import { LEVEL_MAP } from '@/constants/config';
import { Images } from '@/constants/images';
import { getUnavailableSeatNumbers, previewOrder } from '@/services/award';
import { Image, ImageBackground } from 'expo-image';
import React, { forwardRef, useEffect, useImperativeHandle, useState } from 'react';
import {
    ActivityIndicator,
    Alert,
    Dimensions,
    Modal,
    ScrollView,
    StyleSheet,
    Text,
    TouchableOpacity,
    View
} from 'react-native';

const { width: SCREEN_WIDTH } = Dimensions.get('window');

interface NumSelectionModalProps {
  poolId: string;
  onPay: (params: { previewRes: any, chooseNum: number[], boxNum: string }) => void;
}

export interface NumSelectionModalRef {
  show: (box: any) => void;
  close: () => void;
}



export const NumSelectionModal = forwardRef<NumSelectionModalRef, NumSelectionModalProps>(
  ({ poolId, onPay }, ref) => {
    const [visible, setVisible] = useState(false);
    const [box, setBox] = useState<any>(null);
    const [tabs, setTabs] = useState<any[]>([]);
    const [activeTab, setActiveTab] = useState<any>(null);
    
    // Status Maps
    const [useMap, setUseMap] = useState<Record<number, string>>({}); // Sold/Opened (seatNum -> level)
    const [lockMap, setLockMap] = useState<Record<number, number>>({}); // Locked/Pending (seatNum -> seatNum)
    const [checkMap, setCheckMap] = useState<Record<number, number>>({}); // Selected by user (seatNum -> seatNum)

    const [loading, setLoading] = useState(false);

    useImperativeHandle(ref, () => ({
      show: (boxItem: any) => {
        setBox(boxItem);
        setVisible(true);
        setCheckMap({});
        // Initialize Tabs based on box quantity
        // Assuming max 100 per tab like legacy
        const total = boxItem.quantity || 100; // Default or from box
        const newTabs = [];
        const itemsPerTab = 100;
        const count = Math.ceil(total / itemsPerTab);
        
        for (let i = 0; i < count; i++) {
            const start = i * itemsPerTab + 1;
            const end = Math.min((i + 1) * itemsPerTab, total);
            const data = Array.from({ length: end - start + 1 }, (_, k) => k + start);
            newTabs.push({
                title: `${start}~${end}`,
                value: i,
                data
            });
        }
        setTabs(newTabs);
        if (newTabs.length > 0) {
            setActiveTab(newTabs[0]);
            loadData(newTabs[0], boxItem.number);
        }
      },
      close: () => {
        setVisible(false);
      },
    }));

    const loadData = async (tab: any, boxNum: string) => {
        if (!tab || !boxNum) return;
        
        try {
            const start = tab.data[0];
            const end = tab.data[tab.data.length - 1];
            const res = await getUnavailableSeatNumbers(poolId, boxNum, start, end);
            
            if (res) {
                // Determine used (sold) and locked seats
                const newUseMap: Record<number, string> = { ...useMap }; // Merge? Or reset per tab? Legacy merges logic via object assignment but here standard React state update
                // Legacy clears map if not careful? No, it sets properties.
                // Let's reset for the current range to avoid stale data visually if we revisit, but merging is safer for 'global' knowledge. 
                // Efficiency-wise, let's keep it simple.
                
                if (res.usedSeatNumbers) {
                    res.usedSeatNumbers.forEach((item: any) => {
                        newUseMap[item.seatNumber] = item.level;
                    });
                }
                 
                const newLockMap: Record<number, number> = { ...lockMap };
                if (res.applyedSeatNumbers) {
                    res.applyedSeatNumbers.forEach((num: number) => {
                        newLockMap[num] = num;
                    });
                }
                
                setUseMap(newUseMap);
                setLockMap(newLockMap);

                // Remove selected if they became unavailable
                const newCheckMap = { ...checkMap };
                let changed = false;
                Object.keys(newCheckMap).forEach(key => {
                    const num = Number(key);
                    if (newUseMap[num] || newLockMap[num]) {
                        delete newCheckMap[num];
                        changed = true;
                    }
                });
                if (changed) setCheckMap(newCheckMap);
            }
        } catch (error) {
            console.error('Failed to load seat info', error);
        }
    };

    useEffect(() => {
        if (activeTab && box) {
            loadData(activeTab, box.number);
        }
    }, [activeTab]);

    const handleTabChange = (tab: any) => {
        setActiveTab(tab);
    };

    const toggleSelect = (num: number) => {
        if (useMap[num] || lockMap[num]) return;

        setCheckMap(prev => {
            const next = { ...prev };
            if (next[num]) {
                delete next[num];
            } else {
                if (Object.keys(next).length >= 50) {
                    Alert.alert('提示', '最多不超过50发');
                    return prev;
                }
                next[num] = num;
            }
            return next;
        });
    };

    const handleConfirm = async () => {
        const selectedNums = Object.values(checkMap).map(Number);
        if (selectedNums.length === 0) {
            Alert.alert('提示', '请选择号码');
            return;
        }

        setLoading(true);
        try {
            const res = await previewOrder(poolId, selectedNums.length, box.number, selectedNums);
            if (res) {
                 if (res.duplicateSeatNumbers && res.duplicateSeatNumbers.length > 0) {
                      Alert.alert('提示', `${res.duplicateSeatNumbers.join(',')}号被占用`);
                      // Remove duplicates
                      const newCheckMap = { ...checkMap };
                      res.duplicateSeatNumbers.forEach((n: number) => delete newCheckMap[n]);
                      setCheckMap(newCheckMap);
                      // Refresh data
                      loadData(activeTab, box.number);
                      return;
                 }
                 
                 // Proceed to pay callback
                 onPay({ previewRes: res, chooseNum: selectedNums, boxNum: box.number });
                 setVisible(false);
            }
        } catch (error: any) {
            Alert.alert('错误', error?.message || '请求失败');
        } finally {
            setLoading(false);
        }
    };

    const renderItem = (num: number) => {
        const isUsed = !!useMap[num];
        const isLocked = !!lockMap[num];
        const isSelected = !!checkMap[num];
        
        let content = <Text style={[styles.itemText, (isUsed || isLocked) && styles.disabledText]}>{num}号</Text>;
        let style = [styles.item];

        if (isUsed) {
            style.push(styles.levelItem as any);
            const level = useMap[num];
            content = (
                <View style={styles.usedContent}>
                    <Text style={styles.usedNum}>{num}号</Text>
                    <Text style={[styles.levelText, { color: LEVEL_MAP[level]?.color }]}>
                        {LEVEL_MAP[level]?.title || level}
                    </Text>
                </View>
            );
        } else if (isLocked) {
             style.push(styles.lockedItem as any);
             content = (
                <>
                   <Text style={styles.disabledText}>{num}号</Text>
                   <View style={styles.lockIcon}>
                       {/* Icon placeholder or text */}
                       <Text style={{fontSize: 10, color: '#fff'}}>🔒</Text>
                   </View>
                </>
             );
        } else if (isSelected) {
            style.push(styles.selectedItem as any);
            content = (
                <>
                    <Text style={styles.itemText}>{num}号</Text>
                    <View style={styles.checkIcon}>
                         <Text style={{fontSize: 8, color: '#F1423D'}}>✓</Text>
                    </View>
                </>
            );
        }

        return (
            <TouchableOpacity 
                key={num} 
                style={style} 
                onPress={() => toggleSelect(num)}
                disabled={isUsed || isLocked}
            >
                {content}
            </TouchableOpacity>
        );
    };

    const selectedList = Object.values(checkMap);

    return (
      <Modal visible={visible} transparent animationType="slide" onRequestClose={() => setVisible(false)}>
         <View style={styles.overlay}>
             <TouchableOpacity style={styles.mask} activeOpacity={1} onPress={() => setVisible(false)} />
             
             <ImageBackground 
                source={{ uri: Images.box.detail.recordBg }} 
                style={styles.container}
                resizeMode="stretch"
            >
                {/* Header */}
                <View style={styles.header}>
                    <Image source={{ uri: Images.box.detail.recordTitleLeft }} style={styles.titleDecor} contentFit="contain" />
                    <Text style={styles.title}>换盒</Text>
                    <Image source={{ uri: Images.box.detail.recordTitleRight }} style={styles.titleDecor} contentFit="contain" />
                    
                    <TouchableOpacity style={styles.closeBtn} onPress={() => setVisible(false)}>
                         <Text style={styles.closeText}>×</Text>
                    </TouchableOpacity>
                </View>

                {/* Tabs for Ranges */}
                {tabs.length > 1 && (
                     <View style={styles.tabsContainer}>
                        <ScrollView horizontal showsHorizontalScrollIndicator={false} contentContainerStyle={styles.tabsScroll}>
                            {tabs.map(tab => (
                                <TouchableOpacity 
                                    key={tab.title} 
                                    style={[styles.tab, activeTab?.value === tab.value && styles.activeTab]}
                                    onPress={() => handleTabChange(tab)}
                                >
                                    <Text style={[styles.tabText, activeTab?.value === tab.value && styles.activeTabText]}>
                                        {tab.title}
                                    </Text>
                                </TouchableOpacity>
                            ))}
                        </ScrollView>
                    </View>
                )}

                {/* Grid */}
                <ScrollView contentContainerStyle={styles.grid}>
                    {activeTab?.data.map((num: number) => renderItem(num))}
                </ScrollView>

                {/* Bottom Selection Bar */}
                <View style={styles.bottomSection}>
                    <ScrollView horizontal style={styles.selectedScroll} contentContainerStyle={styles.selectedContent}>
                        {selectedList.map((num) => (
                            <View key={num} style={styles.selectedChip}>
                                <Text style={styles.selectedChipText}>{num}号</Text>
                                <TouchableOpacity onPress={() => toggleSelect(Number(num))} style={styles.chipClose}>
                                    <Text style={styles.chipCloseText}>×</Text>
                                </TouchableOpacity>
                            </View>
                        ))}
                    </ScrollView>

                    <TouchableOpacity 
                        style={styles.confirmBtn} 
                        onPress={handleConfirm}
                        disabled={loading}
                    >
                         <ImageBackground source={{ uri: Images.common.loginBg }} style={styles.confirmBtnBg} resizeMode="stretch">
                             {loading ? <ActivityIndicator color="#fff" /> : (
                                 <View style={{ alignItems: 'center' }}>
                                     <Text style={styles.confirmText}>确定选择</Text>
                                     <Text style={styles.subConfirmText}>已选择({selectedList.length})发</Text>
                                 </View>
                             )}
                         </ImageBackground>
                    </TouchableOpacity>
                </View>

            </ImageBackground>
         </View>
      </Modal>
    );
  }
);

const styles = StyleSheet.create({
  overlay: {
    flex: 1,
    backgroundColor: 'rgba(0,0,0,0.5)',
    justifyContent: 'flex-end',
  },
  mask: { flex: 1 },
  container: {
    height: 600,
    paddingTop: 15,
    borderTopLeftRadius: 15,
    borderTopRightRadius: 15,
    overflow: 'hidden',
    backgroundColor: '#fff',
  },
  header: {
      flexDirection: 'row',
      alignItems: 'center',
      justifyContent: 'center',
      marginBottom: 15,
      position: 'relative',
      height: 44,
  },
  title: {
      fontSize: 18,
      fontWeight: 'bold',
      color: '#fff',
      marginHorizontal: 10,
      textShadowColor: '#000',
      textShadowOffset: { width: 1, height: 1 },
      textShadowRadius: 1,
  },
  titleDecor: {
      width: 17,
      height: 19,
  },
  closeBtn: {
      position: 'absolute',
      right: 15,
      top: 0,
      width: 24,
      height: 24,
      backgroundColor: '#ebebeb',
      borderRadius: 12,
      justifyContent: 'center',
      alignItems: 'center',
  },
  closeText: { fontSize: 18, color: '#a2a2a2', marginTop: -2 },
  tabsContainer: {
    height: 40,
    marginBottom: 10,
  },
  tabsScroll: {
    paddingHorizontal: 10,
  },
  tab: {
      paddingVertical: 6,
      paddingHorizontal: 12,
      backgroundColor: '#f5f5f5',
      borderRadius: 20,
      marginRight: 10,
      justifyContent: 'center',
  },
  activeTab: { backgroundColor: '#FFC900' },
  tabText: { fontSize: 12, color: '#666' },
  activeTabText: { color: '#000', fontWeight: 'bold' },
  grid: {
      flexDirection: 'row',
      flexWrap: 'wrap',
      paddingHorizontal: 10,
      paddingBottom: 20,
  },
  item: {
      width: (SCREEN_WIDTH - 20 - 45) / 5, // Approx 5 items per row
      height: ((SCREEN_WIDTH - 20 - 45) / 5) * 0.5,
      margin: 4,
      backgroundColor: '#FFC900',
      borderWidth: 3,
      borderColor: '#000',
      justifyContent: 'center',
      alignItems: 'center',
      borderRadius: 0,
  },
  itemText: { fontSize: 12, fontWeight: 'bold', color: '#000' },
  disabledText: { color: 'rgba(255,255,255,0.3)' },
  levelItem: { backgroundColor: '#e8e8e8', borderColor: '#e8e8e8' },
  lockedItem: { backgroundColor: 'rgba(98, 99, 115, 0.3)', borderColor: 'transparent', borderWidth: 0 },
  selectedItem: { backgroundColor: '#FFC900', borderColor: '#000' }, // Same as default but with icon
  usedContent: { alignItems: 'center' },
  usedNum: { fontSize: 10, opacity: 0.5 },
  levelText: { fontSize: 10, fontWeight: 'bold' },
  lockIcon: { position: 'absolute', bottom: 0, right: 0, backgroundColor: '#000', padding: 2, borderTopLeftRadius: 5 },
  checkIcon: {
      position: 'absolute',
      bottom: 0,
      right: 0,
      backgroundColor: '#fff',
      paddingHorizontal: 4,
      borderTopLeftRadius: 5,
  },
  bottomSection: {
      paddingBottom: 30,
      paddingTop: 10,
      borderTopWidth: 1,
      borderColor: '#eee',
      backgroundColor: '#fff',
  },
  selectedScroll: { maxHeight: 50, marginBottom: 10 },
  selectedContent: { paddingHorizontal: 10 },
  selectedChip: {
      flexDirection: 'row',
      alignItems: 'center',
      backgroundColor: '#FFC900',
      borderWidth: 2,
      borderColor: '#000',
      paddingHorizontal: 8,
      paddingVertical: 4,
      borderRadius: 4,
      marginRight: 8,
      height: 30,
  },
  selectedChipText: { fontSize: 12, fontWeight: 'bold', marginRight: 5 },
  chipClose: { backgroundColor: 'rgba(255,255,255,0.5)', borderRadius: 10, width: 16, height: 16, alignItems: 'center', justifyContent: 'center' },
  chipCloseText: { fontSize: 12, lineHeight: 14 },
  confirmBtn: {
      alignSelf: 'center',
      width: 200,
      height: 50,
  },
  confirmBtnBg: {
      flex: 1,
      justifyContent: 'center',
      alignItems: 'center',
  },
  confirmText: {
      color: '#fff',
      fontSize: 16,
      fontWeight: 'bold',
      textShadowColor: '#000',
      textShadowOffset: { width: 1, height: 1 },
      textShadowRadius: 1,
  },
  subConfirmText: {
      color: '#fff',
      fontSize: 10,
      marginTop: -2,
  },
});