import { parseWechatChannelPrefix, WECHAT_CHANNEL_PREFIX } from './channel-prefix.mjs';
import {
  CONNECTIVITY_TEST_PATTERN,
  GREETING_PATTERN,
  STATUS_PROBE_PATTERN,
  isPageGenerateText,
  isTopicResetText,
  wantsDocxDownload,
} from './patterns.mjs';
import { WECHAT_SESSION_ACTION } from './session-action.mjs';

/**
 * @typedef {object} WechatPageGenerateIntent
 * @property {'page.generate'} kind
 * @property {string} topic
 * @property {boolean} wantsDocx
 *
 * @typedef {object} WechatSessionResetIntent
 * @property {'session.reset'} kind
 * @property {string} sessionAction
 *
 * @typedef {object} WechatStatusProbeIntent
 * @property {'status.probe'} kind
 *
 * @typedef {object} WechatGreetingIntent
 * @property {'greeting'} kind
 *
 * @typedef {object} WechatConnectivityTestIntent
 * @property {'connectivity.test'} kind
 *
 * @typedef {object} WechatGeneralChatIntent
 * @property {'chat.general'} kind
 * @property {string} text
 *
 * @typedef {object} WechatUnsupportedIntent
 * @property {'unsupported'} kind
 * @property {string} msgType
 *
 * @typedef {WechatPageGenerateIntent|WechatSessionResetIntent|WechatStatusProbeIntent|WechatGreetingIntent|WechatConnectivityTestIntent|WechatGeneralChatIntent|WechatUnsupportedIntent} WechatIntent
 */

/**
 * Classify a normalized WeChat inbound intent (from wechat-mp normalizeWechatInboundIntent).
 * @param {{ msgType?: string, agentText?: string, displayText?: string }} intent
 * @returns {WechatIntent}
 */
function withChannelMeta(result, channelPrefix) {
  if (!channelPrefix) return result;
  return { ...result, channelPrefix };
}

export function classifyWechatIntent(intent) {
  const msgType = String(intent?.msgType ?? 'text').toLowerCase();
  const rawText = String(intent?.agentText ?? intent?.displayText ?? '').trim();
  const { channel: channelPrefix, body: text } = parseWechatChannelPrefix(rawText);

  if (msgType === 'text' || msgType === 'voice') {
    if (isTopicResetText(text)) {
      return withChannelMeta(
        { kind: 'session.reset', sessionAction: WECHAT_SESSION_ACTION.RESET },
        channelPrefix,
      );
    }
    if (STATUS_PROBE_PATTERN.test(text)) {
      return withChannelMeta({ kind: 'status.probe' }, channelPrefix);
    }
    if (GREETING_PATTERN.test(text.replace(/[!！。.\s]+$/g, ''))) {
      return withChannelMeta({ kind: 'greeting' }, channelPrefix);
    }
    if (CONNECTIVITY_TEST_PATTERN.test(text.replace(/[!！。.\s]+$/g, ''))) {
      return withChannelMeta({ kind: 'connectivity.test' }, channelPrefix);
    }
    if (channelPrefix === WECHAT_CHANNEL_PREFIX.CHAT) {
      return withChannelMeta({ kind: 'chat.general', text }, channelPrefix);
    }
    if (channelPrefix === WECHAT_CHANNEL_PREFIX.PAGE) {
      return withChannelMeta({
        kind: 'page.generate',
        topic: text,
        wantsDocx: wantsDocxDownload(text),
      }, channelPrefix);
    }
    if (isPageGenerateText(text)) {
      return withChannelMeta({
        kind: 'page.generate',
        topic: text,
        wantsDocx: wantsDocxDownload(text),
      }, channelPrefix);
    }
    return withChannelMeta({ kind: 'chat.general', text }, channelPrefix);
  }

  if (msgType === 'event') {
    return { kind: 'unsupported', msgType: 'event' };
  }

  return { kind: 'chat.general', text: text || `[${msgType}]` };
}

export function isPageGenerateIntent(intent) {
  return classifyWechatIntent(intent).kind === 'page.generate';
}