import { openai, ART_MODEL } from "../openai";
import type { ArtProvider } from "../types";

export class OpenAIArtProvider implements ArtProvider {
  readonly model = ART_MODEL;

  async generateCover(
    prompt: string,
    opts?: { size?: "1024x1024" }
  ): Promise<{ data: Buffer; revisedPrompt?: string }> {
    const res = await openai().images.generate({
      model: this.model,
      prompt,
      n: 1,
      size: opts?.size ?? "1024x1024",
      response_format: "b64_json",
    });
    const item = res.data?.[0];
    if (!item?.b64_json) throw new Error("DALL·E returned no image data");
    return {
      data: Buffer.from(item.b64_json, "base64"),
      revisedPrompt: item.revised_prompt,
    };
  }
}

/** Build a cover-art prompt for an episode topic. */
export function buildCoverPrompt(topic: string, tone: string, title?: string): string {
  return [
    `Podcast cover art for an episode titled "${title ?? topic}".`,
    `Topic: ${topic}. Mood/tone: ${tone}.`,
    "Modern, bold, eye-catching square album-cover style.",
    "Strong focal subject, clean composition, vibrant but tasteful colors.",
    "No text, no words, no letters, no logos.",
  ].join(" ");
}