import 'dart:ui';
import 'dart:math' as math;
import 'package:fis_measure/interfaces/date_types/point.dart';
import 'package:fis_measure/interfaces/enums/items.dart';
import 'package:fis_measure/interfaces/process/items/item.dart';
import 'package:fis_measure/interfaces/process/items/item_metas.dart';
import 'package:fis_measure/interfaces/process/workspace/point_info.dart';
import 'package:fis_measure/process/calcuators/calculator.dart';
import 'package:fis_measure/process/calcuators/curve.dart';
import 'package:fis_measure/process/calcuators/formulas/general.dart';
import 'package:fis_measure/utils/canvas.dart';
import 'package:path_drawing/path_drawing.dart';
import 'package:vid/us/vid_us_unit.dart';
import 'area_abstract.dart';

class Ellipse extends AreaItemAbstract {
  Ellipse(ItemMeta meta, IMeasureItem? parent) : super(meta, parent);

  @override
  bool onExecuteMouse(PointInfo args) {
    if (state == ItemStates.finished) {
      if (args.pointType == PointInfoType.mouseDown) {
        state = ItemStates.waiting;
      }
    }

    if (state == ItemStates.waiting) {
      if (args.pointType == PointInfoType.mouseDown) {
        handleMouseDownWhileWaiting(args);
      }
    } else if (state == ItemStates.running) {
      if (feature == null) return false;
      final f = feature! as EllipseFeature;
      final activeIndex = f.activeIndex;

      switch (args.pointType) {
        case PointInfoType.mouseMove:
          f.innerPoints[activeIndex] = args;
          f.adjustPoints(args);
          break;
        case PointInfoType.mouseDown:
          if (activeIndex == 1) {
            if (f.xAxisEnd == f.xAxisStart) {
              break;
            }
            f.adjustPoints(args);
            f.activeIndex = 2;
          } else if (activeIndex == 2) {
            doFeatureFinish();
          }
          break;
        default:
          return false;
      }

      doCalculate();

      return true;
    }
    return false;
  }

  bool isFirstPointMove = true;
  DPoint touchStartPosition = DPoint(0, 0); // 相对位移起始触摸点
  DPoint currPointLastPosition = DPoint(0, 0); // 当前操作的点之前所在位置

  @override
  bool onExecuteTouch(PointInfo args) {
    if (state == ItemStates.finished) {
      if (args.pointType == PointInfoType.touchDown) {
        state = ItemStates.waiting;
      }
    }

    if (state == ItemStates.waiting) {
      if (args.pointType == PointInfoType.touchDown) {
        isFirstPointMove = true;
        handleTouchDownWhileWaiting(args);
      }
    } else if (state == ItemStates.running) {
      if (feature == null) return false;
      final f = feature! as EllipseFeature;
      if (args.pointType == PointInfoType.touchDown) {
        touchStartPosition = args;
        currPointLastPosition = f.innerPoints[f.activeIndex];
      }
      if (args.pointType == PointInfoType.touchMove) {
        if (isFirstPointMove) {
          PointInfo newStartPoint = args;
          newStartPoint.addOffset(0, -0.2);
          if (isMoveTargetOutOfRange(newStartPoint)) return true;
          for (var element in f.innerPoints) {
            element.update(newStartPoint);
          }
        } else {
          PointInfo newPoint = PointInfo.fromOffset(
              currPointLastPosition
                  .clone()
                  .addVector(args - touchStartPosition)
                  .toOffset(),
              args.pointType);
          newPoint.hostVisualArea = args.hostVisualArea;
          if (isMoveTargetOutOfRange(newPoint)) return true;
          f.innerPoints[f.activeIndex] = newPoint;
          f.adjustPoints(newPoint);
        }
      }
      if (args.pointType == PointInfoType.touchUp) {
        if (isFirstPointMove) {
          isFirstPointMove = false;
          f.activeIndex = 1;
        }
        if (f.activeIndex == 1) {
          if (f.xAxisEnd != f.xAxisStart) {
            f.adjustPoints(args);
            f.activeIndex = 2;
          }
        } else if (f.activeIndex == 2) {
          doFeatureFinish();
        }
      }
      doCalculate();
      return true;
    }
    return false;
  }

  void handleMouseDownWhileWaiting(PointInfo args) {
    // TODO: 判断是否当前area
    // 转换为Area逻辑位置
    final point = args.toAreaLogicPoint();
    feature = EllipseFeature(this, point);
    if (args.hostVisualArea != null) {
      feature!.hostVisualArea = args.hostVisualArea;
    }
    feature!.activeIndex = 1;
    state = ItemStates.running;
  }

  void handleTouchDownWhileWaiting(PointInfo args) {
    // TODO: 判断是否当前area
    // 转换为Area逻辑位置
    final point = args.toAreaLogicPoint();
    feature = EllipseFeature(this, point);
    if (args.hostVisualArea != null) {
      feature!.hostVisualArea = args.hostVisualArea;
    }
    feature!.activeIndex = 0;
    state = ItemStates.running;
  }

  static Ellipse createAreaPerimeter(ItemMeta meta, [IMeasureItem? parent]) {
    final ellipse = Ellipse(meta, parent);
    ellipse.calculator = AreaPerimeterEllipseCal(ellipse);
    return ellipse;
  }

  static Ellipse createVolume(ItemMeta meta, [IMeasureItem? parent]) {
    final ellipse = Ellipse(meta, parent);
    ellipse.calculator = _EllipseVolumeCal(ellipse);
    return ellipse;
  }
}

class EllipseFeature extends AreaItemFeatureAbstract {
  EllipseFeature(Ellipse refItem, DPoint point) : super(refItem) {
    innerPoints.add(point.clone());
    innerPoints.add(point.clone());
    innerPoints.add(point.clone());
    innerPoints.add(point.clone());
  }

  /// 质心
  DPoint get centroid {
    final x = (xAxisStart.x + xAxisEnd.x) * 0.5;
    final y = (xAxisStart.y + xAxisEnd.y) * 0.5;
    return DPoint(x, y);
  }

  DPoint get xAxisStart => innerPoints[0];
  DPoint get xAxisEnd => innerPoints[1];
  DPoint get yAxisStart => innerPoints[2];
  DPoint get yAxisEnd => innerPoints[3];

  @override
  void paint(Canvas canvas, Size size) {
    if (innerPoints.isEmpty) return;

    drawId(canvas, size, idText);

    final xStartOffset = convert2ViewPoint(size, xAxisStart).toOffset();

    if (activeIndex < 1) {
      drawVertex(canvas, xStartOffset, true);
      return;
    } else {
      drawVertex(canvas, xStartOffset);
    }

    final xEndOffset = convert2ViewPoint(size, xAxisEnd).toOffset();
    canvas.drawDashLine(xStartOffset, xEndOffset, 1, 10, paintLinePan);

    final yStartOffset = convert2ViewPoint(size, innerPoints[2]).toOffset();
    final yEndOffset = convert2ViewPoint(size, innerPoints[3]).toOffset();
    final centroidOffset = convert2ViewPoint(size, centroid).toOffset();
    canvas.drawDashLine(yStartOffset, yEndOffset, 1, 10, paintLinePan);
    // canvas.drawDashLine(yStartOffset, xEndOffset, 1, 10, paintLinePan);
    // canvas.drawDashLine(yEndOffset, xEndOffset, 1, 10, paintLinePan);

    final radiusX = getRadiusX(size);
    final radiusY = getRadiusY(size);

    canvas.save();
    final path = Path();
    path.moveTo(xStartOffset.dx, xStartOffset.dy);

    // 以质心为原点旋转到水平方向
    canvas.translate(centroidOffset.dx, centroidOffset.dy);
    final rotateRad = (xEndOffset - xStartOffset).direction;
    canvas.rotate(rotateRad);
    canvas.translate(-centroidOffset.dx, -centroidOffset.dy);

    path.addOval(
      Rect.fromCenter(
        center: centroidOffset,
        width: radiusX * 2,
        height: radiusY * 2,
      ),
    );
    canvas.drawPath(
      dashPath(
        path,
        dashArray: CircularIntervalList<double>(<double>[2.0, 10.0]),
      ),
      paintPan,
    );
    canvas.restore();

    if (activeIndex == 1) {
      drawVertex(canvas, xEndOffset, true);
      drawVertex(canvas, yStartOffset);
      drawVertex(canvas, yEndOffset);
    } else if (activeIndex == 2) {
      drawVertex(canvas, xEndOffset);
      drawVertex(canvas, yEndOffset);
      drawVertex(canvas, yStartOffset, isActive);
    }
  }

  /// X轴半径
  double getRadiusX([Size? fitSize]) {
    if (innerPoints.length < 2) {
      return 0;
    }
    var p1 = xAxisStart;
    var p2 = xAxisEnd;
    if (fitSize != null) {
      p1 = p1.scale2Size(fitSize);
      p2 = p2.scale2Size(fitSize);
    }
    return (p2 - p1).length / 2;
  }

  /// Y轴半径
  double getRadiusY([Size? fitSize]) {
    if (activeIndex > 1) {
      var p = yAxisStart;
      var p2 = yAxisEnd;
      var c = centroid;
      if (fitSize != null) {
        p = p.scale2Size(fitSize);
        p2 = p2.scale2Size(fitSize);
        c = c.scale2Size(fitSize);
      }
      return (p - p2).length / 2;
    } else {
      return getRadiusX(fitSize);
    }
  }

  /// 圆周长
  double getCircumference([Size? fitSize]) {
    double a = getRadiusX(fitSize), b = getRadiusY(fitSize);
    if (a < b) {
      a = b;
      b = a;
    }

    return 2 * math.pi * b + 4 * (a - b);
  }

  /// 面积
  double getArea([Size? fitSize]) {
    return math.pi * getRadiusX(fitSize) * getRadiusY(fitSize);
  }

  /// 计算Y轴坐标点
  void adjustPoints(DPoint point) {
    if (activeIndex < 1) return;

    final refSize = refItem.application.displaySize;
    //  const refSize= Size(1000, 1000);
    // const restoreSize = Size(1 / 1000, 1 / 1000);
    final restoreSize = Size(1 / refSize.width, 1 / refSize.height);
    final p = point.scale2Size(refSize);
    final p1 = xAxisStart.scale2Size(refSize);
    final p2 = xAxisEnd.scale2Size(refSize);
    final double radius;
    if (activeIndex == 2) {
      radius = GeneralFormulas.distance2Line(p1, p2, p);
    } else {
      radius = getRadiusX(refSize);
    }
    final crossPoints = _findCrossPoints(p2, p1, radius);
    final p3Index = _findNearest(p, crossPoints);
    innerPoints[2] = crossPoints[p3Index].scale2Size(restoreSize);
    innerPoints[3] = crossPoints[1 - p3Index].scale2Size(restoreSize);
  }

  static List<DPoint> _findCrossPoints(DPoint a, DPoint b, distance) {
    final dx = b.x - a.x;
    final dy = b.y - a.y;

    final len = (b - a).length;

    /// 单位长度轴上距离增加量
    final udx = dx / len;
    final udy = dy / len;

    final px = -udy;
    final py = udx;

    final centroidX = (a.x + b.x) * 0.5;
    final centroidY = (a.y + b.y) * 0.5;
    final centroid = DPoint(centroidX, centroidY);

    final x1 = centroid.x + px * distance;
    final y1 = centroid.y + py * distance;
    final out1 = DPoint(x1, y1);

    final x2 = centroid.x - px * distance;
    final y2 = centroid.y - py * distance;
    final out2 = DPoint(x2, y2);

    return [out1, out2];
  }

  static int _findNearest(DPoint p, List<DPoint> source) {
    int rst = 0;
    double minLen = (source[0] - p).length;
    for (var i = 1; i < source.length; i++) {
      final len = (source[i] - p).length;
      if (len < minLen) {
        minLen = len;
        rst = i;
      }
    }
    return rst;
  }
}

class _EllipseVolumeCal extends Calculator<Ellipse, double> {
  _EllipseVolumeCal(Ellipse ref) : super(ref);

  @override
  void calculate() {
    if (ref.feature == null) return;

    final feature = ref.feature! as EllipseFeature;
    final viewport = feature.hostVisualArea!.viewport!;
    final size = viewport.convertBoundary;

    double xAxis = feature.getRadiusX(size);
    double yAxis = feature.getRadiusY(size);
    var a = math.max(xAxis, yAxis);
    var b = math.min(xAxis, yAxis);
    var value = math.pi / 6.0 * a * b * b;
    updateFloatValue(value, unit: VidUsUnit.cm3, useRound: true);
  }
}