'use strict';

const PERSONAL_INTAKE_MODES = ['allowlist_only', 'auto_enroll_review', 'auto_enroll_autopilot'];

function normalizePersonalIntakeMode(value) {
  const mode = String(value || '').trim();
  return PERSONAL_INTAKE_MODES.includes(mode) ? mode : 'allowlist_only';
}

function messageTimestamp(raw) {
  const parsed = Number(raw);
  if (!Number.isFinite(parsed)) return 0;
  return parsed > 1e12 ? Math.floor(parsed / 1000) : parsed;
}

function roomIdOf(message = {}) {
  const candidates = [
    message.fromRoomId,
    message.roomId,
    message.chatRoomId,
    message.room?.id,
    message.msgData?.fromRoomId,
    message.msgData?.roomId,
  ];
  for (const value of candidates) {
    const normalized = String(value ?? '').trim();
    if (normalized && !/^(?:0|null|undefined)$/i.test(normalized)) return normalized;
  }
  return '';
}

function isGroupMessage(message = {}) {
  if (roomIdOf(message)) return true;
  if (message.isRoom === true || Number(message.isRoomNotice) === 1) return true;
  return /^(?:group|room)$/i.test(String(message.chatType || '').trim());
}

function messageContent(message = {}) {
  const data = message.msgData || {};
  const candidates = [message.content, data.content, data.text, data.value, data.content?.text, data.content?.content];
  for (const value of candidates) {
    if (typeof value === 'string' && value.trim()) return value.trim();
  }
  return '';
}

function evaluatePolledMessage(message = {}, config = {}) {
  if (![0, 1, 2].includes(Number(message.msgType))) return { eligible: false, reason: 'unsupported_type' };
  if (isGroupMessage(message)) return { eligible: false, reason: 'group_message', roomId: roomIdOf(message) };
  const content = messageContent(message);
  const senderId = String(message.senderId || '');
  if (!content || !senderId) return { eligible: false, reason: 'empty_message' };
  if (senderId === String(config.selfUserId || '')) return { eligible: false, reason: 'self_message' };
  const allowlisted = (config.allowedSenders || []).map(String).includes(senderId);
  const intakeMode = normalizePersonalIntakeMode(config.intakeMode);
  if (!allowlisted && intakeMode === 'allowlist_only') return { eligible: false, reason: 'not_allowlisted' };
  const timestamp = messageTimestamp(message.timestamp);
  if (!timestamp) return { eligible: false, reason: 'invalid_timestamp' };
  // 使用持久化游标恢复停机期间的积压消息；不要再按本次进程启动时间丢弃。
  return { eligible: true, content, senderId, timestamp, allowlisted, unknownContact: !allowlisted, intakeMode };
}

module.exports = {
  PERSONAL_INTAKE_MODES,
  normalizePersonalIntakeMode,
  messageTimestamp,
  roomIdOf,
  isGroupMessage,
  messageContent,
  evaluatePolledMessage,
};