import { afterEach, describe, expect, it, vi } from 'vitest';
import { fetchModFileFromUrl, fetchModFromUrl, getFileName } from './index.js';
import { ItemNotFoundError, NoFileError, SteamApiError, TtsError } from './errors.js';

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

// A minimal valid BSON document: { GameMode: 'Tabletop' }.
const bsonBytes = new Uint8Array([
  28, 0, 0, 0, 2, 71, 97, 109, 101, 77, 111, 100, 101, 0, 9, 0, 0, 0, 84, 97,
  98, 108, 101, 116, 111, 112, 0, 0,
]);

function bsonResponse(): Response {
  return new Response(bsonBytes);
}

describe('fetchModFromUrl', () => {
  it('downloads and deserializes a save from a URL', async () => {
    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(bsonResponse()));
    const mod = await fetchModFromUrl('https://example.com/save.json');
    expect(mod.GameMode).toBe('Tabletop');
  });

  it('throws on a failed download', async () => {
    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(new Response(null, { status: 404 })));
    await expect(fetchModFromUrl('https://example.com/save.json')).rejects.toThrow(
      'Failed to download save file (404)',
    );
  });
});

describe('fetchModFileFromUrl', () => {
  it('returns bytes and a filename derived from the URL', async () => {
    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(bsonResponse()));
    const { data, filename } = await fetchModFileFromUrl(
      'https://example.com/files/mod.json',
    );
    expect(new Uint8Array(data)).toEqual(bsonBytes);
    expect(filename).toBe('mod.json');
  });
});

describe('getFileName', () => {
  it('parses a quoted content-disposition filename', () => {
    expect(
      getFileName('https://example.com/save', 'attachment; filename="mod.json"'),
    ).toBe('mod.json');
  });

  it('parses an unquoted filename', () => {
    expect(
      getFileName('https://example.com/save', 'attachment; filename=mod.json'),
    ).toBe('mod.json');
  });

  it('falls back to the URL path when there is no disposition', () => {
    expect(getFileName('https://example.com/files/mod.json', null)).toBe(
      'mod.json',
    );
  });

  it('falls back to a default when the URL has no path', () => {
    expect(getFileName('https://example.com', null)).toBe('save.json');
  });
});

describe('error classes', () => {
  it('ItemNotFoundError carries a 404 status', () => {
    const err = new ItemNotFoundError('123');
    expect(err).toBeInstanceOf(TtsError);
    expect(err.status).toBe(404);
    expect(err.message).toContain('123');
  });

  it('NoFileError carries a 404 status', () => {
    const err = new NoFileError('123');
    expect(err.status).toBe(404);
    expect(err.message).toContain('123');
  });

  it('SteamApiError defaults to a 502 status', () => {
    const err = new SteamApiError('boom');
    expect(err.status).toBe(502);
  });

  it('TtsError defaults to a 500 status', () => {
    const err = new TtsError('boom');
    expect(err.status).toBe(500);
  });
});