import { act, cleanup, renderHook } from "@testing-library/react";
import { afterEach, describe, expect, it, vi } from "vitest";
import { useGeolocation } from "../src/hooks/useGeolocation";

const originalGeolocation = Object.getOwnPropertyDescriptor(navigator, "geolocation");

afterEach(() => {
  cleanup();
  if (originalGeolocation) Object.defineProperty(navigator, "geolocation", originalGeolocation);
  else Reflect.deleteProperty(navigator, "geolocation");
});

describe("useGeolocation", () => {
  it("derives COG only after movement exceeds GPS noise and clears the watch on stop", () => {
    let success: PositionCallback | undefined;
    const watchPosition = vi.fn((callback: PositionCallback) => {
      success = callback;
      return 23;
    });
    const clearWatch = vi.fn();
    Object.defineProperty(navigator, "geolocation", {
      configurable: true,
      value: { watchPosition, clearWatch, getCurrentPosition: vi.fn() }
    });
    const { result } = renderHook(() => useGeolocation());

    act(() => result.current.start());
    act(() => success?.(positionAt(53, 7, 5, 1_000)));
    expect(result.current.courseDeg).toBeNull();

    act(() => success?.(positionAt(53, 7.00001, 5, 2_000)));
    expect(result.current.courseDeg).toBeNull();

    const receivedAtMs = Date.now();
    act(() => success?.(positionAt(53, 7.0001, 5, 3_000)));
    expect(result.current.courseDeg).toBeCloseTo(90, 0);
    expect(result.current.timestampMs).toBeGreaterThanOrEqual(receivedAtMs);

    act(() => result.current.stop());
    expect(clearWatch).toHaveBeenCalledWith(23);
    expect(result.current.status).toBe("idle");
    expect(result.current.position).toBeNull();
  });
});

function positionAt(lat: number, lon: number, accuracy: number, timestamp: number): GeolocationPosition {
  return {
    coords: {
      latitude: lat,
      longitude: lon,
      accuracy,
      altitude: null,
      altitudeAccuracy: null,
      heading: null,
      speed: 3,
      toJSON: () => ({})
    },
    timestamp,
    toJSON: () => ({})
  };
}