import { Colors } from '@/constants/Colors';
import { useColorScheme } from '@/hooks/useColorScheme';
import { formatTime, getSleepStageColor, SleepStage, type SleepSample } from '@/utils/sleepHealthKit';
import { Ionicons } from '@expo/vector-icons';
import dayjs from 'dayjs';
import React, { useMemo } from 'react';
import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
import Svg, { Rect, Text as SvgText } from 'react-native-svg';

export type SleepStageTimelineProps = {
  sleepSamples: SleepSample[];
  bedtime: string;
  wakeupTime: string;
  onInfoPress?: () => void;
};

export const SleepStageTimeline = ({
  sleepSamples,
  bedtime,
  wakeupTime,
  onInfoPress
}: SleepStageTimelineProps) => {
  const theme = (useColorScheme() ?? 'light') as 'light' | 'dark';
  const colorTokens = Colors[theme];

  // 图表尺寸参数
  const containerWidth = 320;
  const chartPadding = 25; // 左右边距，为时间标签预留空间
  const chartWidth = containerWidth - chartPadding * 2;
  const chartHeight = 80;
  const timelineHeight = 32;
  const timelineY = 24;
  const timeScaleY = timelineY + timelineHeight + 16;

  // 计算时间范围和刻度
  const { timelineData, timeLabels } = useMemo(() => {
    if (!bedtime || !wakeupTime || sleepSamples.length === 0) {
      return { timelineData: [], timeLabels: [] };
    }

    const startTime = dayjs(bedtime);
    const endTime = dayjs(wakeupTime);
    const totalMinutes = endTime.diff(startTime, 'minute');
    
    // 过滤相关睡眠阶段，排除InBed
    const relevantSamples = sleepSamples.filter(sample => 
      sample.value !== SleepStage.InBed
    );

    // 转换样本数据为时间轴数据
    const data = relevantSamples.map(sample => {
      const sampleStart = dayjs(sample.startDate);
      const sampleEnd = dayjs(sample.endDate);
      
      const startOffset = sampleStart.diff(startTime, 'minute');
      const duration = sampleEnd.diff(sampleStart, 'minute');
      
      const x = Math.max(0, (startOffset / totalMinutes) * chartWidth) + chartPadding;
      const width = Math.max(2, (duration / totalMinutes) * chartWidth);
      
      return {
        x,
        width,
        stage: sample.value,
        color: getSleepStageColor(sample.value)
      };
    });

    // 智能生成时间标签，避免重合
    const labels = [];
    const minLabelSpacing = 50; // 最小标签间距（像素）
    
    // 总是显示起始时间
    labels.push({
      time: startTime.format('HH:mm'),
      x: chartPadding
    });

    // 根据睡眠总时长动态调整时间间隔
    const sleepDurationHours = totalMinutes / 60;
    let timeStepMinutes;
    
    if (sleepDurationHours <= 4) {
      timeStepMinutes = 60; // 1小时间隔
    } else if (sleepDurationHours <= 8) {
      timeStepMinutes = 120; // 2小时间隔
    } else {
      timeStepMinutes = 180; // 3小时间隔
    }

    // 添加中间时间标签，确保不重合
    let currentTime = startTime;
    let stepCount = 1;
    
    while (currentTime.add(timeStepMinutes * stepCount, 'minute').isBefore(endTime)) {
      const stepTime = currentTime.add(timeStepMinutes * stepCount, 'minute');
      const x = (stepTime.diff(startTime, 'minute') / totalMinutes) * chartWidth + chartPadding;
      
      // 检查与前一个标签的间距
      const lastLabel = labels[labels.length - 1];
      if (x - lastLabel.x >= minLabelSpacing && x <= containerWidth - chartPadding) {
        labels.push({
          time: stepTime.format('HH:mm'),
          x: x
        });
      }
      
      stepCount++;
    }

    // 总是显示结束时间，但要确保与前一个标签有足够间距
    const endX = containerWidth - chartPadding;
    const lastLabel = labels[labels.length - 1];
    if (endX - lastLabel.x >= minLabelSpacing) {
      labels.push({
        time: endTime.format('HH:mm'),
        x: endX
      });
    } else {
      // 如果空间不够，替换最后一个标签为结束时间
      labels[labels.length - 1] = {
        time: endTime.format('HH:mm'),
        x: endX
      };
    }

    return { timelineData: data, timeLabels: labels };
  }, [sleepSamples, bedtime, wakeupTime, chartWidth]);

  // 如果没有数据，显示空状态
  if (timelineData.length === 0) {
    return (
      <View style={[styles.container, { backgroundColor: colorTokens.background }]}>
        <View style={styles.header}>
          <Text style={[styles.title, { color: colorTokens.text }]}>睡眠阶段图</Text>
          {onInfoPress && (
            <TouchableOpacity style={styles.infoButton} onPress={onInfoPress}>
              <Ionicons name="help-circle-outline" size={20} color={colorTokens.textSecondary} />
            </TouchableOpacity>
          )}
        </View>
        <View style={styles.emptyState}>
          <Text style={[styles.emptyText, { color: colorTokens.textSecondary }]}>
            暂无睡眠阶段数据
          </Text>
        </View>
      </View>
    );
  }

  return (
    <View style={[styles.container, { backgroundColor: colorTokens.background }]}>
      {/* 标题栏 */}
      <View style={styles.header}>
        <Text style={[styles.title, { color: colorTokens.text }]}>睡眠阶段图</Text>
        {onInfoPress && (
          <TouchableOpacity style={styles.infoButton} onPress={onInfoPress}>
            <Ionicons name="help-circle-outline" size={20} color={colorTokens.textSecondary} />
          </TouchableOpacity>
        )}
      </View>

      {/* 睡眠时间范围 */}
      <View style={styles.timeRange}>
        <View style={styles.timePoint}>
          <Text style={[styles.timeLabel, { color: colorTokens.textSecondary }]}>入睡</Text>
          <Text style={[styles.timeValue, { color: colorTokens.text }]}>
            {formatTime(bedtime)}
          </Text>
        </View>
        <View style={styles.timePoint}>
          <Text style={[styles.timeLabel, { color: colorTokens.textSecondary }]}>起床</Text>
          <Text style={[styles.timeValue, { color: colorTokens.text }]}>
            {formatTime(wakeupTime)}
          </Text>
        </View>
      </View>

      {/* SVG 图表 */}
      <View style={styles.chartContainer}>
        <Svg width={containerWidth} height={chartHeight}>
          {/* 绘制睡眠阶段条形图 */}
          {timelineData.map((segment, index) => (
            <Rect
              key={index}
              x={segment.x}
              y={timelineY}
              width={segment.width}
              height={timelineHeight}
              fill={segment.color}
              rx={2}
            />
          ))}
          
          {/* 绘制时间刻度标签 */}
          {timeLabels.map((label, index) => (
            <React.Fragment key={index}>
              {/* 刻度线 */}
              <Rect
                x={label.x - 0.5}
                y={timelineY + timelineHeight}
                width={1}
                height={6}
                fill={colorTokens.border}
              />
              {/* 时间标签 */}
              <SvgText
                x={label.x}
                y={timeScaleY}
                fontSize={11}
                fill={colorTokens.textSecondary}
                textAnchor="middle"
              >
                {label.time}
              </SvgText>
            </React.Fragment>
          ))}
        </Svg>
      </View>

      {/* 图例 */}
      <View style={styles.legend}>
        <View style={styles.legendRow}>
          <View style={styles.legendItem}>
            <View style={[styles.legendDot, { backgroundColor: getSleepStageColor(SleepStage.Deep) }]} />
            <Text style={[styles.legendText, { color: colorTokens.textSecondary }]}>深度睡眠</Text>
          </View>
          <View style={styles.legendItem}>
            <View style={[styles.legendDot, { backgroundColor: getSleepStageColor(SleepStage.Core) }]} />
            <Text style={[styles.legendText, { color: colorTokens.textSecondary }]}>核心睡眠</Text>
          </View>
        </View>
        <View style={styles.legendRow}>
          <View style={styles.legendItem}>
            <View style={[styles.legendDot, { backgroundColor: getSleepStageColor(SleepStage.REM) }]} />
            <Text style={[styles.legendText, { color: colorTokens.textSecondary }]}>快速眼动</Text>
          </View>
          <View style={styles.legendItem}>
            <View style={[styles.legendDot, { backgroundColor: getSleepStageColor(SleepStage.Awake) }]} />
            <Text style={[styles.legendText, { color: colorTokens.textSecondary }]}>清醒时间</Text>
          </View>
        </View>
      </View>
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    borderRadius: 16,
    padding: 16,
    marginBottom: 24,
    shadowColor: '#000',
    shadowOffset: { width: 0, height: 2 },
    shadowOpacity: 0.1,
    shadowRadius: 8,
    elevation: 3,
    marginHorizontal: 4,
  },
  header: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    marginBottom: 16,
  },
  title: {
    fontSize: 16,
    fontWeight: '600',
  },
  infoButton: {
    padding: 4,
  },
  timeRange: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    marginBottom: 20,
  },
  timePoint: {
    alignItems: 'center',
  },
  timeLabel: {
    fontSize: 12,
    fontWeight: '500',
    marginBottom: 4,
  },
  timeValue: {
    fontSize: 16,
    fontWeight: '700',
    letterSpacing: -0.2,
  },
  chartContainer: {
    alignItems: 'center',
    marginBottom: 16,
  },
  emptyState: {
    alignItems: 'center',
    paddingVertical: 32,
  },
  emptyText: {
    fontSize: 14,
    fontStyle: 'italic',
  },
  legend: {
    gap: 8,
  },
  legendRow: {
    flexDirection: 'row',
    justifyContent: 'center',
    gap: 24,
  },
  legendItem: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 6,
  },
  legendDot: {
    width: 8,
    height: 8,
    borderRadius: 4,
  },
  legendText: {
    fontSize: 12,
    fontWeight: '500',
  },
});