/**
 * Product identity — reads from a product.json file or falls back to env vars.
 * Eliminates the need for hardcoded product-config.ts files in every service.
 */

import { readFileSync } from 'node:fs';
import { resolve } from 'node:path';

export interface ProductIdentity {
  productId: string;
  displayName: string;
  licensePrefix: string;
  configDirName: string;
  envVarPrefix: string;
  bundleIdSuffix: string;
  packageName: string;
}

let _cached: ProductIdentity | null = null;

/**
 * Load product identity from a JSON file or environment variables.
 *
 * @param jsonPath - Path to product.json (optional, tries common locations)
 * @returns Product identity object
 */
export function loadProductIdentity(jsonPath?: string): ProductIdentity {
  if (_cached) return _cached;

  // Try loading from file
  const paths = jsonPath
    ? [jsonPath]
    : [
        resolve('shared/product.json'),
        resolve('../shared/product.json'),
        resolve('../../shared/product.json'),
      ];

  for (const p of paths) {
    try {
      const raw = readFileSync(p, 'utf-8');
      _cached = JSON.parse(raw) as ProductIdentity;
      return _cached;
    } catch {
      // Try next path
    }
  }

  // Fallback to env vars / defaults
  _cached = {
    productId: process.env.PRODUCT_ID || 'lysnrai',
    displayName: process.env.DISPLAY_NAME || 'LysnrAI',
    licensePrefix: process.env.LICENSE_PREFIX || 'LYSNR',
    configDirName: process.env.CONFIG_DIR_NAME || '.LysnrAI',
    envVarPrefix: process.env.ENV_VAR_PREFIX || 'LYSNR',
    bundleIdSuffix: process.env.BUNDLE_ID_SUFFIX || 'LysnrAI',
    packageName: process.env.PACKAGE_NAME || 'lysnrai',
  };
  return _cached;
}

/**
 * Convenience: get just the product ID string.
 */
export function getProductId(): string {
  return loadProductIdentity().productId;
}

/**
 * Reset the cache (useful for testing).
 * @internal
 */
export function _resetProductIdentity(): void {
  _cached = null;
}