/**
 * InteractionDispatcher Tests (Task A2).
 * Prüft Event-Routing gegen ein Fake-Werkzeug ohne echte Registry:
 * Reihenfolge down→move→up, ESC/Rechtsklick cancel, move nur bei aktiver Session,
 * unbekanntes Tool → kein Routing.
 */
import { describe, it, expect, vi, afterEach } from 'vitest';
import { InteractionDispatcher } from '../src/interaction/dispatcher';
import type { ToolExtensionV2 } from '../src/plugins/types';
import type { ZoomPanController } from '../src/canvas/ZoomPanController';

function makeFakeZoomPan(): ZoomPanController {
  return {
    screenToWorld: (sx: number, sy: number) => ({ x: sx * 2, y: sy * 3 }),
  } as unknown as ZoomPanController;
}

function makeRecordingTool(id = 'fake'): { tool: ToolExtensionV2; log: string[] } {
  const log: string[] = [];
  const tool: ToolExtensionV2 = {
    manifest: { id, label: 'Fake', icon: 'f', ribbonTab: 'tools' },
    optionsSchema: [],
    handlers: {
      down: () => log.push('down'),
      move: () => log.push('move'),
      up: () => log.push('up'),
      key: () => false,
      cancel: () => log.push('cancel'),
    },
  };
  return { tool, log };
}

function fire(canvas: HTMLCanvasElement, type: string, opts: Partial<PointerEventInit> = {}): PointerEvent {
  const e = new PointerEvent(type, {
    bubbles: true,
    clientX: 100,
    clientY: 50,
    button: 0,
    ...opts,
  });
  if (type === 'pointerdown') canvas.dispatchEvent(e);
  else window.dispatchEvent(e);
  return e;
}

function fireKey(key: string): KeyboardEvent {
  const e = new KeyboardEvent('keydown', { key, bubbles: true });
  window.dispatchEvent(e);
  return e;
}

describe('InteractionDispatcher', () => {
  let canvas: HTMLCanvasElement;

  afterEach(() => {
    canvas?.remove();
  });

  function setup(tool?: ToolExtensionV2) {
    canvas = document.createElement('canvas');
    document.body.appendChild(canvas);
    const dispatcher = new InteractionDispatcher(canvas, {
      zoomPan: makeFakeZoomPan(),
      toolLookup: tool ? () => tool : undefined,
    });
    return { dispatcher };
  }

  it('routet down→move→up in Reihenfolge an das aktive Tool', () => {
    const { tool, log } = makeRecordingTool();
    const { dispatcher } = setup(tool);
    dispatcher.setActive('fake');

    fire(canvas, 'pointerdown');
    fire(window, 'pointermove');
    fire(window, 'pointerup');

    expect(log).toEqual(['down', 'move', 'up']);
    expect(dispatcher.getActive()?.manifest.id).toBe('fake');
  });

  it('ignoriert move/up ohne vorheriges down (Session-Guard)', () => {
    const { tool, log } = makeRecordingTool();
    const { dispatcher } = setup(tool);
    dispatcher.setActive('fake');

    fire(window, 'pointermove'); // keine Session aktiv
    fire(window, 'pointerup');
    expect(log).toEqual([]);
  });

  it('ESC ruft cancel und beendet die Session', () => {
    const { tool, log } = makeRecordingTool();
    const { dispatcher } = setup(tool);
    dispatcher.setActive('fake');

    fire(canvas, 'pointerdown');
    fireKey('Escape');
    expect(log).toEqual(['down', 'cancel']);

    fire(window, 'pointermove'); // Session beendet → kein move mehr
    expect(log).toEqual(['down', 'cancel']);
  });

  it('Rechtsklick bricht ab, ohne down durchzureichen', () => {
    const { tool, log } = makeRecordingTool();
    const { dispatcher } = setup(tool);
    dispatcher.setActive('fake');

    fire(canvas, 'pointerdown', { button: 2 });
    expect(log).toEqual(['cancel']);
  });

  it('setActive(null) deaktiviert Routing komplett', () => {
    const { tool, log } = makeRecordingTool();
    const { dispatcher } = setup(tool);
    dispatcher.setActive('fake');
    dispatcher.setActive(null);
    fire(canvas, 'pointerdown');
    fire(window, 'pointermove');
    expect(log).toEqual([]);
  });

  it('liefert Weltkoordinaten aus zoomPan.screenToWorld', () => {
    let received: { x: number; y: number } | null = null;
    const tool: ToolExtensionV2 = {
      manifest: { id: 'geo', label: 'G', icon: 'g', ribbonTab: 't' },
      optionsSchema: [],
      handlers: { down: (e) => (received = { ...e.world }) },
    };
    const { dispatcher } = setup(tool);
    dispatcher.setActive('geo');
    fire(canvas, 'pointerdown', { clientX: 100, clientY: 50 });
    // fake screenToWorld: x*2, y*3 → (200, 150)
    expect(received).toEqual({ x: 200, y: 150 });
  });
});