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 opentype from 'opentype.js';
import { probeDfont, extractSfntBuffer, registerDfontConverter } from '../../src/converters/dfont.js';
import { resolve, listTargetFormats } from '../../src/converters/registry.js';
import { detectInputMime } from '../../src/mime.js';

let tmpDir;

beforeAll(async () => {
  registerDfontConverter();
  tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'converter-dfont-'));
});

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

describe('probeDfont', () => {
  it('returns true for a real dfont fixture', async () => {
    const buffer = await fs.readFile(path.join(import.meta.dirname, '..', 'fixtures', 'sample.dfont'));
    expect(probeDfont(buffer)).toBe(true);
  });

  it('returns false for content starting with the ICO-colliding magic bytes but no real dfont structure', () => {
    const buffer = Buffer.from([0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x10, 0x10]);
    expect(probeDfont(buffer)).toBe(false);
  });
});

describe('extractSfntBuffer', () => {
  it('extracts a valid, byte-exact standalone sfnt font from the dfont fixture', async () => {
    const buffer = await fs.readFile(path.join(import.meta.dirname, '..', 'fixtures', 'sample.dfont'));
    const sfnt = extractSfntBuffer(buffer);

    const ab = sfnt.buffer.slice(sfnt.byteOffset, sfnt.byteOffset + sfnt.byteLength);
    const font = opentype.parse(ab);
    expect(font.outlinesFormat).toBe('truetype');
    expect(font.glyphs.length).toBe(7);
  });
});

describe('dfont converter registration', () => {
  it('registers dfont as a source for ttf, otf, and woff', () => {
    expect(listTargetFormats('dfont')).toEqual(expect.arrayContaining(['ttf', 'otf', 'woff']));
  });

  it('never registers dfont as a target format', () => {
    expect(listTargetFormats('ttf')).not.toContain('dfont');
    expect(listTargetFormats('otf')).not.toContain('dfont');
    expect(listTargetFormats('woff')).not.toContain('dfont');
  });
});

describe('dfont -> font conversion', () => {
  it('converts the dfont fixture to ttf', async () => {
    const inputPath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.dfont');
    const outputPath = path.join(tmpDir, 'from-dfont.ttf');

    await resolve('dfont', 'ttf').convert(inputPath, outputPath);

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

  it('converts the dfont fixture to woff', async () => {
    const inputPath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.dfont');
    const outputPath = path.join(tmpDir, 'from-dfont.woff');

    await resolve('dfont', 'woff').convert(inputPath, outputPath);

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

  it('converts the dfont fixture to otf', async () => {
    const inputPath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.dfont');
    const outputPath = path.join(tmpDir, 'from-dfont.otf');

    await resolve('dfont', 'otf').convert(inputPath, outputPath);

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