import { DiagramEngine } from "./cmap.js";

/**
 * Present a CMap through the bundled drawing engine.
 *
 * CmapView owns the canvas and concrete cmap.js instance. It creates and
 * destroys drawing objects but contains no concept, placement or persistence
 * rules; CmapEditor remains responsible for interpreting user interaction.
 */
export class CmapView {
  constructor(canvas, onSelection, onActivation, createEngine = null) {
    if (!(canvas instanceof Object)) throw new TypeError("A CMap canvas is required");
    if (createEngine !== null && typeof createEngine !== "function") {
      throw new TypeError("A diagram-engine factory must be a function");
    }
    this.canvas = canvas;
    this.map = createEngine ? createEngine(canvas) : new DiagramEngine(canvas);
    this.map.onSelection(onSelection);
    this.map.onActivation(onActivation);
  }

  createNode(attributes) {
    return this.map.node(attributes);
  }

  createConnector(attributes) {
    return this.map.link(attributes);
  }

  setZoom(factor) {
    this.map.zoom(factor);
  }

  surfaceElement() {
    return this.canvas.querySelector(":scope > .rw-cmap-surface");
  }

  destroy() {
    if (typeof this.map.destroy === "function") this.map.destroy();
  }
}