import { describe, expect, it } from 'vitest';
import { strFromU8, strToU8, unzipSync, zipSync } from 'fflate';
import { useDocument } from '../../store/document';
import { serializeDocument } from '../json';
import { importJsonReplace, readNumFile } from '../operations';
import { NUM_MIMETYPE, NumFileError, packNum, unpackNum } from '../num';

describe('.num files', () => {
  it('round-trip the document JSON exactly', async () => {
    const s = useDocument();
    s.resetToSeed();
    const json = serializeDocument(s.snapshot());
    const bytes = packNum(json);
    expect(unpackNum(bytes)).toBe(json);
    // and import back into the store like a .json file
    s.newDocument();
    importJsonReplace(s, await readNumFile(bytes.slice().buffer));
    expect(serializeDocument(s.snapshot())).toBe(json);
  });

  it('are smaller than the JSON they carry', () => {
    const s = useDocument();
    s.resetToSeed();
    const json = serializeDocument(s.snapshot());
    expect(packNum(json).length).toBeLessThan(json.length);
  });

  it('start with an uncompressed mimetype entry, plus meta.json with an ISO timestamp', () => {
    const bytes = packNum('{}', new Date('2026-09-28T10:00:00Z'));
    // local file header (30 bytes) + "mimetype" (8) -> the stored content
    expect(strFromU8(bytes.subarray(30, 38))).toBe('mimetype');
    expect(strFromU8(bytes.subarray(38, 38 + NUM_MIMETYPE.length))).toBe(NUM_MIMETYPE);
    const meta = JSON.parse(strFromU8(unzipSync(bytes)['meta.json']));
    expect(meta).toEqual({ format: 'numolus', formatVersion: 1, created: '2026-09-28T10:00:00.000Z' });
  });

  it('reject what is not a numolus file', () => {
    expect(() => unpackNum(strToU8('{"version":2}'))).toThrow(NumFileError);
    expect(() => unpackNum(zipSync({ mimetype: strToU8('application/zip') }))).toThrow(/Keine numolus-Datei/);
    expect(() => unpackNum(zipSync({ mimetype: strToU8(NUM_MIMETYPE) }))).toThrow(/kein document.json/);
    const newer = zipSync({
      mimetype: strToU8(NUM_MIMETYPE),
      'meta.json': strToU8('{"formatVersion": 99}'),
      'document.json': strToU8('{}'),
    });
    expect(() => unpackNum(newer)).toThrow(/neueren numolus-Version/);
  });
});