import webSocket from '@ohos.net.webSocket'
import { HttpClient } from '../core/HttpClient'
import { SDKContext } from '../core/SDKContext'
import type {
  ChatType,
  ConversationData,
  FriendRequest,
  GroupJoinRequest,
  HistoryQuery,
  ImGroup,
  ImMessage,
  MsgType,
  PageResult,
  SendMessageParams,
  UserProfile,
} from '../core/Types'

export interface ImEventDelegate {
  onConnected?(): void
  onDisconnected?(code: number, reason: string): void
  onMessage?(msg: ImMessage): void
  onRead?(msg: ImMessage): void
  onRevoke?(data: RevokeData): void
  onError?(message: string): void
}

export interface RevokeData {
  msgId: string
  operatorId: string
}

class WebSocketFrame {
  type: string = ''
  payload: Object = new Object()
}

class WebSocketEnvelope {
  destination: string = ''
  payload: Object = new Object()
}

class AppBody {
  appId: string = ''
}

class HistoryQueryParams {
  appId: string = ''
  page: number = 0
  size: number = 0
  msgType: MsgType = 'TEXT'
  keyword: string = ''
  startTime: string = ''
  endTime: string = ''
}

class ConversationActionBody {
  appId: string = ''
  chatType: ChatType = 'SINGLE'
}

class FriendRequestQueryBody {
  appId: string = ''
  direction: 'incoming' | 'outgoing' = 'incoming'
}

class FriendRequestBody {
  appId: string = ''
  toUserId: string = ''
  remark: string = ''
}

class GroupJoinRequestBody {
  appId: string = ''
  remark: string = ''
}

class EditMessageBody {
  content: string = ''
}

class UpdateProfileBody {
  appId: string = ''
  nickname: string = ''
  avatar: string = ''
  gender: string = ''
}

class DraftBody {
  appId: string = ''
  chatType: ChatType = 'SINGLE'
  draft: string = ''
}

class PinBody {
  appId: string = ''
  chatType: ChatType = 'SINGLE'
  pinned: boolean = false
}

class MuteBody {
  appId: string = ''
  chatType: ChatType = 'SINGLE'
  muted: boolean = false
}

class SendEnvelopePayload {
  messageId: string = ''
  toId: string = ''
  chatType: ChatType = 'SINGLE'
  msgType: MsgType = 'TEXT'
  content: string = ''
  mentionedUserIds: string = ''
}

class RevokeEnvelopePayload {
  msgId: string = ''
}

const MAX_RECONNECT_DELAY = 30_000

export class ImClient {
  private ws: webSocket.WebSocket | null = null
  private reconnectDelay: number = 3_000
  private reconnectTimer: number | null = null
  private destroyed: boolean = false
  delegate: ImEventDelegate | null = null

  connect(): void {
    if (this.destroyed) return
    const config = SDKContext.getConfig()
    const token = SDKContext.getToken() ?? ''
    const url = config.imBaseUrl.replace(/\/$/, '') + '/ws/im?token=' + encodeURIComponent(token)

    this.ws = webSocket.createWebSocket()

    this.ws.on('open', (_err: Error, _value: Object) => {
      this.reconnectDelay = 3_000
      if (config.debug) console.log('[ImClient] connected')
      this.delegate?.onConnected?.()
    })

    this.ws.on('message', (_err: Error, value: string | ArrayBuffer) => {
      try {
        if (typeof value !== 'string') {
          return
        }
        const frame = JSON.parse(value) as WebSocketFrame
        if (frame.type === 'MESSAGE') {
          const message = this.normalizeMessage(frame.payload as ImMessage)
          if (message.status === 'READ') {
            this.delegate?.onRead?.(message)
          }
          if (message.revoked || message.status === 'REVOKED' || message.msgType === 'REVOKED') {
            this.delegate?.onRevoke?.({ msgId: message.id, operatorId: message.fromId })
          }
          this.delegate?.onMessage?.(message)
        } else if (frame.type === 'REVOKE') {
          this.delegate?.onRevoke?.(frame.payload as RevokeData)
        }
      } catch {
        // ignore malformed frames
      }
    })

    this.ws.on('close', (_err: Error, value: webSocket.CloseResult) => {
      this.delegate?.onDisconnected?.(value.code, value.reason)
      if (!this.destroyed) this.scheduleReconnect()
    })

    this.ws.on('error', (_err: Error) => {
      this.delegate?.onError?.(_err.message)
    })

    this.ws.connect(url, {})
  }

  send(params: SendMessageParams): ImMessage {
    const outgoing = this.buildOutgoingMessage(params)
    if (!this.ws) {
      return this.markFailed(outgoing)
    }

    const payload = new SendEnvelopePayload()
    payload.messageId = outgoing.id
    payload.toId = params.toId
    payload.chatType = params.chatType
    payload.msgType = params.msgType
    payload.content = params.content
    if (params.mentionedUserIds !== undefined) {
      payload.mentionedUserIds = params.mentionedUserIds
    }
    const envelope = new WebSocketEnvelope()
    envelope.destination = '/app/chat.send'
    envelope.payload = payload

    this.ws.send(JSON.stringify(envelope), (_err: Error) => {
      if (_err) {
        this.delegate?.onError?.(_err.message)
      }
    })
    return outgoing
  }

  revoke(msgId: string): void {
    if (!this.ws) {
      throw new Error('WebSocket not connected')
    }
    const payload = new RevokeEnvelopePayload()
    payload.msgId = msgId
    const envelope = new WebSocketEnvelope()
    envelope.destination = '/app/chat.revoke'
    envelope.payload = payload
    this.ws.send(JSON.stringify(envelope), (_err: Error) => {
      if (_err) this.delegate?.onError?.(_err.message)
    })
  }

  async fetchHistory(
    toId: string,
    page: number = 0,
    size: number = 20,
    query: HistoryQuery = {},
  ): Promise<PageResult<ImMessage>> {
    const queryString = this.buildHistoryQuery(page, size, query)
    return HttpClient.get<PageResult<ImMessage>>('/api/im/messages/history/' + encodeURIComponent(toId), queryString)
  }

  async fetchGroupHistory(
    groupId: string,
    page: number = 0,
    size: number = 50,
    query: HistoryQuery = {},
  ): Promise<PageResult<ImMessage>> {
    const queryString = this.buildHistoryQuery(page, size, query)
    return HttpClient.get<PageResult<ImMessage>>('/api/im/messages/group-history/' + encodeURIComponent(groupId), queryString)
  }

  async locateHistoryPage(
    toId: string,
    messageId: string,
    pageSize: number = 20,
    maxPages: number = 20,
  ): Promise<ImMessage[] | null> {
    const pageCount = Math.max(maxPages, 1)
    for (let page = 0; page < pageCount; page += 1) {
      const result = await this.fetchHistory(toId, page, pageSize)
      const messages = result.content ?? []
      if (messages.some(item => item.id === messageId)) {
        return messages
      }
      if (messages.length < pageSize) {
        return null
      }
    }
    return null
  }

  async locateGroupHistoryPage(
    groupId: string,
    messageId: string,
    pageSize: number = 50,
    maxPages: number = 20,
  ): Promise<ImMessage[] | null> {
    const pageCount = Math.max(maxPages, 1)
    for (let page = 0; page < pageCount; page += 1) {
      const result = await this.fetchGroupHistory(groupId, page, pageSize)
      const messages = result.content ?? []
      if (messages.some(item => item.id === messageId)) {
        return messages
      }
      if (messages.length < pageSize) {
        return null
      }
    }
    return null
  }

  async listConversations(size: number = 20): Promise<ConversationData[]> {
    return HttpClient.get<ConversationData[]>('/api/im/conversations', this.buildConversationQuery(size))
  }

  async markRead(targetId: string, chatType: ChatType = 'SINGLE'): Promise<void> {
    await HttpClient.put<void>('/api/im/conversations/' + encodeURIComponent(targetId) + '/read', undefined, this.buildConversationActionQuery(chatType))
  }

  async setDraft(targetId: string, chatType: ChatType, draft: string): Promise<void> {
    const params = new DraftBody()
    params.appId = SDKContext.getConfig().appKey
    params.chatType = chatType
    params.draft = draft
    await HttpClient.put<void>('/api/im/conversations/' + encodeURIComponent(targetId) + '/draft', params)
  }

  async setConversationPinned(targetId: string, chatType: ChatType, pinned: boolean): Promise<void> {
    const params = new PinBody()
    params.appId = SDKContext.getConfig().appKey
    params.chatType = chatType
    params.pinned = pinned
    await HttpClient.put<void>('/api/im/conversations/' + encodeURIComponent(targetId) + '/pinned', params)
  }

  async setConversationMuted(targetId: string, chatType: ChatType, muted: boolean): Promise<void> {
    const params = new MuteBody()
    params.appId = SDKContext.getConfig().appKey
    params.chatType = chatType
    params.muted = muted
    await HttpClient.put<void>('/api/im/conversations/' + encodeURIComponent(targetId) + '/muted', params)
  }

  async deleteConversation(targetId: string, chatType: ChatType): Promise<void> {
    await HttpClient.delete<void>('/api/im/conversations/' + encodeURIComponent(targetId), this.buildConversationActionQuery(chatType))
  }

  async listFriends(): Promise<string[]> {
    return HttpClient.get<string[]>('/api/im/friends', this.buildAppQuery())
  }

  async listGroups(): Promise<ImGroup[]> {
    return HttpClient.get<ImGroup[]>('/api/im/groups', this.buildAppQuery())
  }

  async getGroupInfo(groupId: string): Promise<ImGroup> {
    return HttpClient.get<ImGroup>('/api/im/groups/' + encodeURIComponent(groupId), this.buildAppQuery())
  }

  async listGroupMembers(groupId: string): Promise<UserProfile[]> {
    return HttpClient.get<UserProfile[]>(
      '/api/im/groups/' + encodeURIComponent(groupId) + '/members',
      this.buildAppQuery(),
    )
  }

  async searchGroupMembers(groupId: string, keyword: string, size: number = 20): Promise<UserProfile[]> {
    return HttpClient.get<UserProfile[]>(
      '/api/im/groups/' + encodeURIComponent(groupId) + '/members/search',
      this.buildSearchQuery(keyword, size),
    )
  }

  async searchUsers(keyword: string, size: number = 20): Promise<UserProfile[]> {
    return HttpClient.get<UserProfile[]>(
      '/api/im/admin/users/search',
      this.buildSearchQuery(keyword, size),
    )
  }

  async searchGroups(keyword: string, size: number = 20): Promise<ImGroup[]> {
    return HttpClient.get<ImGroup[]>(
      '/api/im/admin/groups/search',
      this.buildSearchQuery(keyword, size),
    )
  }

  async searchMessages(
    keyword: string = '',
    chatType: ChatType | '' = '',
    msgType: MsgType | '' = '',
    page: number = 0,
    size: number = 20,
  ): Promise<PageResult<ImMessage>> {
    return HttpClient.get<PageResult<ImMessage>>(
      '/api/im/admin/messages/search',
      this.buildMessageSearchQuery(keyword, chatType, msgType, page, size),
    )
  }

  async editMessage(messageId: string, content: string): Promise<ImMessage> {
    const body = new EditMessageBody()
    body.content = content
    return HttpClient.put<ImMessage>(
      '/api/im/messages/' + encodeURIComponent(messageId),
      body,
      this.buildAppQuery(),
    )
  }

  async revokeMessage(messageId: string): Promise<ImMessage> {
    return HttpClient.post<ImMessage>(
      '/api/im/messages/' + encodeURIComponent(messageId) + '/revoke',
      this.buildAppBody(),
      this.buildAppQuery(),
    )
  }

  async sendFriendRequest(toUserId: string, remark: string | null = null): Promise<FriendRequest> {
    const params = new FriendRequestBody()
    params.appId = SDKContext.getConfig().appKey
    params.toUserId = toUserId
    if (remark !== null && remark !== '') {
      params.remark = remark
    }
    return HttpClient.post<FriendRequest>('/api/im/friend-requests', params)
  }

  async listFriendRequests(direction: 'incoming' | 'outgoing' = 'incoming'): Promise<FriendRequest[]> {
    return HttpClient.get<FriendRequest[]>('/api/im/friend-requests', this.buildFriendRequestQuery(direction))
  }

  async acceptFriendRequest(requestId: string): Promise<FriendRequest> {
    return HttpClient.post<FriendRequest>('/api/im/friend-requests/' + encodeURIComponent(requestId) + '/accept', this.buildAppBody())
  }

  async rejectFriendRequest(requestId: string): Promise<FriendRequest> {
    return HttpClient.post<FriendRequest>('/api/im/friend-requests/' + encodeURIComponent(requestId) + '/reject', this.buildAppBody())
  }

  async sendGroupJoinRequest(groupId: string, remark: string | null = null): Promise<GroupJoinRequest> {
    const params = new GroupJoinRequestBody()
    params.appId = SDKContext.getConfig().appKey
    if (remark !== null && remark !== '') {
      params.remark = remark
    }
    return HttpClient.post<GroupJoinRequest>('/api/im/groups/' + encodeURIComponent(groupId) + '/join-requests', params)
  }

  async listGroupJoinRequests(groupId: string): Promise<GroupJoinRequest[]> {
    return HttpClient.get<GroupJoinRequest[]>('/api/im/groups/' + encodeURIComponent(groupId) + '/join-requests', this.buildAppQuery())
  }

  async acceptGroupJoinRequest(groupId: string, requestId: string): Promise<GroupJoinRequest> {
    return HttpClient.post<GroupJoinRequest>(
      '/api/im/groups/' + encodeURIComponent(groupId) + '/join-requests/' + encodeURIComponent(requestId) + '/accept',
      this.buildAppBody(),
    )
  }

  async rejectGroupJoinRequest(groupId: string, requestId: string): Promise<GroupJoinRequest> {
    return HttpClient.post<GroupJoinRequest>(
      '/api/im/groups/' + encodeURIComponent(groupId) + '/join-requests/' + encodeURIComponent(requestId) + '/reject',
      this.buildAppBody(),
    )
  }

  async getProfile(userId: string): Promise<UserProfile> {
    return HttpClient.get<UserProfile>('/api/im/accounts/' + encodeURIComponent(userId), this.buildAppQuery())
  }

  async updateProfile(
    userId: string,
    nickname: string | null = null,
    avatar: string | null = null,
    gender: string | null = null,
  ): Promise<UserProfile> {
    const params = new UpdateProfileBody()
    params.appId = SDKContext.getConfig().appKey
    if (nickname !== null) {
      params.nickname = nickname
    }
    if (avatar !== null) {
      params.avatar = avatar
    }
    if (gender !== null) {
      params.gender = gender
    }
    return HttpClient.put<UserProfile>('/api/im/accounts/' + encodeURIComponent(userId), params)
  }

  private buildAppBody(): AppBody {
    const body = new AppBody()
    body.appId = SDKContext.getConfig().appKey
    return body
  }

  private buildAppQuery(): string {
    return 'appId=' + encodeURIComponent(SDKContext.getConfig().appKey)
  }

  private buildConversationActionQuery(chatType: ChatType): string {
    return 'appId=' + encodeURIComponent(SDKContext.getConfig().appKey) + '&chatType=' + encodeURIComponent(chatType)
  }

  private buildConversationQuery(size: number): string {
    return 'appId=' + encodeURIComponent(SDKContext.getConfig().appKey) + '&page=0&size=' + encodeURIComponent(size)
  }

  private buildFriendRequestQuery(direction: 'incoming' | 'outgoing'): string {
    return 'appId=' + encodeURIComponent(SDKContext.getConfig().appKey) + '&direction=' + encodeURIComponent(direction)
  }

  private buildSearchQuery(keyword: string, size: number): string {
    return 'appId=' + encodeURIComponent(SDKContext.getConfig().appKey) +
      '&keyword=' + encodeURIComponent(keyword) +
      '&size=' + encodeURIComponent(size)
  }

  private buildMessageSearchQuery(
    keyword: string,
    chatType: ChatType | '',
    msgType: MsgType | '',
    page: number,
    size: number,
  ): string {
    const parts: string[] = []
    parts.push('appId=' + encodeURIComponent(SDKContext.getConfig().appKey))
    if (keyword !== '') {
      parts.push('keyword=' + encodeURIComponent(keyword))
    }
    if (chatType !== '') {
      parts.push('chatType=' + encodeURIComponent(chatType))
    }
    if (msgType !== '') {
      parts.push('msgType=' + encodeURIComponent(msgType))
    }
    parts.push('page=' + encodeURIComponent(page))
    parts.push('size=' + encodeURIComponent(size))
    return parts.join('&')
  }

  private buildHistoryQuery(page: number, size: number, query: HistoryQuery): string {
    const parts: string[] = []
    parts.push('appId=' + encodeURIComponent(SDKContext.getConfig().appKey))
    parts.push('page=' + encodeURIComponent(page))
    parts.push('size=' + encodeURIComponent(size))
    if (query.msgType !== undefined) {
      parts.push('msgType=' + encodeURIComponent(query.msgType))
    }
    if (query.keyword !== undefined && query.keyword !== '') {
      parts.push('keyword=' + encodeURIComponent(query.keyword))
    }
    if (query.startTime !== undefined) {
      const startValue = query.startTime instanceof Date ? this.formatDateTime(query.startTime) : String(query.startTime)
      parts.push('startTime=' + encodeURIComponent(startValue))
    }
    if (query.endTime !== undefined) {
      const endValue = query.endTime instanceof Date ? this.formatDateTime(query.endTime) : String(query.endTime)
      parts.push('endTime=' + encodeURIComponent(endValue))
    }
    return parts.join('&')
  }

  disconnect(): void {
    this.destroyed = true
    if (this.reconnectTimer !== null) {
      clearTimeout(this.reconnectTimer)
      this.reconnectTimer = null
    }
    this.ws?.close((_err: Error) => {})
    this.ws = null
  }

  private scheduleReconnect(): void {
    if (this.destroyed) return
    const delay = this.reconnectDelay
    if (SDKContext.getConfig().debug) console.log('[ImClient] reconnect in ' + delay + 'ms')
    this.reconnectTimer = setTimeout(() => {
      this.connect()
      this.reconnectDelay = Math.min(this.reconnectDelay * 2, MAX_RECONNECT_DELAY)
    }, delay)
  }

  private buildOutgoingMessage(params: SendMessageParams): ImMessage {
    const messageId = params.messageId ?? this.generateMessageId()
    const userId = SDKContext.getUserId() ?? ''
    const appId = SDKContext.getConfig().appKey
    const message: ImMessage = {
      id: messageId,
      appId,
      fromUserId: userId,
      fromId: userId,
      toId: params.toId,
      chatType: params.chatType,
      msgType: params.msgType,
      content: params.content,
      status: 'SENDING',
      mentionedUserIds: params.mentionedUserIds,
      groupReadCount: 0,
      revoked: false,
      createdAt: Date.now(),
    }
    return message
  }

  private markFailed(message: ImMessage): ImMessage {
    const failed: ImMessage = {
      id: message.id,
      appId: message.appId,
      fromUserId: message.fromUserId,
      fromId: message.fromId,
      toId: message.toId,
      chatType: message.chatType,
      msgType: message.msgType,
      content: message.content,
      status: 'FAILED',
      mentionedUserIds: message.mentionedUserIds,
      groupReadCount: message.groupReadCount,
      revoked: message.revoked,
      createdAt: message.createdAt,
    }
    return failed
  }

  private normalizeMessage(message: ImMessage): ImMessage {
    const normalized: ImMessage = {
      id: message.id,
      appId: message.appId || SDKContext.getConfig().appKey,
      fromUserId: message.fromUserId,
      fromId: message.fromId || message.fromUserId,
      toId: message.toId,
      chatType: message.chatType,
      msgType: message.msgType,
      content: message.content,
      status: message.status,
      mentionedUserIds: message.mentionedUserIds,
      groupReadCount: message.groupReadCount,
      revoked: message.revoked || message.status === 'REVOKED',
      createdAt: message.createdAt,
    }
    return normalized
  }

  private generateMessageId(): string {
    return 'msg_' + Date.now() + '_' + Math.floor(Math.random() * 1000000).toString(16)
  }

  private formatDateTime(value: Date): string {
    const pad = (n: number): string => {
      return n < 10 ? '0' + n : String(n)
    }
    return [
      value.getFullYear(),
      '-',
      pad(value.getMonth() + 1),
      '-',
      pad(value.getDate()),
      'T',
      pad(value.getHours()),
      ':',
      pad(value.getMinutes()),
      ':',
      pad(value.getSeconds()),
    ].join('')
  }

  private toStringValue(value: Date | string | number | undefined): string | undefined {
    if (value === undefined) {
      return undefined
    }
    if (value instanceof Date) {
      return this.formatDateTime(value)
    }
    return String(value)
  }
}