/**
 * ════════════════════════════════════════════════════════════
 * مُصادَق (Musadaq) — Invoices Management Page (Premium Dark)
 * ════════════════════════════════════════════════════════════
 */

import { useState, useEffect } from 'react';
import { motion, AnimatePresence } from 'framer-motion';
import { 
    Upload, 
    Search, 
    Filter, 
    Eye, 
    CheckCircle2, 
    Clock, 
    AlertCircle, 
    ChevronLeft,
    ChevronRight,
    Building2,
    FileText,
    Send,
    Download,
    Trash2,
    Loader2,
    X
} from 'lucide-react';
import apiClient from '../../api/client';

export const InvoicesPage = () => {
    const [invoices, setInvoices] = useState<any[]>([]);
    const [companies, setCompanies] = useState<any[]>([]);
    const [isLoading, setIsLoading] = useState(true);
    const [searchTerm, setSearchTerm] = useState('');
    const [isUploadModalOpen, setIsUploadModalOpen] = useState(false);
    
    // Upload Form State
    const [selectedCompanyId, setSelectedCompanyId] = useState('');
    const [selectedFile, setSelectedFile] = useState<File | null>(null);
    const [isUploading, setIsUploading] = useState(false);

    // View Modal State
    const [viewingInvoice, setViewingInvoice] = useState<any | null>(null);
    const [isViewModalOpen, setIsViewModalOpen] = useState(false);
    const [deleteLoading, setDeleteLoading] = useState<string | null>(null);
    const [submitLoading, setSubmitLoading] = useState<string | null>(null);

    const fetchData = async () => {
        setIsLoading(true);
        try {
            const [compRes, invRes] = await Promise.all([
                apiClient.get('/companies').catch(() => ({ data: [] })),
                apiClient.get('/invoices').catch(() => ({ data: [] }))
            ]);
            setCompanies(compRes.data);
            setInvoices(invRes.data);
        } finally {
            setIsLoading(false);
        }
    };

    useEffect(() => {
        fetchData();
    }, []);

    const handleUpload = async (e: React.FormEvent) => {
        e.preventDefault();
        if (!selectedCompanyId || !selectedFile) return;

        setIsUploading(true);
        const formData = new FormData();
        formData.append('file', selectedFile);

        try {
            await apiClient.post(`/invoices/upload/${selectedCompanyId}`, formData, {
                headers: { 'Content-Type': 'multipart/form-data' }
            });
            setIsUploadModalOpen(false);
            setSelectedFile(null);
            setSelectedCompanyId('');
            fetchData();
        } catch (error) {
            console.error('Upload failed', error);
            alert('حدث خطأ أثناء رفع الفاتورة');
        } finally {
            setIsUploading(false);
        }
    };

    const handleDelete = async (id: string) => {
        if (!confirm('هل أنت متأكد من حذف هذه الفاتورة نهائياً؟')) return;
        setDeleteLoading(id);
        try {
            await apiClient.post(`/invoices/${id}/delete`);
            fetchData();
        } catch (error) {
            alert('فشل حذف الفاتورة');
        } finally {
            setDeleteLoading(null);
        }
    };

    const handleSubmitToJoFotara = async (inv: any) => {
        setSubmitLoading(inv.id);
        try {
            await apiClient.post(`/invoices/${inv.id}/submit`);
            alert('تم الإرسال لـ جو فوترة بنجاح! 🎉');
            fetchData();
        } catch (err) {
            alert('فشل الإرسال لـ جو فوترة. تأكد من إعدادات الشركة وصحة البيانات.');
        } finally {
            setSubmitLoading(null);
        }
    };

    const handleFileChange = (e: React.ChangeEvent<HTMLInputElement>) => {
        if (e.target.files && e.target.files[0]) {
            setSelectedFile(e.target.files[0]);
        }
    };

    const filteredInvoices = invoices.filter(inv => 
        inv.invoice_number?.includes(searchTerm) || 
        inv.company?.name?.toLowerCase().includes(searchTerm.toLowerCase())
    );

    const StatusBadge = ({ invoice }: { invoice: any }) => {
        const status = invoice.status;
        const config: any = {
            approved: { color: 'text-emerald-400 bg-emerald-500/10 border-emerald-500/20', icon: CheckCircle2, label: 'تم التصديق' },
            validated: { color: 'text-blue-400 bg-blue-500/10 border-blue-500/20', icon: CheckCircle2, label: 'جاهز للإرسال' },
            extracted: { color: 'text-indigo-400 bg-indigo-500/10 border-indigo-500/20', icon: CheckCircle2, label: 'تم الاستخراج' },
            uploaded: { color: 'text-amber-400 bg-amber-500/10 border-amber-500/20', icon: Clock, label: 'قيد المعالجة AI' },
            extracting: { color: 'text-amber-400 bg-amber-500/10 border-amber-500/20', icon: Clock, label: 'قيد الاستخراج' },
            validation_failed: { color: 'text-red-400 bg-red-500/10 border-red-500/20', icon: AlertCircle, label: 'خطأ في التحقق' },
        };
        const { color, icon: Icon, label } = config[status] || { color: 'text-slate-400 bg-slate-800', icon: Clock, label: status };
        
        return (
            <span className={`inline-flex items-center gap-1.5 px-3 py-1 rounded-full text-[10px] font-bold border ${color} uppercase tracking-tight`}>
                <Icon className="w-3 h-3" />
                {label}
            </span>
        );
    };

    return (
        <div className="space-y-8 animate-in fade-in duration-700">
            <header className="flex items-center justify-between">
                <div>
                    <h2 className="text-3xl font-black text-white">إدارة الفواتير</h2>
                    <p className="text-slate-400 mt-1">عرض، معالجة، وإرسال الفواتير الضريبية لبوابة الضريبة.</p>
                </div>
                <button 
                    onClick={() => setIsUploadModalOpen(true)}
                    className="bg-emerald-500 hover:bg-emerald-600 text-slate-950 font-bold py-3 px-8 rounded-xl flex items-center gap-2 shadow-lg shadow-emerald-500/20 transition-all active:scale-95"
                >
                    <Upload className="w-5 h-5" />
                    رفع فاتورة جديدة
                </button>
            </header>

            {/* ── Filter & Search Bar ──────────────────────────────── */}
            <div className="flex gap-4">
                <div className="flex-1 bg-slate-900/50 backdrop-blur-xl border border-slate-800/60 rounded-xl px-4 py-3 flex items-center gap-3">
                    <Search className="w-5 h-5 text-slate-500" />
                    <input 
                        type="text" 
                        placeholder="ابحث برقم الفاتورة، اسم الشركة، أو التاريخ..." 
                        className="bg-transparent border-none outline-none flex-1 text-slate-200 text-sm placeholder-slate-500"
                        value={searchTerm}
                        onChange={(e) => setSearchTerm(e.target.value)}
                    />
                </div>
                <button className="bg-slate-800/60 border border-slate-700/50 px-6 rounded-xl flex items-center gap-2 text-slate-300 hover:bg-slate-800 transition-all font-bold text-sm">
                    <Filter className="w-4 h-4" />
                    فلترة
                </button>
            </div>

            {/* ── Invoices Table ───────────────────────────────────── */}
            <div className="bg-slate-900/50 backdrop-blur-xl border border-slate-800/60 rounded-2xl overflow-hidden min-h-[400px] flex flex-col">
                {isLoading ? (
                    <div className="flex-1 flex flex-col justify-center items-center">
                        <Loader2 className="w-8 h-8 text-emerald-500 animate-spin mb-4" />
                        <p className="text-slate-500 text-sm">جاري جلب الفواتير...</p>
                    </div>
                ) : filteredInvoices.length === 0 ? (
                    <div className="flex-1 flex flex-col items-center justify-center p-20 text-center">
                        <div className="w-20 h-20 bg-slate-800 rounded-2xl flex items-center justify-center mb-6 border border-slate-700">
                            <FileText className="w-10 h-10 text-slate-600" />
                        </div>
                        <h3 className="text-xl font-bold text-white mb-2">لا توجد فواتير بعد</h3>
                        <p className="text-slate-500 max-w-sm mb-8">ابدأ برفع أول فاتورة ليقوم محرك الذكاء الاصطناعي باستخراج بياناتها ومصادقتها ضريبياً.</p>
                        <button onClick={() => setIsUploadModalOpen(true)} className="bg-emerald-500 hover:bg-emerald-600 text-slate-950 font-bold py-3 px-8 rounded-xl transition-all">
                             ارفع فاتورتك الأولى
                        </button>
                    </div>
                ) : (
                    <div className="overflow-x-auto">
                        <table className="w-full text-right">
                            <thead className="bg-slate-800/50 border-b border-slate-800/60">
                                <tr>
                                    <th className="px-6 py-4 text-xs font-bold text-slate-400">رقم الفاتورة</th>
                                    <th className="px-6 py-4 text-xs font-bold text-slate-400">الشركة</th>
                                    <th className="px-6 py-4 text-xs font-bold text-slate-400">التاريخ</th>
                                    <th className="px-6 py-4 text-xs font-bold text-slate-400 text-left">المجموع (JOD)</th>
                                    <th className="px-6 py-4 text-xs font-bold text-slate-400">الحالة</th>
                                    <th className="px-6 py-4 text-xs font-bold text-slate-400 text-center">إجراءات</th>
                                </tr>
                            </thead>
                            <tbody className="divide-y divide-slate-800/50">
                                {filteredInvoices.map((inv, idx) => (
                                    <motion.tr 
                                        key={inv.id}
                                        initial={{ opacity: 0, x: 20 }}
                                        animate={{ opacity: 1, x: 0 }}
                                        transition={{ delay: idx * 0.05 }}
                                        className="hover:bg-slate-800/30 transition-colors group cursor-pointer"
                                        onClick={() => {
                                            setViewingInvoice(inv);
                                            setIsViewModalOpen(true);
                                        }}
                                    >
                                        <td className="px-6 py-4 font-bold text-white">{inv.invoice_number || '---'}</td>
                                        <td className="px-6 py-4 text-slate-400">
                                            <div className="flex items-center gap-2">
                                                <Building2 className="w-4 h-4 text-slate-600" />
                                                {inv.company?.name || '---'}
                                            </div>
                                        </td>
                                        <td className="px-6 py-4 text-slate-500 text-sm">
                                            {inv.invoice_date ? new Date(inv.invoice_date).toLocaleDateString('ar-JO') : '---'}
                                        </td>
                                        <td className="px-6 py-4 font-mono font-bold text-emerald-400 text-left">
                                            {Number(inv.grand_total).toLocaleString('en-US', { minimumFractionDigits: 3 })}
                                        </td>
                                        <td className="px-6 py-4"><StatusBadge invoice={inv} /></td>
                                        <td className="px-6 py-4 text-center">
                                            <div className="flex items-center justify-center gap-2" onClick={e => e.stopPropagation()}>
                                                <button 
                                                    onClick={() => { setViewingInvoice(inv); setIsViewModalOpen(true); }}
                                                    className="p-2 text-slate-500 hover:text-emerald-400 hover:bg-emerald-500/10 rounded-lg transition-all"
                                                >
                                                    <Eye className="w-4 h-4" />
                                                </button>
                                                <button 
                                                    onClick={() => handleDelete(inv.id)}
                                                    className="p-2 text-slate-500 hover:text-red-400 hover:bg-red-500/10 rounded-lg transition-all"
                                                >
                                                    {deleteLoading === inv.id ? <Loader2 className="w-4 h-4 animate-spin" /> : <Trash2 className="w-4 h-4" />}
                                                </button>
                                            </div>
                                        </td>
                                    </motion.tr>
                                ))}
                            </tbody>
                        </table>
                    </div>
                )}

                {/* ── Pagination ───────────────────────────────────────── */}
                {!isLoading && filteredInvoices.length > 0 && (
                    <footer className="px-6 py-4 bg-slate-800/30 border-t border-slate-800/60 flex items-center justify-between mt-auto">
                        <p className="text-sm text-slate-500">عرض {filteredInvoices.length} فواتير</p>
                        <div className="flex gap-2">
                            <button className="p-2 text-slate-500 hover:text-white border border-slate-700 rounded-xl bg-slate-800 transition-all">
                                <ChevronRight className="w-5 h-5" />
                            </button>
                            <button className="p-2 text-slate-500 hover:text-white border border-slate-700 rounded-xl bg-slate-800 transition-all">
                                <ChevronLeft className="w-5 h-5" />
                            </button>
                        </div>
                    </footer>
                )}
            </div>

            {/* ── Upload Modal ─────────────────────────────────────── */}
            <AnimatePresence>
                {isUploadModalOpen && (
                    <div className="fixed inset-0 z-50 flex items-center justify-center p-4 bg-slate-950/80 backdrop-blur-md">
                        <motion.div 
                            initial={{ scale: 0.9, opacity: 0 }}
                            animate={{ scale: 1, opacity: 1 }}
                            exit={{ scale: 0.9, opacity: 0 }}
                            className="bg-slate-900 border border-slate-800 p-8 w-full max-w-xl rounded-3xl shadow-2xl relative"
                        >
                            <button onClick={() => setIsUploadModalOpen(false)} className="absolute top-6 left-6 text-slate-500 hover:text-white transition-colors">
                                <X className="w-6 h-6" />
                            </button>
                            
                            <h3 className="text-2xl font-bold text-white mb-2">رفع فاتورة جديدة</h3>
                            <p className="text-slate-400 mb-8 text-sm">اختر الشركة وملف الفاتورة (PDF أو صورة) وسيقوم الذكاء الاصطناعي بالباقي.</p>
                            
                            <form onSubmit={handleUpload} className="space-y-6">
                                <div>
                                    <label className="block text-sm font-bold text-slate-300 mb-2">اختر الشركة</label>
                                    <select 
                                        required
                                        value={selectedCompanyId}
                                        onChange={e => setSelectedCompanyId(e.target.value)}
                                        className="w-full bg-slate-800 border border-slate-700 rounded-xl px-5 py-4 outline-none focus:border-emerald-500/50 transition-all text-white appearance-none cursor-pointer"
                                    >
                                        <option value="">-- اختر شركة --</option>
                                        {companies.map(c => (
                                            <option key={c.id} value={c.id}>{c.name}</option>
                                        ))}
                                    </select>
                                </div>

                                <div>
                                    <label className="block text-sm font-bold text-slate-300 mb-2">ملف الفاتورة</label>
                                    <div className="relative group">
                                        <input 
                                            type="file" 
                                            required
                                            onChange={handleFileChange}
                                            accept=".pdf,image/*"
                                            className="absolute inset-0 w-full h-full opacity-0 cursor-pointer z-10"
                                        />
                                        <div className="border-2 border-dashed border-slate-700 rounded-xl p-10 flex flex-col items-center group-hover:border-emerald-500/50 group-hover:bg-emerald-500/5 transition-all bg-slate-800/50">
                                            <Upload className="w-10 h-10 text-slate-600 mb-4 transition-colors group-hover:text-emerald-500" />
                                            <p className="font-bold text-slate-300 text-center">
                                                {selectedFile ? selectedFile.name : 'اسحب الملف هنا أو انقر للاختيار'}
                                            </p>
                                            <p className="text-xs text-slate-500 mt-2">PDF, JPG, PNG (حد أقصى 10MB)</p>
                                        </div>
                                    </div>
                                </div>

                                <div className="flex gap-4 pt-4">
                                    <button 
                                        type="button"
                                        onClick={() => setIsUploadModalOpen(false)}
                                        className="flex-1 bg-slate-800 text-slate-300 font-bold py-4 rounded-xl hover:bg-slate-700 transition-all"
                                    >
                                        إلغاء
                                    </button>
                                    <button 
                                        type="submit"
                                        disabled={isUploading || !selectedCompanyId || !selectedFile}
                                        className="flex-[2] bg-emerald-500 text-slate-950 font-bold py-4 rounded-xl shadow-lg shadow-emerald-500/20 disabled:opacity-50 flex items-center justify-center gap-3 transition-all"
                                    >
                                        {isUploading ? <Loader2 className="w-5 h-5 animate-spin" /> : <Upload className="w-5 h-5" />}
                                        {isUploading ? 'جاري المعالجة...' : 'ابدأ المعالجة الآن'}
                                    </button>
                                </div>
                            </form>
                        </motion.div>
                    </div>
                )}
            </AnimatePresence>

            {/* ── View Invoice Modal ─────────────────────────────────── */}
            <AnimatePresence>
                {isViewModalOpen && viewingInvoice && (
                    <div className="fixed inset-0 z-[60] flex items-center justify-center p-4 bg-slate-950/90 backdrop-blur-md">
                        <motion.div 
                            initial={{ scale: 0.95, opacity: 0 }}
                            animate={{ scale: 1, opacity: 1 }}
                            exit={{ scale: 0.95, opacity: 0 }}
                            className="bg-slate-900 border border-slate-800 w-full max-w-5xl h-[90vh] rounded-[32px] shadow-2xl flex flex-col overflow-hidden"
                        >
                            <header className="px-8 py-6 border-b border-slate-800 flex items-center justify-between">
                                <div>
                                    <h3 className="text-2xl font-bold text-white">معاينة الفاتورة</h3>
                                    <p className="text-slate-500 text-sm">رقم: {viewingInvoice.invoice_number || '---'} • {viewingInvoice.company?.name}</p>
                                </div>
                                <button 
                                    onClick={() => setIsViewModalOpen(false)}
                                    className="w-10 h-10 flex items-center justify-center rounded-xl bg-slate-800 text-slate-500 hover:text-white transition-all"
                                >
                                    <X className="w-6 h-6" />
                                </button>
                            </header>

                            <div className="flex-1 overflow-auto bg-slate-950 p-8 flex justify-center items-center">
                                <div className="w-full h-full max-w-4xl bg-white rounded-xl overflow-hidden shadow-2xl relative">
                                    <iframe 
                                        src={`${apiClient.defaults.baseURL}/invoices/${viewingInvoice.id}/file?token=${localStorage.getItem('access_token')}#toolbar=0`} 
                                        className="w-full h-full border-none"
                                        title="Invoice Preview"
                                    />
                                    {/* Fallback overlay in case of loading issues */}
                                    <div className="absolute inset-0 pointer-events-none flex items-center justify-center bg-slate-900/10 backdrop-blur-[2px] opacity-0 hover:opacity-100 transition-opacity">
                                        <p className="bg-slate-900/80 text-white px-4 py-2 rounded-lg text-xs">جاري عرض الفاتورة...</p>
                                    </div>
                                </div>
                            </div>
                            
                            <footer className="px-8 py-6 border-t border-slate-800 bg-slate-900/50 flex items-center justify-between">
                                <div className="flex items-center gap-8">
                                    <div>
                                        <p className="text-[10px] uppercase tracking-widest text-slate-500 font-bold mb-1">المجموع الكلي</p>
                                        <p className="text-xl font-black text-emerald-400">{Number(viewingInvoice.grand_total).toLocaleString('en-US', { minimumFractionDigits: 3 })} JOD</p>
                                    </div>
                                    <div className="w-px h-10 bg-slate-800" />
                                    <div>
                                        <p className="text-[10px] uppercase tracking-widest text-slate-500 font-bold mb-1">الحالة</p>
                                        <StatusBadge invoice={viewingInvoice} />
                                    </div>
                                </div>
                                <div className="flex gap-4">
                                    <button 
                                        onClick={() => {
                                            const token = localStorage.getItem('access_token');
                                            window.open(`${apiClient.defaults.baseURL}/invoices/${viewingInvoice.id}/file?token=${token}`, '_blank');
                                        }}
                                        className="px-6 py-3 rounded-xl bg-slate-800 border border-slate-700 text-slate-300 font-bold flex items-center gap-2 hover:bg-slate-700 transition-all"
                                    >
                                        <Download className="w-4 h-4" />
                                        تحميل
                                    </button>
                                    <button 
                                        onClick={() => handleSubmitToJoFotara(viewingInvoice)}
                                        className="bg-emerald-500 hover:bg-emerald-600 text-slate-950 font-bold px-8 py-3 rounded-xl flex items-center gap-2 shadow-lg shadow-emerald-500/20 transition-all"
                                    >
                                        {submitLoading === viewingInvoice.id ? <Loader2 className="w-5 h-5 animate-spin" /> : <Send className="w-4 h-4" />}
                                        إرسال لجو فوترة
                                    </button>
                                </div>
                            </footer>
                        </motion.div>
                    </div>
                )}
            </AnimatePresence>
        </div>
    );
};