import { readdirSync, copyFileSync, mkdirSync, readFileSync } from 'fs';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';
import { parse } from 'yaml';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

export interface TemplateInfo {
  name: string;
  displayName: string;
  description: string;
}

export function listTemplates(): TemplateInfo[] {
  try {
    const entries = readdirSync(__dirname, { withFileTypes: true });
    return entries
      .filter(e => e.isDirectory())
      .map(e => {
        try {
          const meta = parse(readFileSync(join(__dirname, e.name, 'template.yaml'), 'utf-8')) as {
            displayName?: string;
            description?: string;
          };
          return {
            name: e.name,
            displayName: meta.displayName ?? e.name,
            description: meta.description ?? '',
          };
        } catch {
          return { name: e.name, displayName: e.name, description: '' };
        }
      });
  } catch {
    return [];
  }
}

export function copyTemplate(name: string, targetDir: string): void {
  const srcDir = join(__dirname, name);

  let files: string[];
  try {
    files = readdirSync(srcDir).filter(f => f !== 'template.yaml' && !f.startsWith('.'));
  } catch {
    throw new Error(`Template '${name}' not found`);
  }

  mkdirSync(targetDir, { recursive: true });

  for (const file of files) {
    copyFileSync(join(srcDir, file), join(targetDir, file));
  }
}

export function getTemplateYaml(name: string): string {
  const yamlPath = join(__dirname, name, 'template.yaml');
  return readFileSync(yamlPath, 'utf-8');
}