import { useCallback, useEffect, useState } from "react";
import { router } from "expo-router";
import { ActivityIndicator, Alert, Pressable, ScrollView, Text, View } from "react-native";
import { Ionicons } from "@expo/vector-icons";
import type { CustomerInfo, PurchasesOffering, PurchasesPackage } from "react-native-purchases";
import Purchases from "react-native-purchases";
import { getActiveRestaurant } from "@/lib/active-restaurant";
import { configurePurchases, getCurrentOffering, getCustomerInfo, isProActive, PRO_ENTITLEMENT_ID } from "@/lib/purchases";

export default function SubscriptionScreen() {
  const [loading, setLoading] = useState(true);
  const [offering, setOffering] = useState<PurchasesOffering | null>(null);
  const [customerInfo, setCustomerInfo] = useState<CustomerInfo | null>(null);
  const [purchasingPackageId, setPurchasingPackageId] = useState<string | null>(null);
  const [restoring, setRestoring] = useState(false);

  const load = useCallback(async () => {
    const active = await getActiveRestaurant();
    if (!active) {
      router.back();
      return;
    }
    configurePurchases(active.restaurantId);

    try {
      const [offer, info] = await Promise.all([getCurrentOffering(), getCustomerInfo()]);
      setOffering(offer);
      setCustomerInfo(info);
    } catch (err) {
      Alert.alert("Hata", err instanceof Error ? err.message : "Abonelik bilgisi yüklenemedi.");
    } finally {
      setLoading(false);
    }
  }, []);

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

  async function onPurchase(pkg: PurchasesPackage) {
    setPurchasingPackageId(pkg.identifier);
    try {
      const { customerInfo: updated } = await Purchases.purchasePackage(pkg);
      setCustomerInfo(updated);
      if (isProActive(updated)) {
        Alert.alert("Teşekkürler!", "Menulio Pro aktif edildi.");
      }
    } catch (err) {
      const rcError = err as { userCancelled?: boolean; message?: string };
      if (!rcError.userCancelled) {
        Alert.alert("Satın alma başarısız", rcError.message ?? "Bir hata oluştu.");
      }
    } finally {
      setPurchasingPackageId(null);
    }
  }

  async function onRestore() {
    setRestoring(true);
    try {
      const info = await Purchases.restorePurchases();
      setCustomerInfo(info);
      Alert.alert(
        isProActive(info) ? "Abonelik bulundu" : "Aktif abonelik yok",
        isProActive(info) ? "Menulio Pro aboneliğiniz geri yüklendi." : "Bu hesaba bağlı aktif bir abonelik bulunamadı.",
      );
    } catch (err) {
      Alert.alert("Hata", err instanceof Error ? err.message : "Abonelik geri yüklenemedi.");
    } finally {
      setRestoring(false);
    }
  }

  const isPro = customerInfo ? isProActive(customerInfo) : false;
  const expiresAt = customerInfo?.entitlements.active[PRO_ENTITLEMENT_ID]?.expirationDate;

  if (loading) {
    return (
      <View style={{ flex: 1, alignItems: "center", justifyContent: "center", backgroundColor: "#FAF8F5" }}>
        <ActivityIndicator size="large" color="#C8A96B" />
      </View>
    );
  }

  return (
    <ScrollView style={{ flex: 1, backgroundColor: "#FAF8F5" }} contentContainerStyle={{ padding: 20, gap: 16 }}>
      <View style={{ flexDirection: "row", alignItems: "center", gap: 8 }}>
        <Pressable onPress={() => router.back()} style={{ padding: 4 }}>
          <Ionicons name="arrow-back" size={22} color="#1C1917" />
        </Pressable>
        <Text style={{ fontSize: 22, fontWeight: "800", color: "#1C1917" }}>Abonelik</Text>
      </View>

      <View
        style={{
          backgroundColor: isPro ? "#F0FDF4" : "#FFFFFF",
          borderRadius: 16,
          padding: 16,
          borderWidth: 1,
          borderColor: isPro ? "#BBF7D0" : "#E7E5E4",
          flexDirection: "row",
          alignItems: "center",
          gap: 10,
        }}
      >
        <Ionicons name={isPro ? "checkmark-circle" : "information-circle-outline"} size={22} color={isPro ? "#059669" : "#78716C"} />
        <View style={{ flex: 1 }}>
          <Text style={{ fontWeight: "700", color: "#1C1917" }}>{isPro ? "Menulio Pro aktif" : "Ücretsiz plan"}</Text>
          {isPro && expiresAt ? (
            <Text style={{ fontSize: 12, color: "#78716C", marginTop: 2 }}>
              Yenileme: {new Date(expiresAt).toLocaleDateString("tr-TR")}
            </Text>
          ) : null}
        </View>
      </View>

      {!offering || offering.availablePackages.length === 0 ? (
        <Text style={{ color: "#78716C", textAlign: "center", marginTop: 24 }}>
          Şu anda satın alınabilir bir paket bulunamadı.
        </Text>
      ) : (
        <View style={{ gap: 12 }}>
          {offering.availablePackages.map((pkg) => (
            <Pressable
              key={pkg.identifier}
              onPress={() => onPurchase(pkg)}
              disabled={purchasingPackageId !== null}
              style={{
                backgroundColor: "#FFFFFF",
                borderRadius: 16,
                padding: 16,
                borderWidth: 1.5,
                borderColor: "#C8A96B",
                flexDirection: "row",
                justifyContent: "space-between",
                alignItems: "center",
                opacity: purchasingPackageId && purchasingPackageId !== pkg.identifier ? 0.5 : 1,
              }}
            >
              <View>
                <Text style={{ fontSize: 16, fontWeight: "800", color: "#1C1917" }}>
                  {pkg.packageType === "ANNUAL" ? "Yıllık" : "Aylık"}
                </Text>
                <Text style={{ fontSize: 13, color: "#78716C", marginTop: 2 }}>
                  {pkg.product.priceString} / {pkg.packageType === "ANNUAL" ? "yıl" : "ay"}
                </Text>
              </View>
              {purchasingPackageId === pkg.identifier ? (
                <ActivityIndicator color="#C8A96B" />
              ) : (
                <Ionicons name="chevron-forward" size={20} color="#C8A96B" />
              )}
            </Pressable>
          ))}
        </View>
      )}

      <Pressable onPress={onRestore} disabled={restoring} style={{ padding: 12, alignItems: "center" }}>
        {restoring ? (
          <ActivityIndicator color="#78716C" />
        ) : (
          <Text style={{ color: "#78716C", fontSize: 14, fontWeight: "600" }}>Satın Alımları Geri Yükle</Text>
        )}
      </Pressable>
    </ScrollView>
  );
}