/**
 * ─────────────────────────────────────────────
 *  SPB Git — Personal Git Platform
 * ─────────────────────────────────────────────
 *  Author  : Simon-Pierre Boucher
 *  Contact : contact@spboucher.ai
 *  File    : cli/lib/config.mjs
 *  Purpose : ~/.spbgit/config.json loading, saving, validation
 *  License : MIT © Simon-Pierre Boucher
 * ─────────────────────────────────────────────
 */

import { readFileSync, writeFileSync, mkdirSync, chmodSync, existsSync } from 'node:fs';
import { homedir } from 'node:os';
import { join } from 'node:path';

export const CONFIG_DIR = join(homedir(), '.spbgit');
export const CONFIG_PATH = join(CONFIG_DIR, 'config.json');

const DEFAULTS = {
  server: 'https://git.spboucher.ai',
  token: '',
  workspace: join(homedir(), 'code'),
  author: { name: 'Simon-Pierre Boucher', email: 'contact@spboucher.ai' },
};

/** Expand a leading `~` to the home directory. */
export function expandHome(path) {
  if (!path) return path;
  return path.startsWith('~') ? join(homedir(), path.slice(1)) : path;
}

/**
 * @returns {object|null} parsed config or null when not initialized
 */
export function loadCliConfig() {
  if (!existsSync(CONFIG_PATH)) return null;
  try {
    const parsed = JSON.parse(readFileSync(CONFIG_PATH, 'utf8'));
    return { ...DEFAULTS, ...parsed, workspace: expandHome(parsed.workspace ?? DEFAULTS.workspace) };
  } catch {
    return null;
  }
}

/**
 * Load config or exit(1) with a helpful message.
 * @returns {object}
 */
export function requireCliConfig() {
  const config = loadCliConfig();
  if (!config || !config.server) {
    console.error('spbgit is not configured. Run: spbgit init');
    process.exit(1);
  }
  return config;
}

/**
 * Persist config with 600 permissions (contains the PAT).
 * @param {object} config
 */
export function saveCliConfig(config) {
  mkdirSync(CONFIG_DIR, { recursive: true, mode: 0o700 });
  writeFileSync(CONFIG_PATH, JSON.stringify(config, null, 2) + '\n', { mode: 0o600 });
  chmodSync(CONFIG_PATH, 0o600);
}