paint-ui/tools/magic-wand-tool.ts

import { BaseTool } from './base-tool';
import type { PointerState } from '@/types';
import { useSelectionStore } from '@/store/selection-store';
import { useLayerStore } from '@/store/layer-store';
import {
  createMagicWandMask,
  createSelection,
  combineMasks,
} from '@/lib/selection-utils';

export class MagicWandTool extends BaseTool {
  constructor() {
    super('Magic Wand');
  }

  onPointerDown(pointer: PointerState): void {
    this.isActive = true;

    const layer = this.getActiveLayer();
    if (!layer?.canvas) return;

    const ctx = layer.canvas.getContext('2d');
    if (!ctx) return;

    const x = Math.floor(pointer.x);
    const y = Math.floor(pointer.y);

    if (
      x < 0 ||
      x >= layer.canvas.width ||
      y < 0 ||
      y >= layer.canvas.height
    ) {
      return;
    }

    const imageData = ctx.getImageData(
      0,
      0,
      layer.canvas.width,
      layer.canvas.height
    );

    const { selectionMode, feather, tolerance, activeSelection } =
      useSelectionStore.getState();

    const newMask = createMagicWandMask(x, y, imageData, tolerance);

    let finalMask = newMask;

    // Combine with existing selection if needed
    if (activeSelection && selectionMode !== 'new') {
      finalMask = combineMasks(activeSelection.mask, newMask, selectionMode);
    }

    const selection = createSelection(layer.id, finalMask, feather);
    useSelectionStore.getState().setActiveSelection(selection);

    this.isActive = false;
  }

  onPointerMove(): void {
    // Magic wand doesn't need pointer move
  }

  onPointerUp(): void {
    this.isActive = false;
  }

  getCursor(): string {
    return 'crosshair';
  }

  private getActiveLayer() {
    const { activeLayerId, layers } = useLayerStore.getState();
    return layers.find((l) => l.id === activeLayerId);
  }
}