const express = require("express");
const multer = require("multer");
const { spawn } = require("child_process");
const fs = require("fs");

const app = express();
const upload = multer({ dest: "uploads/" });

app.post("/convert", upload.fields([{ name: "audio" }, { name: "image" }]), (req, res) => {
  if (!req.files || !req.files.audio || !req.files.image) {
    console.error("❌ Missing file(s) in request");
    return res.status(400).send("Missing audio or image file.");
  }

  const audioPath = req.files.audio[0].path;
  const imagePath = req.files.image[0].path;
  const output = `output-${Date.now()}.mp4`;

  const args = [
    "-loop", "1",
    "-i", imagePath,
    "-i", audioPath,
    "-c:v", "libx264",
    "-preset", "fast",
    "-tune", "stillimage",
    "-crf", "18",
    "-c:a", "aac",
    "-shortest",
    "-pix_fmt", "yuv420p",
    output
  ];

  console.log(`🚀 Starting FFmpeg conversion: ${output}`);
  const ffmpeg = spawn("ffmpeg", args);

  let lastLog = Date.now();

  ffmpeg.stderr.on("data", (data) => {
    const now = Date.now();
    const text = data.toString();

    // Log a progress update every 3 seconds max
    if (text.includes("frame=") && now - lastLog > 3000) {
      console.log(`[FFmpeg Progress] ${text.trim()}`);
      lastLog = now;
    }

    // If you want verbose output uncomment this:
    // console.log(`[FFmpeg Raw] ${text.trim()}`);
  });

  ffmpeg.on("exit", (code) => {
    if (code !== 0) {
      console.error(`❌ FFmpeg failed with code ${code}`);
      res.status(500).send("Conversion failed");
    } else {
      console.log("✅ FFmpeg finished successfully. Sending file...");
      res.download(output, () => {
        fs.unlinkSync(audioPath);
        fs.unlinkSync(imagePath);
        fs.unlinkSync(output);
      });
    }
  });
});

app.get("/", (req, res) => {
  res.send("🎧 FileConvert API is up.");
});

app.listen(3000, () => console.log("✅ FileConvert API running on http://0.0.0.0:3000"));