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 * as fontkit from 'fontkit';
import { registerFontConverter } from '../../src/converters/font.js';
import { resolve, listTargetFormats } from '../../src/converters/registry.js';
import { detectInputMime } from '../../src/mime.js';

async function parseWithOpentype(fixtureName) {
  const buf = await fs.readFile(path.join(import.meta.dirname, '..', 'fixtures', fixtureName));
  const ab = buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
  return opentype.parse(ab);
}

describe('font fixtures', () => {
  it('sample.otf parses as a CFF-flavored OpenType font', async () => {
    const font = await parseWithOpentype('sample.otf');
    expect(font.outlinesFormat).toBe('cff');
    expect(font.glyphs.length).toBe(1568);
  });

  it('sample.ttf parses as a TrueType font with the same glyph count as sample.otf', async () => {
    const font = await parseWithOpentype('sample.ttf');
    expect(font.outlinesFormat).toBe('truetype');
    expect(font.glyphs.length).toBe(1568);
  });

  it('sample.dfont is a valid dfont container with one embedded sfnt font', async () => {
    const buffer = await fs.readFile(path.join(import.meta.dirname, '..', 'fixtures', 'sample.dfont'));
    const dfont = fontkit.create(buffer);
    const sfntType = dfont.header.map.typeList.types.find((t) => t.name === 'sfnt');
    expect(sfntType.refList).toHaveLength(1);
  });
});

let tmpDir;

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

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

async function glyphCountOf(filePath) {
  const buf = await fs.readFile(filePath);
  const ab = buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
  return opentype.parse(ab).glyphs.length;
}

describe('font converter registration', () => {
  it('registers ttf, otf, and woff as sources and targets of each other', () => {
    expect(listTargetFormats('ttf')).toEqual(expect.arrayContaining(['otf', 'woff']));
    expect(listTargetFormats('otf')).toEqual(expect.arrayContaining(['ttf', 'woff']));
    expect(listTargetFormats('woff')).toEqual(expect.arrayContaining(['ttf', 'otf']));
  });

  it('does not register a format as its own target', () => {
    expect(listTargetFormats('ttf')).not.toContain('ttf');
  });

  it('has no registered converter for cff or cid in either direction', () => {
    expect(listTargetFormats('cff')).toEqual([]);
    expect(listTargetFormats('cid')).toEqual([]);
    expect(resolve('cff', 'ttf')).toBeNull();
    expect(resolve('ttf', 'cff')).toBeNull();
    expect(resolve('cid', 'ttf')).toBeNull();
  });
});

describe('font format conversion', () => {
  it('converts otf to ttf, preserving glyph count', async () => {
    const inputPath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.otf');
    const outputPath = path.join(tmpDir, 'from-otf.ttf');

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

    const detected = await detectInputMime(outputPath);
    expect(detected.mime).toBe('font/ttf');
    expect(await glyphCountOf(outputPath)).toBe(1568);
  });

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

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

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

  it('round-trips ttf -> woff -> ttf, preserving glyph count', async () => {
    const woffPath = path.join(tmpDir, 'roundtrip.woff');
    const ttfPath = path.join(tmpDir, 'roundtrip.ttf');

    await resolve('ttf', 'woff').convert(path.join(import.meta.dirname, '..', 'fixtures', 'sample.ttf'), woffPath);
    await resolve('woff', 'ttf').convert(woffPath, ttfPath);

    expect(await glyphCountOf(ttfPath)).toBe(1568);
  });

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

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

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