'use client'

import Image from 'next/image'
import Link from 'next/link'
import { useEffect, useRef, useState } from 'react'
import { usePathname, useRouter, useSearchParams } from 'next/navigation'
import { useDashboardI18n } from '@/components/I18nProvider'
import PublicShell from '@/components/layout/PublicShell'
import { adminUrl, marketplaceUrl } from '@/lib/urls'
import { API_BASE, EMPLOYEE_PROFILE_KEY } from '@/lib/api'
import { toPublicDashboardPath } from '@/lib/dashboardPaths'

const DASHBOARD_LOGO_SRC = '/dashboard/rentalcardrive.png'

function notifyParent(message: Record<string, unknown>) {
  if (typeof window === 'undefined' || window.parent === window) return
  window.parent.postMessage(message, '*')
}

export default function SignInPageClient({ embedded = false }: { embedded?: boolean }) {
  const { language, theme, setLanguage, setTheme } = useDashboardI18n()
  const pathname = usePathname()
  const router = useRouter()
  const searchParams = useSearchParams()
  const requestedLanguage = searchParams.get('lang')
  const requestedTheme = searchParams.get('theme')
  const initializedFromQuery = useRef(false)
  const dict = {
    en: {
      brandName: 'Space Agency',
      title: 'Sign in',
      subtitle: 'Enter your credentials to access your account.',
      email: 'Email',
      password: 'Password',
      signIn: 'Sign in',
      signingIn: 'Signing in…',
      verify: 'Verify code',
      verifying: 'Verifying…',
      authCode: 'Authentication code',
      enterCode: 'Enter the 6-digit code from your authenticator app.',
      back: 'Back to credentials',
      forgotPassword: 'Forgot your password?',
      invalidCredentials: 'Invalid email or password.',
      passwordNotSet: 'No password set yet. Check your invitation email or use "Forgot your password?"',
      unexpectedError: 'Something went wrong. Please try again.',
    },
    fr: {
      brandName: 'Espace agence',
      title: 'Connexion',
      subtitle: 'Saisissez vos identifiants pour accéder à votre compte.',
      email: 'Email',
      password: 'Mot de passe',
      signIn: 'Connexion',
      signingIn: 'Connexion…',
      verify: 'Vérifier le code',
      verifying: 'Vérification…',
      authCode: "Code d'authentification",
      enterCode: "Entrez le code à 6 chiffres de votre application d'authentification.",
      back: 'Retour aux identifiants',
      forgotPassword: 'Mot de passe oublié ?',
      invalidCredentials: 'Adresse e-mail ou mot de passe invalide.',
      passwordNotSet: `Aucun mot de passe défini. Vérifiez votre e-mail d'invitation ou utilisez « Mot de passe oublié ? »`,
      unexpectedError: 'Une erreur est survenue. Veuillez réessayer.',
    },
    ar: {
      brandName: 'مساحة الوكالة',
      title: 'تسجيل الدخول',
      subtitle: 'أدخل بياناتك للوصول إلى حسابك.',
      email: 'البريد الإلكتروني',
      password: 'كلمة المرور',
      signIn: 'تسجيل الدخول',
      signingIn: 'جارٍ تسجيل الدخول…',
      verify: 'تحقق من الرمز',
      verifying: 'جارٍ التحقق…',
      authCode: 'رمز المصادقة',
      enterCode: 'أدخل الرمز المكون من 6 أرقام من تطبيق المصادقة.',
      back: 'العودة إلى بيانات الدخول',
      forgotPassword: 'نسيت كلمة المرور؟',
      invalidCredentials: 'البريد الإلكتروني أو كلمة المرور غير صحيحة.',
      passwordNotSet: 'لم يتم تعيين كلمة مرور بعد. تحقق من بريد الدعوة أو استخدم "نسيت كلمة المرور؟"',
      unexpectedError: 'حدث خطأ ما. يرجى المحاولة مرة أخرى.',
    },
  }[language]

  useEffect(() => {
    if (initializedFromQuery.current) return

    if (
      (requestedLanguage === 'en' || requestedLanguage === 'fr' || requestedLanguage === 'ar') &&
      requestedLanguage !== language
    ) {
      setLanguage(requestedLanguage)
    }

    if (
      (requestedTheme === 'light' || requestedTheme === 'dark') &&
      requestedTheme !== theme
    ) {
      setTheme(requestedTheme)
    }

    initializedFromQuery.current = true
  }, [language, requestedLanguage, requestedTheme, setLanguage, setTheme, theme])

  useEffect(() => {
    if (!initializedFromQuery.current) return

    const params = new URLSearchParams(searchParams.toString())
    let changed = false

    if (params.get('lang') !== language) {
      params.set('lang', language)
      changed = true
    }

    if (params.get('theme') !== theme) {
      params.set('theme', theme)
      changed = true
    }

    // useSearchParams() can return empty params during hydration without a Suspense boundary.
    // Always preserve embedded=1 when the component was server-rendered as embedded so
    // the router.replace doesn't strip it and trigger an unintended redirect.
    if (embedded && params.get('embedded') !== '1') {
      params.set('embedded', '1')
      changed = true
    }

    if (!changed) return

    const nextQuery = params.toString()
    router.replace(nextQuery ? `${pathname}?${nextQuery}` : pathname, { scroll: false })
  }, [embedded, language, pathname, router, searchParams, theme])

  useEffect(() => {
    const currentPath = window.location.pathname + (window.location.search || '')
    notifyParent({ type: 'rentaldrivego:embedded-path', path: currentPath })
  }, [pathname, searchParams])

  return (
    <PublicShell embedded={embedded}>
      <main className="flex flex-1 items-center justify-center px-4 py-12">
        <div className="w-full max-w-md">
          <div className="mb-8 text-center">
            <div className="flex justify-center">
              <a href={marketplaceUrl} target="_top">
                <Image
                  src={DASHBOARD_LOGO_SRC}
                  alt="RentalDriveGo"
                  width={104}
                  height={104}
                  priority
                  className="h-24 w-24 rounded-[1.75rem] border border-stone-200/80 bg-white/85 p-1.5 shadow-sm transition-colors dark:border-blue-800 dark:bg-blue-950/80"
                />
              </a>
            </div>
            <p className="mt-5 text-xs font-bold uppercase tracking-[0.28em] text-orange-700 dark:text-orange-300">
              RentalDriveGo
            </p>
            <h1 className="mt-3 text-3xl font-black tracking-[-0.03em] text-blue-950 dark:text-stone-50">
              {dict.brandName}
            </h1>
            <p className="mt-2 text-sm text-stone-600 dark:text-stone-300">
              {dict.subtitle}
            </p>
            <div className="mt-4 flex items-center justify-center gap-2">
              {(['en', 'fr', 'ar'] as const).map((lang) => (
                <button
                  key={lang}
                  type="button"
                  onClick={() => setLanguage(lang)}
                  className={`rounded-full px-3 py-1 text-xs font-semibold uppercase tracking-wider transition-colors text-orange-700 dark:text-orange-300 ${
                    language === lang
                      ? 'ring-1 ring-current opacity-100'
                      : 'opacity-45 hover:opacity-80'
                  }`}
                >
                  {lang}
                </button>
              ))}
            </div>
          </div>

          <section className="rounded-[2rem] border border-stone-200/80 bg-white/82 p-8 shadow-[0_30px_80px_rgba(28,25,23,0.08)] backdrop-blur transition-colors dark:border-blue-900 dark:bg-blue-950/78 dark:shadow-[0_30px_80px_rgba(0,0,0,0.26)]">
            <LocalSignInForm dict={dict} />
          </section>
        </div>
      </main>
    </PublicShell>
  )
}

function LocalSignInForm({
  dict,
}: {
  dict: {
    email: string
    password: string
    signIn: string
    signingIn: string
    verify: string
    verifying: string
    authCode: string
    enterCode: string
    back: string
    forgotPassword: string
    invalidCredentials: string
    passwordNotSet: string
    unexpectedError: string
  }
}) {
  const searchParams = useSearchParams()
  const { setLanguage } = useDashboardI18n()
  const [email, setEmail] = useState('')
  const [password, setPassword] = useState('')
  const [totpCode, setTotpCode] = useState('')
  const [step, setStep] = useState<'credentials' | 'totp'>('credentials')
  const [showPassword, setShowPassword] = useState(false)
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)
  const adminNext = searchParams.get('next') || '/dashboard'
  const employeeRedirect = searchParams.get('redirect') || '/dashboard'

  function redirectAdmin(token: string) {
    const hash = new URLSearchParams({ token, next: adminNext }).toString()
    window.location.href = `${adminUrl}/auth-redirect#${hash}`
  }

  async function handleCredentials(e: React.FormEvent) {
    e.preventDefault()
    setLoading(true)
    setError(null)

    try {
      const empRes = await fetch(`${API_BASE}/auth/employee/login`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({ email, password }),
      })
      const empJson = await empRes.json()

      if (empRes.ok && empJson?.data?.employee) {
        const targetPath = toPublicDashboardPath(employeeRedirect)
        if (empJson?.data?.employee) {
          localStorage.setItem(EMPLOYEE_PROFILE_KEY, JSON.stringify(empJson.data.employee))
          const prefLang = empJson.data.employee?.preferredLanguage
          if (prefLang === 'en' || prefLang === 'fr' || prefLang === 'ar') {
            setLanguage(prefLang)
            document.cookie = `rentaldrivego-language=${prefLang}; path=/; max-age=31536000; samesite=lax`
          }
        }
        window.dispatchEvent(new CustomEvent('rentaldrivego:auth-changed'))
        notifyParent({ type: 'rentaldrivego:employee-login', path: targetPath })
        // Use a document navigation here so the authenticated dashboard bootstraps
        // from a fresh request after the token cookie and localStorage are set.
        window.location.replace(targetPath)
        return
      }

      if (empJson?.error === 'password_not_set') {
        setError(dict.passwordNotSet)
        return
      }

      const adminRes = await fetch(`${API_BASE}/admin/auth/login`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({ email, password }),
      })
      const adminJson = await adminRes.json()

      if (adminRes.ok && adminJson?.data?.admin) {
        window.location.href = `${adminUrl}/dashboard`
        return
      }

      if (adminRes.status === 401 && adminJson?.error === 'totp_required') {
        setStep('totp')
        return
      }

      setError(dict.invalidCredentials)
    } catch {
      setError(dict.unexpectedError)
    } finally {
      setLoading(false)
    }
  }

  async function handleTotp(e: React.FormEvent) {
    e.preventDefault()
    setLoading(true)
    setError(null)

    try {
      const normalizedCode = totpCode.trim().toUpperCase()
      const secondFactor = /^\d{6}$/.test(normalizedCode)
        ? { totpCode: normalizedCode }
        : { recoveryCode: normalizedCode }

      const adminRes = await fetch(`${API_BASE}/admin/auth/login`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({ email, password, ...secondFactor }),
      })
      const adminJson = await adminRes.json()

      if (adminRes.ok && adminJson?.data?.admin) {
        window.location.href = `${adminUrl}/dashboard`
        return
      }

      setError(dict.invalidCredentials)
    } catch {
      setError(dict.unexpectedError)
    } finally {
      setLoading(false)
    }
  }

  return (
    <>
      {error ? (
        <div className="mb-5 rounded-[1.5rem] border border-red-200/80 bg-red-50/90 px-4 py-3 text-sm text-red-700 dark:border-red-900/60 dark:bg-red-950/40 dark:text-red-300">
          {error}
        </div>
      ) : null}

      {step === 'credentials' ? (
        <form onSubmit={handleCredentials} className="space-y-5">
          <div>
            <label className="mb-1.5 block text-sm font-medium text-stone-700 dark:text-stone-200">{dict.email}</label>
            <input
              type="email"
              required
              value={email}
              onChange={(e) => setEmail(e.target.value)}
              placeholder="owner@company.com"
              className="w-full rounded-2xl border border-stone-200 bg-white px-4 py-3 text-sm text-stone-900 transition-colors placeholder:text-stone-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-orange-500 dark:border-blue-800 dark:bg-blue-950/80 dark:text-stone-100 dark:placeholder:text-stone-500"
            />
          </div>

          <div>
            <label className="mb-1.5 block text-sm font-medium text-stone-700 dark:text-stone-200">{dict.password}</label>
            <div className="relative">
              <input
                type={showPassword ? 'text' : 'password'}
                required
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                placeholder="••••••••"
                className="w-full rounded-2xl border border-stone-200 bg-white px-4 py-3 pr-10 text-sm text-stone-900 transition-colors placeholder:text-stone-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-orange-500 dark:border-blue-800 dark:bg-blue-950/80 dark:text-stone-100 dark:placeholder:text-stone-500"
              />
              <button
                type="button"
                onClick={() => setShowPassword((v) => !v)}
                className="absolute inset-y-0 right-3 flex items-center text-stone-400 hover:text-stone-700 dark:text-stone-500 dark:hover:text-stone-200"
                tabIndex={-1}
              >
                {showPassword ? (
                  <svg xmlns="http://www.w3.org/2000/svg" className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
                    <path strokeLinecap="round" strokeLinejoin="round" d="M13.875 18.825A10.05 10.05 0 0112 19c-4.478 0-8.268-2.943-9.543-7a9.97 9.97 0 011.563-3.029m5.858.908a3 3 0 114.243 4.243M9.878 9.878l4.242 4.242M9.88 9.88l-3.29-3.29m7.532 7.532l3.29 3.29M3 3l3.59 3.59m0 0A9.953 9.953 0 0112 5c4.478 0 8.268 2.943 9.543 7a10.025 10.025 0 01-4.132 5.411m0 0L21 21" />
                  </svg>
                ) : (
                  <svg xmlns="http://www.w3.org/2000/svg" className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
                    <path strokeLinecap="round" strokeLinejoin="round" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
                    <path strokeLinecap="round" strokeLinejoin="round" d="M2.458 12C3.732 7.943 7.523 5 12 5c4.478 0 8.268 2.943 9.542 7-1.274 4.057-5.064 7-9.542 7-4.477 0-8.268-2.943-9.542-7z" />
                  </svg>
                )}
              </button>
            </div>
          </div>

          <button
            type="submit"
            disabled={loading}
            className="inline-flex w-full justify-center rounded-full bg-orange-600 px-6 py-3 text-sm font-semibold text-white transition hover:bg-orange-700 disabled:cursor-not-allowed disabled:opacity-60 dark:bg-orange-400 dark:text-white dark:hover:bg-orange-300"
          >
            {loading ? dict.signingIn : dict.signIn}
          </button>

          <div className="text-center">
            <Link href="/forgot-password" className="text-sm text-stone-500 underline decoration-stone-300 underline-offset-4 hover:text-stone-900 dark:text-stone-400 dark:decoration-stone-600 dark:hover:text-stone-100">
              {dict.forgotPassword}
            </Link>
          </div>
        </form>
      ) : (
        <form onSubmit={handleTotp} className="space-y-5">
          <div className="rounded-[1.5rem] border border-stone-200/80 bg-stone-50/90 px-4 py-4 text-center text-sm text-stone-600 dark:border-blue-800 dark:bg-blue-950/50 dark:text-stone-300">
            {dict.enterCode}
          </div>

          <div>
            <label className="mb-1.5 block text-sm font-medium text-stone-700 dark:text-stone-200">{dict.authCode}</label>
            <input
              type="text"
              inputMode="text"
              pattern="[0-9A-Za-z-]{6,14}"
              maxLength={14}
              required
              value={totpCode}
              onChange={(e) => setTotpCode(e.target.value.replace(/[^0-9A-Za-z-]/g, '').toUpperCase())}
              placeholder="000000 or XXXX-XXXX-XXXX"
              className="w-full rounded-2xl border border-stone-200 bg-white px-4 py-3 text-center text-xl tracking-[0.45em] text-stone-900 transition-colors placeholder:text-stone-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-orange-500 dark:border-blue-800 dark:bg-blue-950/80 dark:text-stone-100 dark:placeholder:text-stone-500"
            />
          </div>

          <button
            type="submit"
            disabled={loading}
            className="inline-flex w-full justify-center rounded-full bg-orange-600 px-6 py-3 text-sm font-semibold text-white transition hover:bg-orange-700 disabled:cursor-not-allowed disabled:opacity-60 dark:bg-orange-400 dark:text-white dark:hover:bg-orange-300"
          >
            {loading ? dict.verifying : dict.verify}
          </button>

          <button
            type="button"
            onClick={() => {
              setStep('credentials')
              setTotpCode('')
              setError(null)
            }}
            className="w-full text-sm text-stone-500 hover:text-stone-900 dark:text-stone-400 dark:hover:text-stone-100"
          >
            {dict.back}
          </button>
        </form>
      )}
    </>
  )
}