'use client';

import { useState, useEffect } from 'react';
import { useRouter, useSearchParams } from 'next/navigation';
import Link from 'next/link';
import { motion, AnimatePresence } from 'framer-motion';
import {
  Mail,
  Lock,
  Eye,
  EyeOff,
  LogIn,
  AlertCircle,
  Flag,
  Shield,
} from 'lucide-react';

import Card from '@/components/ui/Card';
import Button from '@/components/ui/Button';
import Input from '@/components/ui/Input';
import Heading from '@/components/ui/Heading';
import { useAuth } from '@/lib/auth/AuthContext';
import AuthWorkflowMockup from '@/components/auth/AuthWorkflowMockup';
import UserRolesPreview from '@/components/auth/UserRolesPreview';
import { EnhancedFormError, FormErrorSummary } from '@/components/errors/EnhancedFormError';
import { useEnhancedForm } from '@/lib/hooks/useEnhancedForm';
import { validateLoginForm, type LoginFormValues } from '@/lib/utils/validation';
import { logErrorWithContext } from '@/lib/utils/errorUtils';

export default function LoginPage() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const { refreshSession, session } = useAuth();
  const returnTo = searchParams.get('returnTo') ?? '/dashboard';
  
  const [showPassword, setShowPassword] = useState(false);
  const [showErrorDetails, setShowErrorDetails] = useState(false);
  const [hasInsufficientPermissions, setHasInsufficientPermissions] = useState(false);

  // Check if user is already authenticated
  useEffect(() => {
    if (session) {
      // If there's a returnTo parameter (user was redirected here from a protected route),
      // they might not have permission. Don't auto-redirect them back.
      const returnToParam = searchParams.get('returnTo');
      console.log('[LOGIN] returnToParam:', returnToParam);
      console.log('[LOGIN] returnTo:', returnTo);
      const hasReturnTo = returnToParam !== null;
      if (hasReturnTo) {
        console.log('[LOGIN] Has returnTo, setting insufficient permissions');
        setHasInsufficientPermissions(true);
      } else {
        // No returnTo means they navigated here directly while authenticated
        console.log('[LOGIN] No returnTo, redirecting to dashboard');
        router.replace('/dashboard');
      }
    }
  }, [session, router, returnTo, searchParams]);

  // Use enhanced form hook
  const {
    formState,
    setFormState,
    handleChange,
    handleSubmit,
    setFormError,
  } = useEnhancedForm<LoginFormValues>({
    initialValues: {
      email: '',
      password: '',
      rememberMe: false,
    },
    validate: validateLoginForm,
    component: 'LoginPage',
    onSubmit: async (values) => {
      const { ServiceFactory } = await import('@/lib/services/ServiceFactory');
      const serviceFactory = new ServiceFactory(process.env.NEXT_PUBLIC_API_BASE_URL || 'http://localhost:3001');
      const authService = serviceFactory.createAuthService();
      
      // Log the attempt for debugging
      logErrorWithContext(
        { message: 'Login attempt', values: { ...values, password: '[REDACTED]' } },
        {
          component: 'LoginPage',
          action: 'login-submit',
          formData: { ...values, password: '[REDACTED]' },
        }
      );
      
      await authService.login({
        email: values.email,
        password: values.password,
        rememberMe: values.rememberMe,
      });
      
      // Refresh session in context so header updates immediately
      await refreshSession();
      router.push(returnTo);
    },
    onError: (error, values) => {
      // Show error details toggle in development
      if (process.env.NODE_ENV === 'development') {
        setShowErrorDetails(true);
      }
    },
    onSuccess: () => {
      // Reset error details on success
      setShowErrorDetails(false);
    },
  });

  return (
    <main className="min-h-screen bg-deep-graphite flex">
      {/* Background Pattern */}
      <div className="absolute inset-0 bg-gradient-to-br from-primary-blue/5 via-transparent to-purple-600/5" />
      <div className="absolute inset-0 opacity-5">
        <div className="absolute inset-0" style={{
          backgroundImage: `url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.4'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")`,
        }} />
      </div>

      {/* Left Side - Info Panel (Hidden on mobile) */}
      <div className="hidden lg:flex lg:w-1/2 relative items-center justify-center p-12">
        <div className="max-w-lg">
          {/* Logo */}
          <div className="flex items-center gap-3 mb-8">
            <div className="flex h-12 w-12 items-center justify-center rounded-xl bg-gradient-to-br from-primary-blue/20 to-purple-600/10 border border-primary-blue/30">
              <Flag className="w-6 h-6 text-primary-blue" />
            </div>
            <span className="text-2xl font-bold text-white">GridPilot</span>
          </div>

          <Heading level={2} className="text-white mb-4">
            Your Sim Racing Infrastructure
          </Heading>
          
          <p className="text-gray-400 text-lg mb-8">
            Manage leagues, track performance, join teams, and compete with drivers worldwide. One account, multiple roles.
          </p>

          {/* Role Cards */}
          <UserRolesPreview variant="full" />

          {/* Workflow Mockup */}
          <AuthWorkflowMockup />

          {/* Trust Indicators */}
          <div className="mt-8 flex items-center gap-6 text-sm text-gray-500">
            <div className="flex items-center gap-2">
              <Shield className="w-4 h-4" />
              <span>Secure login</span>
            </div>
            <div className="flex items-center gap-2">
              <span className="text-sm">iRacing verified</span>
            </div>
          </div>
        </div>
      </div>

      {/* Right Side - Login Form */}
      <div className="flex-1 flex items-center justify-center px-4 py-12">
        <div className="relative w-full max-w-md">
          {/* Mobile Logo/Header */}
          <div className="text-center mb-8 lg:hidden">
            <div className="flex h-16 w-16 items-center justify-center rounded-2xl bg-gradient-to-br from-primary-blue/20 to-purple-600/10 border border-primary-blue/30 mx-auto mb-4">
              <Flag className="w-8 h-8 text-primary-blue" />
            </div>
            <Heading level={1} className="mb-2">Welcome Back</Heading>
            <p className="text-gray-400">
              Sign in to continue to GridPilot
            </p>
          </div>

          {/* Desktop Header */}
          <div className="hidden lg:block text-center mb-8">
            <Heading level={2} className="mb-2">Welcome Back</Heading>
            <p className="text-gray-400">
              Sign in to access your racing dashboard
            </p>
          </div>

          <Card className="relative overflow-hidden">
            {/* Background accent */}
            <div className="absolute top-0 right-0 w-32 h-32 bg-gradient-to-bl from-primary-blue/10 to-transparent rounded-bl-full" />

            <form onSubmit={handleSubmit} className="relative space-y-5">
              {/* Email */}
              <div>
                <label htmlFor="email" className="block text-sm font-medium text-gray-300 mb-2">
                  Email Address
                </label>
                <div className="relative">
                  <Mail className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-gray-500" />
                  <Input
                    id="email"
                    name="email"
                    type="email"
                    value={formState.fields.email.value}
                    onChange={handleChange}
                    error={!!formState.fields.email.error}
                    errorMessage={formState.fields.email.error}
                    placeholder="you@example.com"
                    disabled={formState.isSubmitting}
                    className="pl-10"
                    autoComplete="email"
                  />
                </div>
              </div>

              {/* Password */}
              <div>
                <div className="flex items-center justify-between mb-2">
                  <label htmlFor="password" className="block text-sm font-medium text-gray-300">
                    Password
                  </label>
                  <Link href="/auth/forgot-password" className="text-xs text-primary-blue hover:underline">
                    Forgot password?
                  </Link>
                </div>
                <div className="relative">
                  <Lock className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-gray-500" />
                  <Input
                    id="password"
                    name="password"
                    type={showPassword ? 'text' : 'password'}
                    value={formState.fields.password.value}
                    onChange={handleChange}
                    error={!!formState.fields.password.error}
                    errorMessage={formState.fields.password.error}
                    placeholder="••••••••"
                    disabled={formState.isSubmitting}
                    className="pl-10 pr-10"
                    autoComplete="current-password"
                  />
                  <button
                    type="button"
                    onClick={() => setShowPassword(!showPassword)}
                    className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-500 hover:text-gray-300"
                  >
                    {showPassword ? <EyeOff className="w-4 h-4" /> : <Eye className="w-4 h-4" />}
                  </button>
                </div>
              </div>

              {/* Remember Me */}
              <div className="flex items-center justify-between">
                <label className="flex items-center gap-2 cursor-pointer">
                  <input
                    id="rememberMe"
                    name="rememberMe"
                    type="checkbox"
                    checked={formState.fields.rememberMe?.value ?? false}
                    onChange={handleChange}
                    disabled={formState.isSubmitting}
                    className="w-4 h-4 rounded border-charcoal-outline bg-iron-gray text-primary-blue focus:ring-primary-blue focus:ring-offset-0"
                  />
                  <span className="text-sm text-gray-300">Keep me signed in</span>
                </label>
              </div>

              {/* Insufficient Permissions Message */}
              <AnimatePresence>
                {hasInsufficientPermissions && (
                  <motion.div
                    initial={{ opacity: 0, y: -10 }}
                    animate={{ opacity: 1, y: 0 }}
                    exit={{ opacity: 0, y: -10 }}
                    className="p-4 rounded-lg bg-warning-amber/10 border border-warning-amber/30"
                  >
                    <div className="flex items-start gap-3">
                      <AlertCircle className="w-5 h-5 text-warning-amber flex-shrink-0 mt-0.5" />
                      <div className="text-sm text-gray-300">
                        <strong className="text-warning-amber">Insufficient Permissions</strong>
                        <p className="mt-1">
                          You don't have permission to access that page. Please log in with an account that has the required role.
                        </p>
                      </div>
                    </div>
                  </motion.div>
                )}
              </AnimatePresence>

              {/* Enhanced Error Display */}
              <AnimatePresence>
                {formState.submitError && (
                  <EnhancedFormError
                    error={new Error(formState.submitError)}
                    onDismiss={() => {
                      // Clear the error by setting submitError to undefined
                      setFormState(prev => ({ ...prev, submitError: undefined }));
                    }}
                    showDeveloperDetails={showErrorDetails}
                  />
                )}
              </AnimatePresence>

              {/* Submit Button */}
              <Button
                type="submit"
                variant="primary"
                disabled={formState.isSubmitting}
                className="w-full flex items-center justify-center gap-2"
              >
                {formState.isSubmitting ? (
                  <>
                    <div className="w-4 h-4 border-2 border-white border-t-transparent rounded-full animate-spin" />
                    Signing in...
                  </>
                ) : (
                  <>
                    <LogIn className="w-4 h-4" />
                    Sign In
                  </>
                )}
              </Button>
            </form>

            {/* Divider */}
            <div className="relative my-6">
              <div className="absolute inset-0 flex items-center">
                <div className="w-full border-t border-charcoal-outline" />
              </div>
              <div className="relative flex justify-center text-xs">
                <span className="px-4 bg-iron-gray text-gray-500">or continue with</span>
              </div>
            </div>

            {/* Sign Up Link */}
            <p className="mt-6 text-center text-sm text-gray-400">
              Don't have an account?{' '}
              <Link
                href={`/auth/signup${returnTo !== '/dashboard' ? `?returnTo=${encodeURIComponent(returnTo)}` : ''}`}
                className="text-primary-blue hover:underline font-medium"
              >
                Create one
              </Link>
            </p>
          </Card>

          {/* Name Immutability Notice */}
          <div className="mt-6 p-4 rounded-lg bg-iron-gray/30 border border-charcoal-outline">
            <div className="flex items-start gap-3">
              <AlertCircle className="w-5 h-5 text-gray-400 flex-shrink-0 mt-0.5" />
              <div className="text-xs text-gray-400">
                <strong>Note:</strong> Your display name cannot be changed after signup. Please ensure it's correct when creating your account.
              </div>
            </div>
          </div>

          {/* Footer */}
          <p className="mt-6 text-center text-xs text-gray-500">
            By signing in, you agree to our{' '}
            <Link href="/terms" className="text-gray-400 hover:underline">Terms of Service</Link>
            {' '}and{' '}
            <Link href="/privacy" className="text-gray-400 hover:underline">Privacy Policy</Link>
          </p>

          {/* Mobile Role Info */}
          <UserRolesPreview variant="compact" />
        </div>
      </div>
    </main>
  );
}