import { D, I } from "./engine/public.ts";
import { Rect } from "./engine/datatypes.ts";

export type Handlers = {
  onClick?: () => void;
  onSqueeze?: () => void;
};

export class DrawPile {
  #draws: { depth: number; op: () => void; handlers?: Handlers }[];
  #hoveredIndex: number | null;

  constructor() {
    this.#draws = [];
    this.#hoveredIndex = null;
  }

  clear() {
    this.#draws = [];
    this.#hoveredIndex = null;
  }

  add(depth: number, op: () => void) {
    this.#draws.push({ depth, op });
  }

  addClickable(
    depth: number,
    op: (hover: boolean) => void,
    rect: Rect,
    enabled: boolean,
    handlers: {
      onClick?: () => void;
      onSqueeze?: () => void;
    },
  ) {
    let position = I.mousePosition?.offset(D.camera);
    let hovered = false;
    if (position != null) {
      hovered = rect.contains(position);
    }
    if (!enabled) {
      hovered = false;
    }
    if (hovered) {
      this.#hoveredIndex = this.#draws.length;
    }
    this.#draws.push({ depth, op: () => op(hovered), handlers });
  }

  executeOnClick() {
    if (I.isMouseClicked("leftMouse")) {
      let hi = this.#hoveredIndex;
      if (hi != null) {
        let cb = this.#draws[hi]?.handlers?.onClick;
        if (cb != null) {
          cb();
        }
      }
    }

    if (I.isMouseDown("leftMouse")) {
      let hi = this.#hoveredIndex;
      if (hi != null) {
        let cb = this.#draws[hi]?.handlers?.onSqueeze;
        if (cb != null) {
          cb();
        }
      }
    }
  }

  draw() {
    let draws = [...this.#draws];
    draws.sort((d0, d1) => d0.depth - d1.depth);
    for (let d of draws.values()) {
      d.op();
    }
  }
}