import {
  Body,
  Controller,
  Delete,
  Get,
  Param,
  Post,
  Res,
  StreamableFile,
  UseGuards,
} from '@nestjs/common';
import { CommandBus } from '@nestjs/cqrs';
import { ApiTags, ApiOperation, ApiResponse, ApiBearerAuth, ApiProduces } from '@nestjs/swagger';
import { Response } from 'express';
import { CancelUserDeletionCommand } from '../../application/commands/cancel-user-deletion/cancel-user-deletion.command';
import { ExportUserDataCommand } from '../../application/commands/export-user-data/export-user-data.command';
import { type ExportUserDataResult } from '../../application/commands/export-user-data/export-user-data.handler';
import { ForceDeleteUserCommand } from '../../application/commands/force-delete-user/force-delete-user.command';
import { RequestUserDeletionCommand } from '../../application/commands/request-user-deletion/request-user-deletion.command';
import { type JwtPayload } from '../../infrastructure/services/token.service';
import { CurrentUser } from '../decorators/current-user.decorator';
import { Roles } from '../decorators/roles.decorator';
import { ForceDeleteUserDto } from '../dto/force-delete-user.dto';
import { RequestDeletionDto } from '../dto/request-deletion.dto';
import { JwtAuthGuard } from '../guards/jwt-auth.guard';
import { RolesGuard } from '../guards/roles.guard';

@ApiTags('users')
@Controller('users')
export class UserDataController {
  constructor(private readonly commandBus: CommandBus) {}

  @Delete('me')
  @UseGuards(JwtAuthGuard)
  @ApiBearerAuth('JWT')
  @ApiOperation({ summary: 'Request account deletion (30-day grace period)' })
  @ApiResponse({ status: 200, description: 'Deletion scheduled' })
  @ApiResponse({ status: 401, description: 'Unauthorized' })
  async requestDeletion(
    @CurrentUser() user: JwtPayload,
    @Body() dto: RequestDeletionDto,
  ): Promise<{ scheduledAt: Date; message: string }> {
    const result = await this.commandBus.execute(
      new RequestUserDeletionCommand(user.sub, dto.reason),
    );
    return { ...result, message: 'Tài khoản sẽ bị xóa sau 30 ngày' };
  }

  @Post('me/cancel-deletion')
  @UseGuards(JwtAuthGuard)
  @ApiBearerAuth('JWT')
  @ApiOperation({ summary: 'Cancel pending account deletion' })
  @ApiResponse({ status: 201, description: 'Deletion cancelled' })
  @ApiResponse({ status: 401, description: 'Unauthorized' })
  async cancelDeletion(
    @CurrentUser() user: JwtPayload,
  ): Promise<{ message: string }> {
    return this.commandBus.execute(new CancelUserDeletionCommand(user.sub));
  }

  @Get('me/export')
  @UseGuards(JwtAuthGuard)
  @ApiBearerAuth('JWT')
  @ApiProduces('application/json')
  @ApiOperation({
    summary: 'Export user data (GDPR Article 20)',
    description:
      'Streams the full user data export as JSON. ' +
      'Row cap (per collection) defaults to 10 000 rows; size cap defaults to 100 MB. ' +
      'Both are configurable via EXPORT_ROW_CAP and EXPORT_SIZE_CAP_MB env vars.',
  })
  @ApiResponse({ status: 200, description: 'User data exported as streaming JSON' })
  @ApiResponse({ status: 401, description: 'Unauthorized' })
  @ApiResponse({
    status: 413,
    description: 'Export exceeds size cap — contact support for chunked export',
  })
  async exportData(
    @CurrentUser() user: JwtPayload,
    @Res({ passthrough: true }) res: Response,
  ): Promise<StreamableFile> {
    const result: ExportUserDataResult = await this.commandBus.execute(
      new ExportUserDataCommand(user.sub),
    );
    res.setHeader('Content-Type', 'application/json');
    res.setHeader(
      'Content-Disposition',
      `attachment; filename="user-data-${user.sub}.json"`,
    );
    return new StreamableFile(result.stream);
  }

  @Delete(':id/force')
  @UseGuards(JwtAuthGuard, RolesGuard)
  @Roles('ADMIN')
  @ApiBearerAuth('JWT')
  @ApiOperation({ summary: 'Force-delete user immediately (admin only)' })
  @ApiResponse({ status: 200, description: 'User force-deleted' })
  @ApiResponse({ status: 401, description: 'Unauthorized' })
  @ApiResponse({ status: 403, description: 'Forbidden — admin only' })
  async forceDelete(
    @Param('id') id: string,
    @CurrentUser() admin: JwtPayload,
    @Body() dto: ForceDeleteUserDto,
  ): Promise<{ message: string }> {
    return this.commandBus.execute(
      new ForceDeleteUserCommand(id, admin.sub, dto.reason),
    );
  }
}