require('dotenv').config();
const logger = require('../utils/logger');

/**
 * Required environment variables for core operation.
 * The app will refuse to start if these are missing.
 */
const REQUIRED_ENV_VARS = ['WEBEX_ACCESS_TOKEN', 'MERAKI_API_KEY', 'MERAKI_ORG_ID', 'WS_TOKEN'];

/**
 * Recommended environment variables for full functionality.
 * Warnings will be logged but startup will continue.
 */
const RECOMMENDED_ENV_VARS = [
  'SIW_BASE_URL',
  'SIW_USERNAME',
  'SIW_PASSWORD',
  'WS1_BASE_URL',
  'WS1_TOKEN_URL',
  'WS1_CLIENT_ID',
  'WS1_CLIENT_SECRET',
  'WS1_TENANT_CODE',
  // Webex Service App (only needed for `st <store> phone`). Missing values
  // surface as an unavailable banner in phone mode rather than a fatal error.
  'WEBEX_CLIENT_ID',
  'WEBEX_CLIENT_SECRET',
  // Atlas / Xyte (only needed for `st <store> av`). Missing key surfaces as
  // an inline banner in AV mode; MDM-side AV devices still render.
  'ATLAS_AUTH_KEY',
];

function validateEnvironment() {
  const missingRequired = REQUIRED_ENV_VARS.filter(
    key => !process.env[key] || process.env[key].trim() === ''
  );
  const missingRecommended = RECOMMENDED_ENV_VARS.filter(
    key => !process.env[key] || process.env[key].trim() === ''
  );

  if (missingRequired.length > 0) {
    logger.error('Missing required environment variables', { missing: missingRequired });
    throw new Error(`Missing required environment variables: ${missingRequired.join(', ')}`);
  }

  if (missingRecommended.length > 0) {
    logger.warn('Optional environment variables not set; some features may be limited', {
      missing: missingRecommended,
    });
  }

  const wsPort = parseInt(process.env.WS_PORT, 10);
  if (process.env.WS_PORT && (isNaN(wsPort) || wsPort < 1 || wsPort > 65535)) {
    throw new Error('WS_PORT must be a valid port number between 1 and 65535');
  }

  logger.info('Environment validation passed');
}

// Skip validation when running unit tests so tests don't require a fully
// populated .env. Integration tests can opt in by unsetting JEST_WORKER_ID.
if (!process.env.JEST_WORKER_ID) {
  validateEnvironment();
}

module.exports = {
  logLevel: process.env.LOG_LEVEL || 'info',
  webex: {
    token: process.env.WEBEX_ACCESS_TOKEN,
    name: process.env.BOT_NAME || 'StoreHealthAnalyzer',
  },
  meraki: {
    baseUrl: 'https://api.meraki.com/api/v1',
    apiKey: process.env.MERAKI_API_KEY,
    orgId: process.env.MERAKI_ORG_ID,
  },
  ws: {
    port: parseInt(process.env.WS_PORT) || 8080,
    token: process.env.WS_TOKEN,
  },
  siw: {
    baseUrl: process.env.SIW_BASE_URL,
    username: process.env.SIW_USERNAME,
    password: process.env.SIW_PASSWORD,
  },
  mdm: {
    baseUrl: process.env.WS1_BASE_URL,
    tokenUrl: process.env.WS1_TOKEN_URL,
    clientId: process.env.WS1_CLIENT_ID,
    clientSecret: process.env.WS1_CLIENT_SECRET,
    tenantCode: process.env.WS1_TENANT_CODE,
  },
  webexServiceApp: {
    clientId: process.env.WEBEX_CLIENT_ID,
    clientSecret: process.env.WEBEX_CLIENT_SECRET,
    // Absolute path resolved by WebexServiceAppAuth at construction time.
    tokensPath: process.env.WEBEX_TOKENS_PATH || './tokens/webex-service-tokens.json',
  },
  atlas: {
    // Long-lived API key; sent verbatim as the Authorization header value
    // (no Bearer prefix). The Atlas client throws AtlasUnavailableError
    // when this is unset so the AV renderer can show a banner.
    authKey: process.env.ATLAS_AUTH_KEY,
    baseUrl: process.env.ATLAS_BASE_URL || 'https://hub.xyte.io/core/v1',
  },
};