import { useState, useEffect } from 'react';
import { CreditCard, Check, Globe, Loader, ToggleLeft, ShieldAlert, Calendar, TrendingUp, TrendingDown, RefreshCcw } from 'lucide-react';
import { getProductList, getHostingServiceDetails } from '../../services/api';
const CUSTOM_API_BASE_URL = import.meta.env.VITE_CUSTOM_API_BASE_URL || '';

export default function SubscriptionManager({ order, onClose, onRefresh, onAlert }) {
    const [loading, setLoading] = useState(false);
    const [cancelLoading, setCancelLoading] = useState(false);
    const [catalog, setCatalog] = useState([]);
    const [selectedPlan, setSelectedPlan] = useState(null);
    const [isCatalogLoading, setIsCatalogLoading] = useState(true);

    const [serviceDetails, setServiceDetails] = useState(null);
    const [isDetailsLoading, setIsDetailsLoading] = useState(true);

    const [billingPeriod, setBillingPeriod] = useState(order.period || '1M');

    // 1. Récupération des détails techniques (Domaine/IP)
    useEffect(() => {
        const fetchDetails = async () => {
            setIsDetailsLoading(true);
            try {
                const data = await getHostingServiceDetails(order.id);
                setServiceDetails(data);
            } catch (err) {
                console.error("Erreur détails service:", err);
            } finally {
                setIsDetailsLoading(false);
            }
        };
        fetchDetails();
    }, [order.id]);

    const rawOrderTitle = order.title || "";
    const titleParts = rawOrderTitle.split(' pour ');
    const currentPlanName = titleParts[0].trim();
    const currentPlanId = order.product_id;
    const currentBillingPeriod = order.period;

    // 2. Extraction robuste du domaine
    let extractedDomain = "Aucun domaine lié";
    if (serviceDetails?.domain || serviceDetails?.config?.domain) {
        extractedDomain = serviceDetails.domain || serviceDetails.config.domain;
    }

    const renderMarkdownFeatures = (text) => {
        if (!text) return <span className="text-gray-500 italic">Aucune spécification disponible.</span>;
        return text.split('\n').map((line, index) => {
            const cleanLine = line.trim();
            if (cleanLine.startsWith('* ') || cleanLine.startsWith('- ')) {
                return (
                    <div key={index} className="flex items-center gap-3 text-sm font-semibold text-white my-2">
                        <div className="shrink-0 w-5 h-5 rounded-full border border-cyan-500/40 flex items-center justify-center bg-cyan-950/10">
                            <Check className="w-3 h-3 text-cyan-400 stroke-3" />
                        </div>
                        <span>{parseBold(cleanLine.substring(2))}</span>
                    </div>
                );
            }
            return <p key={index} className="text-gray-400 text-xs my-1">{parseBold(cleanLine)}</p>;
        });
    };

    const parseBold = (text) => text.split('**').map((part, i) => i % 2 === 1 ? <strong key={i} className="text-white font-bold">{part}</strong> : part);

    const getProductCardMetrics = (pricing, period) => {
        if (!pricing || !pricing.recurrent) {
            return { displayPrice: "0.00", billingPrice: "0.00", oldDisplayPrice: "0.00", saving: 0, isAvailable: false };
        }

        const recurrent = pricing.recurrent;
        const priceW = recurrent['1W']?.price ? parseFloat(recurrent['1W'].price) : 0;
        const priceM = recurrent['1M']?.price ? parseFloat(recurrent['1M'].price) : 0;
        const priceY = recurrent['1Y']?.price ? parseFloat(recurrent['1Y'].price) : 0;

        let billingPrice = 0, oldBillingPrice = 0, savingPercent = 0, isAvailable = true;
        let displayPrice = 0, oldDisplayPrice = 0;

        if (period === '1W') {
            billingPrice = priceW; oldBillingPrice = priceW;
            displayPrice = priceW * 4.333; oldDisplayPrice = displayPrice;
            if (!priceW) isAvailable = false;
        } else if (period === '1M') {
            billingPrice = priceM; oldBillingPrice = priceW > 0 ? priceW * 4.333 : priceM;
            displayPrice = priceM; oldDisplayPrice = oldBillingPrice;
            if (!priceM) isAvailable = false;
        } else if (period === '1Y') {
            billingPrice = priceY; oldBillingPrice = priceW > 0 ? priceW * 52 : (priceM > 0 ? priceM * 12 : priceY);
            displayPrice = priceY / 12; oldDisplayPrice = oldBillingPrice / 12;
            if (!priceY) isAvailable = false;
        }

        savingPercent = (oldBillingPrice > billingPrice && billingPrice > 0) ? Math.round(((oldBillingPrice - billingPrice) / oldBillingPrice) * 100) : 0;

        return { displayPrice: displayPrice.toFixed(2), billingPrice: billingPrice.toFixed(2), oldDisplayPrice: oldDisplayPrice.toFixed(2), saving: savingPercent, isAvailable };
    };

    const getPlanBadge = (index) => {
        if (index === 0) return { label: "ESSENTIEL", color: "text-gray-400 bg-gray-900 border-gray-700" };
        if (index === 1) return { label: "PLUS POPULAIRE", color: "text-cyan-300 bg-cyan-950 border-cyan-800 shadow-[0_0_10px_rgba(6,182,212,0.3)]" };
        return { label: "PRO", color: "text-amber-400 bg-amber-950 border-amber-800 shadow-[0_0_10px_rgba(245,158,11,0.2)]" };
    };

    useEffect(() => {
        const fetchCatalog = async () => {
            setIsCatalogLoading(true);
            try {
                const data = await getProductList();
                const rawProducts = data.list || data.catalog || (Array.isArray(data) ? data : []);
                const webProducts = rawProducts.filter(p => p.product_category_id === 1);

                if (webProducts.length > 0) {
                    setCatalog(webProducts);
                    const current = webProducts.find(p => currentPlanName.toLowerCase() === p.title.toLowerCase());
                    if (current) setSelectedPlan(current);
                } else {
                    console.warn("Aucun produit de type 'Web Service' n'a été trouvé.");
                    setCatalog([]);
                }
            } catch (err) {
                console.error("Erreur API Catalogue:", err);
            } finally {
                setIsCatalogLoading(false);
            }
        };
        fetchCatalog();
    }, [currentPlanName]);

    const isNoChange = selectedPlan && (currentPlanId === selectedPlan.id) && (currentBillingPeriod === billingPeriod);

    // ==========================================
    // 🧠 LOGIQUE UPGRADE / DOWNGRADE & PRORATA
    // ==========================================
    let migrationLabel = "Valider la modification";
    let buttonColor = "bg-cyan-500 hover:bg-cyan-400 shadow-[0_0_20px_rgba(6,182,212,0.2)]";
    let ActionIcon = null;
    let finalInvoicePrice = 0;
    let isProrataApplied = false;
    let isRefund = false;

    if (selectedPlan && !isNoChange) {
        const currentPrice = parseFloat(order.price) || 0;
        let currentMonthly = currentPrice;
        if (currentBillingPeriod === '1W') currentMonthly = currentPrice * 4.333;
        if (currentBillingPeriod === '1M') currentMonthly = currentPrice;
        if (currentBillingPeriod === '1Y') currentMonthly = currentPrice / 12;

        const selectedMetrics = getProductCardMetrics(selectedPlan.pricing, billingPeriod);
        const selectedMonthly = parseFloat(selectedMetrics.displayPrice);

        const p1 = parseFloat(order.price) || 0;
        const p2 = parseFloat(selectedMetrics.billingPrice) || 0;

        let m = 30;
        if (currentBillingPeriod === '1Y') m = 365;
        if (currentBillingPeriod === '1M') m = 30;
        if (currentBillingPeriod === '1W') m = 7;

        const expiresAt = new Date(order.expires_at);
        const now = new Date();
        let remainingDays = 0;

        if (!isNaN(expiresAt)) {
            remainingDays = Math.max(0, Math.ceil((expiresAt - now) / (1000 * 60 * 60 * 24)));
        }

        if (remainingDays > 0 && remainingDays <= m) {
            const n = m - remainingDays; // Jours écoulés
            finalInvoicePrice = p2 - p1 - (n * (p1 - p2) / m);
            isProrataApplied = true;
        } else {
            finalInvoicePrice = p2;
        }

        isRefund = finalInvoicePrice < -0.01;

        // --- 3. Style du bouton (Triggers : Upgrade / Downgrade / Cycle) ---

        // On récupère le forfait actuel depuis le catalogue pour comparer la "puissance" brute des forfaits
        const currentPlanFromCatalog = catalog.find(p => p.id === currentPlanId);

        // Pour définir la hiérarchie absolue, on compare les prix de base sur 1 Mois
        const baseCurrentPrice = currentPlanFromCatalog?.pricing?.recurrent?.['1M']?.price || 0;
        const baseSelectedPrice = selectedPlan?.pricing?.recurrent?.['1M']?.price || 0;

        const isSamePlan = currentPlanId === selectedPlan.id;
        const isSamePeriod = currentBillingPeriod === billingPeriod;

        if (isSamePlan && !isSamePeriod) {
            // Le pack est identique, seule la période change
            migrationLabel = "Changer de cycle";
            buttonColor = "bg-blue-500 hover:bg-blue-400 text-black shadow-[0_0_20px_rgba(59,130,246,0.2)]";
            ActionIcon = <RefreshCcw className="w-4 h-4" />;
        } else if (!isSamePlan) {
            // Le pack change, on compare la hiérarchie absolue
            if (parseFloat(baseSelectedPrice) > parseFloat(baseCurrentPrice)) {
                migrationLabel = `Valider l'Upgrade`;
                buttonColor = "bg-emerald-500 hover:bg-emerald-400 text-black shadow-[0_0_20px_rgba(16,185,129,0.2)]";
                ActionIcon = <TrendingUp className="w-4 h-4" />;
            } else {
                migrationLabel = "Valider le Downgrade";
                buttonColor = "bg-amber-500 hover:bg-amber-400 text-black shadow-[0_0_20px_rgba(245,158,11,0.2)]";
                ActionIcon = <TrendingDown className="w-4 h-4" />;
            }
        }
    }
    // ==========================================

    const handleMigration = async () => {
        setLoading(true);

        // 🎯 On détermine dynamiquement le type d'action pour la facture
        let actionType = 'upgrade';
        const currentPlanFromCatalog = catalog.find(p => p.id === currentPlanId);
        const baseCurrent = parseFloat(currentPlanFromCatalog?.pricing?.recurrent?.['1M']?.price || 0);
        const baseSelected = parseFloat(selectedPlan?.pricing?.recurrent?.['1M']?.price || 0);

        if (selectedPlan.id === currentPlanId) {
            actionType = 'cycle';
        } else if (baseSelected < baseCurrent) {
            actionType = 'downgrade';
        }

        try {
            const resp = await fetch(`${CUSTOM_API_BASE_URL}/custom_api/nexus_subscription.php`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
                body: new URLSearchParams({
                    action: 'migrate',
                    order_id: order.id,
                    target_plan_id: selectedPlan.id,
                    new_period: billingPeriod,
                    new_price: finalInvoicePrice.toFixed(2),
                    action_type: actionType // 🎯 On envoie l'information au backend !
                })
            });
            const data = await resp.json();
            if (data.status === 'success') {
                onAlert?.("Facture générée", "Redirection...", "success");
                onClose?.();
                setTimeout(() => window.location.href = '/facturation', 2000);
            } else {
                onAlert?.("Erreur", data.error, "error");
            }
        } catch (err) {
            onAlert?.("Erreur", "Problème réseau", "error");
        } finally {
            setLoading(false);
        }
    };

    const handleCancel = async () => {
        if (!window.confirm("Êtes-vous sûr de vouloir résilier cet abonnement ? Le service sera désactivé au prochain cycle de facturation.")) {
            try {
                const response = await cancelSubscription(user.id, order.id);

                // Le message s'adapte tout seul ! 
                // Soit: "Annulé avec effet immédiat et remboursé" 
                // Soit: "Actif jusqu'à la fin de la période"
                alert(response.message);

                // Rafraîchir la liste des abonnements...
            } catch (error) {
                alert("Erreur lors de l'annulation : " + error.message);
            }
        }

        setCancelLoading(true);
        try {
            const resp = await fetch(`${CUSTOM_API_BASE_URL}/custom_api/nexus_subscription.php`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
                body: new URLSearchParams({
                    action: 'cancel',
                    order_id: order.id
                })
            });
            const data = await resp.json();

            if (data.status === 'success') {
                if (onAlert) onAlert("Résilié", data.message || "L'abonnement a été annulé avec succès.", "success");
                if (onRefresh) onRefresh();
                if (onClose) onClose();
            } else {
                if (onAlert) onAlert("Erreur", data.error || "Impossible de résilier l'abonnement.", "error");
            }
        } catch (err) {
            if (onAlert) onAlert("Erreur", "Problème réseau ou serveur.", "error");
        } finally {
            setCancelLoading(false);
        }
    };

    return (
        <div className="flex flex-col w-full max-h-[95vh] md:h-auto md:max-h-[90vh] max-w-6xl mx-auto text-white">

            <div className="shrink-0 space-y-4 mb-4 pr-2">
                <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
                    <div className="bg-[#090f1c] border border-gray-800 p-3.5 rounded-xl flex items-center gap-3">
                        <div className="p-2 bg-gray-950 rounded-lg text-gray-400"><CreditCard className="w-4 h-4" /></div>
                        <div>
                            <p className="text-[10px] uppercase font-bold text-gray-500 tracking-wider">Abonnement Actuel</p>
                            <p className="text-sm font-bold text-white">{currentPlanName}</p>
                        </div>
                    </div>
                    <div className="bg-[#090f1c] border border-gray-800 p-3.5 rounded-xl flex items-center gap-3">
                        <div className="p-2 bg-gray-950 rounded-lg text-cyan-400"><Globe className="w-4 h-4" /></div>
                        <div className="truncate">
                            <p className="text-[10px] uppercase font-bold text-gray-500 tracking-wider">Espace Domaine</p>
                            <p className="text-sm font-mono text-cyan-400 truncate">{extractedDomain}</p>
                        </div>
                    </div>
                </div>

                <div className="bg-[#090f1c] border border-gray-800 p-4 rounded-xl flex flex-col md:flex-row items-start md:items-center justify-between gap-4">
                    <div className="flex items-center gap-3">
                        <div className="p-2 bg-gray-950 rounded-lg text-emerald-400 border border-gray-800/50">
                            <Calendar className="w-4 h-4" />
                        </div>
                        <div>
                            <p className="text-[10px] uppercase font-bold text-gray-500 tracking-wider">Prochain Renouvellement</p>
                            <p className="text-sm font-medium text-gray-300">
                                {order.expires_at ? order.expires_at : "Date non définie"}
                                <span className="text-gray-600 mx-2">|</span>
                                <span className="font-mono text-white font-bold">{order.price || '0.00'} {order.currency || '€'}</span>
                                <span className="text-[10px] text-gray-500 ml-1 uppercase">/ {order.period === '1W' ? 'semaine' : order.period === '1Y' ? 'an' : 'mois'}</span>
                            </p>
                        </div>
                    </div>
                    <a
                        href={`/facturation`}
                        className="text-xs font-bold text-cyan-400 hover:text-cyan-300 transition-colors flex items-center gap-1.5 bg-cyan-950/20 px-4 py-2 rounded-lg border border-cyan-900/30"
                    >
                        Voir les factures
                    </a>
                </div>

                <div className="bg-[#090f1c] p-2 rounded-xl border border-gray-800 flex items-center justify-between">
                    <span className="text-xs font-bold text-gray-400 ml-3 flex items-center gap-2">
                        <ToggleLeft className="w-4 h-4 text-cyan-400" /> Options de renouvellement
                    </span>
                    <div className="flex space-x-1">
                        {[
                            { id: '1W', label: 'Semaine' },
                            { id: '1M', label: 'Mois' },
                            { id: '1Y', label: 'Année' }
                        ].map((p) => (
                            <button
                                key={p.id}
                                onClick={() => setBillingPeriod(p.id)}
                                disabled={loading || cancelLoading}
                                className={`px-5 py-2 rounded-lg text-xs font-black tracking-wide transition-all ${billingPeriod === p.id ? 'bg-cyan-500 text-black shadow-lg shadow-cyan-500/20' : 'text-gray-400 hover:text-white hover:bg-gray-900'} disabled:opacity-50`}
                            >
                                {p.label}
                            </button>
                        ))}
                    </div>
                </div>
            </div>

            <div className="grow pr-2 custom-scrollbar">
                {isCatalogLoading ? (
                    <div className="h-full flex flex-col items-center justify-center text-cyan-400">
                        <Loader className="w-8 h-8 animate-spin mx-auto mb-2" />
                        <p className="text-xs font-mono text-gray-500">Synchronisation des tarifs...</p>
                    </div>
                ) : (
                    <div className="grid grid-cols-1 md:grid-cols-3 gap-5 pt-3 pb-4">
                        {catalog.map((plan, index) => {
                            const metrics = getProductCardMetrics(plan.pricing, billingPeriod);
                            const isSelected = selectedPlan?.id === plan.id;
                            const isCurrentActive = currentPlanId === plan.id && currentBillingPeriod === billingPeriod;
                            const topBadge = getPlanBadge(index);

                            return (
                                <div
                                    key={plan.id}
                                    onClick={() => !loading && !cancelLoading && metrics.isAvailable && setSelectedPlan(plan)}
                                    className={`relative h-full p-6 rounded-2xl border transition-all duration-300 flex flex-col justify-between bg-[#0d1527] mt-3
                                        ${!metrics.isAvailable || loading || cancelLoading ? 'opacity-50 grayscale cursor-not-allowed border-gray-900' : 'cursor-pointer'}
                                        ${isSelected && metrics.isAvailable ? 'border-cyan-500 shadow-[0_0_20px_rgba(6,182,212,0.15)] scale-[1.02] z-10' : 'border-gray-800/80 hover:border-gray-700'} 
                                        ${isCurrentActive ? 'ring-1 ring-gray-700' : ''}`}
                                >
                                    <div className="absolute -top-3 left-1/2 -translate-x-1/2">
                                        <span className={`text-[9px] font-black tracking-widest px-3 py-1 rounded-full border ${topBadge.color}`}>
                                            {topBadge.label}
                                        </span>
                                    </div>

                                    <div className="flex justify-between items-center w-full mb-5 mt-2">
                                        <span className="text-[9px] font-black tracking-widest text-white bg-[#090f1c] px-2.5 py-1 rounded border border-gray-800 uppercase">
                                            {plan.category?.title || "WEB"}
                                        </span>
                                        {metrics.saving > 0 && metrics.isAvailable && (
                                            <span className="text-[10px] font-bold text-[#00df89] bg-[#00df89]/10 border border-[#00df89]/20 px-3 py-0.5 rounded-full uppercase tracking-wide">
                                                Économie {metrics.saving}%
                                            </span>
                                        )}
                                    </div>

                                    <div className="mb-5 shrink-0">
                                        <h4 className="font-bold text-xl text-white tracking-tight mb-3 flex items-center justify-between">
                                            {plan.title}
                                            {isCurrentActive && <span className="text-[9px] font-bold text-orange-500 uppercase tracking-widest bg-orange-900 px-2 py-0.5 rounded border border-orange-800">Actif</span>}
                                        </h4>

                                        {metrics.isAvailable ? (
                                            <>
                                                <div className="flex items-baseline gap-1.5">
                                                    <span className="text-3xl font-black text-cyan-400 tracking-tighter">{metrics.displayPrice} €</span>
                                                    <span className="text-xs text-gray-400 font-medium">/ mois</span>
                                                </div>

                                                {metrics.saving > 0 && (
                                                    <p className="text-xs text-gray-500 line-through mt-1">
                                                        Au lieu de {metrics.oldDisplayPrice} € / mois
                                                    </p>
                                                )}

                                                <div className="mt-3.5 inline-block bg-[#0e2238] border border-cyan-950/40 text-cyan-400 text-[9px] font-black tracking-widest uppercase px-3 py-1.5 rounded-md">
                                                    Facturé {metrics.billingPrice} € par {billingPeriod === '1W' ? 'semaine' : billingPeriod === '1M' ? 'mois' : 'an'}
                                                </div>
                                            </>
                                        ) : (
                                            <div className="py-2">
                                                <span className="text-lg font-bold text-gray-500">Non disponible</span>
                                                <p className="text-[10px] text-gray-600 mt-1 uppercase tracking-wider">Pour ce cycle</p>
                                            </div>
                                        )}
                                    </div>

                                    <div className="border-t border-gray-800/60 pt-4 grow space-y-1.5">
                                        {renderMarkdownFeatures(plan.description)}
                                    </div>
                                </div>
                            );
                        })}
                    </div>
                )}
            </div>

            <div className="shrink-0 mt-auto pt-4 border-t border-gray-800/40 space-y-3">
                {/* 🎯 NOUVEAU : AFFICHAGE DYNAMIQUE (PRORATA ET REMBOURSEMENT) */}
                {selectedPlan && !isNoChange && (
                    <div className={`border p-3 rounded-xl mb-3 flex items-center justify-between transition-colors
                        ${isRefund ? 'bg-amber-950/20 border-amber-900/50' : 'bg-[#0e2238] border-cyan-900/50'}`}
                    >
                        <div>
                            <p className={`text-xs font-bold uppercase tracking-widest ${isRefund ? 'text-amber-400' : 'text-cyan-400'}`}>
                                {isRefund
                                    ? "Remboursement estimé"
                                    : finalInvoicePrice > 0.01
                                        ? "Montant à régler aujourd'hui"
                                        : "Aucun frais immédiat"}
                            </p>
                            {isProrataApplied && <p className="text-[10px] text-gray-500 mt-0.5">Calculé au prorata des jours restants</p>}
                        </div>
                        <div className="text-right">
                            <span className={`text-xl font-black font-mono ${isRefund ? 'text-amber-400' : 'text-white'}`}>
                                {isRefund ? "-" : ""}{Math.abs(finalInvoicePrice).toFixed(2)} €
                            </span>
                        </div>
                    </div>
                )}

                {selectedPlan && (
                    <button
                        onClick={handleMigration}
                        disabled={loading || cancelLoading || isNoChange}
                        className={`w-full py-4 rounded-xl font-black uppercase text-xs tracking-widest transition-all duration-300 flex items-center justify-center gap-3
                            ${isNoChange
                                ? 'bg-gray-900 text-gray-500 border border-gray-800 cursor-not-allowed shadow-none'
                                : buttonColor
                            }`}
                    >
                        {loading ? <Loader className="w-4 h-4 animate-spin" /> : (!isNoChange && ActionIcon)}

                        {loading
                            ? 'Traitement en cours...'
                            : isNoChange
                                ? 'Abonnement actuel (Aucune modification)'
                                : migrationLabel
                        }
                    </button>
                )}

                <button
                    onClick={handleCancel}
                    disabled={loading || cancelLoading}
                    className="w-full flex items-center justify-center gap-2 text-red-400/80 hover:text-red-400 border border-red-950/30 bg-red-950/5 hover:bg-red-950/15 p-3 rounded-xl text-xs font-bold uppercase tracking-wider transition-all disabled:opacity-50 disabled:cursor-not-allowed"
                >
                    {cancelLoading ? <Loader className="w-4 h-4 animate-spin" /> : <ShieldAlert className="w-4 h-4" />}
                    {cancelLoading ? 'Résiliation en cours...' : 'Résilier l\'abonnement réseau'}
                </button>
            </div>
        </div>
    );
}