import { StatusBadge } from '@/components/ui/status-badge';
import { Colors } from '@/constants/theme';
import type { ListResponse } from '@/utils/api';
import api from '@/utils/api';
import { getApiCache } from '@/utils/storage';
import { ActivityIndicator, Toast } from '@ant-design/react-native';
import { Ionicons } from '@expo/vector-icons';
import { useRoute } from '@react-navigation/native';
import clsx from 'clsx';
import { Stack, useNavigation } from 'expo-router';
import { useCallback, useEffect, useRef, useState } from 'react';
import { FlatList, Pressable, Text, TextInput, View } from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import type { Customer, CustomerLoanStatus } from '../(tabs)/customer';

const PAGE_SIZE = 15;
const CACHE_KEY = 'customer_first';
export const CustomerLoanStatusText: Record<NonNullable<CustomerLoanStatus>, string> = {
  idle: '待匹配',
  completed: '已完成',
  unmatch: '匹配失败',
  all: '所有',
  unknow: '未知'
};


export default function CustomerSelectScreen() {
    const insets = useSafeAreaInsets();
    const navigation = useNavigation();
    const route = useRoute();

    const [searchKey, setSearchKey] = useState('');
    const [list, setList] = useState<Customer[]>([]);
    const [loading, setLoading] = useState(true);
    const [activeStatus, setActiveStatus] = useState<CustomerLoanStatus>('idle');

    const startRef = useRef(0);
    const loanStatusRef = useRef<CustomerLoanStatus>('idle');
    const hasMoreRef = useRef(false);
    const loadingRef = useRef(false);
    const searchTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);

    const load = useCallback(async (start: number, loanStatus: CustomerLoanStatus, q?: string) => {
        if (loadingRef.current) return;
        loadingRef.current = true;
        loanStatusRef.current = loanStatus;
        startRef.current = start;
        setLoading(true);

        

        try {
            const res = await api.post<ListResponse<Customer>>('customer/list', {
                start,
                size: PAGE_SIZE,
                loanStatus,
                q,
            });
            if (loanStatusRef.current !== loanStatus) return;
            const next = res?.list ?? [];
            if (start === 0 && !loanStatus && next.length) {
                getApiCache().setObject(CACHE_KEY, res, 60);
            }
            hasMoreRef.current = next.length >= PAGE_SIZE;
            setList((prev) => (start === 0 ? next : prev.concat(next)));
            startRef.current = start + next.length;
            if (!next.length && start > 0) {
                Toast.offline('没有更多数据可加载');
            }
        } catch {
            Toast.fail('加载列表失败！');
        } finally {
            setLoading(false);
            loadingRef.current = false;
        }
    }, []);

    // 首次加载
    useEffect(() => {
        load(0, 'idle');
    }, [load]);

    const loadMore = useCallback(() => {
        if (!hasMoreRef.current || loadingRef.current) return;
        load(startRef.current, loanStatusRef.current, searchKey);
    }, [load, searchKey]);

    const handleSelectStatus = useCallback(
        (status: CustomerLoanStatus) => {
            const next = activeStatus === status ? undefined : status;
            setActiveStatus(next);
            load(0, next, searchKey);
        },
        [activeStatus, load, searchKey]
    );

    const handlePick = useCallback( 
        async (item: Customer) => {
            // @ts-ignore
            const res = await route.params?.onSelect?.(item);
            // alert(res);
            if (false === res) {
                return;
            }
            navigation.goBack();
        },
        [navigation]
    );

    const handleSearch = useCallback((k: string) => {
        setSearchKey(k);
        if (searchTimerRef.current) clearTimeout(searchTimerRef.current);

        searchTimerRef.current = setTimeout(() => {
            load(0, loanStatusRef.current, k);
        }, 600);
    }, [load, searchKey]);
    const handleReset = useCallback(()=> {
        handleSearch('');
    }, [handleSearch]);


    useEffect(() => {
        return () => {
            if (searchTimerRef.current) clearTimeout(searchTimerRef.current);
        };
    }, []);
    // @ts-ignore
    const currentId = route.params?.current;
    const renderItem = useCallback(
        ({ item }: { item: Customer }) => (
            <Pressable
                onPress={() => handlePick(item)}
                className="mb-2 flex-row items-center gap-3 rounded-2xl border border-outline-variant bg-surface-container-lowest px-4 py-3 active:opacity-90 active:scale-[0.99]"
            >
                {currentId === item.id && <Ionicons name='checkmark-circle-sharp' size={20} color={Colors.tint} />}
                <View className="h-10 w-10 items-center justify-center rounded-full bg-primary-fixed">
                    <Text className="text-base font-bold text-primary">{item.name?.[0] ?? '?'}</Text>
                </View>
                <View className="flex-1">
                    <Text className="text-base font-bold text-on-surface" numberOfLines={1}>
                        {item.name}
                    </Text>
                    <Text className="mt-0.5 text-sm text-on-surface-variant" numberOfLines={1}>
                        {item.mobile}
                    </Text>
                </View>
                {item.loan_status && <StatusBadge text={CustomerLoanStatusText[item.loan_status]} variant="secondary" />}
            </Pressable>
        ),
        [handlePick]
    );

    const ListHeader = (
        <>
            <View className="mb-3 flex-row items-center rounded-2xl bg-surface-container-low px-4 py-3">
                <Ionicons name="search-outline" size={20} color="#94a3b8" />
                <TextInput
                    value={searchKey}
                    onChangeText={handleSearch}
                    placeholder="搜索客户姓名 / 手机号"
                    placeholderTextColor="#94a3b8"
                    className="ml-3 flex-1 p-0 text-base text-on-surface"
                />
                {searchKey.length > 0 ? (
                    <Pressable hitSlop={8} onPress={handleReset}>
                        <Ionicons name="close-circle" size={20} color="#94a3b8" />
                    </Pressable>
                ) : null}
            </View>

            <View className="mb-4 flex-row flex-wrap gap-2">
                {Object.entries(CustomerLoanStatusText).map(([key, label]) => {
                    const active = activeStatus === (key as CustomerLoanStatus);
                    return (
                        <Pressable
                            key={key}
                            onPress={() => handleSelectStatus(key as CustomerLoanStatus)}
                            className={clsx("rounded-md px-1 border border-transparent active:opacity-84", {
                                 'border-primary-container': active,
                            })}
                        >
                            <Text
                                className={clsx("text-sm font-bold text-on-surface-variant", {
                                    'text-primary': active
                                })}
                            >
                                {label}
                            </Text>
                        </Pressable>
                    );
                })}
            </View>
        </>
    );

    const ListEmpty =
        !loading ? (
            <View className="items-center rounded-2xl border border-outline-variant bg-surface-container-lowest px-6 py-14">
                <Ionicons name="people-outline" size={44} color="#94a3b8" />
                <Text className="mt-4 text-base text-on-surface-variant">暂无匹配客户</Text>
            </View>
        ) : (
            <View className="flex-row items-center justify-center pt-8">
                <ActivityIndicator />
                <Text className="ml-2">加载中</Text>
            </View>
        );

    const ListFooter =
        loading && list.length > 0 ? (
            <View className="mt-2 flex-row items-center justify-center">
                <ActivityIndicator />
                <Text className="ml-2 pb-4">加载中</Text>
            </View>
        ) : null;

    return (
        <View className="flex-1 bg-surface">
            <Stack.Screen options={{ title: '选择客户' }} />
            <FlatList
                className="flex-1"
                contentContainerStyle={{
                    paddingTop: insets.top + 60,
                    paddingBottom: insets.bottom + 24,
                    paddingHorizontal: 20,
                }}
                data={list}
                keyExtractor={(item) => item.id}
                renderItem={renderItem}
                keyboardShouldPersistTaps="handled"
                showsVerticalScrollIndicator={false}
                ListHeaderComponent={ListHeader}
                ListEmptyComponent={ListEmpty}
                ListFooterComponent={ListFooter}
                onEndReached={loadMore}
                onEndReachedThreshold={0.5}
            />
        </View>
    );
}