"use client";

import { useState } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { ActionButton } from "@/components/ui/action-button";
import { Alert, AlertDescription } from "@/components/ui/alert";
import { Button } from "@/components/ui/button";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import {
  Form,
  FormControl,
  FormField,
  FormItem,
  FormLabel,
  FormMessage,
} from "@/components/ui/form";
import { Input } from "@/components/ui/input";
import { useClientConfig } from "@/lib/clientConfig";
import { api } from "@/lib/trpc";
import { zodResolver } from "@hookform/resolvers/zod";
import { TRPCClientError } from "@trpc/client";
import { AlertCircle, UserX } from "lucide-react";
import { signIn } from "next-auth/react";
import { useForm } from "react-hook-form";
import { z } from "zod";

import { zSignUpSchema } from "@karakeep/shared/types/users";

const VERIFY_EMAIL_ERROR = "Please verify your email address before signing in";

export default function SignUpForm() {
  const form = useForm<z.infer<typeof zSignUpSchema>>({
    resolver: zodResolver(zSignUpSchema),
    defaultValues: {
      email: "",
      name: "",
      password: "",
      confirmPassword: "",
    },
  });
  const [errorMessage, setErrorMessage] = useState("");
  const router = useRouter();
  const clientConfig = useClientConfig();

  const createUserMutation = api.users.create.useMutation();

  if (
    clientConfig.auth.disableSignups ||
    clientConfig.auth.disablePasswordAuth
  ) {
    return (
      <Card className="w-full">
        <CardHeader className="text-center">
          <CardTitle className="text-2xl font-bold">
            Sign Up Unavailable
          </CardTitle>
          <CardDescription>
            Account registration is currently disabled
          </CardDescription>
        </CardHeader>
        <CardContent className="space-y-6">
          <div className="space-y-4">
            <Alert>
              <UserX className="h-4 w-4" />
              <AlertDescription>
                Signups are currently disabled. Please contact an administrator
                for access.
              </AlertDescription>
            </Alert>
            <Button asChild className="w-full">
              <Link href="/signin">Back to Sign In</Link>
            </Button>
          </div>
        </CardContent>
      </Card>
    );
  }

  return (
    <Card className="w-full">
      <CardHeader className="text-center">
        <CardTitle className="text-2xl font-bold">
          Create Your Account
        </CardTitle>
        <CardDescription>
          Join Karakeep to start organizing your bookmarks
        </CardDescription>
      </CardHeader>
      <CardContent className="space-y-6">
        <Form {...form}>
          <form
            onSubmit={form.handleSubmit(async (value) => {
              try {
                await createUserMutation.mutateAsync(value);
              } catch (e) {
                if (e instanceof TRPCClientError) {
                  setErrorMessage(e.message);
                }
                return;
              }
              const resp = await signIn("credentials", {
                redirect: false,
                email: value.email.trim(),
                password: value.password,
              });
              if (!resp || !resp.ok || resp.error) {
                if (resp?.error === VERIFY_EMAIL_ERROR) {
                  router.replace(
                    `/check-email?email=${encodeURIComponent(value.email.trim())}`,
                  );
                } else {
                  setErrorMessage(
                    resp?.error ?? "Hit an unexpected error while signing in",
                  );
                }
                return;
              }
              router.replace("/");
            })}
            className="space-y-4"
          >
            {errorMessage && (
              <Alert variant="destructive">
                <AlertCircle className="h-4 w-4" />
                <AlertDescription>{errorMessage}</AlertDescription>
              </Alert>
            )}

            <FormField
              control={form.control}
              name="name"
              render={({ field }) => (
                <FormItem>
                  <FormLabel>Full Name</FormLabel>
                  <FormControl>
                    <Input
                      type="text"
                      placeholder="Enter your full name"
                      {...field}
                    />
                  </FormControl>
                  <FormMessage />
                </FormItem>
              )}
            />

            <FormField
              control={form.control}
              name="email"
              render={({ field }) => (
                <FormItem>
                  <FormLabel>Email</FormLabel>
                  <FormControl>
                    <Input
                      type="email"
                      placeholder="Enter your email"
                      {...field}
                    />
                  </FormControl>
                  <FormMessage />
                </FormItem>
              )}
            />

            <FormField
              control={form.control}
              name="password"
              render={({ field }) => (
                <FormItem>
                  <FormLabel>Password</FormLabel>
                  <FormControl>
                    <Input
                      type="password"
                      placeholder="Create a password"
                      {...field}
                    />
                  </FormControl>
                  <FormMessage />
                </FormItem>
              )}
            />

            <FormField
              control={form.control}
              name="confirmPassword"
              render={({ field }) => (
                <FormItem>
                  <FormLabel>Confirm Password</FormLabel>
                  <FormControl>
                    <Input
                      type="password"
                      placeholder="Confirm your password"
                      {...field}
                    />
                  </FormControl>
                  <FormMessage />
                </FormItem>
              )}
            />

            <ActionButton
              type="submit"
              loading={
                form.formState.isSubmitting || createUserMutation.isPending
              }
              className="w-full"
            >
              Create Account
            </ActionButton>
          </form>
        </Form>

        <div className="text-center">
          <p className="text-sm text-gray-600">
            Already have an account?{" "}
            <Link
              href="/signin"
              className="font-medium text-blue-600 hover:text-blue-500"
            >
              Sign in
            </Link>
          </p>
        </div>
      </CardContent>
    </Card>
  );
}