// @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,
  type LocalGamePreviewContentSize,
  LocalGamePreviewFrame,
  parseLocalGamePreviewContentSize,
  resolveLocalGamePreviewContentSizeUpdate,
  resolveLocalGamePreviewFitLayout,
} from '../src/features/project-workspace/LocalGamePreviewFrame';

/**
 * 运行画面用 `getBoundingClientRect` 量容器、用 `ResizeObserver` 跟踪；jsdom 两者都不给，这里补一份
 * 最小可驱动的：能改容器矩形、能手放 ResizeObserver 回调、能送跨窗口尺寸上报。
 */
function renderFittedFrame(initialContainer: {
  width: number;
  height: number;
}) {
  let containerRect = initialContainer;
  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;
  return {
    iframe,
    resizeTo(next: { width: number; height: number }) {
      containerRect = next;
      act(() => {
        if (!resizeCallback) {
          throw new Error('ResizeObserver was not registered');
        }
        resizeCallback([], {} as ResizeObserver);
      });
    },
    reportSize(size: LocalGamePreviewContentSize) {
      act(() => {
        window.dispatchEvent(
          new MessageEvent('message', {
            origin: 'http://127.0.0.1:1234',
            source: iframe.contentWindow,
            data: { type: LOCAL_GAME_PREVIEW_SIZE_MESSAGE, ...size },
          }),
        );
      });
    },
    cleanup() {
      view.unmount();
      window.ResizeObserver = previousResizeObserver;
      rectSpy.mockRestore();
    },
  };
}

describe('local game preview viewport fitting', () => {
  it('does not reset the fitted iframe to native size while its container resizes', () => {
    const frame = renderFittedFrame({ width: 800, height: 500 });
    frame.reportSize({
      contentWidth: 800,
      contentHeight: 835,
      viewportWidth: 800,
      viewportHeight: 500,
    });
    expect(frame.iframe.style.height).toBe('835px');

    frame.resizeTo({ width: 1000, height: 600 });
    expect(frame.iframe.style.width).toBe('1000px');
    expect(frame.iframe.style.height).toBe('835px');

    frame.cleanup();
  });

  it('returns the fitted iframe to the container after the host viewport shrinks', () => {
    // 全屏预览把运行视口放大到 1416x808，自适应游戏把视口原样报回来；退出全屏后画布必须跟着
    // 缩回容器尺寸，不能把全屏那一帧的尺寸钉在画布上（改前这里会一直是 1416x808 + 缩放到 0.72）。
    const frame = renderFittedFrame({ width: 1416, height: 808 });
    frame.reportSize({
      contentWidth: 1416,
      contentHeight: 808,
      viewportWidth: 1416,
      viewportHeight: 808,
    });
    expect(frame.iframe.style.width).toBe('1416px');
    expect(frame.iframe.style.height).toBe('808px');

    frame.resizeTo({ width: 1015, height: 660 });
    expect(frame.iframe.style.width).toBe('1015px');
    expect(frame.iframe.style.height).toBe('660px');

    frame.cleanup();
  });

  it('refits to the reported content size after the container shrinks', () => {
    // 容器缩小后先按容器取画布（上一次的内容尺寸已不能代表当前容器），页面在新容器上重新量出
    // 更大的内容（真的溢出）时，画布回到 `max(容器, 内容)` 并把整幅内容等比缩小。
    const frame = renderFittedFrame({ width: 1015, height: 660 });
    frame.reportSize({
      contentWidth: 1015,
      contentHeight: 660,
      viewportWidth: 1015,
      viewportHeight: 660,
    });
    expect(frame.iframe.style.width).toBe('1015px');

    frame.resizeTo({ width: 800, height: 520 });
    expect(frame.iframe.style.width).toBe('800px');

    frame.reportSize({
      contentWidth: 1200,
      contentHeight: 900,
      viewportWidth: 800,
      viewportHeight: 520,
    });
    expect(frame.iframe.style.width).toBe('1200px');
    expect(frame.iframe.style.height).toBe('900px');
    expect(
      Number(/scale\(([\d.]+)\)/u.exec(frame.iframe.style.transform)?.[1]),
    ).toBeCloseTo(520 / 900, 10);

    frame.cleanup();
  });

  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();
  });
});