import {
  Controller,
  Get,
  Post,
  Patch,
  Body,
  Param,
  Query,
  UseGuards,
  HttpCode,
  HttpStatus,
} from '@nestjs/common';
import {
  ApiTags,
  ApiOperation,
  ApiResponse,
  ApiBearerAuth,
  ApiQuery,
  ApiParam,
} from '@nestjs/swagger';
import { MessagesService } from './messages.service';
import { CreateMessageDto, StartConversationDto } from './dto';
import { JwtAuthGuard } from '../auth/guards';
import { CurrentUser } from '../auth/decorators';
import { UserRole } from '@prisma/client';

@ApiTags('Messages')
@Controller('messages')
@UseGuards(JwtAuthGuard)
@ApiBearerAuth('JWT-auth')
export class MessagesController {
  constructor(private readonly messagesService: MessagesService) {}

  // ==========================================
  // GET CONVERSATIONS LIST
  // ==========================================
  @Get('conversations')
  @ApiOperation({ summary: 'Get all conversations for the current user' })
  @ApiResponse({
    status: 200,
    description: 'List of conversations',
    schema: {
      example: [
        {
          id: 'conv-uuid',
          lastMessageAt: '2024-01-01T00:00:00.000Z',
          lastMessageText: 'Hello!',
          unreadCount: 2,
          otherParty: {
            id: 'agent-uuid',
            name: 'John Doe',
            avatar: 'https://...',
            headline: 'Real Estate Agent',
            isOnline: true,
          },
        },
      ],
    },
  })
  async getConversations(
    @CurrentUser('id') userId: string,
    @CurrentUser('role') role: UserRole,
  ) {
    return this.messagesService.getConversations(userId, role);
  }

  // ==========================================
  // START OR GET CONVERSATION
  // ==========================================
  @Post('conversations')
  @HttpCode(HttpStatus.OK)
  @ApiOperation({ summary: 'Start or get existing conversation with an agent' })
  @ApiResponse({
    status: 200,
    description: 'Conversation created or retrieved',
  })
  @ApiResponse({
    status: 403,
    description: 'Connection not accepted',
  })
  async startConversation(
    @CurrentUser('id') userId: string,
    @Body() dto: StartConversationDto,
  ) {
    return this.messagesService.getOrCreateConversation(userId, dto.agentProfileId);
  }

  // ==========================================
  // GET CONVERSATION DETAILS
  // ==========================================
  @Get('conversations/:id')
  @ApiOperation({ summary: 'Get a specific conversation' })
  @ApiParam({ name: 'id', description: 'Conversation ID' })
  @ApiResponse({
    status: 200,
    description: 'Conversation details',
  })
  @ApiResponse({
    status: 404,
    description: 'Conversation not found',
  })
  async getConversation(
    @Param('id') conversationId: string,
    @CurrentUser('id') userId: string,
  ) {
    return this.messagesService.getConversationById(conversationId, userId);
  }

  // ==========================================
  // GET MESSAGES FOR CONVERSATION
  // ==========================================
  @Get('conversations/:id/messages')
  @ApiOperation({ summary: 'Get messages for a conversation' })
  @ApiParam({ name: 'id', description: 'Conversation ID' })
  @ApiQuery({ name: 'page', required: false, type: Number })
  @ApiQuery({ name: 'limit', required: false, type: Number })
  @ApiResponse({
    status: 200,
    description: 'List of messages with pagination',
    schema: {
      example: {
        messages: [
          {
            id: 'msg-uuid',
            content: 'Hello!',
            messageType: 'TEXT',
            status: 'READ',
            createdAt: '2024-01-01T00:00:00.000Z',
            sender: {
              id: 'user-uuid',
              role: 'USER',
              userProfile: {
                firstName: 'Jane',
                lastName: 'Doe',
              },
            },
          },
        ],
        pagination: {
          page: 1,
          limit: 50,
          total: 100,
          pages: 2,
        },
      },
    },
  })
  async getMessages(
    @Param('id') conversationId: string,
    @CurrentUser('id') userId: string,
    @Query('page') page?: string,
    @Query('limit') limit?: string,
  ) {
    return this.messagesService.getMessages(
      conversationId,
      userId,
      page ? parseInt(page, 10) : 1,
      limit ? parseInt(limit, 10) : 50,
    );
  }

  // ==========================================
  // SEND MESSAGE (REST FALLBACK)
  // ==========================================
  @Post('conversations/:id/messages')
  @HttpCode(HttpStatus.CREATED)
  @ApiOperation({ summary: 'Send a message (REST fallback - prefer WebSocket)' })
  @ApiParam({ name: 'id', description: 'Conversation ID' })
  @ApiResponse({
    status: 201,
    description: 'Message created',
  })
  async sendMessage(
    @Param('id') conversationId: string,
    @CurrentUser('id') userId: string,
    @Body() dto: CreateMessageDto,
  ) {
    return this.messagesService.createMessage(conversationId, userId, dto);
  }

  // ==========================================
  // MARK MESSAGES AS READ
  // ==========================================
  @Patch('conversations/:id/read')
  @HttpCode(HttpStatus.OK)
  @ApiOperation({ summary: 'Mark all messages in conversation as read' })
  @ApiParam({ name: 'id', description: 'Conversation ID' })
  @ApiResponse({
    status: 200,
    description: 'Messages marked as read',
  })
  async markAsRead(
    @Param('id') conversationId: string,
    @CurrentUser('id') userId: string,
  ) {
    return this.messagesService.markMessagesAsRead(conversationId, userId);
  }

  // ==========================================
  // GET UNREAD COUNT
  // ==========================================
  @Get('unread-count')
  @ApiOperation({ summary: 'Get total unread message count' })
  @ApiResponse({
    status: 200,
    description: 'Unread count',
    schema: {
      example: { unreadCount: 5 },
    },
  })
  async getUnreadCount(
    @CurrentUser('id') userId: string,
    @CurrentUser('role') role: UserRole,
  ) {
    const unreadCount = await this.messagesService.getTotalUnreadCount(userId, role);
    return { unreadCount };
  }
}