invokeai/frontend/web/src/features/nodes/store/selectors.ts

import type { Selector } from '@reduxjs/toolkit';
import { createSelector } from '@reduxjs/toolkit';
import type { RootState } from 'app/store/store';
import type { NodesState } from 'features/nodes/store/types';
import type { FieldInputInstance } from 'features/nodes/types/field';
import type { InvocationNode, InvocationNodeData } from 'features/nodes/types/invocation';
import { isInvocationNode } from 'features/nodes/types/invocation';
import { assert } from 'tsafe';

export const selectInvocationNode = (nodesSlice: NodesState, nodeId: string): InvocationNode => {
  const node = nodesSlice.nodes.find((node) => node.id === nodeId);
  assert(isInvocationNode(node), `Node ${nodeId} is not an invocation node`);
  return node;
};

export const selectInvocationNodeType = (nodesSlice: NodesState, nodeId: string): string => {
  const node = selectInvocationNode(nodesSlice, nodeId);
  return node.data.type;
};

export const selectNodeData = (nodesSlice: NodesState, nodeId: string): InvocationNodeData => {
  const node = selectInvocationNode(nodesSlice, nodeId);
  return node.data;
};

export const selectFieldInputInstance = (
  nodesSlice: NodesState,
  nodeId: string,
  fieldName: string
): FieldInputInstance | null => {
  const data = selectNodeData(nodesSlice, nodeId);
  return data?.inputs[fieldName] ?? null;
};

export const selectLastSelectedNode = (nodesSlice: NodesState) => {
  const selectedNodes = nodesSlice.nodes.filter((n) => n.selected);
  if (selectedNodes.length === 1) {
    return selectedNodes[0];
  }
  return null;
};

export const selectNodesSlice = (state: RootState) => state.nodes.present;

const createNodesSelector = <T>(selector: Selector<NodesState, T>) => createSelector(selectNodesSlice, selector);
export const selectNodes = createNodesSelector((nodes) => nodes.nodes);
export const selectEdges = createNodesSelector((nodes) => nodes.edges);
export const selectMayUndo = createSelector(
  (state: RootState) => state.nodes,
  (nodes) => nodes.past.length > 0
);
export const selectMayRedo = createSelector(
  (state: RootState) => state.nodes,
  (nodes) => nodes.future.length > 0
);