import { accessSync, constants, mkdirSync, readFileSync, writeFileSync, unlinkSync } from 'fs';
import { dirname, isAbsolute, join, resolve } from 'path';
import { fileURLToPath } from 'url';
import { randomUUID } from 'crypto';

export const APP_ROOT = resolve(dirname(fileURLToPath(import.meta.url)), '..');

function envPath(name, fallback) {
  const value = String(process.env[name] || '').trim();
  if (!value) return resolve(fallback);
  return resolve(isAbsolute(value) ? value : join(APP_ROOT, value));
}

export const DATA_ROOT = envPath('VENDOO_DATA_DIR', APP_ROOT);
export const DB_PATH = envPath('VENDOO_DB_PATH', join(DATA_ROOT, 'db', 'vendoo.db'));
export const UPLOADS_DIR = envPath('VENDOO_UPLOADS_DIR', join(DATA_ROOT, 'uploads'));
export const BACKUP_DIR = envPath('VENDOO_BACKUP_DIR', join(DATA_ROOT, 'backups'));
export const OPERATIONS_DIR = envPath('VENDOO_OPERATIONS_DIR', join(DATA_ROOT, 'operations'));
export const LOG_DIR = envPath('VENDOO_LOG_DIR', join(DATA_ROOT, 'logs'));
export const CONFIG_PATH = envPath('VENDOO_CONFIG_PATH', join(DATA_ROOT, 'config', 'vendoo.env'));
export const MODULES_DIR = envPath('VENDOO_MODULES_DIR', join(DATA_ROOT, 'modules'));
export const MODULE_STATE_PATH = envPath('VENDOO_MODULE_STATE_PATH', join(DATA_ROOT, 'config', 'modules-state.json'));

export const APP_VERSION = JSON.parse(readFileSync(join(APP_ROOT, 'package.json'), 'utf8')).version;

export function ensureRuntimeDirectories() {
  const directories = [dirname(DB_PATH), UPLOADS_DIR, BACKUP_DIR, OPERATIONS_DIR, LOG_DIR, dirname(CONFIG_PATH), MODULES_DIR, dirname(MODULE_STATE_PATH)];
  for (const directory of directories) mkdirSync(directory, { recursive: true });
  return directories;
}

export function verifyRuntimeWritable() {
  ensureRuntimeDirectories();
  const checks = [];
  for (const directory of [dirname(DB_PATH), UPLOADS_DIR, BACKUP_DIR, OPERATIONS_DIR, LOG_DIR, dirname(CONFIG_PATH), MODULES_DIR, dirname(MODULE_STATE_PATH)]) {
    try {
      accessSync(directory, constants.R_OK | constants.W_OK);
      const probe = join(directory, `.vendoo-write-${process.pid}-${randomUUID()}.tmp`);
      writeFileSync(probe, 'ok', { flag: 'wx' });
      unlinkSync(probe);
      checks.push({ path: directory, writable: true });
    } catch (error) {
      checks.push({ path: directory, writable: false, error: error.message });
    }
  }
  return checks;
}

export function runtimePathSummary() {
  return {
    app_root: APP_ROOT,
    data_root: DATA_ROOT,
    database: DB_PATH,
    uploads: UPLOADS_DIR,
    backups: BACKUP_DIR,
    operations: OPERATIONS_DIR,
    logs: LOG_DIR,
    runtime_config: CONFIG_PATH,
    modules: MODULES_DIR,
    module_state: MODULE_STATE_PATH,
  };
}

ensureRuntimeDirectories();