"use server";

import { VertexAI, GenerativeModel, InlineDataPart } from "@google-cloud/vertexai";

export const createTranscription = async (formData: FormData) => {
  // formDataからファイルとプロンプトを受け取る
  const uploadFile = formData.get("file") as File | null;
  const prePrompt = formData.get("prePrompt") as string | null;

  if (!uploadFile || uploadFile.type !== "audio/mp3") {
    console.error("Invalid file");
    return;
  }

  // ほんとは別にbase64にしなくてもいいかも
  const arrayBuffer = await uploadFile.arrayBuffer();
  const buffer = Buffer.from(arrayBuffer);
  const base64 = buffer.toString("base64");

  const vertexAI = new VertexAI({
    project: process.env.VERTEX_PROJECT_ID,
    location: "asia-northeast1",
  });
  if (!vertexAI) {
    console.error("Vertex AI not found");
    return;
  }

  const generativeModel = vertexAI.getGenerativeModel({
    model: "gemini-1.5-pro-001",
  });

  const inlinePart: InlineDataPart = {
    inlineData: {
      data: base64,
      mimeType: "audio/mp3",
    },
  };
  const textPart = {
    text: prePrompt || `音声を書き起こしてください。読みやすいように句読点や改行を追加し読みやすくしてください。`,
  };

  const request = {
    contents: [{ role: "user", parts: [inlinePart, textPart] }],
  };

  const transcriptionPromise = generativeModel.generateContent(request);

  return transcriptionPromise
    .then(result => {
      const text = result.response.candidates
        ?.map(candidate => candidate.content.parts.map(c => c.text))
        .join("\n");
      return text;
    });
};

import { FFmpeg } from "@ffmpeg/ffmpeg";
import { fetchFile, toBlobURL } from "@ffmpeg/util";
import { ProgressEventCallback } from "@ffmpeg/ffmpeg/dist/esm/types";

const ffmpeg = new FFmpeg();
const FFMPEG_CORE_URL = "https://unpkg.com/@ffmpeg/core@0.12.6/dist/umd";

async function convertVideoToMp3(file: File, onProgress: (progress: number) => void): Promise<File> {
    await ffmpeg.load({
        coreURL: await toBlobURL(
            `${FFMPEG_CORE_URL}/ffmpeg-core.js`,
            "text/javascript",
        ),
        wasmURL: await toBlobURL(
            `${FFMPEG_CORE_URL}/ffmpeg-core.wasm`,
            "application/wasm",
        ),
    });

    await ffmpeg.writeFile(file.name, await fetchFile(file));

    const progressCallback: ProgressEventCallback = (e) => {
        onProgress(Math.floor(e.progress * 100));
    };
    ffmpeg.on("progress", progressCallback);

    await ffmpeg.exec(["-i", file.name, "-f", "mp3", "output.mp3"]);
    const mp3Data = await ffmpeg.readFile("output.mp3");
    const mp3File = new File([mp3Data], "output.mp3", {
        type: "audio/mp3",
    });

    ffmpeg.off("progress", progressCallback);
    ffmpeg.deleteFile(file.name);

    return mp3File;
}