import { Colors } from '@/constants/Colors';
import { useAppSelector } from '@/hooks/redux';
import { useColorScheme } from '@/hooks/useColorScheme';
import dayjs from 'dayjs';
import React, { useMemo } from 'react';
import { Dimensions, StyleSheet, Text, View } from 'react-native';


const ActivityHeatMap = () => {
  const colorScheme = useColorScheme();
  const colors = Colors[colorScheme ?? 'light'];

  const activityData = useAppSelector(stat => stat.user.activityHistory);

  // 获取屏幕宽度，计算适合的网格大小
  const screenWidth = Dimensions.get('window').width;
  const containerPadding = 40; // 卡片的左右padding
  const availableWidth = screenWidth - containerPadding;

  // 计算小方块的尺寸（显示最近26周，约6个月）
  const weeksToShow = 26;
  const gapBetweenWeeks = 4; // 周与周之间的间距
  const totalGaps = (weeksToShow - 1) * gapBetweenWeeks;
  const cellWidth = (availableWidth - totalGaps) / weeksToShow;
  const cellSize = Math.max(Math.floor(cellWidth), 8); // 确保最小尺寸

  // 生成最近6个月的活动数据
  const generateActivityData = useMemo(() => {
    const data: { date: string; level: number }[] = [];


    const today = dayjs();
    const startDate = today.subtract(weeksToShow * 7, 'day');

    // 创建服务端数据的日期映射，便于快速查找
    const activityMap = new Map<string, number>();
    if (activityData && activityData.length > 0) {
      activityData.forEach(item => {
        activityMap.set(item.date, item.level);
      });
    }

    for (let i = 0; i <= weeksToShow * 7; i++) {
      const currentDate = startDate.add(i, 'day');
      const dateString = currentDate.format('YYYY-MM-DD');

      // 如果服务端有对应日期的数据，使用服务端的 level；否则为 0
      const level = activityMap.get(dateString) || 0;

      data.push({
        date: dateString,
        level,
      });
    }

    return data;
  }, [activityData, weeksToShow]);

  console.log('generateActivityData', generateActivityData);


  // 根据活跃度计算颜色
  const getActivityColor = (level: number): string => {
    // 由于useColorScheme总是返回'light'，我们直接使用浅色主题的颜色
    switch (level) {
      case 0:
        return colors.separator; // 使用主题分隔线色
      case 1:
      case 2:
        return 'rgba(135,206,235,0.4)';
      case 3:
        return 'rgba(135,206,235,0.65)';
      case 4:
      default:
        return colors.primary;
    }
  };

  // 将数据按周组织
  const organizeDataByWeeks = useMemo(() => {
    const weeks: { date: string; level: number }[][] = [];

    for (let week = 0; week < weeksToShow; week++) {
      const weekData: { date: string; level: number }[] = [];
      for (let day = 1; day <= 7; day++) {
        const dataIndex = week * 7 + day;
        if (dataIndex < generateActivityData.length) {
          weekData.push(generateActivityData[dataIndex] as { date: string; level: number });
        }
      }
      weeks.push(weekData);
    }

    return weeks;
  }, [generateActivityData, weeksToShow]);

  console.log('organizeDataByWeeks', organizeDataByWeeks);


  // 获取月份标签（简化的月份标签系统）
  const getMonthLabels = useMemo(() => {
    const monthNames = ['1月', '2月', '3月', '4月', '5月', '6月',
      '7月', '8月', '9月', '10月', '11月', '12月'];

    // 简单策略：均匀分布4-5个月份标签
    const totalWeeks = weeksToShow;
    const labelPositions: { label: string; position: number }[] = [];

    // 在25%、50%、75%位置放置标签
    const positions = [
      Math.floor(totalWeeks * 0.1),
      Math.floor(totalWeeks * 0.35),
      Math.floor(totalWeeks * 0.65),
      Math.floor(totalWeeks * 0.9)
    ];

    positions.forEach((weekIndex) => {
      if (weekIndex < organizeDataByWeeks.length && organizeDataByWeeks[weekIndex].length > 0) {
        const firstDay = dayjs(organizeDataByWeeks[weekIndex][0].date);
        const month = firstDay.month();
        labelPositions.push({
          label: monthNames[month],
          position: weekIndex
        });
      }
    });

    return labelPositions;
  }, [organizeDataByWeeks, weeksToShow]);

  // 计算活动统计
  const activityStats = useMemo(() => {
    const totalDays = generateActivityData.length;
    const activeDays = generateActivityData.filter(d => d.level > 0).length;
    const totalActivity = generateActivityData.reduce((sum, d) => sum + d.level, 0);

    return {
      totalDays,
      activeDays,
      totalActivity,
      activeRate: Math.round((activeDays / totalDays) * 100)
    };
  }, [generateActivityData]);

  return (
    <View style={[styles.container, { backgroundColor: colors.card }]}>
      {/* 标题和统计 */}
      <View style={styles.header}>
        <View style={styles.titleRow}>
          <Text style={[styles.subtitle, { color: colors.textMuted }]}>
            最近6个月活跃 {activityStats.activeDays} 天
          </Text>
          <View style={[styles.statsBadge, { backgroundColor: colors.ornamentPrimary }]}>
            <Text style={[styles.statsText, { color: colors.primary }]}>
              {activityStats.activeRate}%
            </Text>
          </View>
        </View>

      </View>

      {/* 活动热力图 */}
      <View style={styles.heatMapContainer}>
        {/* 热力图网格 */}
        <View style={styles.gridContainer}>
          {organizeDataByWeeks.map((week, weekIndex) => (
            <View key={weekIndex} style={[styles.week, { width: cellSize }]}>
              {week.map((day, dayIndex) => (
                <View
                  key={day.date}
                  style={[
                    styles.cell,
                    {
                      backgroundColor: getActivityColor(day.level),
                      width: cellSize,
                      height: cellSize,
                      borderRadius: Math.max(cellSize * 0.15, 1.5),
                    },
                  ]}
                />
              ))}
            </View>
          ))}
        </View>

        {/* 月份标签 */}
        <View style={styles.monthLabelsContainer}>
          {getMonthLabels.map((monthData, index) => {
            // 计算标签位置：基于周的位置，但要确保标签不重叠
            const basePosition = (monthData.position / (weeksToShow - 1)) * 100;
            // 限制位置范围，避免标签超出边界
            const leftPercentage = Math.max(0, Math.min(90, basePosition));

            return (
              <Text
                key={`${monthData.label}-${index}`}
                style={[
                  styles.monthLabel,
                  {
                    color: colors.textMuted,
                    position: 'absolute',
                    left: `${leftPercentage}%`
                  }
                ]}
              >
                {monthData.label}
              </Text>
            );
          })}
        </View>
      </View>

      {/* 图例 */}
      <View style={styles.legend}>
        <Text style={[styles.legendText, { color: colors.textMuted }]}>少</Text>
        <View style={styles.legendColors}>
          {[0, 1, 2, 3, 4].map((level) => (
            <View
              key={level}
              style={[
                styles.legendCell,
                {
                  backgroundColor: getActivityColor(level),
                  borderColor: colors.border,
                },
              ]}
            />
          ))}
        </View>
        <Text style={[styles.legendText, { color: colors.textMuted }]}>多</Text>
      </View>
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    borderRadius: 16,
    padding: 20,
    marginBottom: 20,
    shadowColor: 'rgba(135,206,235,0.25)',
    shadowOffset: { width: 0, height: 3 },
    shadowOpacity: 0.12,
    shadowRadius: 6,
    elevation: 3,
    borderWidth: 1,
    borderColor: 'rgba(135,206,235,0.08)',
  },
  header: {
    marginBottom: 8,
  },
  titleRow: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    marginBottom: 6,
  },
  title: {
    fontSize: 18,
    fontWeight: 'bold',
  },
  statsBadge: {
    paddingHorizontal: 12,
    paddingVertical: 4,
    borderRadius: 12,
  },
  statsText: {
    fontSize: 13,
    fontWeight: '600',
  },
  subtitle: {
    fontSize: 14,
    lineHeight: 20,
  },
  heatMapContainer: {
    marginBottom: 18,
  },
  gridContainer: {
    flexDirection: 'row',
    marginBottom: 12,
    paddingHorizontal: 2,
    gap: 2, // 统一的周间距
  },
  week: {
    flexDirection: 'column',
    gap: 1.5,
    flex: 1,
    alignItems: 'center',
  },
  cell: {
    borderWidth: 0,
  },
  monthLabelsContainer: {
    position: 'relative',
    height: 16,
    marginTop: 4,
    paddingHorizontal: 2,
  },
  monthLabel: {
    fontSize: 11,
    fontWeight: '500',
    opacity: 0.8,
    transform: [{ translateX: -12 }],
    minWidth: 24,
    textAlign: 'center',
  },
  legend: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'flex-end',
    gap: 10,
  },
  legendText: {
    fontSize: 10,
    opacity: 0.7,
  },
  legendColors: {
    flexDirection: 'row',
    gap: 4,
  },
  legendCell: {
    width: 8,
    height: 8,
    borderRadius: 2.5,
    borderWidth: 0.5,
  },
});

export default ActivityHeatMap;