import { join, dirname, basename, sep } from 'path';
import { homedir } from 'os';
import { existsSync, mkdirSync } from 'fs';
import { execSync } from 'child_process';
import { fileURLToPath } from 'url';
import { loadEarlySetting } from './early-settings.js';

// Get __dirname that works in both ESM (hooks) and CJS (worker) contexts
function getDirname(): string {
  // CJS context - __dirname exists
  if (typeof __dirname !== 'undefined') {
    return __dirname;
  }
  // ESM context - use import.meta.url
  return dirname(fileURLToPath(import.meta.url));
}

const _dirname = getDirname();

/**
 * Simple path configuration for claude-mem
 * Standard paths based on Claude Code conventions
 */

// Base directories
export const DATA_DIR = loadEarlySetting('CLAUDE_MEM_DATA_DIR', join(homedir(), '.claude-mem'));
// Note: CLAUDE_CONFIG_DIR is a Claude Code setting, not claude-mem, so leave as env var
export const CLAUDE_CONFIG_DIR = process.env.CLAUDE_CONFIG_DIR || join(homedir(), '.claude');

// Data subdirectories
export const ARCHIVES_DIR = join(DATA_DIR, 'archives');
export const LOGS_DIR = join(DATA_DIR, 'logs');
export const TRASH_DIR = join(DATA_DIR, 'trash');
export const BACKUPS_DIR = join(DATA_DIR, 'backups');
export const USER_SETTINGS_PATH = join(DATA_DIR, 'settings.json');
export const DB_PATH = join(DATA_DIR, 'claude-mem.db');
export const VECTOR_DB_DIR = join(DATA_DIR, 'vector-db');

// Claude integration paths
export const CLAUDE_SETTINGS_PATH = join(CLAUDE_CONFIG_DIR, 'settings.json');
export const CLAUDE_COMMANDS_DIR = join(CLAUDE_CONFIG_DIR, 'commands');
export const CLAUDE_MD_PATH = join(CLAUDE_CONFIG_DIR, 'CLAUDE.md');

/**
 * Get project-specific archive directory
 */
export function getProjectArchiveDir(projectName: string): string {
  return join(ARCHIVES_DIR, projectName);
}

/**
 * Get worker socket path for a session
 */
export function getWorkerSocketPath(sessionId: number): string {
  return join(DATA_DIR, `worker-${sessionId}.sock`);
}

/**
 * Ensure a directory exists
 */
export function ensureDir(dirPath: string): void {
  mkdirSync(dirPath, { recursive: true });
}

/**
 * Ensure all data directories exist
 */
export function ensureAllDataDirs(): void {
  ensureDir(DATA_DIR);
  ensureDir(ARCHIVES_DIR);
  ensureDir(LOGS_DIR);
  ensureDir(TRASH_DIR);
  ensureDir(BACKUPS_DIR);
}

/**
 * Ensure all Claude integration directories exist
 */
export function ensureAllClaudeDirs(): void {
  ensureDir(CLAUDE_CONFIG_DIR);
  ensureDir(CLAUDE_COMMANDS_DIR);
}

/**
 * Get current project name from git root or cwd
 */
export function getCurrentProjectName(): string {
  try {
    const gitRoot = execSync('git rev-parse --show-toplevel', {
      cwd: process.cwd(),
      encoding: 'utf8',
      stdio: ['pipe', 'pipe', 'ignore']
    }).trim();
    return basename(gitRoot);
  } catch {
    return basename(process.cwd());
  }
}

/**
 * Find package root directory
 *
 * Works because bundled hooks are in plugin/scripts/,
 * so package root is always two levels up
 */
export function getPackageRoot(): string {
  return join(_dirname, '..', '..');
}

/**
 * Find commands directory in the installed package
 */
export function getPackageCommandsDir(): string {
  const packageRoot = getPackageRoot();
  const commandsDir = join(packageRoot, 'commands');

  if (!existsSync(join(commandsDir, 'save.md'))) {
    throw new Error('Package commands directory missing required files');
  }

  return commandsDir;
}

/**
 * Create a timestamped backup filename
 */
export function createBackupFilename(originalPath: string): string {
  const timestamp = new Date()
    .toISOString()
    .replace(/[:.]/g, '-')
    .replace('T', '_')
    .slice(0, 19);

  return `${originalPath}.backup.${timestamp}`;
}