import { Attrib, ShapeStyles, ShapeType } from "../type";
import { Entity } from "../packages/entity";
import { Shape } from "konva/lib/Shape";
import { Group } from "konva/lib/Group";
import { getAbsoluteTransform } from "./shape-helper";
import { KonvaEventObject } from "konva/lib/Node";

let mouseDisabled = false;
const dragShapes: (Shape | Group)[] = [];
export const disableMouse = () => {
  mouseDisabled = true;
  dragShapes.forEach((shape) => shape.draggable(false));
};
export const enableMouse = () => {
  mouseDisabled = false;
  dragShapes.forEach((shape) => shape.draggable(true));
};

export const openShapeMouseStyles = <T extends Shape | Group>(
  shape: T,
  styles: ShapeStyles,
  namespace = "mouse-style"
) => {
  shape.listening(true);

  const useEvents: string[] = [];
  const useOn = (name: string, cb: (ev: KonvaEventObject<any>) => void) => {
    shape.on(name, cb);
    useEvents.push(name);
  };

  let enter = false;
  let draging = false;
  let active = false;

  const mouseHandler = (ev: KonvaEventObject<any>) => {
    const api = draging
      ? "draging"
      : active
      ? "active"
      : enter
      ? "hover"
      : "common";
    if (!mouseDisabled) {
      styles[api] && styles[api](ev);
    }
  };

  if (styles.hover) {
    useOn(`mouseenter.${namespace}`, (ev) => {
      enter = true;
      mouseHandler(ev);
    });
    useOn(`mouseleave.${namespace}`, (ev) => {
      if (!draging) {
        enter = false;
        mouseHandler(ev);
      }
    });
  }

  if (styles.active) {
    useOn(`click.${namespace} touchend.${namespace}`, (ev) => {
      if (!styles.active) return;
      if (draging) return;
      active = true;
      mouseHandler(ev);

      setTimeout(() => {
        const stage = shape.getStage();
        if (!stage) return;
        stage.on(
          `click.${namespace}${shape.id()} touchend.${namespace}${shape.id()}`,
          (evt) => {
            if (evt.target !== shape) {
              active = false;
              mouseHandler(evt);
            }
            setTimeout(() => {
              if (!stage) return;
              stage.off(
                `click.${namespace}${shape.id()} touchend.${namespace}${shape.id()}`
              );
            });
          }
        );
      });
    });
  }

  useOn(`dragstart.${namespace}`, (ev) => {
    draging = true;
    mouseHandler(ev);
  });
  useOn(`dragend.${namespace}`, (ev) => {
    setTimeout(() => {
      draging = false;
      mouseHandler(ev);
    }, 16);
  });

  return () => {
    shape.listening(false);
    shape.off(useEvents.join(" "));
  };
};

export type DragHandlers<T> = {
  readyHandler?: (ev: KonvaEventObject<any>) => T;
  moveHandler: (
    move: number[],
    readyData: T,
    ev: KonvaEventObject<any>
  ) => void;
  endHandler?: (readyData: T, ev: KonvaEventObject<any>) => void;
};

export const openShapeDrag = <T extends Shape | Group, D>(
  shape: T,
  handler: DragHandlers<D>,
  transform = true,
  tfIncludeSelf = false
) => {
  let readlyData = null as D;

  if (!mouseDisabled) {
    shape.draggable(true);
  }
  dragShapes.push(shape);
  shape.dragBoundFunc((pos, ev) => {
    if (!mouseDisabled) {
      let move = pos;
      if (transform) {
        const tf = getAbsoluteTransform(shape, tfIncludeSelf).invert();
        move = tf.point(pos);
      }
      handler.moveHandler([move.x, move.y], readlyData, ev);
    }
    return shape.absolutePosition();
  });

  if (handler.readyHandler) {
    shape.on("dragstart.drag", (ev) => {
      if (!mouseDisabled) {
        readlyData = handler.readyHandler(ev);
      }
    });
  }

  if (handler.endHandler) {
    shape.on("dragend.drag", (ev) => {
      if (!mouseDisabled) {
        handler.endHandler(readlyData, ev);
      }
    });
  }
  return () => {
    const ndx = dragShapes.indexOf(shape);
    if (~ndx) {
      dragShapes.splice(ndx, 1);
    }
    shape.draggable(false);
    shape.off("dragstart.drag dragend.drag");
  };
};

export type EntityDragHandlers<R extends Attrib, T> = {
  readyHandler?: (attrib: R, ev: KonvaEventObject<any>) => T;
  moveHandler: (
    attrib: R,
    move: number[],
    readyData: T,
    ev: KonvaEventObject<any>
  ) => void;
  endHandler?: (attrib: R, readyData: T, ev: KonvaEventObject<any>) => void;
};
export const openEntityDrag = <T extends Attrib, S extends ShapeType, R>(
  entity: Entity<T, S>,
  handler: EntityDragHandlers<T, R>
) => {
  entity.enableDrag({
    readyHandler(ev) {
      return handler.readyHandler && handler.readyHandler(entity.attrib, ev);
    },
    moveHandler(move: number[], readyData: R, ev) {
      return handler.moveHandler(entity.attrib, move, readyData, ev);
    },
    endHandler(readlyData: R, ev) {
      return (
        handler.endHandler && handler.endHandler(entity.attrib, readlyData, ev)
      );
    },
  });
};

export const shapeTreeEq = (
  parent: ShapeType,
  eq: (shape: ShapeType) => boolean
) => {
  if (eq(parent)) {
    return parent;
  }

  if ("children" in parent) {
    for (const child of parent.children) {
      const e = shapeTreeEq(child, eq);
      if (e) {
        return child;
      }
    }
  }

  return null;
};

export const shapeParentsEq = (
  target: ShapeType,
  eq: (shape: ShapeType) => boolean
) => {
  while (target) {
    if (eq(target)) {
      return target;
    }
    target = target.parent as any;
  }
  return null;
};

export const shapeTreeContain = (parent: ShapeType, target: ShapeType) => {
  const eqShape = shapeTreeEq(parent, (shape) => shape === target);
  return !!eqShape;
};