import OpenAI from "openai";
import * as fs from "fs";
import * as path from "path";
import { StoryConfig } from "./config";

let openaiClient: OpenAI | null = null;
function getOpenAI(): OpenAI {
  if (!openaiClient) {
    openaiClient = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });
  }
  return openaiClient;
}

export async function generateAudio(
  storyConfig: StoryConfig,
  storyName: string,
  chunk: string,
  index: number
): Promise<string> {
  const speechFile = path.join("stories", storyName, "audio", `chunk_${index}.mp3`);

  const mp3 = await getOpenAI().audio.speech.create({
    model: "gpt-4o-mini-tts",
    voice: storyConfig.config.tts_voice_id as unknown as string,
    input: chunk,
    instructions: storyConfig.config.tts_instructions,
  });

  const buffer = Buffer.from(await mp3.arrayBuffer());
  await fs.promises.writeFile(speechFile, buffer);

  return speechFile;
}

export async function generateSingleAudio(storyConfig: StoryConfig, text: string, outputFile: string): Promise<string> {
  const mp3 = await getOpenAI().audio.speech.create({
    model: "gpt-4o-mini-tts",
    voice: storyConfig.config.tts_voice_id as unknown as string,
    input: text,
    instructions: storyConfig.config.tts_instructions,
  });

  const buffer = Buffer.from(await mp3.arrayBuffer());
  await fs.promises.writeFile(outputFile, buffer);

  return outputFile;
}