import { describe, it, expect, beforeAll, afterAll } from 'vitest';
import fs from 'node:fs/promises';
import path from 'node:path';
import os from 'node:os';
import sharp from 'sharp';
import { registerImageToPdfConverter } from '../../src/converters/imageToPdf.js';
import { resolve, listTargetFormats } from '../../src/converters/registry.js';
import { detectInputMime } from '../../src/mime.js';

let tmpDir;

beforeAll(async () => {
  registerImageToPdfConverter();
  tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'converter-image-to-pdf-'));
});

afterAll(async () => {
  await fs.rm(tmpDir, { recursive: true, force: true });
});

describe('image to PDF converter', () => {
  it('registers pdf as a target for every image format', () => {
    expect(listTargetFormats('png')).toContain('pdf');
    expect(listTargetFormats('jpg')).toContain('pdf');
  });

  it('converts a PNG fixture into a valid PDF', async () => {
    const inputPath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.png');
    const outputPath = path.join(tmpDir, 'output.pdf');
    const entry = resolve('png', 'pdf');

    await entry.convert(inputPath, outputPath);

    const detected = await detectInputMime(outputPath);
    expect(detected.mime).toBe('application/pdf');
  });

  it('embeds a JPEG instead of a PNG when a quality is given, shrinking the output for a noisy image', async () => {
    const inputPath = path.join(tmpDir, 'noisy.png');
    await sharp({
      create: {
        width: 256,
        height: 256,
        channels: 3,
        noise: { type: 'gaussian', mean: 128, sigma: 40 },
      },
    })
      .png()
      .toFile(inputPath);

    const defaultOutputPath = path.join(tmpDir, 'default.pdf');
    const compressedOutputPath = path.join(tmpDir, 'compressed.pdf');
    const entry = resolve('png', 'pdf');

    await entry.convert(inputPath, defaultOutputPath);
    await entry.convert(inputPath, compressedOutputPath, { quality: 20 });

    const compressedDetected = await detectInputMime(compressedOutputPath);
    expect(compressedDetected.mime).toBe('application/pdf');

    const [defaultStat, compressedStat] = await Promise.all([
      fs.stat(defaultOutputPath),
      fs.stat(compressedOutputPath),
    ]);
    expect(compressedStat.size).toBeLessThan(defaultStat.size);
  });
});