const savedToken = this.wsToken;
        this.wsToken = null;
        return this.connect(true);
      }
      return;
    }

    return new Promise((resolve, reject) => {
      // Safety timeout: if not open within 10s, give up
      const timeoutId = setTimeout(() => {
        if (this.status === 'connecting') {
          console.error(`[RoomWs] Connection timeout after 10s — closing`);
          this.ws?.close();
          this.setStatus('error');
          reject(new Error('Connection timeout'));
        }
      }, 10_000);

      this.ws!.onopen = () => {
        clearTimeout(timeoutId);
        console.debug('[RoomWs] Connected');
        this.reconnectAttempt = 0;
        this.setStatus('open');
        this.resubscribeAll().catch(() => {});
        resolve();
      };

      this.ws!.onmessage = (ev: MessageEvent) => {
        try {
          const message: WsInMessage = JSON.parse(ev.data);
          this.handleMessage(message);
        } catch (e) {
          console.warn('[RoomWs] parse error:', e);
        }
      };

      this.ws!.onclose = (ev: CloseEvent) => {
        clearTimeout(timeoutId);
        console.debug(`[RoomWs] onclose code=${ev.code} reason=${ev.reason || 'none'} wasClean=${ev.wasClean}`);
        this.ws = null;
        this.setStatus('closed');
        for (const [, req] of this.pendingRequests) {
          clearTimeout(req.timeout);
          req.reject(new Error(`WebSocket closed: ${ev.reason || 'unknown'}`));
        }
        this.pendingRequests.clear();
        if (this.shouldReconnect) {
          this.scheduleReconnect();
        }
      };

      this.ws!.onerror = () => {
        clearTimeout(timeoutId);
        const rs = this.ws?.readyState ?? 'unknown';
        console.error(`[RoomWs] onerror readyState=${rs} url=${wsUrl}`);
        this.setStatus('error');
        this.callbacks.onError?.(new Error(`WebSocket error (readyState=${rs})`));
        reject(new Error(`WebSocket error (readyState=${rs})`));
      };
    });
  }

  disconnect(): void {
    this.shouldReconnect = false;
    if (this.reconnectTimer) {
      clearTimeout(this.reconnectTimer);
      this.reconnectTimer = null;
    }
    if (this.ws) {
      this.setStatus('closing');
      this.ws.close();
      this.ws = null;
    }
    this.setStatus('closed');
  }

  private async request<T = WsResponseData>(action: WsAction, params?: WsRequestParams): Promise<T> {
    if (this.ws && this.status === 'open') {
      return await this.requestWs<T>(action, params);
    }
    return this.requestHttp<T>(action, params);
  }

  private async requestWs<T = WsResponseData>(
    action: WsAction,
    params?: WsRequestParams,
  ): Promise<T> {
    return new Promise<T>((resolve, reject) => {
      const requestId = uuidv7();
      const timeout = setTimeout(() => {
        this.pendingRequests.delete(requestId);
        reject(new Error(`Request timeout: ${action}`));
      }, this.requestTimeout);

      this.pendingRequests.set(requestId, { resolve: resolve as (value: unknown) => void, reject, timeout });

      const request: WsRequest = {
        type: 'request',
        request_id: requestId,
        action,
        params,
      };

      this.ws!.send(JSON.stringify(request));
    });
  }

  private async requestHttp<T>(action: WsAction, params?: WsRequestParams): Promise<T> {
    const endpoint = this.actionToEndpoint(action);
    let path = endpoint.path;
    for (const paramName of endpoint.pathParams) {
      const value = params?.[paramName as keyof WsRequestParams];
      if (value !== undefined && value !== null) {
        path = path.replace(`{${paramName}}`, String(value));
      }
    }

    const url = `${this.baseUrl}/api${path}`;
    const method = endpoint.method;

    const headers: Record<string, string> = {
      'Content-Type': 'application/json',
    };
    if (this.wsToken) {
      headers['Authorization'] = `Bearer ${this.wsToken}`;
    }

    const fullUrl = new URL(url);
    if (method === 'GET' && params) {
      Object.entries(params).forEach(([key, value]) => {
        if (value !== undefined && value !== null && !endpoint.pathParams.includes(key)) {
          fullUrl.searchParams.append(key, String(value));
        }
      });
    }

    const options: RequestInit = {
      method,
      headers,
      credentials: 'include',
    };

    if ((method === 'POST' || method === 'PUT' || method === 'PATCH') && params) {
      const bodyParams: Record<string, unknown> = {};
      Object.entries(params).forEach(([key, value]) => {
        if (value !== undefined && value !== null && !endpoint.pathParams.includes(key)) {
          bodyParams[key] = value;
        }
      });
      options.body = JSON.stringify(bodyParams);
    }

    const response = await fetch(fullUrl.toString(), options);
    if (!response.ok) {
      const errorText = await response.text();
      throw new Error(`HTTP ${response.status}: ${errorText}`);
    }

    const json = await response.json();
    return json.data as T;
  }

  private actionToEndpoint(action: WsAction): { path: string; method: string; pathParams: string[] } {
    switch (action) {
      case 'room.list': return { path: '/project_room/{project_name}/rooms', method: 'GET', pathParams: ['project_name'] };
      case 'room.get': return { path: '/rooms/{room_id}', method: 'GET', pathParams: ['room_id'] };
      case 'room.create': return { path: '/project_room/{project_name}/rooms', method: 'POST', pathParams: ['project_name'] };
      case 'room.update': return { path: '/rooms/{room_id}', method: 'PATCH', pathParams: ['room_id'] };
      case 'room.delete': return { path: '/rooms/{room_id}', method: 'DELETE', pathParams: ['room_id'] };
      case 'category.list': return { path: '/project_room/{project_name}/room-categories', method: 'GET', pathParams: ['project_name'] };
      case 'category.create': return { path: '/project_room/{project_name}/room-categories', method: 'POST', pathParams: ['project_name'] };
      case 'category.update': return { path: '/room-categories/{category_id}', method: 'PATCH', pathParams: ['category_id'] };
      case 'category.delete': return { path: '/room-categories/{category_id}', method: 'DELETE', pathParams: ['category_id'] };
      case 'message.list': return { path: '/rooms/{room_id}/messages', method: 'GET', pathParams: ['room_id'] };
      case 'message.create': return { path: '/rooms/{room_id}/messages', method: 'POST', pathParams: ['room_id'] };
      case 'message.update': return { path: '/rooms/{room_id}/messages/{message_id}', method: 'PATCH', pathParams: ['room_id', 'message_id'] };
      case 'message.revoke': return { path: '/rooms/{room_id}/messages/{message_id}/revoke', method: 'POST', pathParams: ['room_id', 'message_id'] };
      case 'message.get': return { path: '/rooms/{room_id}/messages/{message_id}', method: 'GET', pathParams: ['room_id', 'message_id'] };
      case 'message.edit_history': return { path: '/rooms/{room_id}/messages/{message_id}/edit-history', method: 'GET', pathParams: ['room_id', 'message_id'] };
      case 'message.search': return { path: '/rooms/{room_id}/messages/search', method: 'GET', pathParams: ['room_id'] };
      case 'member.list': return { path: '/rooms/{room_id}/members', method: 'GET', pathParams: ['room_id'] };
      case 'member.add': return { path: '/rooms/{room_id}/members', method: 'POST', pathParams: ['room_id'] };
      case 'member.remove': return { path: '/rooms/{room_id}/members/{user_id}', method: 'DELETE', pathParams: ['room_id', 'user_id'] };
      case 'member.leave': return { path: '/rooms/{room_id}/members/me', method: 'DELETE', pathParams: ['room_id'] };
      case 'member.set_read_seq': return { path: '/rooms/{room_id}/members/me/read-seq', method: 'PATCH', pathParams: ['room_id'] };
      case 'member.update_role': return { path: '/rooms/{room_id}/members/{user_id}/role', method: 'PATCH', pathParams: ['room_id', 'user_id'] };
      case 'pin.list': return { path: '/rooms/{room_id}/pins', method: 'GET', pathParams: ['room_id'] };
      case 'pin.add': return { path: '/rooms/{room_id}/messages/{message_id}/pin', method: 'POST', pathParams: ['room_id', 'message_id'] };
      case 'pin.remove': return { path: '/rooms/{room_id}/messages/{message_id}/pin', method: 'DELETE', pathParams: ['room_id', 'message_id'] };
      case 'thread.list': return { path: '/rooms/{room_id}/threads', method: 'GET', pathParams: ['room_id'] };
      case 'thread.create': return { path: '/rooms/{room_id}/threads', method: 'POST', pathParams: ['room_id'] };
      case 'thread.messages': return { path: '/rooms/{room_id}/threads/{thread_id}/messages', method: 'GET', pathParams: ['room_id', 'thread_id'] };
      case 'reaction.add': return { path: '/rooms/{room_id}/messages/{message_id}/reactions', method: 'POST', pathParams: ['room_id', 'message_id'] };
      case 'reaction.remove': return { path: '/rooms/{room_id}/messages/{message_id}/reactions/{emoji}', method: 'DELETE', pathParams: ['room_id', 'message_id', 'emoji'] };
      case 'reaction.get': return { path: '/rooms/{room_id}/messages/{message_id}/reactions', method: 'GET', pathParams: ['room_id', 'message_id'] };
      case 'reaction.list_batch': return { path: '/rooms/{room_id}/messages/reactions/batch', method: 'GET', pathParams: ['room_id'] };
      case 'ai.list': return { path: '/rooms/{room_id}/ai', method: 'GET', pathParams: ['room_id'] };
      case 'ai.upsert': return { path: '/rooms/{room_id}/ai', method: 'PUT', pathParams: ['room_id'] };
      case 'ai.delete': return { path: '/rooms/{room_id}/ai/{model_id}', method: 'DELETE', pathParams: ['room_id', 'model_id'] };
      case 'notification.list': return { path: '/me/notifications', method: 'GET', pathParams: [] };
      case 'notification.mark_read': return { path: '/me/notifications/{notification_id}/read', method: 'POST', pathParams: ['notification_id'] };
      case 'notification.mark_all_read': return { path: '/me/notifications/read-all', method: 'POST', pathParams: [] };
      case 'notification.archive': return { path: '/me/notifications/{notification_id}/archive', method: 'POST', pathParams: ['notification_id'] };
      case 'mention.list': return { path: '/me/mentions', method: 'GET', pathParams: [] };
      case 'mention.read_all': return { path: '/me/mentions/read-all', method: 'POST', pathParams: [] };
      case 'room.subscribe': return { path: '/ws', method: 'POST', pathParams: [] };
      case 'room.unsubscribe': return { path: '/ws', method: 'POST', pathParams: [] };
      case 'project.subscribe': return { path: '/ws', method: 'POST', pathParams: [] };
      case 'project.unsubscribe': return { path: '/ws', method: 'POST', pathParams: [] };
      default: throw new Error(`Unknown action: ${action}`);
    }
  }

  async roomList(projectName: string, onlyPublic?: boolean): Promise<RoomResponse[]> {
    const data = await this.request<RoomResponse[]>('room.list', {
      project_name: projectName,
      only_public: onlyPublic,
    });
    return Array.isArray(data) ? data : [];
  }

  async roomGet(roomId: string): Promise<RoomResponse | null> {
    const data = await this.request<RoomResponse>('room.get', { room_id: roomId });
    return data || null;
  }

  async roomCreate(
    projectName: string,
    roomName: string,
    isPublic: boolean,
    categoryId?: string,
  ): Promise<RoomResponse> {
    return this.request<RoomResponse>('room.create', {
      project_name: projectName,
      room_name: roomName,
      room_public: isPublic,
      room_category: categoryId,
    });
  }

  async roomUpdate(
    roomId: string,
    updates: {
      roomName?: string;
      isPublic?: boolean;
      categoryId?: string;
    },
  ): Promise<RoomResponse> {
    return this.request<RoomResponse>('room.update', {
      room_id: roomId,
      room_name: updates.roomName,
      room_public: updates.isPublic,
      room_category: updates.categoryId,
    });
  }

  async roomDelete(roomId: string): Promise<boolean> {
    const data = await this.request<boolean>('room.delete', { room_id: roomId });
    return data === true;
  }

  async categoryList(projectName: string): Promise<RoomCategoryResponse[]> {
    const data = await this.request<RoomCategoryResponse[]>('category.list', {
      project_name: projectName,
    });
    return Array.isArray(data) ? data : [];
  }

  async categoryCreate(projectName: string, name: string, position?: number): Promise<RoomCategoryResponse> {
    return this.request<RoomCategoryResponse>('category.create', {
      project_name: projectName,
      name,
      position,
    });
  }

  async categoryUpdate(
    categoryId: string,
    updates: { name?: string; position?: number },
  ): Promise<RoomCategoryResponse> {
    return this.request<RoomCategoryResponse>('category.update', {
      category_id: categoryId,
      name: updates.name,
      position: updates.position,
    });
  }

  async categoryDelete(categoryId: string): Promise<boolean> {
    const data = await this.request<boolean>('category.delete', { category_id: categoryId });
    return data === true;
  }

  async messageList(
    roomId: string,
    options?: {
      beforeSeq?: number;
      afterSeq?: number;
      limit?: number;
    },
  ): Promise<RoomMessageListResponse> {
    const data = await this.request<RoomMessageListResponse>('message.list', {
      room_id: roomId,
      before_seq: options?.beforeSeq,
      after_seq: options?.afterSeq,
      limit: options?.limit,
    });
    return data || { messages: [], total: 0 };
  }

  async messageCreate(
    roomId: string,
    content: string,
    options?: {
      contentType?: string;
      threadId?: string;
      inReplyTo?: string;
    },
  ): Promise<RoomMessageResponse> {
    return this.request<RoomMessageResponse>('message.create', {
      room_id: roomId,
      content,
      content_type: options?.contentType,
      thread_id: options?.threadId,
      in_reply_to: options?.inReplyTo,
    });
  }

  async messageUpdate(messageId: string, content: string): Promise<RoomMessageResponse> {
    return this.request<RoomMessageResponse>('message.update', {
      message_id: messageId,
      content,
    });
  }

  async messageRevoke(messageId: string): Promise<RoomMessageResponse> {
    return this.request<RoomMessageResponse>('message.revoke', { message_id: messageId });
  }

  async messageGet(messageId: string): Promise<RoomMessageResponse | null> {
    return this.request<RoomMessageResponse>('message.get', { message_id: messageId });
  }

  async messageEditHistory(messageId: string): Promise<MessageEditHistoryResponse> {
    const data = await this.request<MessageEditHistoryResponse>('message.edit_history', {
      message_id: messageId,
    });
    return data || { message_id: messageId, history: [], total_edits: 0 };
  }

  async memberList(roomId: string): Promise<RoomMemberResponse[]> {
    const data = await this.request<RoomMemberResponse[]>('member.list', { room_id: roomId });
    return Array.isArray(data) ? data : [];
  }

  async memberAdd(roomId: string, userId: string, role?: string): Promise<RoomMemberResponse> {
    return this.request<RoomMemberResponse>('member.add', {
      room_id: roomId,
      user_id: userId,
      role,
    });
  }

  async memberRemove(roomId: string, userId: string): Promise<boolean> {
    const data = await this.request<boolean>('member.remove', {
      room_id: roomId,
      user_id: userId,
    });
    return data === true;
  }

  async memberLeave(roomId: string): Promise<boolean> {
    const data = await this.request<boolean>('member.leave', { room_id: roomId });
    return data === true;
  }

  async memberSetReadSeq(roomId: string, lastReadSeq: number): Promise<RoomMemberResponse> {
    return this.request<RoomMemberResponse>('member.set_read_seq', {
      room_id: roomId,
      last_read_seq: lastReadSeq,
    });
  }

  async memberUpdateRole(roomId: string, userId: string, role: string): Promise<RoomMemberResponse> {
    return this.request<RoomMemberResponse>('member.update_role', {
      room_id: roomId,
      user_id: userId,
      role,
    });
  }

  async pinList(roomId: string): Promise<PinResponseData[]> {
    const data = await this.request<PinResponseData[]>('pin.list', { room_id: roomId });
    return Array.isArray(data) ? data : [];
  }

  async pinAdd(roomId: string, messageId: string): Promise<PinResponseData> {
    return this.request<PinResponseData>('pin.add', { room_id: roomId, message_id: messageId });
  }

  async pinRemove(roomId: string, messageId: string): Promise<boolean> {
    const data = await this.request<boolean>('pin.remove', { room_id: roomId, message_id: messageId });
    return data === true;
  }

  async threadList(roomId: string): Promise<RoomThreadResponse[]> {
    const data = await this.request<RoomThreadResponse[]>('thread.list', { room_id: roomId });
    return Array.isArray(data) ? data : [];
  }

  async threadCreate(roomId: string, parentSeq: number): Promise<RoomThreadResponse> {
    return this.request<RoomThreadResponse>('thread.create', {
      room_id: roomId,
      parent_seq: parentSeq,
    });
  }

  async threadMessages(
    threadId: string,
    options?: {
      beforeSeq?: number;
      afterSeq?: number;
      limit?: number;
    },
  ): Promise<RoomMessageListResponse> {
    const data = await this.request<RoomMessageListResponse>('thread.messages', {
      thread_id: threadId,
      before_seq: options?.beforeSeq,
      after_seq: options?.afterSeq,
      limit: options?.limit,
    });
    return data || { messages: [], total: 0 };
  }

  async reactionAdd(roomId: string, messageId: string, emoji: string): Promise<ReactionListData> {
    return this.request<ReactionListData>('reaction.add', {
      room_id: roomId,
      message_id: messageId,
      emoji,
    });
  }

  async reactionRemove(roomId: string, messageId: string, emoji: string): Promise<ReactionListData> {
    return this.request<ReactionListData>('reaction.remove', {
      room_id: roomId,
      message_id: messageId,
      emoji,
    });
  }

  async reactionGet(roomId: string, messageId: string): Promise<ReactionListData> {
    const data = await this.request<ReactionListData>('reaction.get', { room_id: roomId, message_id: messageId });
    return data || { message_id: messageId, reactions: [] };
  }

  async reactionListBatch(roomId: string, messageIds: string[]): Promise<ReactionListData[]> {
    if (messageIds.length === 0) return [];
    const data = await this.request<ReactionListData[]>('reaction.list_batch', {
      room_id: roomId,
      message_ids: messageIds,
    });
    return data || [];
  }

  async messageSearch(
    roomId: string,
    query: string,
    options?: {
      limit?: number;
      offset?: number;
    },
  ): Promise<SearchResultData> {
    const data = await this.request<SearchResultData>('message.search', {
      room_id: roomId,
      query,
      limit: options?.limit,
      offset: options?.offset,
    });
    return data || { messages: [], total: 0 };
  }

  async aiList(roomId: string): Promise<AiConfigData[]> {
    const data = await this.request<AiConfigData[]>('ai.list', { room_id: roomId });
    return Array.isArray(data) ? data : [];
  }

  async aiUpsert(
    roomId: string,
    model: string,
    options?: {
      version?: string;
      historyLimit?: number;
      systemPrompt?: string;
      temperature?: number;
      maxTokens?: number;
      useExact?: boolean;
      think?: boolean;
      stream?: boolean;
      minScore?: number;
    },
  ): Promise<AiConfigData> {
    return this.request<AiConfigData>('ai.upsert', {
      room_id: roomId,
      model,
      model_version: options?.version,
      history_limit: options?.historyLimit,
      system_prompt: options?.systemPrompt,
      temperature: options?.temperature,
      max_tokens: options?.maxTokens,
      use_exact: options?.useExact,
      think: options?.think,
      stream: options?.stream,
      min_score: options?.minScore,
    });
  }

  async aiDelete(roomId: string, modelId: string): Promise<boolean> {
    const data = await this.request<boolean>('ai.delete', {
      room_id: roomId,
      model_id: modelId,
    });
    return data === true;
  }

  async notificationList(options?: {
    onlyUnread?: boolean;
    limit?: number;
  }): Promise<NotificationListData> {
    const data = await this.request<NotificationListData>('notification.list', {
      only_unread: options?.onlyUnread,
      limit: options?.limit,
    });
    return data || { notifications: [], total: 0, unread_count: 0 };
  }

  async notificationMarkRead(notificationId: string): Promise<boolean> {
    const data = await this.request<boolean>('notification.mark_read', {
      notification_id: notificationId,
    });
    return data === true;
  }

  async notificationMarkAllRead(): Promise<number> {
    const data = await this.request<number>('notification.mark_all_read', {});
    return typeof data === 'number' ? data : 0;
  }

  async notificationArchive(notificationId: string): Promise<boolean> {
    const data = await this.request<boolean>('notification.archive', {
      notification_id: notificationId,
    });
    return data === true;
  }

  async mentionList(limit?: number): Promise<MentionListData> {
    const data = await this.request<MentionListData>('mention.list', { limit });
    return data || { mentions: [] };
  }

  async mentionReadAll(): Promise<boolean> {
    const data = await this.request<boolean>('mention.read_all', {});
    return data === true;
  }

  async subscribeRoom(roomId: string): Promise<void> {
    this.subscribedRooms.add(roomId);
    // subscribe is WS-only, don't fallback to HTTP
    if (this.status === 'open' && this.ws) {
      try {
        await this.requestWs<SubscribeData>('room.subscribe', { room_id: roomId });
      } catch (err) {
        // WS subscribe failed, add retry logic
        console.warn('[RoomWs] subscribeRoom failed, will retry:', roomId, err);
        // Schedule a retry with delay
        this.retrySubscribeRoom(roomId, 1);
      }
    }
  }

  private async retrySubscribeRoom(roomId: string, attempt: number): Promise<void> {
    if (!this.subscribedRooms.has(roomId)) return; // User unsubscribed
    if (attempt > 3) {
      console.error('[RoomWs] subscribeRoom retry exhausted:', roomId);
      return;
    }
    
    const delay = 1000 * Math.pow(2, attempt - 1); // 1s, 2s, 4s
    console.debug(`[RoomWs] retrying subscribeRoom in ${delay}ms (attempt ${attempt}/3)`);
    
    await new Promise(resolve => setTimeout(resolve, delay));
    
    if (this.status === 'open' && this.ws) {
      try {
        await this.requestWs<SubscribeData>('room.subscribe', { room_id: roomId });
        console.debug('[RoomWs] subscribeRoom retry succeeded:', roomId);
      } catch (err) {
        console.warn('[RoomWs] subscribeRoom retry failed:', roomId, err);
        this.retrySubscribeRoom(roomId, attempt + 1);
      }
    } else {
      // WS not open, will retry when connection is established via resubscribeAll
      console.debug('[RoomWs] WS not open, will retry on reconnect');
    }
  }

  async unsubscribeRoom(roomId: string): Promise<void> {
    this.subscribedRooms.delete(roomId);
    if (this.status === 'open' && this.ws) {
      try {
        await this.requestWs<boolean>('room.unsubscribe', { room_id: roomId });
      } catch {
        // ignore
      }
    }
  }

  async subscribeProject(projectName: string): Promise<void> {
    this.subscribedProjects.add(projectName);
    // subscribe is WS-only, don't fallback to HTTP
    if (this.status === 'open' && this.ws) {
      try {
        await this.requestWs<SubscribeData>('project.subscribe', { project_name: projectName });
      } catch {
        console.warn('[RoomWs] subscribeProject failed:', projectName);
      }
    }
  }

  async unsubscribeProject(projectName: string): Promise<void> {
    this.subscribedProjects.delete(projectName);
    if (this.status === 'open' && this.ws) {
      try {
        await this.requestWs<boolean>('project.unsubscribe', { project_name: projectName });
      } catch {
        // ignore
      }
    }
  }

  private buildWsUrl(): string {
    const wsBase = this.baseUrl.replace(/^http/, 'ws').replace(/^https/, 'wss');
    let url = `${wsBase}/ws`;

    // Add token as query parameter if available
    if (this.wsToken) {
      url = `${url}?token=${this.wsToken}`;
    }

    return url;
  }

  private handleMessage(message: WsInMessage): void {
    if ('type' in message && message.type === 'error') {
      return;
    }

    if ('request_id' in message && 'action' in message) {
      const response = message as WsResponse;
      const req = this.pendingRequests.get(response.request_id);
      if (req) {
        clearTimeout(req.timeout);
        this.pendingRequests.delete(response.request_id);
        if (response.error) {
          req.reject(new Error(`${response.error.error}: ${response.error.message}`));
        } else {
          req.resolve(response.data as WsResponseData);
        }
      }
    }

    if ('type' in message && message.type === 'event') {
      this.handlePushEvent(message as WsEvent);
    }
  }

  private handlePushEvent(event: WsEvent): void {
    if (!event.event) return;

    // Parse backend event type string to typed payload
    switch (event.event) {
      case 'room.message':
      case 'room_message':
        this.callbacks.onRoomMessage?.(event.data as RoomMessagePayload);
        break;
      case 'project.event':
      case 'project_event':
        this.dispatchProjectEvent(event.data as ProjectEventPayload);
        break;
      case 'ai.stream_chunk':
      case 'ai_stream_chunk':
        this.callbacks.onAiStreamChunk?.(event.data as AiStreamChunkPayload);
        break;
      case 'room.reaction_updated':
      case 'room_reaction_updated':
        this.callbacks.onRoomReactionUpdated?.(event.data as RoomReactionUpdatedPayload);
        break;
      default:
        // Unknown event type - ignore silently
        break;
    }
  }

  private dispatchProjectEvent(event: ProjectEventPayload): void {
    switch (event.event_type) {
      case 'message_edited':
        this.callbacks.onMessageEdited?.({
          message_id: event.message_id ?? '',
          room_id: event.room_id ?? '',
          edited_at: event.timestamp,
        } as import('./ws-protocol').MessageEditedPayload);
        break;
      case 'message_revoked':
        this.callbacks.onMessageRevoked?.({
          message_id: event.message_id ?? '',
          room_id: event.room_id ?? '',
          revoked_at: event.timestamp,
          revoked_by: '',
        } as import('./ws-protocol').MessageRevokedPayload);
        break;
      case 'message_pinned':
        this.callbacks.onMessagePinned?.({
          message_id: event.message_id ?? '',
          room_id: event.room_id ?? '',
          pinned_by: '',
          pinned_at: event.timestamp,
        } as import('./ws-protocol').MessagePinnedPayload);
        break;
      case 'message_unpinned':
        this.callbacks.onMessageUnpinned?.({
          message_id: event.message_id ?? '',
          room_id: event.room_id ?? '',
        } as import('./ws-protocol').MessageUnpinnedPayload);
        break;
      default:
        // Other project events (member_joined, room_created, etc.)
        this.callbacks.onProjectEvent?.(event);
        break;
    }
  }

  private setStatus(status: RoomWsStatus): void {
    this.status = status;
    this.callbacks.onStatusChange?.(status);
  }

  private async resubscribeAll(): Promise<void> {
    for (const roomId of this.subscribedRooms) {
      try {
        await this.request('room.subscribe', { room_id: roomId });
      } catch (err) {
        // Resubscribe failure is non-fatal — messages still arrive via REST poll.
        // Log at warn level so operators can observe patterns (e.g. auth expiry).
        console.warn(`[RoomWs] resubscribe room failed (will retry on next reconnect): ${roomId}`, err);
      }
    }
    for (const projectName of this.subscribedProjects) {
      try {
        await this.request('project.subscribe', { project_name: projectName });
      } catch (err) {
        console.warn(`[RoomWs] resubscribe project failed (will retry on next reconnect): ${projectName}`, err);
      }
    }
  }

  private scheduleReconnect(): void {
    if (!this.shouldReconnect) return;

    // Exponential backoff with full jitter (uniform random within the backoff window).
    // Without jitter, all disconnected clients reconnect at exactly the same time
    // (thundering herd) after a server restart, overwhelming it.
    const baseDelay = this.reconnectBaseDelay * Math.pow(2, this.reconnectAttempt);
    const cappedDelay = Math.min(baseDelay, this.reconnectMaxDelay);
    const jitter = Math.random() * cappedDelay;
    const delay = Math.floor(jitter);
    this.reconnectAttempt++;

    this.reconnectTimer = setTimeout(() => {
      this.reconnectTimer = null;
      this.connect().catch(() => {});
    }, delay);
  }
}

export function createRoomWsClient(
  baseUrl: string,
  callbacks: RoomWsCallbacks = {},
  options?: {
    reconnectBaseDelay?: number;
    reconnectMaxDelay?: number;
    requestTimeout?: number;
    wsToken?: string;
  },
): RoomWsClient {
  return new RoomWsClient(baseUrl, callbacks, options);
}