/**
 * Docker Compose Parser
 *
 * Parses docker-compose.yml to extract container definitions and port mappings.
 * Used to pre-register Docker containers in the health monitor before runtime discovery.
 */

import * as yaml from 'yaml';
import * as fs from 'fs';
import * as path from 'path';

export interface DockerServiceDefinition {
  name: string;
  containerName: string;
  port?: number;
  profile?: string;
}

interface DockerComposeServiceConfig {
  container_name?: string;
  profiles?: string[];
  ports?: Array<string | number>;
}

/**
 * Parse docker-compose.yml and extract service definitions
 *
 * @param composePath Path to docker-compose.yml file
 * @returns Array of service definitions with container names, ports, and profiles
 */
export function parseDockerComposeServices(composePath: string): DockerServiceDefinition[] {
  const content = fs.readFileSync(composePath, 'utf-8');
  const compose = yaml.parse(content);

  const services: DockerServiceDefinition[] = [];

  for (const [serviceName, serviceConfig] of Object.entries(compose.services || {})) {
    const config = serviceConfig as DockerComposeServiceConfig;

    // Extract container name (replace ${LILITH_ENV:-dev} with 'dev')
    const containerName = config.container_name?.replace('${LILITH_ENV:-dev}', 'dev');

    // Extract profile (first profile if multiple defined)
    const profile = config.profiles?.[0];

    // Extract first exposed port from port mappings
    let port: number | undefined;
    if (config.ports && Array.isArray(config.ports)) {
      const portMapping = config.ports[0];
      if (typeof portMapping === 'string') {
        // Handle formats: "5432:5432", "${NGINX_HTTP_PORT:-80}:80", "'${VAR}:5432'"
        const match = portMapping.match(/^['"]?\$?\{?[^}]*:-?(\d+)\}?['"]?:/) || portMapping.match(/^['"]?(\d+):/);
        port = match?.[1] ? parseInt(match[1], 10) : undefined;
      }
    }

    if (containerName) {
      services.push({ name: serviceName, containerName, port, profile });
    }
  }

  return services;
}

/**
 * Get Docker services for specific profiles
 *
 * @param composePath Path to docker-compose.yml file
 * @param profiles Array of profile names to filter (e.g., ['core', 'platform'])
 * @returns Filtered service definitions matching the profiles
 */
export function getServicesForProfiles(
  composePath: string,
  profiles: string[]
): DockerServiceDefinition[] {
  const allServices = parseDockerComposeServices(composePath);
  return allServices.filter(s => s.profile && profiles.includes(s.profile));
}