// src/lib/verifications.js — pure helpers for the Verifier component.

// Derive an rkey from a record uri: at://did/collection/rkey
export const rkeyFromUri = (uri) => (uri ? uri.split('/').pop() : null);

// Deterministic rkey for a verification record: "v-" + base64url(subject DID).
// Atproto rkeys allow [A-Za-z0-9._~-]; base64url output is only A-Za-z0-9_-,
// so this is always valid and collision-free per subject — putRecord with this
// rkey is an idempotent upsert (re-verifying the same DID never duplicates).
export const verificationRkey = (subjectDid) =>
  'v-' + btoa(subjectDid).replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');

// Split an array into chunks of at most `size` (last chunk may be smaller).
export const chunkArray = (items, size) => {
  if (!Array.isArray(items) || items.length === 0) return [];

  if (!Number.isInteger(size) || size < 1) throw new Error('chunkArray: size must be a positive integer');
  const chunks = [];

  for (let i = 0; i < items.length; i += size) {
    chunks.push(items.slice(i, i + size));
  }

  return chunks;
};

/**
 * Staleness decision for one verification, given the stored record and the
 * account's current profile (or null when the account no longer resolves).
 *
 * @param {Object} stored {handle, displayName}
 * @param {Object|null} profile current profile {did, handle, displayName}
 * @returns {{stale: boolean, gone: boolean, currentHandle: string|null, currentDisplayName: string|null}}
 */
export const assessProfile = (stored, profile) => {
  if (!profile) {
    return { stale: false, gone: true, currentHandle: null, currentDisplayName: null };
  }

  const currentHandle = profile.handle;
  const currentDisplayName = profile.displayName || currentHandle;

  return {
    stale: currentHandle !== stored.handle || currentDisplayName !== stored.displayName,
    gone: false,
    currentHandle,
    currentDisplayName,
  };
};