// @vitest-environment jsdom

import { afterEach, describe, expect, test, vi } from 'vitest';

import {
  PUZZLE_REFERENCE_IMAGE_MAX_DATA_URL_LENGTH,
  cropPuzzleReferenceImageDataUrl,
  isPuzzleReferenceImageSquare,
  readPuzzleReferenceImageForUpload,
  readPuzzleReferenceImageAsDataUrl,
} from './puzzleReferenceImage';

afterEach(() => {
  vi.unstubAllGlobals();
  vi.restoreAllMocks();
});

function stubFileReader(dataUrl: string) {
  class MockFileReader {
    result: string | null = null;
    error: Error | null = null;
    onload: null | (() => void) = null;
    onerror: null | (() => void) = null;

    readAsDataURL() {
      this.result = dataUrl;
      this.onload?.();
    }
  }

  vi.stubGlobal('FileReader', MockFileReader as unknown as typeof FileReader);
}

function stubImage(width = 4096, height = 3072) {
  class MockImage {
    onload: null | (() => void) = null;
    onerror: null | (() => void) = null;
    naturalWidth = width;
    naturalHeight = height;
    width = width;
    height = height;

    set src(_value: string) {
      this.onload?.();
    }
  }

  vi.stubGlobal('Image', MockImage as unknown as typeof Image);
}

function stubCanvas(dataUrls: string[]) {
  const drawImage = vi.fn();
  const toDataURL = vi
    .fn()
    .mockImplementation(
      () => dataUrls.shift() ?? 'data:image/jpeg;base64,small',
    );
  const originalCreateElement = document.createElement.bind(document);
  vi.spyOn(document, 'createElement').mockImplementation((tagName) => {
    if (tagName !== 'canvas') {
      return originalCreateElement(tagName);
    }
    return {
      width: 0,
      height: 0,
      getContext: () => ({
        drawImage,
        fillRect: vi.fn(),
        fillStyle: '',
        imageSmoothingEnabled: false,
        imageSmoothingQuality: 'low',
      }),
      toDataURL,
    } as unknown as HTMLCanvasElement;
  });
  return { drawImage, toDataURL };
}

describe('readPuzzleReferenceImageAsDataUrl', () => {
  test('compresses large puzzle reference images before JSON upload', async () => {
    stubFileReader(`data:image/png;base64,${'A'.repeat(3 * 1024 * 1024)}`);
    stubImage();
    const { drawImage, toDataURL } = stubCanvas([
      `data:image/jpeg;base64,${'B'.repeat(1200)}`,
      `data:image/jpeg;base64,${'C'.repeat(1000)}`,
      `data:image/jpeg;base64,${'D'.repeat(1400)}`,
    ]);

    const file = new File(['x'.repeat(2 * 1024 * 1024)], 'reference.png', {
      type: 'image/png',
    });
    const dataUrl = await readPuzzleReferenceImageAsDataUrl(file);

    expect(dataUrl).toBe(`data:image/jpeg;base64,${'C'.repeat(1000)}`);
    expect(drawImage).toHaveBeenCalledWith(expect.anything(), 0, 0, 1536, 1152);
    expect(toDataURL).toHaveBeenCalledWith('image/jpeg', 0.84);
    expect(toDataURL).toHaveBeenCalledWith('image/jpeg', 0.76);
    expect(toDataURL).toHaveBeenCalledWith('image/jpeg', 0.68);
  });

  test('rejects reference images that still exceed the upload budget', async () => {
    stubFileReader(
      `data:image/png;base64,${'A'.repeat(PUZZLE_REFERENCE_IMAGE_MAX_DATA_URL_LENGTH + 1)}`,
    );
    stubImage();
    stubCanvas([
      `data:image/jpeg;base64,${'B'.repeat(PUZZLE_REFERENCE_IMAGE_MAX_DATA_URL_LENGTH + 1)}`,
      `data:image/jpeg;base64,${'C'.repeat(PUZZLE_REFERENCE_IMAGE_MAX_DATA_URL_LENGTH + 2)}`,
      `data:image/jpeg;base64,${'D'.repeat(PUZZLE_REFERENCE_IMAGE_MAX_DATA_URL_LENGTH + 3)}`,
    ]);

    const file = new File(['x'.repeat(2 * 1024 * 1024)], 'reference.png', {
      type: 'image/png',
    });

    await expect(readPuzzleReferenceImageAsDataUrl(file)).rejects.toThrow(
      '参考图过大，请换一张尺寸更小的图片。',
    );
  });
});

describe('puzzle reference image square crop helpers', () => {
  test('reports square upload dimensions without opening crop flow', async () => {
    const sourceDataUrl = 'data:image/png;base64,square';
    stubFileReader(sourceDataUrl);
    stubImage(512, 512);

    const file = new File(['x'], 'square.png', { type: 'image/png' });
    const result = await readPuzzleReferenceImageForUpload(file);

    expect(result).toEqual({
      dataUrl: sourceDataUrl,
      width: 512,
      height: 512,
    });
    expect(isPuzzleReferenceImageSquare(result)).toBe(true);
  });

  test('crops non-square uploads to a centered square data URL', async () => {
    const sourceDataUrl = 'data:image/png;base64,wide';
    const croppedDataUrl = 'data:image/jpeg;base64,cropped';
    stubImage(800, 600);
    const { drawImage, toDataURL } = stubCanvas([
      `data:image/jpeg;base64,${'A'.repeat(30)}`,
      croppedDataUrl,
      `data:image/jpeg;base64,${'B'.repeat(40)}`,
    ]);

    const dataUrl = await cropPuzzleReferenceImageDataUrl({
      source: sourceDataUrl,
      cropX: 100,
      cropY: 0,
      cropSize: 600,
    });

    expect(dataUrl).toBe(croppedDataUrl);
    expect(drawImage).toHaveBeenCalledWith(
      expect.anything(),
      100,
      0,
      600,
      600,
      0,
      0,
      600,
      600,
    );
    expect(toDataURL).toHaveBeenCalledWith('image/jpeg', 0.88);
  });
});