import {
  arrayPositionToCanvas,
  canvasPointToArray,
  eventToArrayPosition,
  eventToCanvasPoint,
  fitArrayViewport,
  hitTestMicrophone,
  keyboardNudgeForKey,
  niceGridStep,
} from "/apps/array-builder/canvas-view.js";

function assertNear(actual, expected, tolerance, label) {
  assert(Math.abs(actual - expected) <= tolerance, label + ": expected " + expected + ", received " + actual);
}

function fixture() {
  return {
    aperture: { width: 0.4, height: 0.2 },
    microphones: [
      { id: "mic-001", position: [-0.1, -0.05, 0] },
      { id: "mic-002", position: [0.1, 0.05, 0.01] },
    ],
  };
}

test("Array canvas fit은 x/y에 동일 축척을 사용하고 좌표를 왕복한다", () => {
  const viewport = fitArrayViewport(800, 420, fixture());
  const point = [0.075, -0.025, 0.012];
  const pixel = arrayPositionToCanvas(point, viewport);
  const roundTrip = canvasPointToArray(pixel, viewport, { z: point[2] });
  assertNear(roundTrip[0], point[0], 1e-12, "x round trip");
  assertNear(roundTrip[1], point[1], 1e-12, "y round trip");
  assertNear(roundTrip[2], point[2], 1e-12, "z preserved");
  const oneCentimeterX = arrayPositionToCanvas([0.01, 0, 0], viewport).x -
    arrayPositionToCanvas([0, 0, 0], viewport).x;
  const oneCentimeterY = arrayPositionToCanvas([0, 0.01, 0], viewport).y -
    arrayPositionToCanvas([0, 0, 0], viewport).y;
  assertNear(Math.abs(oneCentimeterX), Math.abs(oneCentimeterY), 1e-12, "equal x/y scale");
});

test("Array canvas 좌표는 화면 위쪽을 양의 y로 해석한다", () => {
  const viewport = fitArrayViewport(500, 500, fixture());
  const upper = canvasPointToArray(
    { x: viewport.plot.x + viewport.plot.width / 2, y: viewport.plot.y },
    viewport,
  );
  const lower = canvasPointToArray(
    { x: viewport.plot.x + viewport.plot.width / 2, y: viewport.plot.y + viewport.plot.height },
    viewport,
  );
  assert(upper[1] > lower[1], "canvas top maps to larger array y");
  assertNear(upper[1], viewport.yMax, 1e-12, "top is yMax");
  assertNear(lower[1], viewport.yMin, 1e-12, "bottom is yMin");
});

test("PointerEvent-like 좌표 변환은 DOM 없이 canvas와 plot 경계에 clamp할 수 있다", () => {
  const viewport = fitArrayViewport(640, 360, fixture());
  const rect = { left: 100, top: 50, width: 640, height: 360 };
  const canvasPoint = eventToCanvasPoint({ clientX: 50, clientY: 500 }, rect, { clamp: true });
  assertEqual(canvasPoint.x, 0, "client x clamps to canvas left");
  assertEqual(canvasPoint.y, 360, "client y clamps to canvas bottom");
  const position = eventToArrayPosition(
    { clientX: -500, clientY: 900 },
    rect,
    viewport,
    { clamp: true, clampToCanvas: true, z: 0.02 },
  );
  assertNear(position[0], viewport.xMin, 1e-12, "event x clamps to plot xMin");
  assertNear(position[1], viewport.yMin, 1e-12, "event y clamps to plot yMin");
  assertEqual(position[2], 0.02, "event conversion carries z");
});

test("Array canvas hit test는 반경 안의 가장 가까운 마이크와 채널 index를 돌려준다", () => {
  const arrayDefinition = fixture();
  const viewport = fitArrayViewport(800, 420, arrayDefinition);
  const micPixel = arrayPositionToCanvas(arrayDefinition.microphones[1].position, viewport);
  const hit = hitTestMicrophone(
    { x: micPixel.x + 3, y: micPixel.y - 2 },
    arrayDefinition.microphones,
    viewport,
    8,
  );
  assertEqual(hit.id, "mic-002", "closest microphone id");
  assertEqual(hit.index, 1, "physical channel index");
  assertNear(hit.distancePx, Math.hypot(3, 2), 1e-12, "pixel distance");
  assertEqual(hitTestMicrophone({ x: 0, y: 0 }, arrayDefinition.microphones, viewport, 2), null, "miss");
});

test("Array canvas grid와 keyboard nudge의 순수 helper가 1/2/5 및 y-up 규칙을 따른다", () => {
  const candidates = [niceGridStep(0.008), niceGridStep(0.08), niceGridStep(0.8), niceGridStep(8)];
  for (const step of candidates) {
    const magnitude = 10 ** Math.floor(Math.log10(step));
    const normalized = Math.round(step / magnitude);
    assert([1, 2, 5, 10].includes(normalized), "grid step uses 1/2/5 decade");
  }
  assertEqual(keyboardNudgeForKey("ArrowLeft", 0.002).dx, -0.002, "left nudge");
  assertEqual(keyboardNudgeForKey("ArrowUp", 0.002).dy, 0.002, "up is positive y");
  assertEqual(keyboardNudgeForKey("ArrowDown", 0.002, true).dy, -0.02, "shift multiplies by ten");
  assertEqual(keyboardNudgeForKey("Enter", 0.002), null, "non-arrow key ignored");
});