"use client"

import { fetchWithAuth } from "@/lib/apiClient";
import { Button } from "@/components/ui/button"
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
import { ArrowLeft, Eye, EyeOff } from "lucide-react"
import Link from "next/link"
import { useState } from "react"
import { useRouter } from "next/navigation"
import { Logo } from "@/components/Logo"

export default function LoginPage() {
  const [showPassword, setShowPassword] = useState(false)
  const [email, setEmail] = useState("")
  const [password, setPassword] = useState("")
  const [error, setError] = useState("")
  const router = useRouter()

  const handleLogin = async (e: React.FormEvent) => {
    e.preventDefault()
    setError("")

    try {
      const res = await fetch("/api/auth/login", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ email, password })
      })

      const data = await res.json()

      if (data.success) {
        if (typeof window !== "undefined") {
          // Set auth_token cookie required by Next.js 16 proxy.ts middleware
          const cookieVal = data.role === "admin" ? "admin" : (data.token || "authenticated");
          document.cookie = `auth_token=${cookieVal}; path=/; max-age=2592000; SameSite=Lax`;

          localStorage.setItem("activeUserId", data.user_id || data.token);
          // Store the JWT as the active session token
          const sessionToken = data.token;
          localStorage.setItem("active_session_token", sessionToken);
          
          if (data.token && data.token !== "admin") {
            try {
              await fetchWithAuth(`/api/users/${data.user_id}/session`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ session_token: sessionToken })
              });
            } catch (e) {
              console.warn("Session update skipped", e);
            }
          }

          if (data.role === "admin") {
            window.location.href = "/admin";
          } else {
            window.location.href = "/dashboard";
          }
        }
      } else {
        setError(data.error || "Invalid email or password.")
      }
    } catch (err) {
      setError("An error occurred. Please try again.")
    }
  }

  return (
    <div className="min-h-screen bg-background flex flex-col items-center justify-center p-6 selection:bg-[var(--cyan-ai-20)]">
      <Link href="/" className="absolute top-8 left-8 text-muted-foreground hover:text-foreground flex items-center gap-2 transition-colors font-medium">
        <ArrowLeft size={16} /> Back to Home
      </Link>
      
      <div className="w-full max-w-md space-y-8 animate-in fade-in slide-in-from-bottom-8 duration-700">
        <div className="flex justify-center mb-8">
          <Logo href="/" className="w-72" imageClassName="object-contain" height={80} />
        </div>

        <Card className="border-border bg-secondary/10 backdrop-blur-xl shadow-2xl shadow-[var(--cyan-ai-10)] rounded-[2rem] overflow-hidden">
          <CardHeader className="text-center pb-2">
            <CardTitle className="text-2xl font-bold tracking-tight">Welcome back</CardTitle>
            <CardDescription className="text-muted-foreground">Enter your credentials to access your dashboard.</CardDescription>
          </CardHeader>
          <CardContent className="space-y-6 pt-4">
            <form onSubmit={handleLogin} className="space-y-6">
              <div className="space-y-4">
              <div className="space-y-2">
                <label className="text-sm font-bold text-foreground">Email</label>
                <input 
                  type="email" 
                  value={email}
                  onChange={(e) => setEmail(e.target.value)}
                  placeholder="student@example.com" 
                  suppressHydrationWarning
                  className="w-full bg-background border border-border rounded-xl px-4 py-3 text-sm focus:outline-none focus:ring-2 focus:ring-[var(--cyan-ai)] focus:border-transparent transition-all"
                />
              </div>
              <div className="space-y-2">
                <div className="flex items-center justify-between">
                  <label className="text-sm font-bold text-foreground">
                    Password
                  </label>
                  <Link href="/forgot-password" className="text-xs font-bold text-[var(--cyan-ai)] hover:text-[var(--cyan-ai-80)] transition-colors">Forgot password?</Link>
                </div>
                <div className="relative">
                  <input 
                    type={showPassword ? "text" : "password"} 
                    value={password}
                    onChange={(e) => setPassword(e.target.value)}
                    placeholder="••••••••" 
                    suppressHydrationWarning
                    className="w-full bg-background border border-border rounded-xl px-4 py-3 text-sm focus:outline-none focus:ring-2 focus:ring-[var(--cyan-ai)] focus:border-transparent transition-all pr-10"
                  />
                  <button 
                    type="button" 
                    onClick={() => setShowPassword(!showPassword)}
                    className="absolute right-3 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground transition-colors"
                  >
                    {showPassword ? <EyeOff size={16} /> : <Eye size={16} />}
                  </button>
                </div>
              </div>
              </div>

              {error && (
                <div className="p-3 bg-red-500/10 border border-red-500/20 rounded-xl text-red-500 text-sm font-medium text-center">
                  {error}
                </div>
              )}

              <Button type="submit" className="w-full rounded-xl h-12 font-bold text-base bg-foreground text-background hover:bg-foreground/90 transition-all shadow-[0_0_15px_-5px_var(--cyan-ai)]">
                Sign In
              </Button>
            </form>

          </CardContent>
        </Card>

        <p className="text-center text-sm text-muted-foreground font-medium">
          Don't have an account? <Link href="/signup" className="font-bold text-foreground hover:text-primary transition-colors">Sign up</Link>
        </p>
      </div>
    </div>
  )
}