import { router, useFocusEffect, useNavigation } from 'expo-router';
import {
    View,
    Text,
    ScrollView,
    Pressable,
    StyleSheet,
    Image,
    BackHandler,
    Alert,
    Linking,
    AppState,
    Modal,
    ActivityIndicator
} from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import NormalButton from '../../../../component/global/normal_button';
import { PreviousPageBlackSvg } from '../../../../component/global/SVG';
import { useChargingStore } from '../../../../providers/scan_qr_payload_store';
import { useCallback, useEffect, useLayoutEffect, useRef, useState } from 'react';
import useUserInfoStore from '../../../../providers/userinfo_store';
import { chargeStationService } from '../../../../service/chargeStationService';
import { authenticationService } from '../../../../service/authService';
import axios from 'axios';
import sha256 from 'crypto-js/sha256';
import { walletService } from '../../../../service/walletService';
import AsyncStorage from '@react-native-async-storage/async-storage';
const TotalPayment = () => {
    const {
        promotion_code,
        stationID,
        sum_of_coupon,
        scanned_qr_code,
        coupon_detail,
        total_power,
        processed_coupon_store,
        setPromotionCode,
        setCouponDetail,
        setTotalPower,
        setProcessedCouponStore,
        setSumOfCoupon,
        setCurrentPriceStore
    } = useChargingStore();
    const [currentPriceTotalPayment, setCurrentPriceTotalPayment] = useState<number | null>(null);
    const [walletBalance, setWalletBalance] = useState<number | null>(null);
    const [loading, setLoading] = useState(false);
    const [outTradeNo, setOutTradeNo] = useState('');
    const [isExpectingPayment, setIsExpectingPayment] = useState(false);
    const paymentInitiatedTime = useRef(null);
    const PAYMENT_CHECK_TIMEOUT = 5 * 60 * 1000; // 5 minutes in milliseconds
    const appState = useRef(AppState.currentState);
    const [totalPrice, setTotalPrice] = useState<number | null>(null);
    const [paymentStatus, setPaymentStatus] = useState(null);

    const [loadingModalVisible, setLoadingModalVisible] = useState(false);
    //fetch current price based on using coupon or not. use coupon = $3.5
    useEffect(() => {
        const fetchCurrentPrice = async () => {
            try {
                //if promotion_code.length > 0, fetch original price, otherwise fetch current price
                //then calculate total price for display purpose
                if (promotion_code.length > 0) {
                    const response = await chargeStationService.getOriginalPriceInPay(stationID);
                    setCurrentPriceTotalPayment(response);
                    let totalPrice = Number(total_power) * Number(response) - Number(sum_of_coupon);
                    if (totalPrice < 0) {
                        totalPrice = 0;
                    } else {
                        totalPrice = totalPrice;
                    }
                    setTotalPrice(totalPrice);
                } else {
                    const response = await chargeStationService.getCurrentPriceInPay(stationID);
                    setCurrentPriceTotalPayment(response);
                    let totalPrice = Number(total_power) * Number(response);
                    setTotalPrice(totalPrice);
                }
            } catch (error) {
                // More specific error handling
                if (axios.isAxiosError(error)) {
                    const errorMessage = error.response?.data?.message || 'Network error occurred';
                    Alert.alert('Error', `Unable to fetch price: ${errorMessage}`, [
                        {
                            text: 'OK',
                            onPress: () => {
                                cleanupData();
                                router.push('/mainPage');
                            }
                        }
                    ]);
                } else {
                    Alert.alert('Error', 'An unexpected error occurred while fetching the price', [
                        {
                            text: 'OK',
                            onPress: () => {
                                cleanupData();
                                router.push('/mainPage');
                            }
                        }
                    ]);
                }
            }
        };
        fetchCurrentPrice();
    }, []);
    // Add this effect to handle Android back button
    useFocusEffect(
        useCallback(() => {
            const onBackPress = () => {
                cleanupData();
                if (router.canGoBack()) {
                    router.back();
                } else {
                    router.replace('/scanQrPage');
                }
                return true;
            };

            const subscription = BackHandler.addEventListener('hardwareBackPress', onBackPress);
            return () => subscription.remove()
            // return () => BackHandler.removeEventListener('hardwareBackPress', onBackPress);
        }, [])
    );

    //check payment status

    useEffect(() => {
        const subscription = AppState.addEventListener('change', (nextAppState: any) => {
            if (
                appState.current.match(/inactive|background/) &&
                nextAppState === 'active' &&
                isExpectingPayment &&
                // outTradeNo &&
                paymentInitiatedTime.current
            ) {
                const currentTime = new Date().getTime();
                if (currentTime - paymentInitiatedTime.current < PAYMENT_CHECK_TIMEOUT) {
                    checkPaymentStatus();
                } else {
                    // Payment check timeout reached
                    setIsExpectingPayment(false);
                    setOutTradeNo('');
                    paymentInitiatedTime.current = null;
                    Alert.alert(
                        'Payment Timeout',
                        'The payment status check has timed out. Please check your payment history.'
                    );
                }
            }
            appState.current = nextAppState;
        });

        return () => {
            subscription.remove();
        };
    }, [outTradeNo, isExpectingPayment]);
    const navigation = useNavigation();

    useLayoutEffect(() => {
        navigation.setOptions({
            gestureEnabled: false
        });
    }, [navigation]);
    const checkPaymentStatus = async () => {
        try {
            // console.log('outTradeNo in scanQR Page checkpaymentstatus ', outTradeNo);
            const result = await walletService.checkPaymentStatus(outTradeNo);
            setPaymentStatus(result);
            // console.log('checkPaymentStatus from scan QR checkpaymentStatus', result);

            if (result && !result.some((item) => item.errmsg?.includes('處理中'))) {
                // Payment successful
                // console.log('totalFee', totalFee);
                Alert.alert('付款已成功', `你已成功增值。請重新掃描去啟動充電槍。`, [
                    {
                        text: '確認',
                        onPress: async () => {
                            cleanupData();
                            router.push('/mainPage');
                        }
                    }
                ]);
            } else {
                Alert.alert('付款失敗', '請再試一次。', [
                    {
                        text: '確定',
                        onPress: () => {
                            cleanupData();
                            router.push('/mainPage');
                        }
                    }
                ]);
            }
            setIsExpectingPayment(false);
            setOutTradeNo('');
            paymentInitiatedTime.current = null;
        } catch (error) {
            console.error('Failed to check payment status:', error);
            Alert.alert('Error', 'Failed to check payment status. Please check your payment history.');
        }
    };
    const showLoadingAndNavigate = async () => {
        setLoadingModalVisible(true);

        // Wait for 2 seconds
        await new Promise((resolve) => setTimeout(resolve, 2000));
        cleanupData();
        setLoadingModalVisible(false);
        router.navigate('(auth)/(tabs)/(home)/mainPage');
        router.push('(auth)/(tabs)/(charging)/chargingPage');
    };

    const cleanupData = () => {
        setPromotionCode([]);
        setCouponDetail([]);
        setProcessedCouponStore([]);
        setSumOfCoupon(0);
        setTotalPower(null);
    };
    const handlePay = async () => {
        try {
            let car, user_id, walletBalance, price_for_pay;
            setLoading(true);
            if (currentPriceTotalPayment === null) {
                Alert.alert('Please wait', 'Still loading price information...');
                return;
            }
            //fetch car with proper try catch
            try {
                car = await chargeStationService.getUserDefaultCars();
                if (!car?.data?.id) {
                    Alert.alert('Failed to fetch UDCC', 'Please try again later');
                    return;
                }
            } catch (error) {
                console.error('Failed to fetch user default car:', error);
                Alert.alert('Failed to fetch UDC', 'Please try again later');
                return;
            }
            //fetch user id with proper try catch
            try {
                user_id = await authenticationService.getUserInfo();
                if (!user_id?.data?.id) {
                    Alert.alert('Failed to fetch userID', 'Please try again later');
                    return;
                }
            } catch (error) {
                console.error('Failed to fetch user ID:', error);
                Alert.alert('Failed to fetch user ID', 'Please try again later');
                return;
            }

            // fetch user wallet with proper try catch
            try {
                walletBalance = await walletService.getWalletBalance();
            } catch (error) {
                console.error('Failed to fetch user wallet:', error);
                Alert.alert('Failed to fetch user wallet', 'Please try again later');
                return;
            }

            //now i have all information ready, i check penalty reservation
            //by first fetching all history, then check if penalty_fee > 0 and penalty_paid_status is false
            //if there is any, i will show an alert to the user, and once click the alert it will takes them to a page that show the detail of the reservation.
            try {
                const reservationHistories = await chargeStationService.fetchReservationHistories();
                // console.log('reservationHistories', reservationHistories);
                //here if i successfully fetch the reservationHistories, i will check if there are penalty, if i cannot fetch, i will simply continue the payment flow
                if (reservationHistories || Array.isArray(reservationHistories)) {
                    const unpaidPenalties = reservationHistories.filter(
                        (reservation: any) => reservation.penalty_fee > 0 && reservation.penalty_paid_status === false
                    );
                    const mostRecentUnpaidReservation = unpaidPenalties.reduce((mostRecent: any, current: any) => {
                        return new Date(mostRecent.created_at) > new Date(current.created_at) ? mostRecent : current;
                    }, unpaidPenalties[0]);

                    if (unpaidPenalties.length > 0) {
                        Alert.alert(
                            '未付罰款',
                            '您有未支付的罰款。請先支付罰款後再重新掃描充電。',
                            [
                                {
                                    text: '查看詳情',
                                    onPress: () => {
                                        // Navigate to a page showing penalty details
                                        cleanupData();
                                        router.push({
                                            pathname: '(auth)/(tabs)/(home)/penaltyPaymentPage',
                                            params: {
                                                book_time: mostRecentUnpaidReservation.book_time,
                                                end_time: mostRecentUnpaidReservation.end_time,
                                                actual_end_time: mostRecentUnpaidReservation.actual_end_time,
                                                penalty_fee: mostRecentUnpaidReservation.penalty_fee,
                                                format_order_id: mostRecentUnpaidReservation.format_order_id,
                                                id: mostRecentUnpaidReservation.id
                                            }
                                        });
                                    }
                                },
                                {
                                    text: '返回',
                                    onPress: () => {
                                        cleanupData();
                                        if (router.canGoBack()) {
                                            router.push('/mainPage');
                                        } else {
                                            router.push('/mainPage');
                                        }
                                    }
                                }
                            ],
                            { cancelable: false }
                        );
                        return;
                    }
                }
            } catch (error) {
                Alert.alert('Error', 'Failed to fetch reservation histories for penalty checking purpose');
            }

            const now = new Date();
            const end_time_map: {
                [key: number]: number;
            } = {
                20: 25,
                25: 30,
                30: 40,
                40: 45,
                80: 120
            };
            const end_time = new Date(now.getTime() + end_time_map[total_power] * 60000);

            const payloadForPay = {
                stationID: stationID,
                connector: scanned_qr_code,
                user: user_id.data.id,
                book_time: now.toISOString(),
                end_time: end_time.toISOString(),
                total_power: total_power,
                total_fee: total_power * currentPriceTotalPayment,
                promotion_code: promotion_code,
                with_coupon: promotion_code.length > 0 ? true : false,
                car: car.data.id,
                type: 'walking',
                is_ic_call: false
            };

            // check if user has enough wallet, if not, link to qf pay page
            if (totalPrice === null) {
                Alert.alert('Error', 'Unable to fetch totalPrice', [
                    {
                        text: 'OK',
                        onPress: () => {
                            cleanupData();
                            router.push('/mainPage');
                        }
                    }
                ]);
                return;
            }
            if (walletBalance < totalPrice) {
                const needToPay = totalPrice - walletBalance;
                oneTimeCharging(needToPay);
                return;
            } else {
                // if user has enough wallet, proceed to payment
                try {
                    const response = await walletService.newSubmitPayment(
                        payloadForPay.stationID,
                        payloadForPay.connector,
                        payloadForPay.user,
                        payloadForPay.book_time,
                        payloadForPay.end_time,
                        payloadForPay.total_power,
                        payloadForPay.total_fee,
                        payloadForPay.promotion_code,
                        payloadForPay.with_coupon,
                        payloadForPay.car,
                        payloadForPay.type,
                        payloadForPay.is_ic_call
                    );

                    if (response.error) {
                        console.log('Error1', response.error);
                        // Handle error response from the service
                        Alert.alert('掃描失敗 請稍後再試。', response.message || '未知錯誤', [
                            {
                                text: '返回主頁',
                                onPress: () => {
                                    cleanupData();
                                    router.push('/mainPage');
                                }
                            }
                        ]);
                        return;
                    }

                    if (response === 200 || response === 201) {
                        Alert.alert('啟動成功', '請按下確認並等待頁面稍後自動跳轉至充電介面', [
                            {
                                text: '確認',
                                onPress: showLoadingAndNavigate
                            }
                        ]);
                    } else {
                        console.log('Error111', response, payloadForPay.connector);

                        Alert.alert('掃描失敗 請稍後再試。', response.error_msg || '未知錯誤', [
                            {
                                text: '返回主頁',
                                onPress: () => {
                                    cleanupData();
                                    router.push('/mainPage');
                                }
                            }
                        ]);
                    }
                } catch (error) {
                    console.error('Payment submission failed:', error);
                    Alert.alert('錯誤', '付款提交失敗，請稍後再試。', [
                        {
                            text: 'OK',
                            onPress: () => {
                                cleanupData();
                                router.push('/mainPage');
                            }
                        }
                    ]);
                }
            }
        } catch (error) {
        } finally {
            setLoading(false);
        }
    };
    function formatTime(utcTimeString: any) {
        // Parse the UTC time string
        const date = new Date(utcTimeString);

        // Add 8 hours
        date.setHours(date.getHours());

        // Format the date
        const year = date.getFullYear();
        const month = String(date.getMonth() + 1).padStart(2, '0');
        const day = String(date.getDate()).padStart(2, '0');
        const hours = String(date.getHours()).padStart(2, '0');
        const minutes = String(date.getMinutes()).padStart(2, '0');
        const seconds = String(date.getSeconds()).padStart(2, '0');

        // Return the formatted string
        return `${year}-${month}-${day} ${hours}:${minutes}:${seconds}`;
    }

    const oneTimeCharging = async (inputAmount: number) => {
        try {
            const response = await walletService.getOutTradeNo();
            if (response) {
                setOutTradeNo(response);
                setIsExpectingPayment(true);
                paymentInitiatedTime.current = new Date().getTime();
                const now = new Date();
                const formattedTime = formatTime(now);

                let amount = Math.round(inputAmount * 100);
                const origin = 'https://openapi-hk.qfapi.com/checkstand/#/?';
                const obj = {
                    // appcode: '6937EF25DF6D4FA78BB2285441BC05E9',
                    appcode: '636E234FB30D43598FC8F0140A1A7282',
                    goods_name: 'Crazy Charge 錢包增值',
                    out_trade_no: response,
                    paysource: 'crazycharge_checkout',
                    return_url: 'https://crazycharge.com.hk/completed',
                    failed_url: 'https://crazycharge.com.hk/failed',
                    notify_url: 'https://api.crazycharge.com.hk/api/v1/clients/qfpay/webhook',
                    sign_type: 'sha256',
                    txamt: amount,
                    txcurrcd: 'HKD',
                    txdtm: formattedTime
                };

                const paramStringify = (json, flag?) => {
                    let str = '';
                    let keysArr = Object.keys(json);
                    keysArr.sort().forEach((val) => {
                        if (json[val] === undefined || json[val] === null) return;
                        str += `${val}=${flag ? encodeURIComponent(json[val]) : json[val]}&`;
                    });
                    return str.slice(0, -1);
                };

                // const api_key = '8F59E31F6ADF4D2894365F2BB6D2FF2C';
                const api_key = '3E2727FBA2DA403EA325E73F36B07824';
                const params = paramStringify(obj);
                const sign = sha256(`${params}${api_key}`).toString();
                const url = `${origin}${paramStringify(obj, true)}&sign=${sign}`;

                try {
                    const supported = await Linking.canOpenURL(url);
                    if (supported) {
                        Alert.alert('', '偵測到您錢包餘額不足，現在為您跳轉到充值頁面', [
                            {
                                text: '確定',
                                onPress: async () => {
                                    await Linking.openURL(url);
                                }
                            }
                        ]);
                    } else {
                        Alert.alert('錯誤', '請稍後再試');
                    }
                } catch (error) {
                    console.error('Top-up failed:', error);
                    Alert.alert('Error', '一次性付款失敗，請稍後再試');
                }
            } else {
                Alert.alert('Error', 'failed to fetch outTradeNo.');
            }
        } catch (error) {
            Alert.alert('錯誤', '一次性付款失敗，請稍後再試');
        }
    };

    return (
        <SafeAreaView className="flex-1 bg-white" edges={['top', 'left', 'right']}>
            <Modal transparent={true} visible={loadingModalVisible} animationType="fade">
                <View className="flex-1 justify-center items-center bg-black/50">
                    <View className="bg-white p-6 rounded-lg items-center">
                        <ActivityIndicator size="large" color="#02677D" />
                        <Text className="mt-3">請稍候...</Text>
                    </View>
                </View>
            </Modal>
            <ScrollView className="flex-1 mx-[5%]" showsVerticalScrollIndicator={false}>
                <View style={{ marginTop: 25 }}>
                    <Pressable
                        onPress={() => {
                            if (router.canGoBack()) {
                                router.back();
                            } else {
                                cleanupData();
                                router.replace('/scanQrPage');
                            }
                        }}
                    >
                        <PreviousPageBlackSvg />
                    </Pressable>
                </View>
                <View style={{ marginTop: 25 }}>
                    <Text style={{ fontSize: 45, paddingBottom: 12 }}>付款概要</Text>

                    <View>
                        <View className="flex-row justify-between">
                            <Text className="text-base lg:text-lg ">充電費用</Text>
                            <Text className="text-base lg:text-lg">
                                HK $ {currentPriceTotalPayment ? currentPriceTotalPayment * total_power : 'Loading...'}
                            </Text>
                        </View>

                        <Text style={styles.grayColor} className="text-sm lg:text-base mt-4">
                            結算電度數 : {total_power == 80 ? '充滿停機' : `${total_power} KWh`}
                        </Text>
                        <Text style={styles.grayColor} className="text-sm lg:text-base mt-4">
                            每度電價錢 : $ {currentPriceTotalPayment ? currentPriceTotalPayment : 'Loading...'}
                        </Text>
                        <Text style={styles.grayColor} className="text-sm lg:text-base mt-4">
                          注: 跨時段充電將按不同時段的單價分別計费，實際充電量可能浮動
                        </Text>
                        <View className="h-0.5 my-3 bg-[#f4f4f4]" />

                        {processed_coupon_store && processed_coupon_store.length > 0 && (
                            <Text className="text-base lg:text-lg mb-4 lg:mb-6">優惠劵</Text>
                        )}
                        {processed_coupon_store &&
                            processed_coupon_store?.map((couponObj: any) => (
                                <View
                                    key={`${couponObj.coupon_detail.amount}-${couponObj.coupon_detail.expire_date}`}
                                    className="flex flex-row items-center justify-between"
                                >
                                    <View className="flex flex-row items-start ">
                                        <Image
                                            className="w-6 lg:w-8 xl:w-10 h-6 lg:h-8 xl:h-10"
                                            source={require('../../../../assets/couponlogo.png')}
                                        />
                                        <View key={couponObj.coupon_detail.id} className="flex flex-col ml-2 lg:ml-4 ">
                                            <Text className="text-base lg:text-xl text-[#888888] ">
                                                ${couponObj.coupon_detail.amount} 現金劵
                                            </Text>
                                            <Text className=" text-sm lg:text-base my-1 lg:mt-2 lg:mb-4 text-[#888888]">
                                                有效期{'  '}
                                                <Text className="font-[500] text-[#02677D]">
                                                    至 {couponObj.coupon_detail.expire_date.slice(0, 10)}
                                                </Text>
                                            </Text>
                                        </View>
                                    </View>

                                    {/* x 1 */}
                                    <View className="flex flex-row items-center">
                                        <Text className="text-sm lg:text-base">X {'  '}</Text>
                                        <View className="w-8 h-8 rounded-full bg-[#02677D] flex items-center justify-center">
                                            <Text className="text-white text-center text-lg">
                                                {couponObj.frequency}
                                            </Text>
                                        </View>
                                    </View>
                                </View>
                            ))}

                        {processed_coupon_store && processed_coupon_store.length > 0 && (
                            <View className="h-0.5 my-3 bg-[#f4f4f4]" />
                        )}
                        <View className="flex-row justify-between">
                            <Text className="text-xl">總計</Text>
                            <Text className="text-3xl">HK$ {totalPrice !== null ? totalPrice : 'Loading...'}</Text>
                        </View>
                        <View className="mt-4 ">
                            <NormalButton
                                title={
                                    <Text
                                        style={{
                                            color: 'white',
                                            fontSize: 16,
                                            fontWeight: '800'
                                        }}
                                    >
                                        {loading ? '處理中...' : '付款確認'}
                                    </Text>
                                }
                                onPress={handlePay}
                                extendedStyle={{ padding: 24 }}
                            />
                        </View>
                        <View className="h-8" />
                    </View>
                </View>
            </ScrollView>
        </SafeAreaView>
    );
};

export default TotalPayment;
const styles = StyleSheet.create({
    grayColor: {
        color: '#888888'
    },
    greenColor: {
        color: '#02677D'
    }
});
