import { describe, expect, it } from 'vitest';

import { BinaryReader } from '../binary/BinaryReader.js';
import { resolveParserLimits } from '../parser/limits.js';
import { parseFssHttpDataElementPackage } from './data-elements.js';
import { FSSHTTP_OBJECT } from './types.js';

function start(type: number, compound: boolean, body: number[]): number[] {
  const raw = (body.length << 9) | (type << 3) | (compound ? 0x04 : 0x00);
  return [raw & 0xff, raw >>> 8, ...body];
}

function end(type: number): number[] {
  return [(type << 2) | 0x01];
}

function objectGroupDataEntry(): number[] {
  return start(FSSHTTP_OBJECT.objectGroupDataExcluded, false, [
    0x03, // One object reference.
    0x00, // Nil ExGUID.
    0x03, // One cell reference.
    0x00, // Nil context ExGUID.
    0x00, // Nil object-space ExGUID.
    0x00, // Excluded object data size.
  ]);
}

function packageWithReferenceArrays(entryCount: number): Uint8Array {
  const dataEntries = Array.from({ length: entryCount }, () =>
    objectGroupDataEntry()
  ).flat();
  return Uint8Array.from([
    ...start(FSSHTTP_OBJECT.dataElementPackage, true, [0x00]),
    ...start(FSSHTTP_OBJECT.dataElement, true, [
      0x00, // Nil data-element ExGUID.
      0x00, // Nil serial number.
      0x0b, // Object Group data-element type (5).
    ]),
    ...start(FSSHTTP_OBJECT.objectGroupDeclaration, true, []),
    ...end(FSSHTTP_OBJECT.objectGroupDeclaration),
    ...start(FSSHTTP_OBJECT.objectGroupData, true, []),
    ...dataEntries,
    ...end(FSSHTTP_OBJECT.objectGroupData),
    ...end(FSSHTTP_OBJECT.dataElement),
    ...end(FSSHTTP_OBJECT.dataElementPackage),
  ]);
}

describe('FSSHTTPB data elements', () => {
  it('enforces one aggregate budget across many reference arrays', () => {
    const bytes = packageWithReferenceArrays(16);

    expect(() =>
      parseFssHttpDataElementPackage(
        // Every array contains one reference, but the package contains 32.
        new BinaryReader(bytes),
        resolveParserLimits({ maxObjectReferences: 31 })
      )
    ).toThrowError(
      expect.objectContaining({
        code: 'LIMIT_EXCEEDED',
        structure: 'FSSHTTPB object and cell references',
      })
    );

    const parsed = parseFssHttpDataElementPackage(
      new BinaryReader(bytes),
      resolveParserLimits({ maxObjectReferences: 32 })
    );
    expect(parsed.objectGroups.values().next().value?.data).toHaveLength(16);
  });
});