import { beforeEach, describe, expect, it, vi } from 'vitest';
import { choosePdfSliceHeight, pdfBlockBreakOffsets } from '../pdfExport.ts';

const mocks = vi.hoisted(() => ({
  addImage: vi.fn(),
  save: vi.fn(),
  jsPDF: vi.fn(),
  html2canvas: vi.fn(),
}));

vi.mock('jspdf', () => ({
  jsPDF: mocks.jsPDF,
}));

vi.mock('html2canvas', () => ({
  default: mocks.html2canvas,
}));

describe('exportCardToPdf compression', () => {
  beforeEach(() => {
    mocks.addImage.mockReset();
    mocks.save.mockReset();
    mocks.jsPDF.mockReset();
    mocks.html2canvas.mockReset();
    mocks.jsPDF.mockImplementation(function JsPDF() {
      return {
        internal: { pageSize: { getWidth: () => 210, getHeight: () => 297 } },
        addPage: vi.fn(),
        addImage: mocks.addImage,
        save: mocks.save,
      };
    });
    mocks.html2canvas.mockImplementation(async () => {
      const canvas = document.createElement('canvas');
      canvas.width = 800;
      canvas.height = 400;
      return canvas;
    });
  });

  it('embeds JPEG pages in a compressed jsPDF document', async () => {
    vi.spyOn(HTMLCanvasElement.prototype, 'getContext').mockReturnValue({
      fillStyle: '',
      fillRect: vi.fn(),
      drawImage: vi.fn(),
    } as unknown as CanvasRenderingContext2D);
    const toDataURL = vi
      .spyOn(HTMLCanvasElement.prototype, 'toDataURL')
      .mockReturnValue('data:image/jpeg;base64,xx');

    const { exportCardToPdf } = await import('../pdfExport.ts');
    await exportCardToPdf(document.createElement('div'), 'Laporan.pdf');

    expect(mocks.jsPDF).toHaveBeenCalledWith(expect.objectContaining({ compress: true }));
    expect(toDataURL).toHaveBeenCalledWith('image/jpeg', expect.any(Number));
    const quality = toDataURL.mock.calls.find((call) => call[0] === 'image/jpeg')?.[1] as number;
    expect(quality).toBeGreaterThan(0);
    expect(quality).toBeLessThan(1);
    expect(mocks.addImage).toHaveBeenCalledWith(
      expect.any(String),
      'JPEG',
      expect.any(Number),
      expect.any(Number),
      expect.any(Number),
      expect.any(Number)
    );
    expect(mocks.save).toHaveBeenCalledWith('Laporan.pdf');

    toDataURL.mockRestore();
    vi.restoreAllMocks();
  });
});

describe('pdf page breaks', () => {
  it('does not defer an oversized table past the header', () => {
    const usableHeight = 1200;
    const breaks = pdfBlockBreakOffsets([{ top: 80, bottom: 5000 }], usableHeight);
    expect(breaks).not.toContain(80);
    expect(breaks).toContain(5000);
    expect(choosePdfSliceHeight(0, 5000, usableHeight, breaks)).toBe(usableHeight);
  });

  it('keeps a small chart whole by breaking before it when it no longer fits', () => {
    const usableHeight = 400;
    const breaks = pdfBlockBreakOffsets([{ top: 350, bottom: 500 }], usableHeight);
    expect(breaks).toEqual(expect.arrayContaining([350, 500]));
    expect(choosePdfSliceHeight(0, 900, usableHeight, breaks)).toBe(350);
  });
});