import 'package:fis_common/event/event_type.dart';
import 'package:fis_measure/interfaces/date_types/point.dart';
import 'package:fis_measure/interfaces/process/calculators/calculator.dart';
import 'package:fis_measure/interfaces/process/calculators/output.dart';
import 'package:fis_measure/interfaces/process/calculators/values.dart';
import 'package:fis_measure/interfaces/process/items/item.dart';
import 'package:fis_measure/process/items/item.dart';
import 'package:fis_measure/process/items/item_feature.dart';
import 'package:flutter/foundation.dart';
import 'package:vid/us/vid_us_unit.dart';

abstract class Calculator<T extends IMeasureItem, TValue>
    implements ICalculator<TValue> {
  late T _ref;

  Calculator(T ref) {
    _ref = ref;
  }

  T get ref => _ref;

  @override
  var outputChanged = FEventHandler<OutputItem<TValue>?>();

  @override
  void finishOnce() {}

  @override
  Future<void> calculateAsync() async {}

  @protected
  FloatValue? updateFloatValue(
    double value, {
    VidUsUnit? unit,
    bool useUnitY = false,
    bool useRound = false,
  }) {
    if (ref.feature == null) return null;
    final feature = ref.feature! as MeasureItemFeature;
    if (unit == null) {
      final viewport = feature.hostVisualArea!.viewport!;
      unit = useUnitY ? viewport.yUnit : viewport.xUnit;
    }
    final output = ref.meta.outputs.first;
    final val = useRound ? roundDouble(value, output.fractionalDigits) : value;
    return feature.updateFloatValue(
      ref.meta.outputs.first,
      val,
      unit,
    );
  }

  @protected
  StringValue? updateStringValue(String value) {
    if (ref.feature == null) return null;
    final feature = ref.feature! as MeasureItemFeature;
    return feature.updateStringValue(ref.meta.outputs.first, value);
  }

  /// 对double四舍五入
  double roundDouble(double value, [int digits = 2]) {
    final digitsStr = value.toStringAsFixed(digits);
    final result = double.parse(digitsStr);
    return result;
  }

  /// 获取结果精度
  @protected
  int getResultDigits(OutputItem item) {
    int fractionalDigits = 2;

    VidUsUnit? targetUnit = item.unit;
    switch (targetUnit) {
      case VidUsUnit.mm:
        fractionalDigits = 3;
        break;
      case VidUsUnit.mm2:
        fractionalDigits = 4;
        break;
      case VidUsUnit.mm3:
        fractionalDigits = 5;
        break;
      case VidUsUnit.msec:
        fractionalDigits = 3;
        break;
      default:
        // fractionalDigits = GetConfigDigits(item);
        break;
    }
    return fractionalDigits;
  }

  @protected
  double? pickChildFloatValue(MeasureItem item) {
    if (item.calculator == null) return null;
    ValueBase? value;
    if (item.measuredFeatures.isNotEmpty) {
      value = item.measuredFeatures.first.value;
    } else if (item.feature != null) {
      value = item.feature!.value;
    }
    if (value != null) {
      return (value as FloatValue).value ?? 0;
    }
    return null;
  }

  @protected
  FloatValue? pickChildToFloatValue(MeasureItem item) {
    if (item.calculator == null) return null;
    ValueBase? value;
    if (item.measuredFeatures.isNotEmpty) {
      value = item.measuredFeatures.first.value;
    } else if (item.feature != null) {
      value = item.feature!.value;
    }
    if (value != null) {
      return value as FloatValue;
    }
    return null;
  }

  @protected
  TF? findChildFeature<TF extends MeasureItemFeature>(MeasureItem child) {
    if (child.measuredFeatures.isNotEmpty) {
      return child.measuredFeatures.first as TF;
    }
    return child.feature as TF?;
  }

  DPoint convertTimeMotionPoint(MeasureItemFeature feature, DPoint point) {
    final viewport = feature.hostVisualArea!.viewport!;
    final layout = feature.hostVisualArea!.displayRegion;

    final pointClone = point.clone();
    pointClone.addOffset(-layout.left, -layout.top);

    final physicalPoint = viewport.convert(pointClone);
    final coordinateOffset = viewport.region;
    final y = -physicalPoint.y + coordinateOffset.top;
    final x = physicalPoint.x + coordinateOffset.left;
    return DPoint(x, y);
  }
}