// This program has been developed by students from the bachelor Computer Science at Utrecht
// University within the Software Project course.
// © Copyright Utrecht University (Department of Information and Computing Sciences)
import { getByTestId, render } from '@testing-library/react';
import userEvent from '@testing-library/user-event';
import useFlowStore from '../../../../../src/pages/VisProgPage/visualProgrammingUI/VisProgStores';
import VisProgPage from '../../../../../src/pages/VisProgPage/VisProg';



class ResizeObserver {
  observe() {}
  unobserve() {}
  disconnect() {}
}
window.ResizeObserver = ResizeObserver;

jest.mock('@neodrag/react', () => ({
  useDraggable: (ref: React.RefObject<HTMLElement>, options: any) => {
    // We access the real useEffect from React to attach a listener
    // This bridges the gap between the test's userEvent and the component's logic
    const { useEffect } = jest.requireActual('react');
    
    useEffect(() => {
      const element = ref.current;
      if (!element) return;

      // When the test fires a "pointerup" (end of click/drag), 
      // we manually trigger the library's onDragEnd callback.
      const handlePointerUp = (e: PointerEvent) => {
        if (options.onDragEnd) {
          options.onDragEnd({ event: e });
        }
      };

      element.addEventListener('pointerup', handlePointerUp as EventListener);
      return () => {
        element.removeEventListener('pointerup', handlePointerUp as EventListener);
      };
    }, [ref, options]);
  },
}));

// We will mock @xyflow/react so we control screenToFlowPosition
jest.mock('@xyflow/react', () => {
  const actual = jest.requireActual('@xyflow/react');
  return {
    ...actual,
    useReactFlow: () => ({
      screenToFlowPosition: ({ x, y }: { x: number; y: number }) => ({
        x: x - 100,
        y: y - 100,
      }),
    }),
  };
});

describe("Drag & drop node creation", () => {

  test("drops a phase node inside the canvas and adds it with transformed position", async () => {
    const user = userEvent.setup();

    const { container } = render(<VisProgPage />);

    // --- Mock ReactFlow bounding box ---
    // Your DndToolbar checks these values:
    const flowEl = container.querySelector('.react-flow');
    jest.spyOn(flowEl!, 'getBoundingClientRect').mockReturnValue({
      left: 0,
      right: 800,
      top: 0,
      bottom: 600,
      width: 800,
      height: 600,
      x: 0,
      y: 0,
      toJSON: () => {},
    });

  
    const phaseLabel = getByTestId(container, 'draggable-phase')
  
    await user.pointer([
      // touch the screen at element1
      {keys: '[TouchA>]', target: phaseLabel},
      // move the touch pointer to element2
      {pointerName: 'TouchA', coords: {x: 300, y: 250}},
      // release the touch pointer at the last position (element2)
      {keys: '[/TouchA]'},
    ]);

    // Read the Zustand store
    const { nodes } = useFlowStore.getState();

    // --- Assertions ---
    expect(nodes.length).toBe(1);

    const node = nodes[0];

    expect(node.type).toBe("phase");

    // UUID Expression
    expect(node.id).toMatch(
    /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i
    );

    // screenToFlowPosition was mocked to subtract 100
    expect(node.position).toEqual({
      x: 200,
      y: 150,
    });
  });
});