"use client"

import { useState } from "react"
import { getSession, signIn } from "next-auth/react"
import { useRouter } from "next/navigation"
import { AlertCircle, Eye, EyeOff, ShieldCheck } from "lucide-react"

import { Button } from "@/components/ui/button"
import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"
import { ThemeToggle } from "@/components/theme-toggle"
import { useAppName } from "@/components/providers/app-config-provider"

export default function SignInPage() {
  const appName = useAppName()

  const [email, setEmail] = useState("")
  const [password, setPassword] = useState("")
  const [showPassword, setShowPassword] = useState(false)
  const [isLoading, setIsLoading] = useState(false)
  const [error, setError] = useState("")
  const router = useRouter()

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    setIsLoading(true)
    setError("")

    try {
      const result = await signIn("credentials", {
        email,
        password,
        redirect: false,
      })

      if (result?.error) {
        setError("Ungültige Anmeldedaten")
      } else {
        const session = await getSession()
        if (session) {
          router.push("/admin")
          router.refresh()
        }
      }
    } catch {
      setError("Ein Fehler ist aufgetreten")
    } finally {
      setIsLoading(false)
    }
  }

  return (
    <div className="flex min-h-screen flex-col bg-background">
      <div className="flex justify-end p-4">
        <ThemeToggle />
      </div>

      <main className="flex flex-1 items-center justify-center px-6 pb-20">
        <div className="w-full max-w-sm space-y-6">
          <div className="flex flex-col items-center gap-3 text-center">
            <div className="flex size-11 items-center justify-center rounded-xl bg-brand text-brand-foreground">
              <ShieldCheck className="size-6" />
            </div>
            <div className="space-y-1.5">
              <h1 className="text-xl leading-none font-semibold tracking-tight">
                {appName}
              </h1>
              <p className="text-sm text-muted-foreground">
                Anmeldung zum Admin-Portal
              </p>
            </div>
          </div>

          <form onSubmit={handleSubmit} className="space-y-4">
            {error && (
              <div className="flex items-center gap-2.5 rounded-lg border border-destructive/30 bg-destructive/5 p-3 text-sm text-destructive">
                <AlertCircle className="size-4 shrink-0" />
                {error}
              </div>
            )}

            <div className="space-y-2">
              <Label htmlFor="email">E-Mail-Adresse</Label>
              <Input
                id="email"
                type="email"
                autoComplete="username"
                value={email}
                onChange={(e) => setEmail(e.target.value)}
                placeholder="name@firma.de"
                required
                disabled={isLoading}
              />
            </div>

            <div className="space-y-2">
              <Label htmlFor="password">Passwort</Label>
              <div className="relative">
                <Input
                  id="password"
                  type={showPassword ? "text" : "password"}
                  autoComplete="current-password"
                  value={password}
                  onChange={(e) => setPassword(e.target.value)}
                  placeholder="••••••••"
                  required
                  disabled={isLoading}
                  className="pr-10"
                />
                <Button
                  type="button"
                  variant="ghost"
                  size="icon-sm"
                  className="absolute top-1/2 right-0.5 -translate-y-1/2 text-muted-foreground"
                  onClick={() => setShowPassword(!showPassword)}
                  disabled={isLoading}
                >
                  {showPassword ? <EyeOff /> : <Eye />}
                  <span className="sr-only">Passwort anzeigen</span>
                </Button>
              </div>
            </div>

            <Button type="submit" className="w-full" disabled={isLoading}>
              {isLoading ? "Anmeldung…" : "Anmelden"}
            </Button>
          </form>

          <p className="text-center text-xs text-muted-foreground">
            Zugang nur für berechtigte Administratoren
          </p>
        </div>
      </main>
    </div>
  )
}