import React, { useState, useCallback, useRef } from 'react';
import { View, TouchableOpacity, ActivityIndicator, Linking, ScrollView, Dimensions, NativeSyntheticEvent, NativeScrollEvent } from 'react-native';
import { useRouter } from 'expo-router';
import { tw, MyText } from 'common-ui';
import { useNavigationTarget } from 'common-ui/hooks/useNavigationTarget';
import { MaterialIcons, Ionicons } from '@expo/vector-icons';
import dayjs from 'dayjs';
import { trpc } from '@/src/trpc-client';
import { Image } from 'expo-image';
import { orderStatusManipulator } from '@/src/lib/string-manipulators';
import { useGetEssentialConsts } from '@/src/hooks/prominent-api-hooks';
import { useUserDetails } from '@/src/contexts/AuthContext';

const { width: screenWidth } = Dimensions.get('window');
const CARD_WIDTH = (screenWidth - 48) * 0.95; // card width (24px padding each side), reduced 5%
const SNAP_INTERVAL = CARD_WIDTH + 24; // card + right margin = page width

interface OrderItem {
  productName: string;
  quantity: number;
  price: number;
  amount: number;
  image: string | null;
}

interface Order {
  id: number;
  orderId: string;
  orderDate: string;
  deliveryStatus: string;
  deliveryDate?: string;
  orderStatus: string;
  cancelReason: string | null;
  totalAmount: number;
  deliveryCharge: number;
  paymentMode: string;
  paymentStatus: string;
  refundStatus: string;
  refundAmount: number | null;
  userNotes: string | null;
  items: OrderItem[];
  discountAmount?: number;
  isFlashDelivery: boolean;
  createdAt: string;
}

interface OrderCardProps {
  order: Order;
  onPress: () => void;
  supportMobile?: string | null;
}

function OrderCard({ order, onPress, supportMobile }: OrderCardProps) {
  return (
    <TouchableOpacity
      style={{ width: CARD_WIDTH, marginRight: 24 }}
      onPress={onPress}
      activeOpacity={0.8}
    >
      <View style={tw`bg-gradient-to-r from-amber-50 to-orange-50 rounded-2xl p-4 border-2 border-amber-300`}>
        <View style={tw`flex-row items-center justify-between mb-3`}>
          <View style={tw`flex-row items-center`}>
            <View style={tw`w-2 h-2 rounded-full bg-amber-500 mr-2`} />
            <MyText style={tw`text-[10px] font-bold text-amber-600 uppercase tracking-wider`}>Upcoming Order</MyText>
          </View>
          {order.isFlashDelivery && (
            <View style={tw`px-2 py-0.5 bg-amber-200 rounded-full flex-row items-center`}>
              <MaterialIcons name="bolt" size={10} color="#D97706" style={tw`mr-0.5`} />
              <MyText style={tw`text-[8px] font-black text-amber-700 uppercase`}>FLASH</MyText>
            </View>
          )}
        </View>

        <View style={tw`flex-row justify-between items-start mb-3`}>
          <View>
            <MyText style={tw`text-lg font-extrabold text-gray-900`}>#{order.orderId}</MyText>
            <MyText style={tw`text-xs text-gray-500 mt-0.5`}>
              {order.items.length} {order.items.length === 1 ? 'item' : 'items'} • ₹{order.totalAmount}
            </MyText>
          </View>
          <View style={tw`bg-white px-2 py-1 rounded-lg border border-amber-200`}>
            <MyText style={tw`text-[10px] font-bold text-amber-700 uppercase`}>{orderStatusManipulator(order.deliveryStatus)}</MyText>
          </View>
        </View>

        <View style={tw`flex-row items-center`}>
          <MaterialIcons
            name={order.isFlashDelivery ? "bolt" : "schedule"}
            size={14}
            color="#D97706"
            style={tw`mr-1.5`}
          />
          <MyText style={tw`text-xs font-medium text-amber-800`}>
            {order.isFlashDelivery
              ? "30-Min Delivery"
              : (() => {
                  const startTime = dayjs(order.deliveryDate);
                  const endTime = startTime.add(1, 'hour');
                  return `${startTime.format("DD MMM, hh:mm A")} - ${endTime.format("hh:mm A")}`;
                })()
            }
          </MyText>
        </View>

        {order.items.length > 0 && (
          <View style={tw`flex-row items-center mt-3 pt-3 border-t border-amber-200`}>
            <View style={tw`flex-row`}>
              {order.items.slice(0, 3).map((item, idx) => (
                <View
                  key={idx}
                  style={[
                    tw`w-8 h-8 rounded-lg bg-white border border-amber-200 items-center justify-center`,
                    { marginLeft: idx > 0 ? -8 : 0 }
                  ]}
                >
                  <Image
                    source={{ uri: item.image || undefined }}
                    style={tw`w-full h-full rounded-lg`}
                  />
                </View>
              ))}
              {order.items.length > 3 && (
                <View style={tw`w-8 h-8 rounded-lg bg-amber-100 border border-amber-200 items-center justify-center ml-2`}>
                  <MyText style={tw`text-[9px] font-bold text-amber-700`}>+{order.items.length - 3}</MyText>
                </View>
              )}
            </View>
            <MyText style={tw`text-xs text-amber-700 font-medium ml-2`}>Track Order</MyText>
            <Ionicons name="chevron-forward" size={14} color="#D97706" style={tw`ml-auto`} />
          </View>
        )}

        {/* Support Mobile Number */}
        {supportMobile && (
          <TouchableOpacity
            style={tw`flex-row items-center mt-3 pt-3 border-t border-amber-200`}
            onPress={() => Linking.openURL(`tel:${supportMobile}`)}
          >
            <MaterialIcons name="phone-in-talk" size={14} color="#D97706" style={tw`mr-1.5`} />
            <MyText style={tw`text-xs text-amber-700 font-medium`}>
              Need help? Call {supportMobile}
            </MyText>
          </TouchableOpacity>
        )}
      </View>
    </TouchableOpacity>
  );
}

export default function NextOrderGlimpse() {
  const router = useRouter();
  const { setNavigationTarget } = useNavigationTarget();
  const userDetails = useUserDetails();
  const [currentIndex, setCurrentIndex] = useState(0);
  const scrollViewRef = useRef<ScrollView>(null);

  const { data: ordersData, isLoading: ordersLoading } = trpc.user.order.getOrders.useQuery({
    page: 1,
    pageSize: 50,
  }, {
    enabled: !!userDetails,
  });

  const { data: essentialConsts } = useGetEssentialConsts();

  const allOrders: Order[] = ordersData?.data || [];

  const upcomingOrders = allOrders.filter(order => {
    if (order.orderStatus.toLowerCase() === 'cancelled') return false;
    if (order.deliveryStatus.toLowerCase() === 'success') return false;

    return true;
  });

  upcomingOrders.sort((a, b) => {
    if (a.isFlashDelivery && !b.isFlashDelivery) return -1;
    if (!a.isFlashDelivery && b.isFlashDelivery) return 1;

    if (a.isFlashDelivery && b.isFlashDelivery) {
      return dayjs(b.createdAt).diff(dayjs(a.createdAt));
    }

    if (a.deliveryDate && b.deliveryDate) {
      return dayjs(a.deliveryDate).diff(dayjs(b.deliveryDate));
    }

    return 0;
  });

  const handleScroll = useCallback((event: NativeSyntheticEvent<NativeScrollEvent>) => {
    const index = Math.round(event.nativeEvent.contentOffset.x / SNAP_INTERVAL);
    setCurrentIndex(Math.min(Math.max(index, 0), upcomingOrders.length - 1));
  }, [upcomingOrders.length]);

  const handleOrderPress = useCallback((order: Order) => {
    setNavigationTarget(`/(drawer)/(tabs)/me/my-orders/${order.id}`);
    router.replace('/(drawer)/(tabs)/me');
  }, [router, setNavigationTarget]);

  if (!userDetails) {
    return null;
  }

  if (ordersLoading) {
    return (
      <View style={tw`px-6 mb-4`}>
        <View style={tw`bg-white rounded-2xl p-4 border border-gray-100`}>
          <ActivityIndicator size="small" color="#3B82F6" />
        </View>
      </View>
    );
  }

  if (upcomingOrders.length === 0) {
    return null;
  }

  return (
    <View style={tw`mb-4`}>
      <ScrollView
        ref={scrollViewRef}
        horizontal
        showsHorizontalScrollIndicator={false}
        decelerationRate="fast"
        snapToInterval={SNAP_INTERVAL}
        contentContainerStyle={tw`px-6`}
        onScroll={handleScroll}
        onMomentumScrollEnd={handleScroll}
        scrollEventThrottle={16}
      >
        {upcomingOrders.map((order) => (
          <OrderCard
            key={order.id}
            order={order}
            onPress={() => handleOrderPress(order)}
            supportMobile={essentialConsts?.supportMobile}
          />
        ))}
      </ScrollView>

      {/* Pagination Dots */}
      {upcomingOrders.length > 1 && (
        <View style={tw`flex-row justify-center mt-2`}>
          {upcomingOrders.map((_, index) => (
            <View
              key={index}
              style={tw`mx-1 w-2 h-2 rounded-full ${index === currentIndex ? 'bg-amber-500' : 'bg-amber-200'}`}
            />
          ))}
        </View>
      )}
    </View>
  );
}