import 'dart:ui' as ui;

import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:vbvs_app/common/color/appConstants.dart';
import 'package:vbvs_app/common/util/FitTool.dart';
import 'package:vbvs_app/common/util/MyUtils.dart';

class BarData {
  final int st; // 起始时间（毫秒）
  final int et; // 结束时间（毫秒）
  final double value; // 柱子高度
  final int id;
  final String name;
  final Color color;

  BarData({
    required this.st,
    required this.et,
    required this.value,
    required this.id,
    required this.name,
    required this.color,
  });
}

class BarChartWidget extends StatelessWidget {
  final List<BarData> data;
  final int startTime; // 毫秒时间戳
  final int endTime; // 毫秒时间戳
  final double maxYValue; // Y轴最大值
  final int yStepCount; // Y轴分段数

  const BarChartWidget({
    super.key,
    required this.data,
    required this.startTime,
    required this.endTime,
    required this.maxYValue,
    this.yStepCount = 5,
  });

  @override
  Widget build(BuildContext context) {
    return CustomPaint(
      size: Size(double.infinity, 500.rpx),
      painter: BarChartPainter(
        data,
        startTime,
        endTime,
        maxYValue: maxYValue,
        yStepCount: yStepCount,
      ),
    );
  }
}

class BarChartPainter extends CustomPainter {
  final List<BarData> data;
  final int startTime;
  final int endTime;
  final double maxYValue;
  final int yStepCount;

  final double topPadding = 0; // 控制顶部间距
  final double bottomPadding = 0; // 控制底部间距
  final double leftPadding = 30.rpx;
  // final double labelHeight = 50.rpx;

  BarChartPainter(
    this.data,
    this.startTime,
    this.endTime, {
    required this.maxYValue,
    this.yStepCount = 5,
  });

  @override
  void paint(Canvas canvas, Size size) {
    final chartWidth = size.width - leftPadding;
    final chartHeight = size.height - topPadding - bottomPadding;
    final totalDuration = endTime - startTime;

    final textPainter = TextPainter(textDirection: ui.TextDirection.ltr);
    final stepValue = maxYValue / yStepCount;

    // 绘制 Y 轴刻度线和文字
    for (int i = 0; i <= yStepCount; i++) {
      final value = stepValue * i;
      final y = topPadding + chartHeight - (value / maxYValue) * chartHeight;

      // 横线
      // canvas.drawLine(
      //   Offset(leftPadding, y),
      //   Offset(size.width, y),
      //   Paint()
      //     ..color = Colors.grey.withOpacity(0.3)
      //     ..strokeWidth = 0.5,
      // );
      final dashPaint = Paint()
        ..color = Colors.grey.withOpacity(0.5)
        ..strokeWidth = 0.5;

      drawDashedLine(
          canvas, Offset(leftPadding, y), Offset(size.width, y), dashPaint);

      // Y轴刻度文字
      textPainter.text = TextSpan(
        text: value.toStringAsFixed(0),
        style: TextStyle(
          fontSize: 20.rpx,
          color: themeController.currentColor.sc4,
        ),
      );
      textPainter.layout();
      textPainter.paint(
          canvas,
          Offset(
              leftPadding - textPainter.width - 4, y - textPainter.height / 2));
    }

    // X轴时间刻度
    final startDate = DateTime.fromMillisecondsSinceEpoch(startTime);
    final endDate = DateTime.fromMillisecondsSinceEpoch(endTime);
    final hourStep = const Duration(hours: 1);
    final xPaint = Paint()..color = Colors.grey;

    final xAxisY = topPadding + chartHeight;

    // 绘制整点小时刻度
    for (DateTime t = startDate; t.isBefore(endDate); t = t.add(hourStep)) {
      final x = ((t.millisecondsSinceEpoch - startTime) / totalDuration) *
              chartWidth +
          leftPadding;

      final timeLabel = (t == startDate || t == endDate)
          ? DateFormat('HH:mm').format(t)
          : DateFormat('h').format(t);

      textPainter.text = TextSpan(
        text: timeLabel,
        style: TextStyle(
          fontSize: AppConstants().smaller_text_fontSize,
          color: themeController.currentColor.sc4,
        ),
      );
      textPainter.layout();
      textPainter.paint(canvas, Offset(x - textPainter.width / 2, xAxisY + 4));
    }

    // ✅ 强制绘制结束时间刻度（确保显示）
    final endX =
        ((endTime - startTime) / totalDuration) * chartWidth + leftPadding;
    final endLabel = DateFormat('HH:mm').format(endDate);
    textPainter.text = TextSpan(
      text: endLabel,
      style: TextStyle(
        fontSize: AppConstants().smaller_text_fontSize,
        color: themeController.currentColor.sc4,
      ),
    );
    textPainter.layout();
    textPainter.paint(canvas, Offset(endX - textPainter.width / 2, xAxisY + 4));

    // 绘制柱子
    for (final d in data) {
      final left =
          ((d.st - startTime) / totalDuration) * chartWidth + leftPadding;
      final right =
          ((d.et - startTime) / totalDuration) * chartWidth + leftPadding;
      final barHeight = (d.value / maxYValue) * chartHeight;
      final top = topPadding + chartHeight - barHeight;

      final barPaint = Paint()..color = d.color;

      canvas.drawRect(
          Rect.fromLTRB(left, top, right, topPadding + chartHeight), barPaint);
    }
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) => true;

  void drawDashedLine(Canvas canvas, Offset start, Offset end, Paint paint,
      {double dashWidth = 5, double dashSpace = 3}) {
    double totalLength = (end.dx - start.dx).abs();
    double dashCount = (totalLength / (dashWidth + dashSpace)).floorToDouble();

    double dx = start.dx;
    final dy = start.dy;

    for (int i = 0; i < dashCount; i++) {
      final from = Offset(dx, dy);
      final to = Offset(dx + dashWidth, dy);
      canvas.drawLine(from, to, paint);
      dx += dashWidth + dashSpace;
    }
  }
}