const express = require("express");
const fs = require("fs");
const path = require("path");
const { exec } = require("child_process");
const crypto = require("crypto");

const PORT = process.env.PORT || 3000;
const DATA_FILE = path.join(__dirname, "commands.json");
const CEC_TIMEOUT_MS = 15000;

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

function loadCommands() {
  try {
    return JSON.parse(fs.readFileSync(DATA_FILE, "utf8"));
  } catch {
    return [];
  }
}

function saveCommands(commands) {
  fs.writeFileSync(DATA_FILE, JSON.stringify(commands, null, 2) + "\n");
}

// Alle gespeicherten Befehle
app.get("/api/commands", (req, res) => {
  res.json(loadCommands());
});

// Neuen Befehl anlegen
app.post("/api/commands", (req, res) => {
  const name = (req.body.name || "").trim();
  const command = (req.body.command || "").trim();
  if (!name || !command) {
    return res.status(400).json({ error: "Name und Command dürfen nicht leer sein." });
  }
  const commands = loadCommands();
  const entry = { id: crypto.randomUUID(), name, command };
  commands.push(entry);
  saveCommands(commands);
  res.status(201).json(entry);
});

// Befehl löschen
app.delete("/api/commands/:id", (req, res) => {
  const commands = loadCommands();
  const remaining = commands.filter((c) => c.id !== req.params.id);
  if (remaining.length === commands.length) {
    return res.status(404).json({ error: "Befehl nicht gefunden." });
  }
  saveCommands(remaining);
  res.json({ ok: true });
});

// Befehl als Shell-Kommando ausführen
app.post("/api/commands/:id/run", (req, res) => {
  const entry = loadCommands().find((c) => c.id === req.params.id);
  if (!entry) {
    return res.status(404).json({ error: "Befehl nicht gefunden." });
  }

  exec(entry.command, { timeout: CEC_TIMEOUT_MS }, (error, stdout, stderr) => {
    const output = (stdout + stderr).trim();

    if (error?.killed) {
      return res.status(504).json({
        error: `Befehl wurde nach ${CEC_TIMEOUT_MS / 1000}s abgebrochen (${error.signal}).`,
        command: entry.command,
        output,
      });
    }

    if (error && typeof error.code !== "number") {
      return res.status(500).json({
        error: `Befehl konnte nicht ausgeführt werden: ${error.message}`,
        command: entry.command,
      });
    }

    const exitCode = error ? error.code : 0;
    res.json({ ok: exitCode === 0, exitCode, command: entry.command, output });
  });
});

app.listen(PORT, () => {
  console.log(`CEC-Tool läuft auf http://localhost:${PORT}`);
});