// frontend/app/page.jsx
'use client';

import { useEffect, useState } from 'react';
import Link from 'next/link';
import { useRouter } from 'next/navigation';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Tabs, TabsList, TabsTrigger, TabsContent } from '@/components/ui/tabs';
import {
  Dialog, DialogTrigger, DialogContent, DialogHeader, DialogTitle, DialogDescription,
} from '@/components/ui/dialog';
import { Label } from '@/components/ui/label';
import { Input } from '@/components/ui/input';
import { login as authLogin, logout as authLogout, me as fetchMe, credentials, authHeaders } from '@/app/_auth/client';

export default function HomePage() {
  const router = useRouter();
  const [me, setMe] = useState(null);
  const [loading, setLoading] = useState(true);

  // login dialog states
  const [open, setOpen] = useState(false);
  const [username, setUsername] = useState('');
  const [password, setPassword] = useState('');
  const [submitting, setSubmitting] = useState(false);
  const [err, setErr] = useState('');

  // โหลดสถานะผู้ใช้แบบไม่ redirect
  useEffect(() => {
    let cancelled = false;
    (async () => {
      try {
        const user = await fetchMe();
        if (!cancelled) setMe(user);
      } finally {
        if (!cancelled) setLoading(false);
      }
    })();
    return () => { cancelled = true; };
  }, []);

  async function handleLogin(e) {
    e?.preventDefault();
    setSubmitting(true);
    setErr('');
    try {
      const user = await authLogin({ username, password });
      if (!user) {
        setErr('ชื่อผู้ใช้หรือรหัสผ่านไม่ถูกต้อง');
        return;
      }
      setMe(user);
      setOpen(false);
      router.push('/dashboard');
    } catch {
      setErr('เกิดข้อผิดพลาดในการเชื่อมต่อเซิร์ฟเวอร์');
    } finally {
      setSubmitting(false);
    }
  }

  async function handleLogout() {
    await authLogout().catch(() => {});
    setMe(null);
  }

  if (loading) {
    return (
      <div className="space-y-6">
        <div className="w-56 rounded h-7 bg-muted animate-pulse" />
        <div className="grid gap-4 md:grid-cols-3">
          {[...Array(3)].map((_, i) => <div key={i} className="rounded h-28 bg-muted animate-pulse" />)}
        </div>
      </div>
    );
  }

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <h2 className="text-2xl font-bold">Welcome to DMS</h2>

        {/* แถบสถานะล็อกอิน + ปุ่ม */}
        <div className="flex items-center gap-2">
          {me ? (
            <>
              <span className="text-sm text-muted-foreground">สวัสดี, <b>{me.first_name || me.username}</b></span>
              <Button variant="secondary" onClick={() => router.push('/dashboard')}>Go to Dashboard</Button>
              <Button variant="outline" onClick={handleLogout}>Logout</Button>
            </>
          ) : (
            <Dialog open={open} onOpenChange={setOpen}>
              <DialogTrigger asChild>
                <Button>Login</Button>
              </DialogTrigger>
              <DialogContent className="sm:max-w-[420px]">
                <DialogHeader>
                  <DialogTitle>เข้าสู่ระบบ</DialogTitle>
                  <DialogDescription>กรอกชื่อผู้ใช้และรหัสผ่านของคุณ</DialogDescription>
                </DialogHeader>
                <form onSubmit={handleLogin} className="grid gap-3">
                  <div className="grid gap-1.5">
                    <Label htmlFor="username">Username</Label>
                    <Input id="username" value={username} onChange={e => setUsername(e.target.value)} required />
                  </div>
                  <div className="grid gap-1.5">
                    <Label htmlFor="password">Password</Label>
                    <Input id="password" type="password" value={password} onChange={e => setPassword(e.target.value)} required />
                  </div>
                  {err && <p className="text-sm text-red-600">{err}</p>}
                  <Button type="submit" disabled={submitting}>{submitting ? 'กำลังเข้าสู่ระบบ...' : 'Login'}</Button>
                </form>
              </DialogContent>
            </Dialog>
          )}
        </div>
      </div>

      {/* เนื้อหาอื่น ๆ (เหมือนเดิม) */}
      <Tabs defaultValue="overview" className="w-full">
        <TabsList>
          <TabsTrigger value="overview">Overview</TabsTrigger>
          <TabsTrigger value="activity">Activity</TabsTrigger>
        </TabsList>

        <TabsContent value="overview">
          <div className="grid gap-4 mt-4 md:grid-cols-3">
            <Card><CardHeader><CardTitle>📑 RFAs</CardTitle></CardHeader><CardContent><p className="text-3xl font-bold">24</p></CardContent></Card>
            <Card><CardHeader><CardTitle>📐 Drawings</CardTitle></CardHeader><CardContent><p className="text-3xl font-bold">112</p></CardContent></Card>
            <Card><CardHeader><CardTitle>📤 Transmittals</CardTitle></CardHeader><CardContent><p className="text-3xl font-bold">8</p></CardContent></Card>
          </div>
        </TabsContent>

        <TabsContent value="activity">
          <div className="mt-4 space-y-3">
            <p>✔️ User <b>editor01</b> uploaded Drawing D-2025-07</p>
            <p>✔️ Transmittal T-2025-02 issued to Contractor</p>
            <p>✔️ RFA R-2025-03 marked as Resolved</p>
          </div>
        </TabsContent>
      </Tabs>

      <div className="pt-2">
        <Button asChild disabled={!me}><Link href="/dashboard">Go to Dashboard</Link></Button>
        {!me && <span className="ml-2 text-sm text-muted-foreground">กรุณา Login ก่อน</span>}
      </div>
    </div>
  );
}