import { Image } from "expo-image";
import Alipay from "expo-native-alipay";
import { useRouter } from "expo-router";
import React, { useEffect, useState } from "react";
import {
    ActivityIndicator,
    Alert,
    AppState,
    ImageBackground,
    Modal,
    Platform,
    ScrollView,
    StyleSheet,
    Text,
    TouchableOpacity,
    View,
} from "react-native";
import { useSafeAreaInsets } from "react-native-safe-area-context";

import { Images } from "@/constants/images";
import { Address, getDefaultAddress } from "@/services/address";
import { takeApply, takePreview } from "@/services/award";

interface GroupedGoods {
  total: number;
  data: {
    id: string;
    cover: string;
    spuId: string;
    level: string;
    name?: string;
  };
}

interface CheckoutModalProps {
  visible: boolean;
  selectedItems: Array<{
    id: string;
    spu: { id: string; name: string; cover: string };
    level: string;
  }>;
  onClose: () => void;
  onSuccess: () => void;
}

export default function CheckoutModal({
  visible,
  selectedItems,
  onClose,
  onSuccess,
}: CheckoutModalProps) {
  const router = useRouter();
  const insets = useSafeAreaInsets();
  const [loading, setLoading] = useState(false);
  const [submitting, setSubmitting] = useState(false);
  const [address, setAddress] = useState<Address | null>(null);
  const [expressAmount, setExpressAmount] = useState(0);
  const [goodsList, setGoodsList] = useState<GroupedGoods[]>([]);

  const [verifyLoading, setVerifyLoading] = useState(false);

  const showAlert = (msg: string) => {
    if (Platform.OS === "web") window.alert(msg);
    else Alert.alert("提示", msg);
  };

  useEffect(() => {
    if (visible && selectedItems.length > 0) {
      loadData();
    }
  }, [visible, selectedItems]);

  const loadData = async () => {
    setLoading(true);
    try {
      // 获取默认地址
      const addr = await getDefaultAddress();
      setAddress(addr);

      // 获取提货预览
      const ids = selectedItems.map((item) => item.id);
      const res = await takePreview(ids, addr?.id || "");
      if (res) {
        setExpressAmount(res.expressAmount || 0);
      }

      // 合并相同商品
      const goodsMap: Record<string, GroupedGoods> = {};
      selectedItems.forEach((item) => {
        const key = `${item.spu.id}_${item.level}`;
        if (goodsMap[key]) {
          goodsMap[key].total += 1;
        } else {
          goodsMap[key] = {
            total: 1,
            data: {
              id: item.id,
              cover: item.spu.cover,
              spuId: item.spu.id,
              level: item.level,
              name: item.spu.name,
            },
          };
        }
      });
      setGoodsList(Object.values(goodsMap));
    } catch (e) {
      console.error("加载提货信息失败:", e);
    }
    setLoading(false);
  };

  const goToAddress = () => {
    onClose();
    router.push("/address?type=1" as any);
  };

  /*
   * Handle Submit with Payment Choice
   */
  const handleSubmit = async () => {
    if (!address) {
      showAlert("请选择收货地址");
      return;
    }

    if (expressAmount > 0) {
      Alert.alert("支付运费", `需支付运费 ¥${expressAmount}`, [
        { text: "取消", style: "cancel" },
        { text: "钱包支付", onPress: () => processTakeApply("WALLET") },
        { text: "支付宝支付", onPress: () => processTakeApply("ALIPAY_APP") },
      ]);
    } else {
      processTakeApply("WALLET");
    }
  };

  const processTakeApply = async (paymentType: string) => {
    if (submitting) return;
    setSubmitting(true);
    try {
      const ids = selectedItems.map((item) => item.id);
      const res: any = await takeApply(ids, address!.id, paymentType);

      console.log("Take Apply Res:", res, paymentType);

      if (paymentType === "ALIPAY_APP" && res?.payInfo) {
        let appStateSub: any = null;
        let isResolved = false;

        try {
          if (Platform.OS === "ios")
            Alipay.setAlipayScheme("alipay2021005175632205");

          appStateSub = AppState.addEventListener(
            "change",
            async (nextAppState) => {
              if (nextAppState === "active" && !isResolved) {
                setTimeout(async () => {
                  if (!isResolved) {
                    isResolved = true;
                    setVerifyLoading(false);
                    showAlert("支付完成正在核实");
                    onSuccess();
                  }
                }, 500);
              }
            },
          );

          const result = await Alipay.pay(res.payInfo);
          if (isResolved) return;
          isResolved = true;
          setVerifyLoading(false);
          console.log("Alipay Result:", result);
          if (result?.resultStatus === "9000") {
            showAlert("提货成功");
            onSuccess();
          } else {
            showAlert("支付未完成");
          }
        } catch (e) {
          isResolved = true;
          setVerifyLoading(false);
          console.error("Alipay Error:", e);
          showAlert("调用支付宝失败");
        } finally {
          setVerifyLoading(false);
          if (appStateSub) {
            appStateSub.remove();
          }
        }
      } else if (res) {
        // Wallet payment or free success
        showAlert("提货成功");
        onSuccess();
      }
    } catch (e) {
      console.error("提货失败:", e);
      // Usually axios interceptor handles error alerts, but just in case
      // showAlert('提货失败');
    }
    setSubmitting(false);
  };

  return (
    <Modal
      visible={visible}
      transparent
      animationType="slide"
      onRequestClose={onClose}
    >
      <View style={styles.overlay}>
        <TouchableOpacity
          style={styles.overlayBg}
          onPress={onClose}
          activeOpacity={1}
        />
        <View style={[styles.container, { paddingBottom: insets.bottom + 20 }]}>
          {/* 标题 */}
          <View style={styles.header}>
            <Text style={styles.title}>提货</Text>
            <TouchableOpacity style={styles.closeBtn} onPress={onClose}>
              <Text style={styles.closeBtnText}>×</Text>
            </TouchableOpacity>
          </View>

          {loading ? (
            <View style={styles.loadingBox}>
              <ActivityIndicator size="large" color="#FC7D2E" />
            </View>
          ) : (
            <>
              {/* 商品列表 */}
              <View style={styles.goodsSection}>
                <ScrollView horizontal showsHorizontalScrollIndicator={false}>
                  {goodsList.map((goods, idx) => (
                    <View key={idx} style={styles.goodsItem}>
                      <Image
                        source={{ uri: goods.data.cover }}
                        style={styles.goodsImg}
                        contentFit="contain"
                      />
                      <View style={styles.goodsCount}>
                        <Text style={styles.goodsCountText}>
                          x{goods.total}
                        </Text>
                      </View>
                    </View>
                  ))}
                </ScrollView>
              </View>

              {/* 运费 */}
              {expressAmount > 0 && (
                <View style={styles.feeRow}>
                  <Text style={styles.feeLabel}>运费</Text>
                  <Text style={styles.feeValue}>¥{expressAmount}</Text>
                </View>
              )}

              {/* 收货地址 */}
              <TouchableOpacity
                style={styles.addressSection}
                onPress={goToAddress}
              >
                {!address ? (
                  <Text style={styles.noAddress}>请填写收货地址</Text>
                ) : (
                  <View style={styles.addressInfo}>
                    <Text style={styles.addressName}>
                      {address.contactName} {address.contactNo}
                    </Text>
                    <Text style={styles.addressDetail}>
                      {address.province}
                      {address.city}
                      {address.district}
                      {address.address}
                    </Text>
                  </View>
                )}
                <Text style={styles.arrowIcon}>›</Text>
              </TouchableOpacity>

              {/* 提交按钮 */}
              <TouchableOpacity
                style={styles.submitBtn}
                onPress={handleSubmit}
                disabled={submitting}
              >
                <ImageBackground
                  source={{ uri: Images.common.loginBtn }}
                  style={styles.submitBtnBg}
                  resizeMode="contain"
                >
                  <Text style={styles.submitBtnText}>
                    {submitting ? "提交中..." : "确定发货"}
                  </Text>
                </ImageBackground>
              </TouchableOpacity>
            </>
          )}
        </View>
      </View>

      {/* 支付结果轮询确认加载中 */}
      <Modal
        visible={verifyLoading}
        transparent
        animationType="fade"
        onRequestClose={() => {}}
      >
        <View style={styles.verifyLoadingOverlay}>
          <View style={styles.verifyLoadingBox}>
            <ActivityIndicator size="large" color="#ff9600" />
            <Text style={styles.verifyLoadingText}>正在确认支付结果...</Text>
          </View>
        </View>
      </Modal>
    </Modal>
  );
}

const styles = StyleSheet.create({
  verifyLoadingOverlay: {
    ...StyleSheet.absoluteFillObject,
    backgroundColor: "rgba(0,0,0,0.4)",
    justifyContent: "center",
    alignItems: "center",
    zIndex: 9999,
  },
  verifyLoadingBox: {
    backgroundColor: "rgba(0,0,0,0.8)",
    padding: 20,
    borderRadius: 12,
    alignItems: "center",
  },
  verifyLoadingText: {
    color: "#fff",
    marginTop: 10,
    fontSize: 14,
  },
  overlay: { flex: 1, justifyContent: "flex-end" },
  overlayBg: {
    position: "absolute",
    top: 0,
    left: 0,
    right: 0,
    bottom: 0,
    backgroundColor: "rgba(0,0,0,0.5)",
  },
  container: {
    backgroundColor: "#fff",
    borderTopLeftRadius: 15,
    borderTopRightRadius: 15,
    paddingHorizontal: 14,
  },
  header: {
    flexDirection: "row",
    alignItems: "center",
    justifyContent: "center",
    paddingVertical: 20,
    position: "relative",
  },
  title: { fontSize: 16, fontWeight: "bold", color: "#000" },
  closeBtn: {
    position: "absolute",
    right: 0,
    top: 15,
    width: 24,
    height: 24,
    backgroundColor: "#ebebeb",
    borderRadius: 12,
    justifyContent: "center",
    alignItems: "center",
  },
  closeBtnText: { fontSize: 18, color: "#a2a2a2", lineHeight: 20 },
  loadingBox: { height: 200, justifyContent: "center", alignItems: "center" },
  goodsSection: { paddingVertical: 10 },
  goodsItem: {
    width: 79,
    height: 103,
    backgroundColor: "#fff",
    borderRadius: 6,
    marginRight: 8,
    alignItems: "center",
    justifyContent: "center",
    position: "relative",
    borderWidth: 1,
    borderColor: "#eaeaea",
  },
  goodsImg: { width: 73, height: 85 },
  goodsCount: {
    position: "absolute",
    top: 0,
    right: 0,
    backgroundColor: "#ff6b00",
    borderRadius: 2,
    paddingHorizontal: 4,
    paddingVertical: 2,
  },
  goodsCountText: { color: "#fff", fontSize: 10, fontWeight: "bold" },
  feeRow: {
    flexDirection: "row",
    justifyContent: "space-between",
    alignItems: "center",
    paddingVertical: 8,
  },
  feeLabel: { fontSize: 14, color: "#333" },
  feeValue: { fontSize: 14, color: "#ff6b00", fontWeight: "bold" },
  addressSection: {
    flexDirection: "row",
    alignItems: "center",
    paddingVertical: 10,
    borderTopWidth: 1,
    borderTopColor: "#f0f0f0",
  },
  noAddress: { flex: 1, fontSize: 16, fontWeight: "bold", color: "#333" },
  addressInfo: { flex: 1 },
  addressName: { fontSize: 14, color: "#333", fontWeight: "bold" },
  addressDetail: { fontSize: 12, color: "#666", marginTop: 4 },
  arrowIcon: { fontSize: 20, color: "#999", marginLeft: 10 },
  submitBtn: { alignItems: "center", marginTop: 15 },
  submitBtnBg: {
    width: 260,
    height: 60,
    justifyContent: "center",
    alignItems: "center",
  },
  submitBtnText: { color: "#000", fontSize: 16, fontWeight: "bold" },
});