/**
 * Shared utility to check for deprecated authentication environment variables.
 * Used by both prebuild.mts (build time) and startServer.js (Docker runtime).
 *
 * IMPORTANT: Keep this file as CommonJS (.js) for compatibility with startServer.js
 */

const MIGRATION_DOC_BASE = 'https://lobehub.com/docs/self-hosting/migration/v2/auth';

/**
 * Deprecated environment variable checks configuration
 * @type {Array<{
 *   name: string;
 *   getVars: () => string[];
 *   message: string;
 *   docUrl?: string;
 *   formatVar?: (envVar: string) => string;
 *   severity?: 'error' | 'warning';
 * }>}
 */
const DEPRECATED_CHECKS = [
  {
    docUrl: `${MIGRATION_DOC_BASE}/nextauth-to-betterauth`,
    getVars: () =>
      Object.keys(process.env).filter(
        (key) => key.startsWith('NEXT_AUTH') || key.startsWith('NEXTAUTH'),
      ),
    message: 'NextAuth has been removed from LobeChat. Please migrate to Better Auth.',
    name: 'NextAuth',
  },
  {
    docUrl: `${MIGRATION_DOC_BASE}/clerk-to-betterauth`,
    getVars: () =>
      ['NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY', 'CLERK_SECRET_KEY', 'CLERK_WEBHOOK_SECRET'].filter(
        (key) => process.env[key],
      ),
    message: 'Clerk has been removed from LobeChat. Please migrate to Better Auth.',
    name: 'Clerk',
  },
  {
    formatVar: (envVar) => {
      const mapping = {
        ENABLE_MAGIC_LINK: 'AUTH_ENABLE_MAGIC_LINK',
        NEXT_PUBLIC_AUTH_EMAIL_VERIFICATION: 'AUTH_EMAIL_VERIFICATION',
        NEXT_PUBLIC_ENABLE_MAGIC_LINK: 'AUTH_ENABLE_MAGIC_LINK',
      };
      return `${envVar} → Please use ${mapping[envVar]} instead`;
    },
    getVars: () =>
      [
        'ENABLE_MAGIC_LINK',
        'NEXT_PUBLIC_AUTH_EMAIL_VERIFICATION',
        'NEXT_PUBLIC_ENABLE_MAGIC_LINK',
      ].filter((key) => process.env[key]),
    message: 'Please update to the new environment variable names.',
    name: 'Deprecated Auth',
  },
  {
    getVars: () => (process.env['NEXT_PUBLIC_SERVICE_MODE'] ? ['NEXT_PUBLIC_SERVICE_MODE'] : []),
    message:
      'LobeChat 2.0 no longer supports client-side database mode. This environment variable is now obsolete and can be removed.',
    name: 'Service Mode',
  },
  {
    getVars: () => (process.env['ACCESS_CODE'] ? ['ACCESS_CODE'] : []),
    message:
      'ACCESS_CODE is no longer supported in LobeChat 2.0. Please use Better Auth authentication system instead.',
    name: 'Access Code',
  },
  {
    getVars: () =>
      process.env['NEXT_PUBLIC_ENABLE_BETTER_AUTH'] ? ['NEXT_PUBLIC_ENABLE_BETTER_AUTH'] : [],
    message:
      'NEXT_PUBLIC_ENABLE_BETTER_AUTH is no longer needed. Better Auth is now automatically detected via AUTH_SECRET presence.',
    name: 'Better Auth Flag',
  },
  {
    getVars: () => ['NEXT_PUBLIC_AUTH_URL', 'AUTH_URL'].filter((key) => process.env[key]),
    message:
      'AUTH_URL is no longer needed. The authentication URL is now automatically detected from request headers.',
    name: 'Auth URL',
  },
  {
    docUrl: `${MIGRATION_DOC_BASE}/nextauth-to-betterauth`,
    formatVar: (envVar) => {
      const mapping = {
        AUTH_AZURE_AD_ID: 'AUTH_MICROSOFT_ID',
        AUTH_AZURE_AD_SECRET: 'AUTH_MICROSOFT_SECRET',
        AUTH_AZURE_AD_TENANT_ID: 'AUTH_MICROSOFT_TENANT_ID',
        AZURE_AD_CLIENT_ID: 'AUTH_MICROSOFT_ID',
        AZURE_AD_CLIENT_SECRET: 'AUTH_MICROSOFT_SECRET',
        AZURE_AD_TENANT_ID: 'AUTH_MICROSOFT_TENANT_ID',
      };
      return `${envVar} → ${mapping[envVar]}`;
    },
    getVars: () =>
      [
        'AZURE_AD_CLIENT_ID',
        'AZURE_AD_CLIENT_SECRET',
        'AZURE_AD_TENANT_ID',
        'AUTH_AZURE_AD_ID',
        'AUTH_AZURE_AD_SECRET',
        'AUTH_AZURE_AD_TENANT_ID',
      ].filter((key) => process.env[key]),
    message:
      'Azure AD provider has been renamed to Microsoft. Please update your environment variables.',
    name: 'Azure AD',
  },
  {
    formatVar: (envVar) => {
      const mapping = {
        ZITADEL_CLIENT_ID: 'AUTH_ZITADEL_ID',
        ZITADEL_CLIENT_SECRET: 'AUTH_ZITADEL_SECRET',
        ZITADEL_ISSUER: 'AUTH_ZITADEL_ISSUER',
      };
      return `${envVar} → Please use ${mapping[envVar]} instead`;
    },
    getVars: () =>
      ['ZITADEL_CLIENT_ID', 'ZITADEL_CLIENT_SECRET', 'ZITADEL_ISSUER'].filter(
        (key) => process.env[key],
      ),
    message: 'ZITADEL environment variables have been renamed.',
    name: 'ZITADEL',
  },
  {
    formatVar: () => 'OIDC_JWKS_KEY → Please use JWKS_KEY instead',
    getVars: () => (process.env['OIDC_JWKS_KEY'] ? ['OIDC_JWKS_KEY'] : []),
    message: 'OIDC_JWKS_KEY has been renamed to JWKS_KEY.',
    name: 'OIDC JWKS',
  },
  {
    formatVar: () => 'APP_URL should not end with a trailing slash',
    getVars: () => (process.env['APP_URL']?.endsWith('/') ? ['APP_URL'] : []),
    message:
      'APP_URL ends with a trailing slash which causes double slashes in redirect URLs (e.g., https://example.com//). Please remove the trailing slash.',
    name: 'APP_URL Trailing Slash',
  },
  {
    docUrl: `${MIGRATION_DOC_BASE}/providers/casdoor`,
    getVars: () => {
      const providers = process.env['AUTH_SSO_PROVIDERS'] || '';
      if (providers.includes('casdoor') && !process.env['CASDOOR_WEBHOOK_SECRET']) {
        return ['CASDOOR_WEBHOOK_SECRET'];
      }
      return [];
    },
    message:
      'Casdoor webhook is recommended for syncing user data (email, avatar, etc.) to LobeChat. This is especially important for users migrating from NextAuth to Better Auth - users without email configured in Casdoor will not be able to login. Consider configuring CASDOOR_WEBHOOK_SECRET following the documentation.',
    name: 'Casdoor Webhook',
    severity: 'warning',
  },
  {
    docUrl: `${MIGRATION_DOC_BASE}/providers/logto`,
    getVars: () => {
      const providers = process.env['AUTH_SSO_PROVIDERS'] || '';
      if (providers.includes('logto') && !process.env['LOGTO_WEBHOOK_SIGNING_KEY']) {
        return ['LOGTO_WEBHOOK_SIGNING_KEY'];
      }
      return [];
    },
    message:
      'Logto webhook is recommended for syncing user data (email, avatar, etc.) to LobeChat. This is especially important for users migrating from NextAuth to Better Auth - users without email configured in Logto will not be able to login. Consider configuring LOGTO_WEBHOOK_SIGNING_KEY following the documentation.',
    name: 'Logto Webhook',
    severity: 'warning',
  },
  {
    docUrl: `${MIGRATION_DOC_BASE}/nextauth-to-betterauth`,
    formatVar: (envVar) => {
      const mapping = {
        AUTH_MICROSOFT_ENTRA_ID_BASE_URL: 'AUTH_MICROSOFT_AUTHORITY_URL',
        AUTH_MICROSOFT_ENTRA_ID_ID: 'AUTH_MICROSOFT_ID',
        AUTH_MICROSOFT_ENTRA_ID_SECRET: 'AUTH_MICROSOFT_SECRET',
        AUTH_MICROSOFT_ENTRA_ID_TENANT_ID: 'AUTH_MICROSOFT_TENANT_ID',
      };
      return `${envVar} → ${mapping[envVar]}`;
    },
    getVars: () =>
      [
        'AUTH_MICROSOFT_ENTRA_ID_ID',
        'AUTH_MICROSOFT_ENTRA_ID_SECRET',
        'AUTH_MICROSOFT_ENTRA_ID_TENANT_ID',
        'AUTH_MICROSOFT_ENTRA_ID_BASE_URL',
      ].filter((key) => process.env[key]),
    message:
      'Microsoft Entra ID provider has been renamed to Microsoft. Please update your environment variables.',
    name: 'Microsoft Entra ID',
  },
  {
    docUrl: MIGRATION_DOC_BASE,
    getVars: () => {
      const hasEmailService =
        process.env['SMTP_HOST'] || process.env['EMAIL_SERVICE_PROVIDER'] === 'resend';
      const hasEmailVerification = process.env['AUTH_EMAIL_VERIFICATION'] === '1';
      if (hasEmailService && !hasEmailVerification) {
        return ['AUTH_EMAIL_VERIFICATION'];
      }
      return [];
    },
    message:
      'Email service is configured but email verification is disabled. Consider setting AUTH_EMAIL_VERIFICATION=1 to verify user email ownership during registration.',
    name: 'Email Verification',
    severity: 'warning',
  },
];

/**
 * Print a single deprecation block (error or warning)
 */
function printIssueBlock(name, vars, message, docUrl, formatVar, severity = 'error') {
  const isWarning = severity === 'warning';
  const icon = isWarning ? '⚠️' : '❌';
  const log = isWarning ? console.warn : console.error;

  log(`\n${icon} ${name}`);
  log('─'.repeat(50));
  log(
    isWarning
      ? 'Missing recommended environment variables:'
      : 'Detected deprecated environment variables:',
  );
  for (const envVar of vars) {
    log(`  • ${formatVar ? formatVar(envVar) : envVar}`);
  }
  log(`\n${message}`);
  if (docUrl) {
    log(`📖 Documentation: ${docUrl}`);
  }
}

/**
 * Check for deprecated authentication environment variables and exit if found
 * @param {object} options
 * @param {string} [options.action='redeploy'] - Action hint in error message ('redeploy' or 'restart')
 */
function checkDeprecatedAuth(options = {}) {
  const { action = 'redeploy' } = options;

  const errors = [];
  const warnings = [];

  for (const check of DEPRECATED_CHECKS) {
    const foundVars = check.getVars();
    if (foundVars.length > 0) {
      const issue = { ...check, foundVars };
      if (check.severity === 'warning') {
        warnings.push(issue);
      } else {
        errors.push(issue);
      }
    }
  }

  // Print warnings (non-blocking)
  if (warnings.length > 0) {
    console.warn('\n' + '═'.repeat(70));
    console.warn(`⚠️  WARNING: Found ${warnings.length} recommended configuration(s) missing`);
    console.warn('═'.repeat(70));

    for (const issue of warnings) {
      printIssueBlock(
        issue.name,
        issue.foundVars,
        issue.message,
        issue.docUrl,
        issue.formatVar,
        'warning',
      );
    }

    console.warn('\n' + '═'.repeat(70));
    console.warn('These are recommendations. Your application will still run.');
    console.warn('═'.repeat(70) + '\n');
  }

  // Print errors and exit (blocking)
  if (errors.length > 0) {
    console.error('\n' + '═'.repeat(70));
    console.error(`❌ ERROR: Found ${errors.length} deprecated environment variable issue(s)!`);
    console.error('═'.repeat(70));

    for (const issue of errors) {
      printIssueBlock(
        issue.name,
        issue.foundVars,
        issue.message,
        issue.docUrl,
        issue.formatVar,
        'error',
      );
    }

    console.error('\n' + '═'.repeat(70));
    console.error(`Please update your environment variables and ${action}.`);
    console.error('═'.repeat(70) + '\n');
    process.exit(1);
  }
}

module.exports = { checkDeprecatedAuth };