import { describe, expect, test } from "bun:test";
import { createViewportPointerPanHandler, handleViewportWheel } from "./viewport";

const ignoredState = undefined as never;

describe("viewport input", () => {
  test("wheel dispatches zoom around point", () => {
    const dispatched: unknown[] = [];
    const consumed = handleViewportWheel({
      event: { position: { x: 10, y: 20 }, delta: { x: 0, y: -100 }, altKey: false, ctrlKey: false, metaKey: false, shiftKey: false },
      globalConsumer: () => false,
      currentZoom: 1,
      dispatch: (commandId, payload) => {
        dispatched.push({ commandId, payload });
        return ignoredState;
      },
    });

    expect(consumed).toBe(true);
    expect(dispatched[0]).toEqual({ commandId: "viewport.zoomAroundPoint", payload: { zoom: Math.exp(0.1), point: { x: 10, y: 20 } } });
  });

  test("global wheel consumer prevents command dispatch", () => {
    let called = false;
    const consumed = handleViewportWheel({
      event: { position: { x: 0, y: 0 }, delta: { x: 0, y: 1 }, altKey: false, ctrlKey: false, metaKey: false, shiftKey: false },
      globalConsumer: () => true,
      currentZoom: 1,
      dispatch: () => {
        called = true;
        return ignoredState;
      },
    });

    expect(consumed).toBe(true);
    expect(called).toBe(false);
  });

  test("middle mouse drag dispatches viewport pan", () => {
    const dispatched: unknown[] = [];
    const pan = createViewportPointerPanHandler({
      globalConsumer: () => false,
      getCurrentZoom: () => 2,
      dispatch: (commandId, payload) => {
        dispatched.push({ commandId, payload });
        return ignoredState;
      },
    });

    expect(pan.pointerDown(basePointer({ buttons: 4, position: { x: 10, y: 10 } }))).toBe(true);
    expect(pan.pointerMove(basePointer({ buttons: 4, position: { x: 14, y: 6 } }))).toBe(true);
    expect(dispatched[0]).toEqual({ commandId: "viewport.pan", payload: { delta: { x: -2, y: 2 } } });
  });
});

function basePointer(overrides: Partial<Parameters<ReturnType<typeof createViewportPointerPanHandler>["pointerDown"]>[0]> = {}) {
  return {
    pointerId: 1,
    pointerType: "mouse" as const,
    position: { x: 0, y: 0 },
    buttons: 0,
    altKey: false,
    ctrlKey: false,
    metaKey: false,
    shiftKey: false,
    ...overrides,
  };
}