/**
 * Split a Zapier/middleware request into chain vs archive parts.
 * @module splitRequest
 */

import { createHash } from 'node:crypto';

/**
 * @param {string} data
 * @returns {string}
 */
export function sha256Hex(data) {
  return createHash('sha256').update(String(data), 'utf8').digest('hex');
}

/**
 * @param {object} body
 * @returns {{
 *   chain: { sha256: string, hashAlg: string, data?: string },
 *   archivePuts: Array<{ kind: string, sha256: string, record: object }>,
 *   includeAttached: boolean
 * }}
 */
export function splitRequest(body = {}) {
  const sha256 = (body.sha256 || (body.data != null ? sha256Hex(body.data) : '')).toLowerCase();
  if (!sha256) {
    throw new Error('data or sha256 is required');
  }
  const includeAttached = Boolean(body.includeAttached);
  const archivePuts = [];
  if (body.publicMetadata && Object.keys(body.publicMetadata).length) {
    archivePuts.push({
      kind: 'publicMeta',
      sha256,
      record: { publicMetadata: body.publicMetadata },
    });
  }
  if (body.privateMetadata && Object.keys(body.privateMetadata).length) {
    archivePuts.push({
      kind: 'privateMeta',
      sha256,
      record: { privateMetadata: body.privateMetadata },
    });
  }
  const files = Array.isArray(body.files) ? body.files : [];
  for (const f of files) {
    const bytes = f.contentBase64
      ? Buffer.from(String(f.contentBase64), 'base64')
      : Buffer.from(String(f.data ?? ''), 'utf8');
    const fileHash = sha256Hex(bytes);
    archivePuts.push({
      kind: 'file',
      sha256,
      record: {
        path: f.path || f.filename || 'file.bin',
        size: bytes.length,
        contentSha256: fileHash,
        contentBase64: bytes.toString('base64'),
      },
    });
  }
  return {
    chain: {
      sha256,
      hashAlg: body.hashAlg || 'SHA256',
      data: body.data,
    },
    archivePuts,
    includeAttached,
  };
}