import type { ImageProvider, OpenAIImageResponse } from '../types';

export class OpenAIProvider implements ImageProvider {
  private apiKey: string;

  constructor(apiKey?: string) {
    this.apiKey = apiKey || process.env.OPENAI_API_KEY || '';
    if (!this.apiKey) {
      throw new Error('OPENAI_API_KEY environment variable is required');
    }
  }

  async generate(prompt: string): Promise<Buffer> {
    const response = await fetch('https://api.openai.com/v1/images/generations', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        Authorization: `Bearer ${this.apiKey}`,
      },
      body: JSON.stringify({
        model: 'dall-e-3',
        prompt: prompt,
        n: 1,
        size: '1024x1024',
        quality: 'standard',
        response_format: 'url',
      }),
    });

    if (!response.ok) {
      const error = await response.text();
      throw new Error(`OpenAI API error: ${response.status} - ${error}`);
    }

    const data = (await response.json()) as OpenAIImageResponse;

    if (!data.data || data.data.length === 0) {
      throw new Error('No image data returned from OpenAI API');
    }

    const imageUrl = data.data[0].url;
    if (!imageUrl) {
      throw new Error('No image URL in OpenAI response');
    }

    // Download the image
    const imageResponse = await fetch(imageUrl);
    if (!imageResponse.ok) {
      throw new Error(`Failed to download image: ${imageResponse.status}`);
    }

    const arrayBuffer = await imageResponse.arrayBuffer();
    return Buffer.from(arrayBuffer);
  }
}