'use client';

import { useEffect, useMemo, useState } from 'react';
import Link from 'next/link';
import { useRouter, useSearchParams } from 'next/navigation';
import { Video, Loader2, KeyRound, UserPlus } from 'lucide-react';
import { signIn } from 'next-auth/react';
import { Button } from '@/components/ui/button';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { getSafeCallbackUrl } from '@/lib/safe-redirect';

export interface RegisterInvitation {
  email: string;
  inviterName: string;
  roleLabel: string;
  scopeLabel: string;
  targetName: string | null;
}

interface RegisterPageClientProps {
  requireInviteCode: boolean;
  googleEnabled: boolean;
  githubEnabled: boolean;
  invitation?: RegisterInvitation | null;
  /** Preview lookup was rate-limited, so `invitation` says nothing about its validity. */
  invitationLookupThrottled?: boolean;
}

export default function RegisterPageClient({
  requireInviteCode,
  googleEnabled,
  githubEnabled,
  invitation = null,
  invitationLookupThrottled = false,
}: RegisterPageClientProps) {
  const router = useRouter();
  const searchParams = useSearchParams();
  const invitationToken = useMemo(() => searchParams.get('invitationToken') || '', [searchParams]);
  const invitedEmail = useMemo(
    () => invitation?.email || searchParams.get('email') || '',
    [invitation, searchParams]
  );
  // Where to send the user once they are signed in — for invitations this points back
  // at /invitations/accept so they land on the workspace/project they were invited to
  // instead of the onboarding wizard.
  const callbackUrl = useMemo(
    () => getSafeCallbackUrl(searchParams.get('callbackUrl')),
    [searchParams]
  );
  const isInvitationFlow = invitationToken.length > 0;
  const shouldShowInviteCode = requireInviteCode && !isInvitationFlow;
  const loginHref =
    callbackUrl === '/dashboard'
      ? '/login'
      : `/login?callbackUrl=${encodeURIComponent(callbackUrl)}`;
  const [isLoading, setIsLoading] = useState(false);
  const [oauthLoading, setOauthLoading] = useState<string | null>(null);
  const [error, setError] = useState('');
  const [formData, setFormData] = useState({
    name: '',
    email: '',
    password: '',
    confirmPassword: '',
    inviteCode: '',
  });

  useEffect(() => {
    if (!invitedEmail) return;
    setFormData((prev) => ({
      ...prev,
      email: invitedEmail,
    }));
  }, [invitedEmail]);

  const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    setFormData((prev) => ({
      ...prev,
      [e.target.name]: e.target.value,
    }));
    setError('');
  };

  const handleRegister = async (e: React.FormEvent) => {
    e.preventDefault();
    setError('');
    setIsLoading(true);

    if (formData.password !== formData.confirmPassword) {
      setError('Passwords do not match');
      setIsLoading(false);
      return;
    }

    if (formData.password.length < 8) {
      setError('Password must be at least 8 characters');
      setIsLoading(false);
      return;
    }

    try {
      const response = await fetch('/api/auth/register', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          name: formData.name,
          email: formData.email,
          password: formData.password,
          inviteCode: shouldShowInviteCode ? formData.inviteCode || undefined : undefined,
          invitationToken: invitationToken || undefined,
        }),
      });

      const data = await response.json();

      if (!response.ok) {
        setError(data.error || 'Registration failed');
        return;
      }

      const callbackParam = `&callbackUrl=${encodeURIComponent(callbackUrl)}`;
      if (data.data?.emailVerificationRequired) {
        router.push(`/verify-email?email=${encodeURIComponent(formData.email)}${callbackParam}`);
      } else {
        router.push(`/login?registered=true${callbackParam}`);
      }
    } catch {
      setError('Something went wrong. Please try again.');
    } finally {
      setIsLoading(false);
    }
  };

  const handleOAuthSignUp = async (provider: string) => {
    setOauthLoading(provider);
    setError('');
    await signIn(provider, { callbackUrl });
  };

  const hasOAuth = googleEnabled || githubEnabled;
  const anyLoading = isLoading || oauthLoading !== null;

  return (
    <div className="min-h-screen flex items-center justify-center p-4 bg-background">
      <div className="w-full max-w-md">
        <Link href="/" className="flex items-center justify-center gap-2 mb-8">
          <Video className="h-8 w-8 text-primary" />
          <span className="font-bold text-2xl">OpenFrame</span>
        </Link>

        <Card>
          <CardHeader className="text-center">
            <CardTitle className="flex items-center justify-center gap-2">
              <UserPlus className="h-5 w-5" />
              Create Account
            </CardTitle>
            <CardDescription>Join OpenFrame to collaborate on video projects</CardDescription>
          </CardHeader>
          <CardContent>
            {/* OAuth Buttons */}
            {hasOAuth && (
              <div className="space-y-2 mb-4">
                {googleEnabled && (
                  <Button
                    type="button"
                    variant="outline"
                    className="w-full"
                    disabled={anyLoading}
                    onClick={() => handleOAuthSignUp('google')}
                  >
                    {oauthLoading === 'google' ? (
                      <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                    ) : (
                      <svg className="h-4 w-4 mr-2" viewBox="0 0 24 24" aria-hidden="true">
                        <path
                          d="M22.56 12.25c0-.78-.07-1.53-.2-2.25H12v4.26h5.92c-.26 1.37-1.04 2.53-2.21 3.31v2.77h3.57c2.08-1.92 3.28-4.74 3.28-8.09z"
                          fill="#4285F4"
                        />
                        <path
                          d="M12 23c2.97 0 5.46-.98 7.28-2.66l-3.57-2.77c-.98.66-2.23 1.06-3.71 1.06-2.86 0-5.29-1.93-6.16-4.53H2.18v2.84C3.99 20.53 7.7 23 12 23z"
                          fill="#34A853"
                        />
                        <path
                          d="M5.84 14.09c-.22-.66-.35-1.36-.35-2.09s.13-1.43.35-2.09V7.07H2.18C1.43 8.55 1 10.22 1 12s.43 3.45 1.18 4.93l2.85-2.22.81-.62z"
                          fill="#FBBC05"
                        />
                        <path
                          d="M12 5.38c1.62 0 3.06.56 4.21 1.64l3.15-3.15C17.45 2.09 14.97 1 12 1 7.7 1 3.99 3.47 2.18 7.07l3.66 2.84c.87-2.6 3.3-4.53 6.16-4.53z"
                          fill="#EA4335"
                        />
                      </svg>
                    )}
                    Continue with Google
                  </Button>
                )}
                {githubEnabled && (
                  <Button
                    type="button"
                    variant="outline"
                    className="w-full"
                    disabled={anyLoading}
                    onClick={() => handleOAuthSignUp('github')}
                  >
                    {oauthLoading === 'github' ? (
                      <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                    ) : (
                      <svg
                        className="h-4 w-4 mr-2"
                        viewBox="0 0 24 24"
                        aria-hidden="true"
                        fill="currentColor"
                      >
                        <path d="M12 2C6.477 2 2 6.484 2 12.017c0 4.425 2.865 8.18 6.839 9.504.5.092.682-.217.682-.483 0-.237-.008-.868-.013-1.703-2.782.605-3.369-1.343-3.369-1.343-.454-1.158-1.11-1.466-1.11-1.466-.908-.62.069-.608.069-.608 1.003.07 1.531 1.032 1.531 1.032.892 1.53 2.341 1.088 2.91.832.092-.647.35-1.088.636-1.338-2.22-.253-4.555-1.113-4.555-4.951 0-1.093.39-1.988 1.029-2.688-.103-.253-.446-1.272.098-2.65 0 0 .84-.27 2.75 1.026A9.564 9.564 0 0112 6.844c.85.004 1.705.115 2.504.337 1.909-1.296 2.747-1.027 2.747-1.027.546 1.379.202 2.398.1 2.651.64.7 1.028 1.595 1.028 2.688 0 3.848-2.339 4.695-4.566 4.943.359.309.678.92.678 1.855 0 1.338-.012 2.419-.012 2.747 0 .268.18.58.688.482A10.019 10.019 0 0022 12.017C22 6.484 17.522 2 12 2z" />
                      </svg>
                    )}
                    Continue with GitHub
                  </Button>
                )}
              </div>
            )}

            {/* Divider */}
            {hasOAuth && (
              <div className="relative mb-4">
                <div className="absolute inset-0 flex items-center">
                  <span className="w-full border-t" />
                </div>
                <div className="relative flex justify-center text-xs uppercase">
                  <span className="bg-card px-2 text-muted-foreground">or continue with email</span>
                </div>
              </div>
            )}

            <form onSubmit={handleRegister} className="space-y-4">
              {isInvitationFlow && invitation ? (
                <div className="p-3 rounded-md bg-primary/10 text-sm space-y-1">
                  <p>
                    {invitation.inviterName} invited you to{' '}
                    <strong>
                      {invitation.targetName
                        ? `${invitation.targetName} (${invitation.scopeLabel})`
                        : `a ${invitation.scopeLabel}`}
                    </strong>{' '}
                    as {invitation.roleLabel}.
                  </p>
                  <p className="text-muted-foreground">
                    Create your account below — you&apos;ll be taken straight to it.
                  </p>
                </div>
              ) : isInvitationFlow && invitationLookupThrottled ? (
                <div className="p-3 rounded-md bg-amber-500/10 text-sm">
                  We couldn&apos;t check this invitation right now. Please wait a few minutes and
                  open the link again.
                </div>
              ) : isInvitationFlow ? (
                <div className="p-3 rounded-md bg-amber-500/10 text-sm">
                  This invitation link is no longer valid. Ask whoever invited you for a new one.
                </div>
              ) : shouldShowInviteCode ? (
                <>
                  <div className="space-y-2">
                    <Label htmlFor="inviteCode" className="flex items-center gap-2">
                      <KeyRound className="h-4 w-4 text-amber-500" />
                      Invite Code
                    </Label>
                    <Input
                      id="inviteCode"
                      name="inviteCode"
                      type="text"
                      placeholder="Enter your invite code"
                      value={formData.inviteCode}
                      onChange={handleChange}
                      required
                      disabled={isLoading}
                      className="border-amber-500/30 focus:border-amber-500"
                    />
                    <p className="text-xs text-muted-foreground">
                      An invite code is required to create an account
                    </p>
                  </div>

                  <div className="h-px bg-border my-4" />
                </>
              ) : null}

              <div className="space-y-2">
                <Label htmlFor="name">Full Name</Label>
                <Input
                  id="name"
                  name="name"
                  type="text"
                  placeholder="John Doe"
                  value={formData.name}
                  onChange={handleChange}
                  required
                  disabled={isLoading}
                  minLength={2}
                />
              </div>

              <div className="space-y-2">
                <Label htmlFor="email">Email</Label>
                <Input
                  id="email"
                  name="email"
                  type="email"
                  placeholder="you@example.com"
                  value={formData.email}
                  onChange={handleChange}
                  required
                  disabled={isLoading}
                  readOnly={Boolean(invitation)}
                  className={invitation ? 'bg-muted text-muted-foreground' : undefined}
                />
                {invitation && (
                  <p className="text-xs text-muted-foreground">
                    The invitation is tied to this address.
                  </p>
                )}
              </div>

              <div className="space-y-2">
                <Label htmlFor="password">Password</Label>
                <Input
                  id="password"
                  name="password"
                  type="password"
                  placeholder="••••••••"
                  value={formData.password}
                  onChange={handleChange}
                  required
                  disabled={isLoading}
                  minLength={8}
                />
              </div>

              <div className="space-y-2">
                <Label htmlFor="confirmPassword">Confirm Password</Label>
                <Input
                  id="confirmPassword"
                  name="confirmPassword"
                  type="password"
                  placeholder="••••••••"
                  value={formData.confirmPassword}
                  onChange={handleChange}
                  required
                  disabled={isLoading}
                />
              </div>

              {error && (
                <div className="p-3 rounded-md bg-destructive/10 text-destructive text-sm">
                  {error}
                </div>
              )}

              <Button type="submit" className="w-full" disabled={anyLoading}>
                {isLoading && <Loader2 className="h-4 w-4 mr-2 animate-spin" />}
                Create Account
              </Button>
            </form>

            <p className="text-center text-sm text-muted-foreground mt-6">
              Already have an account?{' '}
              <Link href={loginHref} className="text-primary hover:underline">
                Sign in
              </Link>
            </p>
          </CardContent>
        </Card>

        <p className="text-center text-xs text-muted-foreground mt-4">
          By continuing, you agree to our{' '}
          <Link href="/terms" className="underline hover:text-foreground">
            Terms of Service
          </Link>{' '}
          and{' '}
          <Link href="/privacy" className="underline hover:text-foreground">
            Privacy Policy
          </Link>
        </p>
      </div>
    </div>
  );
}