import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:vbvs_app/common/util/FitTool.dart';
import 'package:vbvs_app/common/util/MyUtils.dart';

class TimeSeriesPoint {
  final int timestamp;
  final double value;
  TimeSeriesPoint(this.timestamp, this.value);
}

class TimeSeriesChart extends StatelessWidget {
  final int startTime; // 毫秒时间戳
  final int endTime;
  final double yMin;
  final double yMax;
  final List<TimeSeriesPoint> dataPoints;

  const TimeSeriesChart({
    Key? key,
    required this.startTime,
    required this.endTime,
    required this.yMin,
    required this.yMax,
    required this.dataPoints,
  }) : super(key: key);

  // 计算总分钟数
  double get _totalMinutes {
    return (endTime - startTime) / (1000 * 60);
  }

  // 生成X轴刻度标签
  Map<double, String> _generateXLabels() {
    final labels = <double, String>{};
    final startDate = DateTime.fromMillisecondsSinceEpoch(startTime);
    final endDate = DateTime.fromMillisecondsSinceEpoch(endTime);

    // 0分钟位置：起始时间
    labels[0.0] =
        '${startDate.hour.toString().padLeft(2, '0')}:${startDate.minute.toString().padLeft(2, '0')}';

    // 计算总小时数
    final int hourMs = 60 * 60 * 1000;
    final int totalHours = (endTime - startTime) ~/ hourMs;

    // 按照参考代码的逻辑，当小时数超过8时，跳着显示
    if (totalHours <= 8) {
      // 显示每个整点
      DateTime currentHour = DateTime(
        startDate.year,
        startDate.month,
        startDate.day,
        startDate.hour,
      );

      // 如果起始时间不是整点，从下一个整点开始
      if (startDate.minute > 0 ||
          startDate.second > 0 ||
          startDate.millisecond > 0) {
        currentHour = currentHour.add(Duration(hours: 1));
      }

      while (currentHour.millisecondsSinceEpoch < endTime) {
        final int timeMs = currentHour.millisecondsSinceEpoch;

        if (timeMs > startTime && timeMs < endTime) {
          // 检查是否太靠近边界
          if (timeMs - startTime < 10 * 60 * 1000 ||
              endTime - timeMs < 10 * 60 * 1000) {
            currentHour = currentHour.add(Duration(hours: 1));
            continue;
          }

          // 计算从起始时间到当前整点的分钟数
          final minutesFromStart =
              (currentHour.millisecondsSinceEpoch - startTime) / (1000 * 60);
          labels[minutesFromStart] = '${currentHour.hour}';
        }

        currentHour = currentHour.add(Duration(hours: 1));
      }
    } else {
      // 超过8小时，跳着显示
      final int labelInterval = (totalHours / 6).ceil(); // 分成大约6个标签

      DateTime firstLabelHour = DateTime(
        startDate.year,
        startDate.month,
        startDate.day,
        startDate.hour + (labelInterval - (startDate.hour % labelInterval)),
        0,
        0,
        0,
        0,
      );

      // 确保第一个标签在开始时间之后
      if (firstLabelHour.millisecondsSinceEpoch <= startTime) {
        firstLabelHour = firstLabelHour.add(Duration(hours: labelInterval));
      }

      DateTime currentHour = firstLabelHour;
      while (currentHour.millisecondsSinceEpoch < endTime) {
        final int timeMs = currentHour.millisecondsSinceEpoch;

        // 确保标签离边界足够远
        if (timeMs - startTime >= hourMs && endTime - timeMs >= hourMs) {
          final minutesFromStart =
              (currentHour.millisecondsSinceEpoch - startTime) / (1000 * 60);
          labels[minutesFromStart] = '${currentHour.hour}';
        }

        currentHour = currentHour.add(Duration(hours: labelInterval));
      }
    }

    // 最后位置：结束时间
    labels[_totalMinutes] =
        '${endDate.hour.toString().padLeft(2, '0')}:${endDate.minute.toString().padLeft(2, '0')}';

    return labels;
  }

  // 时间戳映射到X坐标（分钟数）
  double _timeToX(double timestamp) {
    final minutesFromStart = (timestamp - startTime) / (1000 * 60);
    return minutesFromStart.clamp(0.0, _totalMinutes);
  }

  @override
  Widget build(BuildContext context) {
    final xLabels = _generateXLabels();
    final labelPositions = xLabels.keys.toList()..sort();
    final midY = (yMin + yMax) / 2;

    // 将数据点分割成多个连续段，遇到value=-1时断开
    List<List<FlSpot>> lineSegments = [];
    List<FlSpot> currentSegment = [];

    for (var point in dataPoints) {
      if (point.value != -1) {
        // 有效数据点，添加到当前段
        currentSegment.add(FlSpot(
          _timeToX(point.timestamp.toDouble()),
          point.value,
        ));
      } else if (currentSegment.isNotEmpty) {
        // 遇到无效点且当前段不为空，结束当前段
        lineSegments.add(currentSegment);
        currentSegment = [];
      }
    }

    // 添加最后一个段（如果有）
    if (currentSegment.isNotEmpty) {
      lineSegments.add(currentSegment);
    }

    return AspectRatio(
      aspectRatio: 2,
      child: LineChart(
        LineChartData(
          minX: 0,
          maxX: _totalMinutes,
          minY: yMin < 0 ? yMin : 0,
          maxY: yMax,
          gridData: FlGridData(show: false),
          extraLinesData: ExtraLinesData(
            horizontalLines: [
              HorizontalLine(
                  y: 0,
                  color: themeController.currentColor.sc4,
                  strokeWidth: 1.rpx),
              HorizontalLine(
                  y: yMin,
                  color: themeController.currentColor.sc9,
                  strokeWidth: 1.rpx,
                  dashArray: [5, 5]),
              HorizontalLine(
                  y: yMax,
                  color: themeController.currentColor.sc9,
                  strokeWidth: 1.rpx,
                  dashArray: [5, 5]),
              HorizontalLine(
                  y: midY,
                  color: themeController.currentColor.sc4,
                  strokeWidth: 1.rpx,
                  dashArray: [5, 5]),
            ],
          ),
          titlesData: FlTitlesData(
            bottomTitles: AxisTitles(
              sideTitles: SideTitles(
                showTitles: true,
                reservedSize: 30,
                interval: 1, // 现在每个单位是1分钟
                getTitlesWidget: (value, meta) {
                  // 四舍五入到最接近的整数
                  final roundedValue = value.roundToDouble();

                  // 检查是否在标签位置
                  for (var position in labelPositions) {
                    if ((position - roundedValue).abs() < 0.5) {
                      final label = xLabels[position] ?? '';
                      return Padding(
                        padding: const EdgeInsets.only(top: 8.0),
                        child: Text(label,
                            style: TextStyle(
                                color: themeController.currentColor.sc4,
                                fontSize: 16.rpx)),
                      );
                    }
                  }

                  return const SizedBox.shrink();
                },
              ),
            ),
            leftTitles: AxisTitles(
              sideTitles: SideTitles(
                showTitles: true,
                reservedSize: 40.rpx,
                interval: 1,
                getTitlesWidget: (value, meta) {
                  // 只显示 yMin, midY, yMax, 和 0
                  if ((value - 0).abs() < 0.01) {
                    return Text('0',
                        style: TextStyle(
                            color: themeController.currentColor.sc4,
                            fontSize: 16.rpx));
                  } else if ((value - yMin).abs() < 0.01) {
                    return Text(yMin.toStringAsFixed(0),
                        style: TextStyle(
                            color: themeController.currentColor.sc4,
                            fontSize: 16.rpx));
                  } else if ((value - midY).abs() < 0.01) {
                    return Text(midY.toStringAsFixed(0),
                        style: TextStyle(
                            color: themeController.currentColor.sc4,
                            fontSize: 16.rpx));
                  } else if ((value - yMax).abs() < 0.01) {
                    return Text(yMax.toStringAsFixed(0),
                        style: TextStyle(
                            color: themeController.currentColor.sc4,
                            fontSize: 16.rpx));
                  } else {
                    return const SizedBox.shrink();
                  }
                },
              ),
            ),
            rightTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
            topTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
          ),
          borderData: FlBorderData(
            show: true,
            border: Border(
              bottom: BorderSide(color: Colors.grey.withOpacity(0.3)),
              left: BorderSide.none,
              right: BorderSide.none,
              top: BorderSide.none,
            ),
          ),
          lineBarsData: lineSegments.map((segment) {
            return LineChartBarData(
              spots: segment,
              isCurved: false,
              color: themeController.currentColor.sc2,
              barWidth: 2,
              dotData: FlDotData(show: false),
              preventCurveOverShooting: true,
            );
          }).toList(),
        ),
      ),
    );
  }
}