import { useState } from 'react';
import type { ReactElement, SyntheticEvent } from 'react';
import { ApiError } from '@altricade/core/api';
import { useSession } from '../../../entities/session';

type Mode = 'login' | 'register';

export const AuthForm = (): ReactElement => {
  const { login, register } = useSession();
  const [mode, setMode] = useState<Mode>('login');
  const [username, setUsername] = useState('');
  const [displayName, setDisplayName] = useState('');
  const [password, setPassword] = useState('');
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState(false);

  const submit = async (event: SyntheticEvent): Promise<void> => {
    event.preventDefault();
    setBusy(true);
    setError(null);
    try {
      if (mode === 'login') {
        await login({ username, password });
      } else {
        await register({ username, displayName, password });
      }
    } catch (caught) {
      setError(caught instanceof ApiError ? caught.message : 'Something went wrong');
    } finally {
      setBusy(false);
    }
  };

  return (
    <main className="auth">
      <div className="auth-card">
        <div className="auth-brand">
          <span className="auth-mark" aria-hidden="true">
            A
          </span>
          <h1 className="auth-wordmark">Altricade</h1>
          <p className="auth-tagline">
            {mode === 'login' ? 'Welcome back.' : 'Create your account.'}
          </p>
        </div>
        <form className="auth-form" onSubmit={(event) => void submit(event)}>
          <label className="field-label">
            Username
            <input
              className="field"
              placeholder="username"
              autoComplete="username"
              value={username}
              onChange={(event) => {
                setUsername(event.target.value);
              }}
            />
          </label>
          {mode === 'register' ? (
            <label className="field-label">
              Display name
              <input
                className="field"
                placeholder="Your name"
                value={displayName}
                onChange={(event) => {
                  setDisplayName(event.target.value);
                }}
              />
            </label>
          ) : null}
          <label className="field-label">
            Password
            <input
              className="field"
              type="password"
              placeholder="••••••••"
              autoComplete={mode === 'login' ? 'current-password' : 'new-password'}
              value={password}
              onChange={(event) => {
                setPassword(event.target.value);
              }}
            />
          </label>
          {error !== null ? <p className="form-error">{error}</p> : null}
          <button type="submit" className="btn-primary" disabled={busy}>
            {busy ? 'Please wait…' : mode === 'login' ? 'Log in' : 'Create account'}
          </button>
        </form>
        <p className="auth-switch">
          {mode === 'login' ? "Don't have an account?" : 'Already have an account?'}{' '}
          <button
            type="button"
            className="link"
            onClick={() => {
              setMode(mode === 'login' ? 'register' : 'login');
              setError(null);
            }}
          >
            {mode === 'login' ? 'Sign up' : 'Log in'}
          </button>
        </p>
      </div>
    </main>
  );
};