import 'dart:ui';
import 'dart:math' as math;

import 'package:fis_measure/interfaces/date_types/point.dart';
import 'package:fis_measure/interfaces/date_types/vector.dart';
import 'package:fis_measure/interfaces/enums/items.dart';
import 'package:fis_measure/interfaces/process/calculators/values.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/items/types.dart';
import 'package:fis_measure/interfaces/process/workspace/application.dart';
import 'package:fis_measure/interfaces/process/workspace/point_info.dart';
import 'package:fis_measure/process/calcuators/curve.dart';
import 'package:fis_measure/process/calcuators/formulas/general.dart';
import 'package:fis_measure/process/items/item.dart';
import 'package:fis_measure/process/items/item_feature.dart';
import 'package:fis_measure/process/primitives/polyline.dart';
import 'package:fis_measure/process/primitives/area_abstract.dart';
import 'package:fis_measure/process/primitives/utils/auto_snap.dart';
import 'package:fis_measure/process/unit/convert/convert.dart';
import 'package:fis_measure/utils/canvas.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:get/get.dart';
import 'package:path_drawing/path_drawing.dart';
import 'package:vid/us/vid_us_unit.dart';

import 'spline.dart';
import 'utils/line.dart';
import 'utils/spline.dart';

enum LvSimpsonStep {
  none,
  splineBeginEdit,
  splineEditing,
  splineEndEdit,
  splineCompleted,
  done,
}

class SimpsonPath extends AreaItemAbstract with AutoSnapMixin {
  static const int splitterCount = 20;
  static const double maxPointsCount = 10000;

  SimpsonPath(ItemMeta meta, IMeasureItem? parent) : super(meta, parent);

  PointInfo? firstPoint;

  @protected
  LvSimpsonStep lvSimpsonStep = LvSimpsonStep.none;

  @override
  // SimpsonPathFeature? get feature => super.feature as SimpsonPathFeature;
  SimpsonPathFeature? get feature {
    if (super.feature == null) {
      return null;
    }
    return super.feature as SimpsonPathFeature;
  }

  @override
  bool onExecuteMouse(PointInfo args) {
    if (state == ItemStates.finished) {
      if (args.pointType == PointInfoType.mouseDown) {
        state = ItemStates.waiting;
        lvSimpsonStep = LvSimpsonStep.none;
        snapState = false;
      }
    }

    if (state == ItemStates.waiting) {
      if (args.pointType == PointInfoType.mouseDown) {
        handleMouseDownWhileWaiting(args);
      }
    } else if (state == ItemStates.running) {
      switch (args.pointType) {
        case PointInfoType.mouseUp:
          return false;
        case PointInfoType.mouseDown:
          if (lvSimpsonStep == LvSimpsonStep.splineCompleted) {
            feature!.adjustEndPoint(args.toAreaLogicPoint());
            lvSimpsonStep = LvSimpsonStep.done;
            state = ItemStates.finished;
            // CaliperExtension.ShowCaliper();
            doFeatureFinish();
          } else {
            final lineLen = (args - firstPoint!).length;
            if ((feature!.innerPoints.length > 3 &&
                    GeneralFormulas.doubleAlmostEquals(lineLen, 0)) ||
                feature!.innerPoints.length >= maxPointsCount) {
              lvSimpsonStep = LvSimpsonStep.splineCompleted;
              feature!.fixedSpline();
            } else {
              feature!.adopt(args.toAreaLogicPoint());
            }
          }
          break;
        case PointInfoType.mouseMove:
          if (lvSimpsonStep == LvSimpsonStep.splineCompleted) {
            feature!.adjustEndPoint(args.toAreaLogicPoint());
          } else {
            if (!snapState) {
              // checkAutoSnap(args, false);
              if (checkAutoSnap(args, false)) {
                lvSimpsonStep = LvSimpsonStep.splineCompleted;
                feature!.fixedSpline();
              } else {
                feature!.adopt(args.toAreaLogicPoint());
              }
            }
            if (snapState) {
              feature!.updateActivePoint(args.toAreaLogicPoint());
            }
          }
          break;
        default:
          break;
      }
    }

    doCalculate();
    if (args.pointType == PointInfoType.mouseDown) {
      // doFeatureFinish();
      // if (state == ItemStates.waiting || state == ItemStates.finished) {
      if (state == ItemStates.waiting) {
        state = ItemStates.running;
      }
      if (state == ItemStates.running) {
        updateStatus();
      }
    }

    if (args.pointType == PointInfoType.mouseMove) {
      updateStatus();
    }
    return true;
  }

  @override
  bool onExecuteTouch(PointInfo args) {
    // TODO: implement onExecuteTouch
    throw UnimplementedError();
  }

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

  void updateStatus() {
    switch (lvSimpsonStep) {
      case LvSimpsonStep.splineCompleted:
        firstPoint = null;
        if (feature != null) {
          feature!.activeIndex = feature!.innerPoints.length;
        }
        break;
      case LvSimpsonStep.done:
        state = ItemStates.finished;
        if (feature != null) {
          feature!.activeIndex = -1;
        }
        break;
      default:
        break;
    }
  }

  static SimpsonPath create(ItemMeta meta, [IMeasureItem? parent]) {
    final path = SimpsonPath(meta, parent);
    return path;
  }
}

class SimpsonPathFeature extends AreaItemFeatureAbstract {
  static const autoGetApexPoint = false; // TODO

  late Map<int, double> horizontalSplitterLegths;
  late DPoint moveBasedPoint;

  IPathGeometry? _pathGeometry;
  List<DPoint>? _splinePoints;
  IPathGeometry? _spline;
  late DPoint _centerLineFixedPoint;
  late DPoint _centerLineMovablePoint;

  late MovablePointsInfo _movablePtsInfo;
  late DPoint _leftPoint;
  late DPoint _rightPoint;
  late DPoint _apexPoint;

  SimpsonPathFeature(AreaItemAbstract refItem) : super(refItem) {
    _splinePoints = [];
    _centerLineFixedPoint = DPointExt.empty;
    _centerLineMovablePoint = DPointExt.empty;

    _movablePtsInfo = MovablePointsInfo.empty();
    _leftPoint = DPointExt.empty;
    _rightPoint = DPointExt.empty;
    _apexPoint = DPointExt.empty;

    moveBasedPoint = DPointExt.empty;
    horizontalSplitterLegths = {};
  }

  @override
  SimpsonPath get refItem => super.refItem as SimpsonPath;

  DPoint get centerLineMovablePoint => _centerLineMovablePoint;
  set centerLineMovablePoint(DPoint val) {
    if (val != _centerLineMovablePoint) {
      _centerLineMovablePoint = val;

      updateSplitters();
      _onVertexPointChanged();
    }
  }

  DPoint get centerLineFixedPoint => _centerLineFixedPoint;

  MovablePointsInfo get movablePtsInfo => _movablePtsInfo;
  set movablePtsInfo(MovablePointsInfo val) {
    if (val != _movablePtsInfo) {
      _movablePtsInfo = val;
      _onSplineMovablePointsInfoChanged();
    }
  }

  DPoint get leftPoint => _leftPoint;
  set leftPoint(DPoint val) {
    if (val != _leftPoint) {
      _leftPoint = val;
      _onVertexPointChanged();
    }
  }

  DPoint get rightPoint => _rightPoint;
  set rightPoint(DPoint val) {
    if (val != _rightPoint) {
      _rightPoint = val;
      _onVertexPointChanged();
    }
  }

  DPoint get apexPoint => _apexPoint;
  set apexPoint(DPoint val) {
    if (val != _apexPoint) {
      _apexPoint = val;
      _onVertexPointChanged();
    }
  }

  double get centerLineLength {
    final p1 = convert2CmPoint(_centerLineFixedPoint);
    final p2 = convert2CmPoint(_centerLineMovablePoint);
    double value = (p2 - p1).length.abs();
    return value;
  }

  double get area {
    final points = innerPoints.map((e) => convert2CmPoint(e)).toList();
    double value = AreaPerimeterCal.calcArea(points);
    return value;
  }

  DPoint convert2CmPoint(DPoint logicPoint) {
    final viewport = hostVisualArea!.viewport!;
    final p = viewport.convert(logicPoint);
    p.x = UnitValueConverter.convert(viewport.xUnit, VidUsUnit.cm, p.x);
    p.y = UnitValueConverter.convert(viewport.yUnit, VidUsUnit.cm, p.y);
    return p;
  }

  bool isClosed = false; // TODO

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

    drawId(canvas, size);

    final points = innerPoints.map((e) => convert2ViewPoint(size, e)).toList();
    final startPoint = points.first;
    drawVertex(canvas, startPoint.toOffset(), points.length == 1);

    if (points.length > 1) {
      final Path path = Path();
      path.moveTo(startPoint.x, startPoint.y);
      for (var i = 1; i < points.length; i++) {
        final point = points[i];
        path.lineTo(point.x, point.y);
      }
      if (isClosed) {
        path.lineTo(startPoint.x, startPoint.y);
      }
      canvas.drawPath(
        path,
        paintLinePan,
      );
    }

    if (_pathGeometry != null) {
      _drawGeometry(canvas, size, _pathGeometry!);
    }

    // 此处仅供调试绘制参考点
    // canvas.drawCircle(
    //   convert2ViewPoint(size, centerLineFixedPoint).toOffset(),
    //   10,
    //   Paint()
    //     ..color = Colors.blue
    //     ..style = PaintingStyle.fill,
    // );
    // canvas.drawCircle(
    //   convert2ViewPoint(size, centerLineMovablePoint).toOffset(),
    //   10,
    //   Paint()
    //     ..color = Colors.red
    //     ..style = PaintingStyle.fill,
    // );

    drawVertex(canvas, centerLineMovablePoint.toOffset(), isActive);
  }

  void _drawGeometry(Canvas canvas, Size size, IPathGeometry geometry) {
    Path? path;
    if (geometry is PathGeometryContainer) {
      for (var childGeometry in geometry.geometries) {
        _drawGeometry(canvas, size, childGeometry);
      }
    } else if (geometry is PathGeometry) {
      path = Path();
      for (var i = 0; i < geometry.points.length; i++) {
        final point = convert2ViewPoint(size, geometry.points[i]);
        if (i == 0) {
          path.moveTo(point.x, point.y);
        } else {
          path.lineTo(point.x, point.y);
        }
      }
    } else if (geometry is LineGeometry) {
      path = Path();
      DPoint point;
      point = convert2ViewPoint(size, geometry.start);
      path.moveTo(point.x, point.y);
      point = convert2ViewPoint(size, geometry.end);
      path.lineTo(point.x, point.y);
    }

    if (path != null) {
      canvas.drawPath(path, paintLinePan);
    }
  }

  @override
  void adopt(DPoint point) {
    super.adopt(point);
    recreateSpline(false);
  }

  void updateActivePoint(DPoint point) {
    if (activeIndex > 0 && activeIndex <= innerPoints.length) {
      activePoint = point;
      recreateSpline(false);
    }
  }

  DPoint get activePoint {
    if (activeIndex < 0 || activeIndex >= innerPoints.length) {
      throw IndexError.withLength(activeIndex, innerPoints.length);
    }
    return innerPoints[activeIndex];
  }

  set activePoint(DPoint val) {
    if (activeIndex < 0 || activeIndex >= innerPoints.length) {
      throw IndexError.withLength(activeIndex, innerPoints.length);
    }
    innerPoints[activeIndex] = val;
  }

  void fixedSpline() {
    if (innerPoints.isEmpty) {
      return;
    }
    _centerLineFixedPoint = DPoint(
      (innerPoints.last.x + innerPoints.first.x) * 0.5,
      (innerPoints.last.y + innerPoints.first.y) * 0.5,
    );

    var movablePoint = DPoint(0, double.infinity);

    var isFindMin =
        innerPoints[innerPoints.length >> 1].y - innerPoints[0].y < 0;
    if (autoGetApexPoint) {
      movablePoint =
          isFindMin ? movablePoint : DPoint(0, double.negativeInfinity);
    }

    for (DPoint point in innerPoints) {
      if (autoGetApexPoint && innerPoints.isNotEmpty) {
        if (isFindMin) {
          if (point.y < movablePoint.y) {
            movablePoint = point;
          }
        } else {
          if (point.y > movablePoint.y) {
            movablePoint = point;
          }
        }
      } else {
        if (point.y < movablePoint.y) {
          movablePoint = point;
        }
      }
    }

    if (_centerLineMovablePoint != movablePoint) {
      _centerLineMovablePoint = movablePoint;
      if (!_centerLineMovablePoint.isEmpty) {
        // TODO 重设光标位置，暂不支持
        // _centerLineMovablePoint.SynchToMainMonitorScreen(HostArea);
      }
    }
    updateSplitters();
    _onVertexPointChanged();
  }

  void adjustEndPoint(DPoint point) {
    if (innerPoints.isEmpty) {
      return;
    }
    var endPoint = point;
    double minDistance = double.infinity;
    // if (_splinePoints != null && _splinePoints!.isNotEmpty) {
    //   for (DPoint splinePoint in _splinePoints!) {
    //     double distance = (point - splinePoint).length;
    //     if (distance < minDistance) {
    //       minDistance = distance;
    //       endPoint = splinePoint;
    //     }
    //   }
    // }
    // TODO: _splinePoints填充和此处时序有问题，先用innerPoints代替，有性能问题，后续解决
    if (innerPoints.isNotEmpty) {
      final splinePoints = innerPoints.take(innerPoints.length - 1);
      for (DPoint splinePoint in splinePoints) {
        double distance = (point - splinePoint).length;
        if (distance < minDistance) {
          minDistance = distance;
          endPoint = splinePoint;
        }
      }
    }
    centerLineMovablePoint = endPoint;
  }

  void recreateSpline(bool isClosed) {
    // if (_breaker.Paused) {
    //   return;
    // }
    final generator = SimpsonGeometryGenerator();
    _pathGeometry ??= generator.createPathGeometry();

    double tempCircumference = 0;
    _spline = generator.createSpline(
      innerPoints,
      0.5,
      null,
      isClosed,
      false,
      0.005,
      tempCircumference,
      _splinePoints,
    );

    if (_spline != null && _splinePoints != null) {
      // _pathGeometry!.addGeometry(_spline!);
    }
  }

  void updateSplitters() {
    recreateSpline(true);

    if (_spline != null && !_centerLineMovablePoint.isEmpty) {
      var generator = SimpsonGeometryGenerator();
      _pathGeometry!.clear();

      if (innerPoints.isNotEmpty) {
        // _pathGeometry!.addGeometry(_spline!);

        horizontalSplitterLegths = {};
        generator.createSplitters(
          _pathGeometry!,
          _spline!,
          _centerLineFixedPoint,
          _centerLineMovablePoint,
          horizontalSplitterLegths,
        );

        _pathGeometry!.addLineGeometry(
          _centerLineFixedPoint,
          _centerLineMovablePoint,
        );
      }
    }
  }

  void _onVertexPointChanged() {}
  void _onSplineMovablePointsInfoChanged() {}
}

class SimpsonGeometryGenerator {
  static const int splitterCount = 20;

  void createSplitters(
    IPathGeometry pathGeometry,
    IPathGeometry spline,
    DPoint centerLineFixedPoint,
    DPoint centerLineMovablePoint,
    Map<int, double> horizontalSplitterLegths,
  ) {
    if (centerLineFixedPoint.isEmpty || centerLineMovablePoint.isEmpty) {
      return;
    }

    // 先放大点，防止计算过程中丢失过多精度，导致角度错误
    final size = Get.find<IApplication>().displaySize;
    DPoint pointA = centerLineFixedPoint.clone().scale2Size(size);
    DPoint pointB = centerLineMovablePoint.clone().scale2Size(size);
    // 用于恢复百分比点
    final reversalSize = Size(1 / size.width, 1 / size.height);

    // Center line
    DVector centerLine = pointB - pointA;

    DVector centerPerLine = centerLine / splitterCount.toDouble();
    final verticalVector = DVector(-centerLine.y, centerLine.x) * 50;

    //Create a 20 splitters path geometry
    PathGeometryContainer temSplittersGeometry = PathGeometryContainer(Path());
    for (var i = 0; i < splitterCount; i++) {
      final center = pointA
          .clone()
          .addVector(centerPerLine * i.toDouble())
          .addVector(centerPerLine / 2);
      DPoint p1 = center.clone().addVector(verticalVector);
      DPoint p2 = center.clone().subtractVector(verticalVector);
      final lineGeometry = LineGeometry(p1, p2);
      temSplittersGeometry.addGeometry(lineGeometry);
    }

    final spline2 = PathGeometryContainer(Path());
    final sss =
        (spline as PathGeometryContainer).geometries.first as PathGeometry;
    spline2.addGeometry(
        PathGeometry(sss.points.map((e) => e.scale2Size(size)).toList()));

    //Get intersection points
    List<DPoint> points = getIntersectionPoints(temSplittersGeometry, spline2);

    List<DPoint> leftPoints = [];
    List<DPoint> rightPoints = [];
    //Split point by center line
    const double constMagnify = 1.0;
    for (DPoint point in points) {
      var magnifyPoint = point.clone();
      magnifyPoint.x *= constMagnify;
      magnifyPoint.y *= constMagnify;

      DVector line = magnifyPoint -
          DPoint(
            (pointA.x + pointB.x) / 2.0 * constMagnify,
            (pointA.y + pointB.y) / 2.0 * constMagnify,
          );

      double angleToCenter = DVector.angleBetween(line, centerLine);

      if (angleToCenter >= 0.0) {
        leftPoints.add(point);
      } else {
        rightPoints.add(point);
      }
    }

    double angleToVertical =
        DVector.angleBetween(verticalVector, DVector(1, 0));

    //order point by vertical axis value
    orderByCalc(DPoint point) => rotaeY(
          point,
          pointA,
          angleToVertical * math.pi / 180.0,
        );

    leftPoints.sort((a, b) {
      final vA = orderByCalc(a);
      final vB = orderByCalc(b);
      return vA.compareTo(vB);
    });
    rightPoints.sort((a, b) {
      final vA = orderByCalc(a);
      final vB = orderByCalc(b);
      return vA.compareTo(vB);
    });

    var finalLeftPoint = leftPoints;
    var finalRightPoint = rightPoints;

    if (finalLeftPoint.length == finalRightPoint.length &&
        finalLeftPoint.length == splitterCount) {
      for (int i = 0; i < splitterCount; i++) {
        // 恢复百分比点
        final pL = finalLeftPoint[i].scale2Size(reversalSize);
        final pR = finalRightPoint[i].scale2Size(reversalSize);
        horizontalSplitterLegths[i + 1] = (pL - pR).length;
        // pathGeometry.addLineGeometry(finalLeftPoint[i], finalRightPoint[i]);
        pathGeometry.addLineGeometry(pL, pR);
      }
      // print("Output!!!!");
      // print(((spline as PathGeometryContainer).geometries.first as PathGeometry)
      //     .points);
      // print([centerLineFixedPoint, centerLineMovablePoint]);
      // print(leftPoints);
      // print(rightPoints);
    } else {}
  }

  IPathGeometry? createSpline(
    List<DPoint> sourcePoints,
    double tension,
    List<double>? tensions,
    bool isClosed,
    bool isFilled,
    double tolerance,
    double length,
    List<DPoint>? splinePoints,
  ) {
    length = 0;
    if (sourcePoints.isEmpty) {
      return null;
    }
    // List<DPoint> samplePoints = [];
    // var points = SplineUtils.create(
    //   sourcePoints,
    //   tension: tension,
    //   tensions: tensions,
    //   isClosed: isClosed,
    //   tolerance: tolerance,
    //   closeByStraightLine: true,
    //   samplePoints: samplePoints,
    //   isSimpsonSpline: true,
    // );
    final points = sourcePoints; // TODO: !!!!!!! 创建收缩Spline有问题，先不计算了，有性能问题再优化
    splinePoints = points;

    final pathGeometry = PathGeometry(points);
    final continer = PathGeometryContainer(Path());
    continer.addGeometry(pathGeometry);
    return continer;
  }

  IPathGeometry createPathGeometry() {
    return PathGeometryContainer(Path());
  }

  static double rotaeY(DPoint point, DPoint cenPoint, double theta) {
    return math.sin(theta) * (point.x - cenPoint.x) +
        math.cos(theta) * (point.y - cenPoint.y) +
        cenPoint.y;
  }

  List<DPoint> getIntersectionPoints(IPathGeometry g1, IPathGeometry g2) {
    final result = <DPoint>[];
    final splittersGeometry = g1 as PathGeometryContainer;
    final splineGeometry =
        (g2 as PathGeometryContainer).geometries.first as PathGeometry;

    for (var splitter in splittersGeometry.geometries) {
      splitter as LineGeometry;
      DPoint lastPoint = splineGeometry.points.first;
      final endLimit = splineGeometry.points.length - 1;
      for (var i = 1; i < splineGeometry.points.length; i++) {
        final currPoint = splineGeometry.points[i];
        final crossPoint = LineUtils.calculateIntersection(
          splitter.start,
          splitter.end,
          lastPoint,
          currPoint,
        );
        if (crossPoint != null) {
          if (LineUtils.isPointOnLine(lastPoint, currPoint, crossPoint)) {
            result.add(crossPoint);
          }
        }
        if (i != endLimit) {
          lastPoint = currPoint;
        }
      }
    }
    return result;
  }
}

class PathGeometryContainer implements IPathGeometry {
  final geometries = <IPathGeometry>[];
  late final Path control;

  PathGeometryContainer(Path geometry) {
    control = geometry;
  }

  @override
  void addGeometry(IPathGeometry geometry) {
    geometries.add(geometry);
  }

  @override
  void clear() {
    geometries.clear();
  }

  @override
  void addLineGeometry(
    DPoint centerLineFixedPoint,
    DPoint centerLineMovablePoint,
  ) {
    addGeometry(LineGeometry(centerLineFixedPoint, centerLineMovablePoint));
  }
}

class PathGeometry implements IPathGeometry {
  final List<DPoint> points;

  PathGeometry(this.points);

  @override
  void addGeometry(IPathGeometry spline) {}

  @override
  void addLineGeometry(
      DPoint centerLineFixedPoint, DPoint centerLineMovablePoint) {}

  @override
  void clear() {}
}

class LineGeometry implements IPathGeometry {
  final DPoint start;
  final DPoint end;

  LineGeometry(this.start, this.end);

  @override
  void addGeometry(IPathGeometry spline) {}

  @override
  void addLineGeometry(
      DPoint centerLineFixedPoint, DPoint centerLineMovablePoint) {}

  @override
  void clear() {}

  void rotateTransform(double angle, double centerX, double centerY) {
    rotatePoint(start, centerX, centerY, angle);
    rotatePoint(end, centerX, centerY, angle);
  }

  static void rotatePoint(
    DPoint point,
    double centerX,
    double centerY,
    double angle,
  ) {
    double radians = angle * math.pi / 180;
    double cosTheta = math.cos(radians);
    double sinTheta = math.sin(radians);

    point.x = centerX +
        (point.x - centerX) * cosTheta -
        (point.y - centerY) * sinTheta;
    point.y = centerY +
        (point.x - centerX) * sinTheta +
        (point.y - centerY) * cosTheta;
  }
}

abstract class IPathGeometry {
  void clear();
  void addGeometry(IPathGeometry spline);
  void addLineGeometry(
      DPoint centerLineFixedPoint, DPoint centerLineMovablePoint);
}

extension DPointExt on DPoint {
  static final empty = DPoint(double.minPositive, double.minPositive);

  bool get isEmpty {
    return this == empty;
  }
}

class MovablePointsInfo {
  int index;
  int start;
  int end;

  MovablePointsInfo(this.index, this.start, this.end);

  factory MovablePointsInfo.empty() {
    return MovablePointsInfo(-1, -1, -1);
  }
}