'use client'

import { useEffect, useState, type FormEvent } from 'react'
import { getApiBase, setToken } from '../lib/auth'
import AuthLayout from '../ui/AuthLayout'

type LoginMode = 'jellyfin' | 'local'
type LoginOptions = { showJellyfinLogin: boolean; showLocalLogin: boolean; showForgotPassword: boolean; showSignupLink: boolean }
const DEFAULT_OPTIONS: LoginOptions = { showJellyfinLogin: true, showLocalLogin: true, showForgotPassword: true, showSignupLink: true }

export default function LoginPage() {
  const [username, setUsername] = useState('')
  const [password, setPassword] = useState('')
  const [showPassword, setShowPassword] = useState(false)
  const [mode, setMode] = useState<LoginMode>('jellyfin')
  const [options, setOptions] = useState<LoginOptions>(DEFAULT_OPTIONS)
  const [optionsReady, setOptionsReady] = useState(false)
  const [banner, setBanner] = useState<{ message: string; tone: string } | null>(null)
  const [error, setError] = useState('')
  const [loading, setLoading] = useState(false)
  const canSignIn = options.showJellyfinLogin || options.showLocalLogin
  const selectedMode: LoginMode = mode === 'jellyfin' && options.showJellyfinLogin ? 'jellyfin' : options.showLocalLogin ? 'local' : 'jellyfin'

  useEffect(() => {
    const controller = new AbortController()
    const load = async () => {
      try {
        const response = await fetch(`${getApiBase()}/site/public`, { signal: controller.signal })
        if (!response.ok) throw new Error('Options unavailable')
        const data = await response.json()
        if (controller.signal.aborted) return
        setOptions({
          showJellyfinLogin: data?.login?.showJellyfinLogin !== false,
          showLocalLogin: data?.login?.showLocalLogin !== false,
          showForgotPassword: data?.login?.showForgotPassword !== false,
          showSignupLink: data?.login?.showSignupLink !== false,
        })
        if (data?.banner?.enabled && typeof data.banner.message === 'string' && data.banner.message.trim().toLowerCase() !== 'beta environment') {
          setBanner({ message: data.banner.message, tone: data.banner.tone || 'info' })
        }
      } catch {
        // Keep the normal sign-in methods available during a settings outage.
      } finally {
        if (!controller.signal.aborted) setOptionsReady(true)
      }
    }
    void load()
    return () => controller.abort()
  }, [])

  const submit = async (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault()
    if (loading || !canSignIn || !optionsReady) return
    setError('')
    setLoading(true)
    try {
      const response = await fetch(`${getApiBase()}${selectedMode === 'jellyfin' ? '/auth/jellyfin/login' : '/auth/login'}`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
        body: new URLSearchParams({ username: username.trim(), password }),
        credentials: 'include',
      })
      if (!response.ok) {
        setError(response.status === 429 ? 'Too many attempts. Please wait a moment and try again.'
          : response.status >= 500 ? 'Sign-in is temporarily unavailable. Please try again shortly.'
          : response.status === 403 ? 'This account cannot sign in. Please contact an administrator.'
          : 'Check your username and password, then try again.')
        return
      }
      const data = await response.json()
      if (!data?.authenticated) { setError('Could not sign in. Please try again.'); return }
      setToken('cookie')
      const next = new URLSearchParams(window.location.search).get('next') || ''
      window.location.assign(/^\/issues\/confirm\/\d+$/.test(next) ? next : '/welcome')
    } catch {
      setError('Could not reach Magent. Check your connection and try again.')
    } finally { setLoading(false) }
  }

  return (
    <AuthLayout title="Welcome back." description="Sign in to your media workspace." footer={
      optionsReady && options.showSignupLink && <>Have an invite? <a href="/signup">Create an account <span aria-hidden="true">↗</span></a></>
    }>
        {banner && <p className={`account-notice ${['error', 'maintenance'].includes(banner.tone) ? 'is-error' : 'is-status'}`} role="status">{banner.message}</p>}
        {optionsReady && options.showJellyfinLogin && options.showLocalLogin && <div className="login-methods" role="group" aria-label="Sign-in account">
          <button type="button" aria-pressed={selectedMode === 'jellyfin'} disabled={loading} onClick={() => { setMode('jellyfin'); setError('') }}>Grizzlyflix</button>
          <button type="button" aria-pressed={selectedMode === 'local'} disabled={loading} onClick={() => { setMode('local'); setError('') }}>Magent</button>
        </div>}
        {!optionsReady ? <p className="account-hint" role="status">Loading sign-in…</p> : !canSignIn ? <p className="account-notice is-error" role="alert">Sign-in is currently unavailable. Please contact an administrator.</p> : (
          <form className="account-form login-form" onSubmit={submit}>
            <p className="login-method-help">{selectedMode === 'jellyfin' ? 'Use your Grizzlyflix / Jellyfin account.' : 'Use your Magent account.'}</p>
            <label htmlFor="login-username">Username</label>
            <input id="login-username" name="username" value={username} onChange={(event) => setUsername(event.target.value)} autoComplete="username" autoCapitalize="none" spellCheck={false} required disabled={loading} />
            <div className="login-password-label"><label htmlFor="login-password">Password</label>{options.showForgotPassword && <a href="/forgot-password">Forgot password?</a>}</div>
            <div className="login-password-field">
              <input id="login-password" name="password" type={showPassword ? 'text' : 'password'} value={password} onChange={(event) => setPassword(event.target.value)} autoComplete="current-password" required disabled={loading} />
              <button type="button" className="password-visibility" aria-label={showPassword ? 'Hide password' : 'Show password'} aria-pressed={showPassword} onClick={() => setShowPassword(!showPassword)}>
                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.7" aria-hidden="true"><path d="M2 12s3.5-7 10-7 10 7 10 7-3.5 7-10 7S2 12 2 12Z" /><circle cx="12" cy="12" r="3" />{showPassword && <path d="m3 3 18 18" />}</svg>
              </button>
            </div>
            {error && <p className="account-notice is-error" role="alert">{error}</p>}
            <button type="submit" className="account-primary login-submit" disabled={loading}>{loading ? 'Signing in…' : 'Sign in'}<span aria-hidden="true">→</span></button>
          </form>
        )}
    </AuthLayout>
  )
}