const fs = require("fs");
const os = require("os");
const path = require("path");
const express = require("express");
const http = require("http");
const { Server } = require("socket.io");
const pino = require("pino");
const { generateMusicPlan } = require("./lib/music/generator");
const { loadMeta } = require("./lib/training");

const PORT = Number(process.env.PORT || 0);
const log = pino({ name: "ai-music" });

const app = express();
app.use(express.json());

app.get("/health", (req, res) => {
  try {
    const meta = loadMeta();
    res.json({ ok: true, uptime: process.uptime(), training: { step: meta.step, loss: meta.loss } });
  } catch (err) {
    log.error({ err: err.message }, "health check failed");
    res.status(500).json({ ok: false, error: err.message });
  }
});

app.post("/api/generate", (req, res) => {
  try {
    const plan = generateMusicPlan(req.body || {});
    res.json(plan);
  } catch (err) {
    log.warn({ err: err.message }, "api generation failed");
    res.status(400).json({ ok: false, error: err.message });
  }
});

app.use(express.static(path.join(__dirname, "public")));

const server = http.createServer(app);
const io = new Server(server, { cors: { origin: "*" } });

io.on("connection", socket => {
  log.info({ id: socket.id }, "client connected");
  socket.on("disconnect", () => log.info({ id: socket.id }, "client disconnected"));

  socket.on("generate-music", params => {
    log.info({ id: socket.id, params }, "music generation requested");
    try {
      const plan = generateMusicPlan(params || {});
      socket.emit("music-generated", plan);
    } catch (err) {
      log.error({ id: socket.id, err: err.message }, "generation failed");
      socket.emit("music-generated", { ok: false, error: err.message });
    }
  });
});

server.listen(PORT, () => {
  const addr = server.address();
  const port = typeof addr === "object" && addr ? addr.port : 0;
  log.info({ port }, "ai music server listening");
  try { fs.writeFileSync(path.join(os.homedir(), ".skynet_port"), String(port)); }
  catch (err) { log.warn({ err: err.message }, "failed to persist port file"); }
});