import konva from "konva";
import {
  Attrib,
  ShapeStyles,
  ShapeStylesStatus,
  ShapeStylesStatusKey,
  ShapeType,
} from "../type";
import { DEV } from "../env";
import { Group } from "konva/lib/Group";
import { Layer } from "konva/lib/Layer";
import { Stage } from "konva/lib/Stage";
import { reactive, toRaw, watch, watchEffect } from "vue";
import {
  DragHandlers,
  openShapeDrag,
  openShapeMouseStyles,
} from "../shared/shape-mose";
import { Container } from "./container";
import mitt from "mitt";

export type EntityBaseProps = {
  reactive?: boolean;
  readonly?: boolean;
};

export type EntityProps<T extends Attrib> = EntityBaseProps & {
  name?: string;
  attrib: T;
  zIndex?: number;
  teleport?: ShapeType;
};

type ParentShapeType<T extends ShapeType> = T extends Layer
  ? Stage
  : T extends Stage
  ? null
  : Group;

export type EntityTypeEvent<T extends string, R> = {
  [key in T]: R;
};

export type EntityEvent = {
  created: void;
  mounted: void;
  destroyed: void;
  statusChange: Partial<ShapeStylesStatus> | null;
  updateAttrib: void;
  shapeStatusChange: {
    type?: "click" | "mouse";
    current: ShapeStylesStatusKey;
    before: ShapeStylesStatusKey;
  };
  "*": void;
};

export type EntityType<
  T extends Attrib,
  S extends ShapeType,
  P extends EntityProps<T> = EntityProps<T>,
  K extends Entity<T, S> = Entity<T, S, any>,
  EK extends string = string,
  ER = any
> = (new (props: P) => K) & { EventHandler?: { [key in EK]: ER } };

export abstract class Entity<
  T extends Attrib = Attrib,
  S extends ShapeType = ShapeType,
  E extends EntityEvent = EntityEvent
> {
  props: EntityProps<T>;

  bus = mitt<E>();
  container: Container<
    string,
    Attrib,
    ShapeType,
    EntityType<Attrib, ShapeType>
  >;
  attrib: T;
  shape: S;
  name: string;

  private zIndex: number;
  teleport: ParentShapeType<S>;

  children: Entity<Attrib, ShapeType, any>[] = [];
  parent: Entity<Attrib, ShapeType>;

  constructor(props: EntityProps<T>) {
    this.name = props.name;
    this.teleport = props.teleport as any;
    this.props = props;
    this.attrib = props.reactive ? (reactive(props.attrib) as T) : props.attrib;
    this.zIndex = props.zIndex || 0;
  }

  abstract initShape(): S;
  getShape() {
    return this.shape;
  }

  abstract diffRedraw(): void;
  redraw() {
    this.diffRedraw();
    this.children.forEach((child) => child.redraw());
  }

  setAttrib(newAttrib: Partial<T>) {
    if (newAttrib.id !== this.attrib.id) {
      console.error("id 确定后无法更改");
    }

    newAttrib.id = this.attrib.id;
    if (this.props.reactive) {
      if (toRaw(newAttrib) !== toRaw(this.attrib)) {
        this.attrib = (
          this.props.reactive ? reactive(newAttrib) : newAttrib
        ) as T;
        this.bus.emit("updateAttrib");
        this.initReactive();
      }
    } else {
      this.attrib = newAttrib as T;
      this.diffRedraw();
    }
  }

  private destoryReactive: () => void;
  private flush: "pre" | "post" | "sync" = "pre";
  protected initReactive(flush = this.flush) {
    this.destoryReactive && this.destoryReactive();
    let isStop = false;
    const stop = watchEffect(
      () => {
        isStop || this.diffRedraw();
      },
      { flush }
    );
    this.flush = flush;
    return () => {
      isStop = true;
      stop();
    };
  }

  init() {
    this.shape = this.initShape();
    this.shape.id(this.name);
    this.bus.emit("created");
  }

  mount(tel?: ParentShapeType<S>) {
    if (this.shape instanceof Stage) {
      throw "stage 为顶级容器无法挂载";
    } else if (tel && this.shape instanceof Layer && !(tel instanceof Stage)) {
      console.log(this.name, tel);
      throw "layer 只能挂载到 Stage";
    }

    if (this.teleport && this.teleport === tel) {
      return;
    }

    this.children.sort((a, b) => a.zIndex - b.zIndex);

    const parentShape = (tel || this.parent.shape) as Layer;
    parentShape.add(this.shape);

    this.teleport = parentShape as unknown as ParentShapeType<S>;
    this.setZIndex(this.zIndex);

    if (this.props.reactive) {
      this.destoryReactive = this.initReactive();
    }

    if (DEV) {
      let raw = { ...this.attrib };
      watch(
        () => this.attrib.id,
        (newId, oldId) => {
          if (newId !== oldId) {
            console.error("changeId", raw, this.attrib, newId, oldId);
          }
        },
        { flush: "sync" }
      );
    }
  }

  isMounted = false;
  mounted() {
    this.diffRedraw();
    this.children.forEach((child) => child.mounted());
    this.isMounted = true;
    this.bus.emit("mounted");
  }

  setParent(parent: Entity<any, any> | null) {
    if (this.parent) {
      const ndx = this.parent.children.indexOf(this as any);
      ~ndx && this.parent.children.splice(ndx, 1);
    }

    this.parent = parent;
    if (parent) {
      this.parent.children.push(this as any);
    }
  }

  private getLevelNdx(parent = this.parent) {
    if (parent) {
      const level = parent.children;
      for (let i = level.length - 1; i >= 0; i--) {
        if (level[i] !== this && level[i].zIndex <= this.zIndex) {
          return i;
        }
      }
      return -1;
    }
    return null;
  }

  setZIndex(index: number) {
    this.zIndex = index;
    const packNdx = this.getLevelNdx();
    if (packNdx === null) return;

    const packChild = this.parent.children;
    const oldNdx = packChild.indexOf(this);

    if (oldNdx !== packNdx + 1) {
      let rep: any = this;
      for (let i = packNdx + 1; i < packChild.length; i++) {
        const temp = packChild[i];
        packChild[i] = rep;
        rep = temp;
      }
    }

    const parentShape = this.teleport as any;
    const levelShapes = parentShape.children;
    const shapeNdx =
      packNdx === -1
        ? 0
        : levelShapes.indexOf(packChild[packNdx].getShape()) + 1;
    const oldShapeNdx = levelShapes.indexOf(this.shape);

    if (oldShapeNdx !== shapeNdx) {
      if (shapeNdx !== 0) {
        let repShape: any = this.shape;
        for (let i = shapeNdx; i < levelShapes.length; i++) {
          const temp = levelShapes[i];
          parentShape.add(repShape);
          repShape.zIndex(i);
          repShape = temp;
        }
      } else {
        this.shape.zIndex(0);
      }
    }
  }

  private dragDestory: () => void;
  enableDrag<S>(draghandler: DragHandlers<S>) {
    this.disableDrag();
    this.dragDestory = openShapeDrag(this.shape, draghandler);
  }
  disableDrag() {
    this.dragDestory && this.dragDestory();
    this.dragDestory = null;
  }

  activeDestory: () => void;
  enableActive(activeCallback: (isActive: boolean) => void) {
    this.disableActive();
    this.activeDestory = openShapeMouseStyles(
      this.shape,
      {
        active: () => activeCallback(true),
        bus: this.bus as any,
        common: () => activeCallback(false),
      },
      "mouse-active"
    );
  }
  disableActive() {
    this.activeDestory && this.activeDestory();
    this.activeDestory = null;
  }

  private mouseActDestory: () => void;
  enableMouseAct(styles: ShapeStyles) {
    this.disableMouseAct();
    this.mouseActDestory = openShapeMouseStyles(
      this.shape,
      { ...styles, bus: this.bus as any },
      "act-mouse"
    );
  }
  disableMouseAct() {
    this.mouseActDestory && this.mouseActDestory();
    this.mouseActDestory = null;
  }
  visible(visibled: boolean) {
    this.shape.visible(visibled);
  }

  destory() {
    while (this.children.length) {
      this.children[0].destory();
    }

    this.setParent(null);
    this.destoryReactive && this.destoryReactive();
    this.disableDrag();
    this.disableActive();
    this.disableMouseAct();

    if (DEV) {
      console.log(this.name, "destory");
    }
    if (this.shape instanceof konva.Group) {
      this.shape.destroyChildren();
    } else {
      this.shape.destroy();
    }
    if (this.parent) {
      const ndx = this.parent.children.indexOf(this);
      ~ndx && this.parent.children.splice(ndx, 1);
    }
    this.bus.emit("destroyed");
    this.bus.off("*");
  }

  find(name: string): Entity {
    for (const child of this.children) {
      if (child.name === name) {
        return child;
      }
      const childQueryed = child.find(name);
      if (childQueryed) {
        return childQueryed;
      }
    }
    return null;
  }
}