// @vitest-environment jsdom

import { act, render } from '@testing-library/react';
import { createElement } from 'react';
import { describe, expect, it, vi } from 'vitest';

import {
  LOCAL_GAME_PREVIEW_SIZE_MESSAGE,
  LocalGamePreviewFrame,
  parseLocalGamePreviewContentSize,
  resolveLocalGamePreviewContentSizeUpdate,
  resolveLocalGamePreviewFitLayout,
} from '../src/features/project-workspace/LocalGamePreviewFrame';

describe('local game preview viewport fitting', () => {
  it('does not reset the fitted iframe to native size while its container resizes', () => {
    let containerRect = { width: 800, height: 500 };
    let resizeCallback: ResizeObserverCallback | null = null;
    const rectSpy = vi
      .spyOn(HTMLElement.prototype, 'getBoundingClientRect')
      .mockImplementation(
        () =>
          ({
            ...containerRect,
            x: 0,
            y: 0,
            top: 0,
            right: containerRect.width,
            bottom: containerRect.height,
            left: 0,
            toJSON: () => ({}),
          }) as DOMRect,
      );
    const previousResizeObserver = window.ResizeObserver;
    window.ResizeObserver = class {
      constructor(callback: ResizeObserverCallback) {
        resizeCallback = callback;
      }

      observe() {}
      unobserve() {}
      disconnect() {}
    };

    const view = render(
      createElement(LocalGamePreviewFrame, {
        preview: { status: 'running', url: 'http://127.0.0.1:1234/' },
        title: 'preview',
      }),
    );
    const iframe = view.getByTitle('preview') as HTMLIFrameElement;
    act(() => {
      window.dispatchEvent(
        new MessageEvent('message', {
          origin: 'http://127.0.0.1:1234',
          source: iframe.contentWindow,
          data: {
            type: LOCAL_GAME_PREVIEW_SIZE_MESSAGE,
            contentWidth: 800,
            contentHeight: 835,
            viewportWidth: 800,
            viewportHeight: 500,
          },
        }),
      );
    });
    expect(iframe.style.height).toBe('835px');

    containerRect = { width: 1000, height: 600 };
    act(() => {
      if (!resizeCallback) throw new Error('ResizeObserver was not registered');
      resizeCallback([], {} as ResizeObserver);
    });
    expect(iframe.style.width).toBe('1000px');
    expect(iframe.style.height).toBe('835px');

    view.unmount();
    window.ResizeObserver = previousResizeObserver;
    rectSpy.mockRestore();
  });

  it('keeps the current fit while the iframe reports its first host-applied viewport measurement', () => {
    const nativeViewport = { width: 1200, height: 700 };
    const appliedViewport = { width: 1200, height: 1000 };
    const current = {
      contentWidth: 1200,
      contentHeight: 1000,
      viewportWidth: 1200,
      viewportHeight: 700,
    };
    const firstAppliedViewportReport = {
      contentWidth: 1200,
      contentHeight: 700,
      viewportWidth: 1200,
      viewportHeight: 1000,
    };

    expect(
      resolveLocalGamePreviewContentSizeUpdate(
        current,
        firstAppliedViewportReport,
        nativeViewport,
        appliedViewport,
        nativeViewport,
      ),
    ).toBe(current);
  });

  it('does not let a delayed native report restart the fitted viewport loop', () => {
    const nativeViewport = { width: 1200, height: 700 };
    const appliedViewport = { width: 1200, height: 1000 };
    const current = {
      contentWidth: 1200,
      contentHeight: 1000,
      viewportWidth: 1200,
      viewportHeight: 700,
    };
    const delayedNativeReport = {
      contentWidth: 1200,
      contentHeight: 1000,
      viewportWidth: 1200,
      viewportHeight: 700,
    };

    expect(
      resolveLocalGamePreviewContentSizeUpdate(
        current,
        delayedNativeReport,
        nativeViewport,
        appliedViewport,
        appliedViewport,
      ),
    ).toBe(current);
  });

  it('keeps the current fit while a resized container applies its next viewport', () => {
    const resizedContainer = { width: 1000, height: 600 };
    const current = {
      contentWidth: 800,
      contentHeight: 835,
      viewportWidth: 800,
      viewportHeight: 500,
    };
    const appliedViewport = resolveLocalGamePreviewFitLayout(
      resizedContainer,
      current,
    );
    const resizedViewportReport = {
      contentWidth: 1000,
      contentHeight: 818,
      viewportWidth: appliedViewport.width,
      viewportHeight: appliedViewport.height,
    };

    expect(appliedViewport).toEqual({
      width: 1000,
      height: 835,
      scale: 600 / 835,
    });
    expect(
      resolveLocalGamePreviewContentSizeUpdate(
        current,
        resizedViewportReport,
        resizedContainer,
        appliedViewport,
        { width: 800, height: 835 },
      ),
    ).toBe(current);
  });

  it('keeps a game at native size when its content fits', () => {
    expect(
      resolveLocalGamePreviewFitLayout(
        { width: 1200, height: 700 },
        {
          contentWidth: 1200,
          contentHeight: 700,
          viewportWidth: 1200,
          viewportHeight: 700,
        },
      ),
    ).toEqual({ width: 1200, height: 700, scale: 1 });
  });

  it('scales the complete game document into the available viewport', () => {
    expect(
      resolveLocalGamePreviewFitLayout(
        { width: 1200, height: 700 },
        {
          contentWidth: 1200,
          contentHeight: 1000,
          viewportWidth: 1200,
          viewportHeight: 700,
        },
      ),
    ).toEqual({ width: 1200, height: 1000, scale: 0.7 });
  });

  it('accepts the native viewport report and keeps viewport out of fit state', () => {
    const nativeViewport = { width: 1200, height: 700 };
    const report = {
      contentWidth: 1200,
      contentHeight: 1000,
      viewportWidth: 1200,
      viewportHeight: 700,
    };

    expect(
      resolveLocalGamePreviewContentSizeUpdate(
        null,
        report,
        nativeViewport,
        nativeViewport,
      ),
    ).toEqual(report);
  });

  it('accepts changed content after the fitted iframe viewport has stabilized', () => {
    const nativeViewport = { width: 1200, height: 700 };
    const current = {
      contentWidth: 1200,
      contentHeight: 1000,
      viewportWidth: 1200,
      viewportHeight: 700,
    };
    const changed = {
      contentWidth: 1200,
      contentHeight: 1400,
      viewportWidth: 1200,
      viewportHeight: 1000,
    };

    expect(
      resolveLocalGamePreviewContentSizeUpdate(
        current,
        changed,
        nativeViewport,
        {
          width: 1200,
          height: 1000,
        },
        { width: 1200, height: 1000 },
      ),
    ).toEqual({
      contentWidth: 1200,
      contentHeight: 1400,
      viewportWidth: 1200,
      viewportHeight: 700,
    });
  });

  it('shrinks the fitted frame when content becomes shorter inside a stable applied viewport', () => {
    const nativeViewport = { width: 1200, height: 700 };
    const current = {
      contentWidth: 1200,
      contentHeight: 1000,
      viewportWidth: 1200,
      viewportHeight: 700,
    };
    const changed = {
      contentWidth: 1200,
      contentHeight: 800,
      viewportWidth: 1200,
      viewportHeight: 1000,
    };

    const updated = resolveLocalGamePreviewContentSizeUpdate(
      current,
      changed,
      nativeViewport,
      { width: 1200, height: 1000 },
      { width: 1200, height: 1000 },
    );
    expect(updated).toEqual({
      contentWidth: 1200,
      contentHeight: 800,
      viewportWidth: 1200,
      viewportHeight: 700,
    });
    expect(resolveLocalGamePreviewFitLayout(nativeViewport, updated)).toEqual({
      width: 1200,
      height: 800,
      scale: 0.875,
    });
  });

  it('keeps the current state for repeated content dimensions and fit viewport feedback', () => {
    const nativeViewport = { width: 1200, height: 700 };
    const current = {
      contentWidth: 1200,
      contentHeight: 1400,
      viewportWidth: 1200,
      viewportHeight: 700,
    };

    expect(
      resolveLocalGamePreviewContentSizeUpdate(
        current,
        { ...current, viewportHeight: 1400 },
        nativeViewport,
        { width: 1200, height: 1400 },
      ),
    ).toBe(current);
  });

  it('ignores delayed reports from a stale fitted viewport', () => {
    const nativeViewport = { width: 1200, height: 700 };
    const current = {
      contentWidth: 1200,
      contentHeight: 1400,
      viewportWidth: 1200,
      viewportHeight: 700,
    };

    expect(
      resolveLocalGamePreviewContentSizeUpdate(
        current,
        {
          contentWidth: 1200,
          contentHeight: 1100,
          viewportWidth: 1200,
          viewportHeight: 1000,
        },
        nativeViewport,
        { width: 1200, height: 1400 },
      ),
    ).toBe(current);
  });

  it('rejects malformed or unrelated cross-frame messages', () => {
    expect(
      parseLocalGamePreviewContentSize({
        type: LOCAL_GAME_PREVIEW_SIZE_MESSAGE,
        contentWidth: 1200,
        contentHeight: Number.NaN,
        viewportWidth: 1200,
        viewportHeight: 700,
      }),
    ).toBeNull();
    expect(
      parseLocalGamePreviewContentSize({
        type: 'unrelated',
        contentWidth: 1200,
        contentHeight: 700,
        viewportWidth: 1200,
        viewportHeight: 700,
      }),
    ).toBeNull();
  });
});