import {
  BadRequestException,
  Body,
  Controller,
  Headers,
  HttpCode,
  Logger,
  Post,
  Req,
} from '@nestjs/common';
import {
  ApiBody,
  ApiOperation,
  ApiResponse,
  ApiTags,
  ApiBadRequestResponse,
  ApiProperty,
  ApiPropertyOptional,
} from '@nestjs/swagger';
import { Request } from 'express';
import { StatsAdClickPublisherService } from './stats-ad-click.publisher.service';
import { extractClientIp } from '../../utils/client-ip.util';
import { Transform } from 'class-transformer';
import { IsOptional, IsString, Matches } from 'class-validator';

export class AdClickRequestDto {
  @ApiProperty({ description: '用户唯一设备ID', example: 'xxxxxx' })
  @IsString()
  uid!: string;

  @ApiProperty({ description: '渠道ID', example: 'AAA' })
  @IsString()
  channelId!: string;

  @ApiProperty({
    description: '广告 Mongo ObjectId',
    example: '64b7c2f967ce4d6799c047d1',
  })
  @IsString()
  adsId!: string; // ✅ required

  @ApiPropertyOptional({
    description: 'Optional IPv4 hint (empty string/null accepted).',
    example: '1.2.3.4',
  })
  @Transform(({ value }) => {
    if (value === '' || value === null || value === undefined) {
      return undefined;
    }
    return typeof value === 'string' ? value.trim() : value;
  })
  @IsOptional()
  @Matches(
    /^(25[0-5]|2[0-4]\d|1\d{2}|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d{2}|[1-9]?\d)){3}$/,
    { message: 'ipv4 must be a valid IPv4 address' },
  )
  ipv4?: string;
}

@ApiTags('Ads Stats')
@Controller('stats')
export class AdsStatsController {
  private readonly logger = new Logger(AdsStatsController.name);

  constructor(private readonly publisher: StatsAdClickPublisherService) {}

  @Post('ad-click')
  @HttpCode(202)
  @ApiOperation({
    summary: '广告点击上报',
    description: '用于广告点击统计。uid、channelId、adsId 必填。',
  })
  @ApiBody({
    type: AdClickRequestDto,
    description: 'uid、channelId、adsId 必填（adsId 为 Mongo ObjectId）',
    examples: {
      example: {
        summary: '示例',
        value: {
          uid: 'xxxxxx',
          channelId: 'AAA',
          adsId: '64b7c2f967ce4d6799c047d1',
        },
      },
    },
  })
  @ApiResponse({
    status: 202,
    description: '已接收（异步处理）',
    schema: { example: { ok: true } },
  })
  @ApiBadRequestResponse({
    description: '参数错误（缺少 uid/channelId/adsId）',
  })
  publishAdClick(
    @Req() req: Request,
    @Body() body: AdClickRequestDto,
  ): { ok: true } {
    if (!body?.uid || !body?.channelId || !body?.adsId) {
      throw new BadRequestException('uid, channelId and adsId are required');
    }

    const clientIp =
      // `ipv4` is a frontend-provided hint, used only when present & validated;
      // backend extraction remains the fallback.
      body.ipv4 || extractClientIp(req);

    this.publisher.publishAdClick({
      uid: body.uid,
      channelId: body.channelId,
      adsId: body.adsId,
      headers: req.headers,
      clientIp,
    });

    return { ok: true };
  }
}