import * as plugins from './plugins.js';
import type { IDcRouterOptions } from '../ts/classes.dcrouter.js';

/**
 * Parses a comma-separated env var into a string array.
 * Returns undefined if the env var is not set or empty.
 */
function parseCommaSeparated(envVar: string | undefined): string[] | undefined {
  if (!envVar || envVar.trim() === '') return undefined;
  return envVar.split(',').map((s) => s.trim()).filter(Boolean);
}

/**
 * Parses a comma-separated env var into a number array.
 * Returns undefined if the env var is not set or empty.
 */
function parseCommaSeparatedNumbers(envVar: string | undefined): number[] | undefined {
  const parts = parseCommaSeparated(envVar);
  if (!parts) return undefined;
  return parts.map((s) => parseInt(s, 10)).filter((n) => !isNaN(n));
}

/**
 * Builds IDcRouterOptions from environment variables for OCI container mode.
 *
 * If DCROUTER_CONFIG_PATH is set and the file exists, it is loaded as a JSON base config.
 * Individual env vars are then applied as overrides on top.
 */
export function getOciContainerConfig(): IDcRouterOptions {
  let options: IDcRouterOptions = {};

  // Load JSON config file if specified
  const configPath = process.env.DCROUTER_CONFIG_PATH;
  if (configPath && plugins.fs.existsSync(configPath)) {
    const raw = plugins.fs.readFileSync(configPath, 'utf8');
    options = JSON.parse(raw);
    console.log(`[OCI Container] Loaded config from ${configPath}`);
  }

  // Apply env var overrides
  if (process.env.DCROUTER_BASE_DIR) {
    options.baseDir = process.env.DCROUTER_BASE_DIR;
  }

  // TLS config
  const tlsEmail = process.env.DCROUTER_TLS_EMAIL;
  const tlsDomain = process.env.DCROUTER_TLS_DOMAIN;
  if (tlsEmail || tlsDomain) {
    options.tls = {
      ...options.tls,
      contactEmail: tlsEmail || options.tls?.contactEmail || '',
      ...(tlsDomain ? { domain: tlsDomain } : {}),
    };
  }

  // Network config
  if (process.env.DCROUTER_PUBLIC_IP) {
    options.publicIp = process.env.DCROUTER_PUBLIC_IP;
  }

  const proxyIps = parseCommaSeparated(process.env.DCROUTER_PROXY_IPS);
  if (proxyIps) {
    options.proxyIps = proxyIps;
  }

  // DNS config
  const nsDomains = parseCommaSeparated(process.env.DCROUTER_DNS_NS_DOMAINS);
  if (nsDomains) {
    options.dnsNsDomains = nsDomains;
  }

  const dnsScopes = parseCommaSeparated(process.env.DCROUTER_DNS_SCOPES);
  if (dnsScopes) {
    options.dnsScopes = dnsScopes;
  }

  // Email config
  const emailHostname = process.env.DCROUTER_EMAIL_HOSTNAME;
  const emailPorts = parseCommaSeparatedNumbers(process.env.DCROUTER_EMAIL_PORTS);
  if (emailHostname || emailPorts) {
    options.emailConfig = {
      ...options.emailConfig,
      ...(emailHostname ? { hostname: emailHostname } : {}),
      ...(emailPorts ? { ports: emailPorts } : {}),
      domains: options.emailConfig?.domains || [],
      routes: options.emailConfig?.routes || [],
    } as IDcRouterOptions['emailConfig'];
  }

  // Cache config
  const cacheEnabled = process.env.DCROUTER_CACHE_ENABLED;
  if (cacheEnabled !== undefined) {
    options.cacheConfig = {
      ...options.cacheConfig,
      enabled: cacheEnabled === 'true',
    };
  }

  return options;
}