chat-service.js

'use strict';

const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
const CHAT_LINK_RE = /(?:\b[a-z][a-z0-9+.-]*:\/\/[^\s<]+|\bmailto:[^\s<]+|\bwww\.[^\s<]+|\b(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z]{2,63}(?:[/?#][^\s<]*)?)/i;

const isUuid = (value) => typeof value === 'string' && UUID_RE.test(value.trim());

const orderedFriendPair = (first, second) => {
  if (!isUuid(first) || !isUuid(second)) throw new Error('Enter a valid ChainLens ID');
  const a = first.trim().toLowerCase();
  const b = second.trim().toLowerCase();
  if (a === b) throw new Error('You cannot add yourself as a friend');
  return a < b ? [a, b] : [b, a];
};

const isGiphyMediaUrl = (value) => {
  try {
    const url = new URL(value);
    const host = url.hostname.toLowerCase();
    return url.protocol === 'https:' && (host === 'giphy.com' || host.endsWith('.giphy.com'));
  } catch {
    return false;
  }
};

const containsChatLink = (value) => typeof value === 'string' && CHAT_LINK_RE.test(value);

const normalizeChatContent = (type, value, { allowLinks = true } = {}) => {
  const messageType = type === 'gif' ? 'gif' : 'text';
  if (typeof value !== 'string') throw new Error('Message content must be text');
  const content = value.trim();

  if (messageType === 'text') {
    if (!content) throw new Error('Write a message first');
    if (content.length > 500) throw new Error('Messages can be up to 500 characters');
    if (!allowLinks && containsChatLink(content)) {
      throw new Error('Links can only be sent in direct messages');
    }
  } else {
    if (content.length > 2048 || !isGiphyMediaUrl(content)) {
      throw new Error('Choose a GIF from the GIPHY picker');
    }
  }

  return { message_type: messageType, content };
};

// ─── Read cursors ────────────────────────────────────────────────────────────
// `conversation` is 'world' for World Chat and 'dm:<friendship_id>' for a direct
// thread. The same keys the cl_chat_reads table stores (sql/cl_chat.sql).

const WORLD_CONVERSATION = 'world';

const chatConversationKey = (friendshipId) => {
  if (friendshipId === undefined || friendshipId === null) return WORLD_CONVERSATION;
  const id = Number(friendshipId);
  if (!Number.isSafeInteger(id) || id < 1) throw new Error('Invalid conversation');
  return `dm:${id}`;
};

/**
 * Shape the cl_chat_unread rows into the badge payload.
 *
 * Threads with nothing unread are dropped rather than returned as zeroes: the
 * client indexes this by friend id to badge its list, and a poll that carries
 * one entry per friendship grows with the friend list for no benefit.
 */
const summarizeChatUnread = (rows, pendingRequests = 0) => {
  const conversations = (Array.isArray(rows) ? rows : [])
    .map(row => ({
      friendship_id: Number(row.friendship_id),
      friend_id: row.friend_id,
      unread: Number(row.unread) || 0,
    }))
    .filter(row => Number.isSafeInteger(row.friendship_id) && row.friend_id && row.unread > 0);

  return {
    pending_requests: Math.max(0, Number(pendingRequests) || 0),
    unread_direct: conversations.reduce((total, row) => total + row.unread, 0),
    conversations,
  };
};

module.exports = {
  isUuid, orderedFriendPair, isGiphyMediaUrl, containsChatLink, normalizeChatContent,
  WORLD_CONVERSATION, chatConversationKey, summarizeChatUnread,
};