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

const CONFIG_MODE = 0o600;
const DIR_MODE = 0o700;

// Paths are resolved lazily (on every call) so that the global `--config`
// flag — which sets STOKE_CONFIG_FILE from a preAction hook — takes effect
// even though this module is required before the CLI parses its arguments.
function getConfigDir() {
  if (process.env.STOKE_CONFIG_DIR) return process.env.STOKE_CONFIG_DIR;
  if (process.env.FORGEJO_CONFIG_DIR) return process.env.FORGEJO_CONFIG_DIR;
  // Per the XDG spec, $XDG_CONFIG_HOME already points at the config root
  // (it replaces ~/.config, it does not live inside it).
  if (process.env.XDG_CONFIG_HOME) return path.join(process.env.XDG_CONFIG_HOME, 'stoke');
  return path.join(os.homedir(), '.config', 'stoke');
}

function getConfigPath() {
  return process.env.STOKE_CONFIG_FILE
    || process.env.FORGEJO_CONFIG_FILE
    || path.join(getConfigDir(), 'config.json');
}

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

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

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

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

module.exports = {
  getConfigDir,
  getConfigPath,
  loadConfig,
  saveConfig,
  clearConfig,
};