/**
 * Embedded Stripe Connect Onboarding Component
 *
 * Uses Stripe's Connect embedded components to provide a seamless
 * onboarding experience without redirecting users away from the app.
 */

import React, { useState, useCallback, useEffect, useRef } from 'react';
import {
  ConnectComponentsProvider,
  ConnectAccountOnboarding,
} from '@stripe/react-connect-js';
import { loadConnectAndInitialize } from '@stripe/connect-js';
import type { StripeConnectInstance } from '@stripe/connect-js';
import {
  CheckCircle,
  AlertCircle,
  Loader2,
  CreditCard,
  Wallet,
  Building2,
} from 'lucide-react';
import { useTranslation } from 'react-i18next';
import { createAccountSession, refreshConnectStatus, ConnectAccountInfo } from '../api/payments';
import { useDarkMode } from '../hooks/useDarkMode';

// Get appearance config based on dark mode
const getAppearance = (isDark: boolean) => ({
  overlays: 'drawer' as const,
  variables: {
    // Brand colors - using your blue theme
    colorPrimary: '#3b82f6',  // brand-500
    colorBackground: isDark ? '#1f2937' : '#ffffff',  // gray-800 / white
    colorText: isDark ? '#f9fafb' : '#111827',  // gray-50 / gray-900
    colorSecondaryText: isDark ? '#9ca3af' : '#6b7280',  // gray-400 / gray-500
    colorBorder: isDark ? '#374151' : '#e5e7eb',  // gray-700 / gray-200
    colorDanger: '#ef4444',  // red-500

    // Typography - matching Inter font
    fontFamily: 'Inter, system-ui, -apple-system, sans-serif',
    fontSizeBase: '14px',
    fontSizeSm: '12px',
    fontSizeLg: '16px',
    fontSizeXl: '18px',
    fontWeightNormal: '400',
    fontWeightMedium: '500',
    fontWeightBold: '600',

    // Spacing & Borders - matching your rounded-lg style
    spacingUnit: '12px',
    borderRadius: '8px',

    // Form elements
    formBackgroundColor: isDark ? '#111827' : '#f9fafb',  // gray-900 / gray-50
    formBorderColor: isDark ? '#374151' : '#d1d5db',  // gray-700 / gray-300
    formHighlightColorBorder: '#3b82f6',  // brand-500
    formAccentColor: '#3b82f6',  // brand-500

    // Buttons
    buttonPrimaryColorBackground: '#3b82f6',  // brand-500
    buttonPrimaryColorText: '#ffffff',
    buttonSecondaryColorBackground: isDark ? '#374151' : '#f3f4f6',  // gray-700 / gray-100
    buttonSecondaryColorText: isDark ? '#f9fafb' : '#374151',  // gray-50 / gray-700
    buttonSecondaryColorBorder: isDark ? '#4b5563' : '#d1d5db',  // gray-600 / gray-300

    // Action colors
    actionPrimaryColorText: '#3b82f6',  // brand-500
    actionSecondaryColorText: isDark ? '#9ca3af' : '#6b7280',  // gray-400 / gray-500

    // Badge colors
    badgeNeutralColorBackground: isDark ? '#374151' : '#f3f4f6',  // gray-700 / gray-100
    badgeNeutralColorText: isDark ? '#d1d5db' : '#4b5563',  // gray-300 / gray-600
    badgeSuccessColorBackground: isDark ? '#065f46' : '#d1fae5',  // green-800 / green-100
    badgeSuccessColorText: isDark ? '#6ee7b7' : '#065f46',  // green-300 / green-800
    badgeWarningColorBackground: isDark ? '#92400e' : '#fef3c7',  // amber-800 / amber-100
    badgeWarningColorText: isDark ? '#fcd34d' : '#92400e',  // amber-300 / amber-800
    badgeDangerColorBackground: isDark ? '#991b1b' : '#fee2e2',  // red-800 / red-100
    badgeDangerColorText: isDark ? '#fca5a5' : '#991b1b',  // red-300 / red-800

    // Offset background (used for layered sections)
    offsetBackgroundColor: isDark ? '#111827' : '#f9fafb',  // gray-900 / gray-50
  },
});

interface ConnectOnboardingEmbedProps {
  connectAccount: ConnectAccountInfo | null;
  tier: string;
  onComplete?: () => void;
  onError?: (error: string) => void;
}

type LoadingState = 'idle' | 'loading' | 'ready' | 'error' | 'complete';

const ConnectOnboardingEmbed: React.FC<ConnectOnboardingEmbedProps> = ({
  connectAccount,
  tier,
  onComplete,
  onError,
}) => {
  const { t } = useTranslation();
  const isDark = useDarkMode();
  const [stripeConnectInstance, setStripeConnectInstance] = useState<StripeConnectInstance | null>(null);
  const [loadingState, setLoadingState] = useState<LoadingState>('idle');
  const [errorMessage, setErrorMessage] = useState<string | null>(null);

  // Track the theme that was used when initializing
  const initializedThemeRef = useRef<boolean | null>(null);
  // Flag to trigger auto-reinitialize
  const [needsReinit, setNeedsReinit] = useState(false);

  const isActive = connectAccount?.status === 'active' && connectAccount?.charges_enabled;

  // Detect theme changes when onboarding is already open
  useEffect(() => {
    if (loadingState === 'ready' && initializedThemeRef.current !== null && initializedThemeRef.current !== isDark) {
      // Theme changed while onboarding is open - trigger reinitialize
      setNeedsReinit(true);
    }
  }, [isDark, loadingState]);

  // Handle reinitialization
  useEffect(() => {
    if (needsReinit) {
      setStripeConnectInstance(null);
      initializedThemeRef.current = null;
      setNeedsReinit(false);
      // Re-run initialization
      (async () => {
        setLoadingState('loading');
        setErrorMessage(null);

        try {
          const response = await createAccountSession();
          const { client_secret, publishable_key } = response.data;

          const instance = await loadConnectAndInitialize({
            publishableKey: publishable_key,
            fetchClientSecret: async () => client_secret,
            appearance: getAppearance(isDark),
          });

          setStripeConnectInstance(instance);
          setLoadingState('ready');
          initializedThemeRef.current = isDark;
        } catch (err: any) {
          console.error('Failed to reinitialize Stripe Connect:', err);
          const message = err.response?.data?.error || err.message || t('payments.failedToInitializePayment');
          setErrorMessage(message);
          setLoadingState('error');
          onError?.(message);
        }
      })();
    }
  }, [needsReinit, isDark, t, onError]);

  // Initialize Stripe Connect (user-triggered)
  const initializeStripeConnect = useCallback(async () => {
    if (loadingState === 'loading' || loadingState === 'ready') return;

    setLoadingState('loading');
    setErrorMessage(null);

    try {
      // Fetch account session from our backend
      const response = await createAccountSession();
      const { client_secret, publishable_key } = response.data;

      // Initialize the Connect instance with theme-aware appearance
      const instance = await loadConnectAndInitialize({
        publishableKey: publishable_key,
        fetchClientSecret: async () => client_secret,
        appearance: getAppearance(isDark),
      });

      setStripeConnectInstance(instance);
      setLoadingState('ready');
      initializedThemeRef.current = isDark;
    } catch (err: any) {
      console.error('Failed to initialize Stripe Connect:', err);
      const message = err.response?.data?.error || err.message || t('payments.failedToInitializePayment');
      setErrorMessage(message);
      setLoadingState('error');
      onError?.(message);
    }
  }, [loadingState, onError, t, isDark]);

  // Handle onboarding completion
  const handleOnboardingExit = useCallback(async () => {
    // Refresh status from Stripe to sync the local database
    try {
      await refreshConnectStatus();
    } catch (err) {
      console.error('Failed to refresh Connect status:', err);
    }
    setLoadingState('complete');
    onComplete?.();
  }, [onComplete]);

  // Handle errors from the Connect component
  const handleLoadError = useCallback((loadError: { error: { message?: string }; elementTagName: string }) => {
    console.error('Connect component load error:', loadError);
    const message = loadError.error.message || t('payments.failedToLoadPaymentComponent');
    setErrorMessage(message);
    setLoadingState('error');
    onError?.(message);
  }, [onError, t]);

  // Account type display
  const getAccountTypeLabel = () => {
    switch (connectAccount?.account_type) {
      case 'standard':
        return t('payments.standardConnect');
      case 'express':
        return t('payments.expressConnect');
      case 'custom':
        return t('payments.customConnect');
      default:
        return t('payments.connect');
    }
  };

  // If account is already active, show status
  if (isActive) {
    return (
      <div className="space-y-6">
        <div className="bg-green-50 dark:bg-green-900/20 border border-green-200 dark:border-green-800 rounded-lg p-4">
          <div className="flex items-start gap-3">
            <CheckCircle className="text-green-600 dark:text-green-400 shrink-0 mt-0.5" size={20} />
            <div className="flex-1">
              <h4 className="font-medium text-green-800 dark:text-green-300">{t('payments.stripeConnected')}</h4>
              <p className="text-sm text-green-700 dark:text-green-400 mt-1">
                {t('payments.stripeConnectedDesc')}
              </p>
            </div>
          </div>
        </div>

        <div className="bg-gray-50 dark:bg-gray-700/50 rounded-lg p-4">
          <h4 className="font-medium text-gray-900 dark:text-white mb-3">{t('payments.accountDetails')}</h4>
          <div className="space-y-2 text-sm">
            <div className="flex justify-between">
              <span className="text-gray-600 dark:text-gray-400">{t('payments.accountType')}:</span>
              <span className="text-gray-900 dark:text-white">{getAccountTypeLabel()}</span>
            </div>
            <div className="flex justify-between">
              <span className="text-gray-600 dark:text-gray-400">{t('payments.status')}:</span>
              <span className="px-2 py-0.5 text-xs font-medium rounded-full bg-green-100 dark:bg-green-900/30 text-green-800 dark:text-green-300">
                {connectAccount.status}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-gray-600 dark:text-gray-400">{t('payments.charges')}:</span>
              <span className="flex items-center gap-1 text-green-600 dark:text-green-400">
                <CreditCard size={14} />
                {t('payments.enabled')}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-gray-600 dark:text-gray-400">{t('payments.payouts')}:</span>
              <span className="flex items-center gap-1 text-green-600 dark:text-green-400">
                <Wallet size={14} />
                {connectAccount.payouts_enabled ? t('payments.enabled') : t('payments.pending')}
              </span>
            </div>
          </div>
        </div>
      </div>
    );
  }

  // Completion state
  if (loadingState === 'complete') {
    return (
      <div className="bg-green-50 dark:bg-green-900/20 border border-green-200 dark:border-green-800 rounded-lg p-6 text-center">
        <CheckCircle className="mx-auto text-green-600 dark:text-green-400 mb-3" size={48} />
        <h4 className="font-medium text-green-800 dark:text-green-300 text-lg">{t('payments.onboardingComplete')}</h4>
        <p className="text-sm text-green-700 dark:text-green-400 mt-2">
          {t('payments.stripeSetupComplete')}
        </p>
      </div>
    );
  }

  // Error state
  if (loadingState === 'error') {
    return (
      <div className="space-y-4">
        <div className="bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 rounded-lg p-4">
          <div className="flex items-start gap-3">
            <AlertCircle className="text-red-600 dark:text-red-400 shrink-0 mt-0.5" size={20} />
            <div className="flex-1">
              <h4 className="font-medium text-red-800 dark:text-red-300">{t('payments.setupFailed')}</h4>
              <p className="text-sm text-red-700 dark:text-red-400 mt-1">{errorMessage}</p>
            </div>
          </div>
        </div>
        <button
          onClick={() => {
            setLoadingState('idle');
            setErrorMessage(null);
          }}
          className="w-full px-4 py-2 text-sm font-medium text-gray-700 dark:text-gray-200 bg-gray-100 dark:bg-gray-700 rounded-lg hover:bg-gray-200 dark:hover:bg-gray-600"
        >
          {t('payments.tryAgain')}
        </button>
      </div>
    );
  }

  // Idle state - show start button
  if (loadingState === 'idle') {
    return (
      <div className="space-y-4">
        <div className="bg-blue-50 dark:bg-blue-900/20 border border-blue-200 dark:border-blue-800 rounded-lg p-4">
          <div className="flex items-start gap-3">
            <Building2 className="text-blue-600 dark:text-blue-400 shrink-0 mt-0.5" size={20} />
            <div className="flex-1">
              <h4 className="font-medium text-blue-800 dark:text-blue-300">{t('payments.setUpPayments')}</h4>
              <p className="text-sm text-blue-700 dark:text-blue-400 mt-1">
                {t('payments.tierPaymentDescriptionWithOnboarding', { tier })}
              </p>
              <ul className="mt-3 space-y-1 text-sm text-blue-700 dark:text-blue-400">
                <li className="flex items-center gap-2">
                  <CheckCircle size={14} />
                  {t('payments.securePaymentProcessing')}
                </li>
                <li className="flex items-center gap-2">
                  <CheckCircle size={14} />
                  {t('payments.automaticPayouts')}
                </li>
                <li className="flex items-center gap-2">
                  <CheckCircle size={14} />
                  {t('payments.pciCompliance')}
                </li>
              </ul>
            </div>
          </div>
        </div>

        <button
          onClick={initializeStripeConnect}
          className="w-full flex items-center justify-center gap-2 px-4 py-3 text-sm font-medium text-white bg-brand-500 rounded-lg hover:bg-brand-600 transition-colors"
        >
          <CreditCard size={18} />
          {t('payments.startPaymentSetup')}
        </button>
      </div>
    );
  }

  // Loading state
  if (loadingState === 'loading') {
    return (
      <div className="flex flex-col items-center justify-center py-12">
        <Loader2 className="animate-spin text-brand-500 mb-4" size={40} />
        <p className="text-gray-600 dark:text-gray-400">{t('payments.initializingPaymentSetup')}</p>
      </div>
    );
  }

  // Ready state - show embedded onboarding
  if (loadingState === 'ready' && stripeConnectInstance) {
    return (
      <div className="space-y-4">
        <div className="bg-gray-50 dark:bg-gray-700/50 border border-gray-200 dark:border-gray-600 rounded-lg p-4">
          <h4 className="font-medium text-gray-900 dark:text-white mb-2">{t('payments.completeAccountSetup')}</h4>
          <p className="text-sm text-gray-600 dark:text-gray-400">
            {t('payments.fillOutInfoForPayment')}
          </p>
        </div>

        <div className="border border-gray-200 dark:border-gray-600 rounded-lg overflow-hidden bg-white dark:bg-gray-800 p-4">
          <ConnectComponentsProvider connectInstance={stripeConnectInstance}>
            <ConnectAccountOnboarding
              onExit={handleOnboardingExit}
              onLoadError={handleLoadError}
            />
          </ConnectComponentsProvider>
        </div>
      </div>
    );
  }

  return null;
};

export default ConnectOnboardingEmbed;