import { Injectable, Logger } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import OpenAI from 'openai';

@Injectable()
export class AiImageGenerationService {
  private readonly logger = new Logger(AiImageGenerationService.name);
  private openai: OpenAI | null = null;
  private isAvailable: boolean = false;

  constructor(private configService: ConfigService) {
    const apiKey = this.configService.get<string>('OPENAI_API_KEY');
    if (apiKey) {
      try {
        this.openai = new OpenAI({ apiKey });
        this.isAvailable = true;
        this.logger.log('OpenAI service initialized successfully');
      } catch (error) {
        this.logger.warn('Failed to initialize OpenAI service');
      }
    } else {
      this.logger.warn(
        'OPENAI_API_KEY not configured - AI image generation disabled',
      );
    }
  }

  async generateImage(
    prompt: string,
    size: '256x256' | '512x512' | '1024x1024' = '1024x1024',
  ): Promise<string> {
    if (!this.isAvailable || !this.openai) {
      this.logger.warn('OpenAI service is not available');
      throw new Error(
        'AI image generation is not configured. Please set OPENAI_API_KEY environment variable.',
      );
    }

    this.logger.log(`Generating image for prompt: ${prompt}`);
    try {
      const response = await this.openai.images.generate({
        model: 'dall-e-3',
        prompt: prompt,
        n: 1,
        size: size,
      });

      return response.data?.[0]?.url || '';
    } catch (error) {
      this.logger.error('DALL-E Generation Error:', error);
      throw new Error('AI image generation failed');
    }
  }
}