import type { ActionArgs, LoaderArgs, MetaFunction } from '@remix-run/node';
import { json, redirect } from '@remix-run/node';
import {
  Form,
  Link,
  useActionData,
  useLoaderData,
  useSearchParams
} from '@remix-run/react';
import * as React from 'react';
import {
  TextInput,
  Box,
  Group,
  Button,
  PasswordInput,
  Text,
  Title,
  Popover,
  Progress
} from '@mantine/core';
import { AtSign, Check, Lock, X } from 'react-feather';
import { createUserSession, getUserId } from '~/session.server';
import { countUsers, createUser, getUserByEmail } from '~/models/user.server';
import { safeRedirect, validateEmail } from '~/utils';
import { isSignupAllowed } from '~/config.server';

export async function loader({ request }: LoaderArgs) {
  const userId = await getUserId(request);
  if (userId) return redirect('/time-entries');

  const isFirstUser = (await countUsers()) === 0;

  if (!(await isSignupAllowed())) {
    return redirect('/login');
  }

  return json({
    isFirstUser
  });
}

export async function action({ request }: ActionArgs) {
  const isFirstUser = (await countUsers()) === 0;

  if (!isSignupAllowed() && !isFirstUser) {
    return json(
      {
        errors: {
          email: 'User signup is disabled',
          password: null,
          confirmPassword: null
        }
      },
      { status: 418 }
    );
  }

  const formData = await request.formData();
  const email = formData.get('email');
  const password = formData.get('password');
  const confirmPassword = formData.get('confirmPassword');
  const redirectTo = safeRedirect(formData.get('redirectTo'), '/');

  if (!validateEmail(email)) {
    return json(
      {
        errors: {
          email: 'Email is invalid',
          password: null,
          confirmPassword: null
        }
      },
      { status: 400 }
    );
  }

  if (typeof password !== 'string' || password.length === 0) {
    return json(
      {
        errors: {
          email: null,
          password: 'Password is required',
          confirmPassword: null
        }
      },
      { status: 400 }
    );
  }

  if (password.length < 8) {
    return json(
      {
        errors: {
          email: null,
          password: 'Password is too short',
          confirmPassword: null
        }
      },
      { status: 400 }
    );
  }

  if (password !== confirmPassword) {
    return json(
      {
        errors: {
          email: null,
          password: 'Passwords do not match',
          confirmPassword: 'Passwords do not match'
        }
      },
      { status: 400 }
    );
  }

  const existingUser = await getUserByEmail(email);
  if (existingUser) {
    return json(
      {
        errors: {
          email: 'A user already exists with this email',
          password: null,
          confirmPassword: null
        }
      },
      { status: 400 }
    );
  }

  const user = await createUser(email, password, isFirstUser);

  return createUserSession({
    request,
    userId: user.id,
    remember: false,
    redirectTo
  });
}

export const meta: MetaFunction = () => {
  return {
    title: 'Sign Up | WorkTimer',
    description:
      'WorkTimer is a time tracking app. Helps you track your time spent on projects.'
  };
};

function PasswordRequirement({
  meets,
  label
}: {
  meets: boolean;
  label: string;
}) {
  return (
    <Text
      color={meets ? 'teal' : 'red'}
      sx={{ display: 'flex', alignItems: 'center' }}
      mt={7}
      size="sm"
    >
      {meets ? <Check size={14} /> : <X size={14} />} <Box ml={10}>{label}</Box>
    </Text>
  );
}

const requirements = [
  { re: /[0-9]/, label: 'Includes number' },
  { re: /[a-z]/, label: 'Includes lowercase letter' },
  { re: /[A-Z]/, label: 'Includes uppercase letter' },
  { re: /[$&+,:;=?@#|'<>.^*()%!-]/, label: 'Includes special symbol' }
];

function getStrength(password: string) {
  let multiplier = password.length > 7 ? 0 : 1;

  requirements.forEach((requirement) => {
    if (!requirement.re.test(password)) {
      multiplier += 1;
    }
  });

  return Math.max(100 - (100 / (requirements.length + 1)) * multiplier, 10);
}

export default function SignUpPage() {
  const [searchParams] = useSearchParams();
  const redirectTo = searchParams.get('redirectTo') ?? undefined;
  const loaderData = useLoaderData<typeof loader>();
  const actionData = useActionData<typeof action>();
  const emailRef = React.useRef<HTMLInputElement>(null);
  const passwordRef = React.useRef<HTMLInputElement>(null);

  const [popoverOpened, setPopoverOpened] = React.useState(false);
  const [password, setPassword] = React.useState('');
  const checks = requirements.map((requirement, index) => (
    <PasswordRequirement
      key={index}
      label={requirement.label}
      meets={requirement.re.test(password)}
    />
  ));

  const strength = getStrength(password);
  const color = strength === 100 ? 'teal' : strength > 50 ? 'yellow' : 'red';

  React.useEffect(() => {
    if (actionData?.errors?.email) {
      emailRef.current?.focus();
    } else if (actionData?.errors?.password) {
      passwordRef.current?.focus();
    }
  }, [actionData]);

  return (
    <Box sx={{ maxWidth: 300 }} mx="auto">
      <Title order={2} my="lg">
        Sign up
      </Title>
      <Form method="post" noValidate>
        <TextInput
          mb={12}
          withAsterisk
          label="Email address"
          placeholder="your@email.com"
          icon={<AtSign size={16} />}
          id="email"
          ref={emailRef}
          required
          autoFocus={true}
          name="email"
          type="email"
          autoComplete="email"
          aria-invalid={actionData?.errors?.email ? true : undefined}
          error={actionData?.errors?.email}
          errorProps={{ children: actionData?.errors?.email }}
        />

        <Popover
          opened={popoverOpened}
          position="bottom"
          width="target"
          transition="pop"
        >
          <Popover.Target>
            <div
              onFocusCapture={() => setPopoverOpened(true)}
              onBlurCapture={() => setPopoverOpened(false)}
            >
              <PasswordInput
                mb={12}
                withAsterisk
                required
                label="Password"
                id="password"
                ref={passwordRef}
                placeholder="********"
                icon={<Lock size={16} />}
                name="password"
                type="password"
                autoComplete="new-password"
                value={password}
                onChange={(event) => setPassword(event.target.value)}
                aria-invalid={actionData?.errors?.password ? true : undefined}
                error={actionData?.errors?.password ? true : undefined}
                errorProps={{ children: actionData?.errors?.password }}
              />
            </div>
          </Popover.Target>
          <Popover.Dropdown>
            <Progress
              color={color}
              value={strength}
              size={5}
              style={{ marginBottom: 10 }}
            />
            <PasswordRequirement
              label="Includes at least 8 characters"
              meets={password.length > 7}
            />
            {checks}
          </Popover.Dropdown>
        </Popover>

        <PasswordInput
          mb={12}
          withAsterisk
          required
          label="Confirm password"
          id="confirm-password"
          ref={passwordRef}
          placeholder="********"
          icon={<Lock size={16} />}
          name="confirmPassword"
          type="password"
          autoComplete="new-password"
          aria-invalid={actionData?.errors?.confirmPassword ? true : undefined}
          error={actionData?.errors?.confirmPassword ? true : undefined}
          errorProps={{ children: actionData?.errors?.confirmPassword }}
        />

        <input type="hidden" name="redirectTo" value={redirectTo} />

        <Group position="center" mt="xl">
          <Button type="submit">Create account</Button>
        </Group>

        {!loaderData.isFirstUser && (
          <Box
            mt="md"
            sx={{
              textAlign: 'center'
            }}
          >
            Already have an account?{' '}
            <Link to="/login">
              <strong>Log in</strong>
            </Link>
          </Box>
        )}
      </Form>
    </Box>
  );
}