Genarrative/packages/image-canvas-core/src/selection.ts

import type { CanvasGenerationDialogState, CanvasLayer } from './types';

export const CANVAS_GENERATION_SELECTION_PREFIX = 'generation-dialog:';

export function getCanvasGenerationSelectionId(dialogId: string) {
  return `${CANVAS_GENERATION_SELECTION_PREFIX}${dialogId}`;
}

export function getCanvasGenerationDialogIdFromSelectionId(targetId: string) {
  return targetId.startsWith(CANVAS_GENERATION_SELECTION_PREFIX)
    ? targetId.slice(CANVAS_GENERATION_SELECTION_PREFIX.length)
    : null;
}

export function isCanvasGenerationSelectionId(targetId: string) {
  return getCanvasGenerationDialogIdFromSelectionId(targetId) !== null;
}

export function getSelectedLayerIds(selectionIds: string[]) {
  return selectionIds.filter(
    (selectionId) => !isCanvasGenerationSelectionId(selectionId),
  );
}

export function getSelectedGenerationDialogIds(selectionIds: string[]) {
  return selectionIds.flatMap((selectionId) => {
    const dialogId = getCanvasGenerationDialogIdFromSelectionId(selectionId);
    return dialogId ? [dialogId] : [];
  });
}

export function dedupeSelectionIds(selectionIds: string[]) {
  return Array.from(new Set(selectionIds));
}

export function firstSelectedLayerId(selectionIds: string[]) {
  return getSelectedLayerIds(selectionIds)[0] ?? null;
}

export function normalizeCanvasSelectionIds({
  selectionIds,
  layers,
  generationDialogs,
}: {
  selectionIds: string[];
  layers: CanvasLayer[];
  generationDialogs: CanvasGenerationDialogState[];
}) {
  const layerIds = new Set(layers.map((layer) => layer.id));
  const generationDialogIds = new Set(
    generationDialogs.map((dialog) => dialog.id),
  );
  return dedupeSelectionIds(selectionIds).filter((selectionId) => {
    if (isCanvasGenerationSelectionId(selectionId)) {
      const dialogId = getCanvasGenerationDialogIdFromSelectionId(selectionId);
      return Boolean(dialogId && generationDialogIds.has(dialogId));
    }
    return layerIds.has(selectionId);
  });
}

export function resolvePointerSelection({
  targetId,
  selectedIds,
  isMultiSelectGesture,
}: {
  targetId: string;
  selectedIds: string[];
  isMultiSelectGesture: boolean;
}) {
  if (!isMultiSelectGesture) {
    if (selectedIds.includes(targetId)) {
      return selectedIds;
    }
    return [targetId];
  }
  if (!selectedIds.includes(targetId)) {
    return [...selectedIds, targetId];
  }
  if (selectedIds.length <= 1) {
    return [targetId];
  }
  return selectedIds.filter((selectedId) => selectedId !== targetId);
}