const path = require('node:path');
const os = require('node:os');
const fs = require('node:fs');

const CONFIG_DIR = process.env.STOKE_CONFIG_DIR
  || process.env.FORGEJO_CONFIG_DIR
  || path.join(process.env.XDG_CONFIG_HOME || os.homedir(), '.config', 'stoke');
const CONFIG_PATH = process.env.STOKE_CONFIG_FILE
  || process.env.FORGEJO_CONFIG_FILE
  || path.join(CONFIG_DIR, 'config.json');
const CONFIG_MODE = 0o600;
const DIR_MODE = 0o700;

function ensureConfigDir() {
  fs.mkdirSync(CONFIG_DIR, { recursive: true, mode: DIR_MODE });
}

function loadConfig() {
  try {
    const raw = fs.readFileSync(CONFIG_PATH, 'utf8');
    return JSON.parse(raw);
  } catch (err) {
    if (err.code === 'ENOENT') return null;
    throw new Error(`Failed to read config at ${CONFIG_PATH}: ${err.message}`);
  }
}

function saveConfig(config) {
  ensureConfigDir();
  const tmp = `${CONFIG_PATH}.tmp`;
  fs.writeFileSync(tmp, JSON.stringify(config, null, 2), { mode: CONFIG_MODE });
  fs.renameSync(tmp, CONFIG_PATH);
  try {
    fs.chmodSync(CONFIG_PATH, CONFIG_MODE);
  } catch {
    // ignore on platforms where chmod is unsupported
  }
}

function clearConfig() {
  try {
    fs.unlinkSync(CONFIG_PATH);
  } catch (err) {
    if (err.code !== 'ENOENT') throw err;
  }
}

module.exports = {
  CONFIG_DIR,
  CONFIG_PATH,
  loadConfig,
  saveConfig,
  clearConfig,
};