Jyotisha/frontend/src/lib/agent-reply.ts

import type { ConsultationDomain } from "./consultation-domain-registry.ts";
import { consultationDomainDefinition } from "./consultation-domain-registry.ts";
import type { ConsultationEntrypoint } from "./consultation-entrypoint.ts";
import {
  isGeneralDailyFortuneQuestion,
} from "./consultation-entrypoint.ts";
import { shanghaiDateParts } from "./session-shanghai-clock.ts";

export type ReplyTheme = ConsultationDomain;

import type { ConsultationReplyMetadata } from "./consultation-reply-metadata.ts";

const GENERIC_SESSION_TITLES = new Set([
  "新对话",
  "深入看今日",
  "从今日问起",
  "查看今日运势",
  "生时校正",
  "再次校正",
  "一般占星咨询",
  "深入看今日主题咨询",
]);

function readTitle(value: string): string | undefined {
  const title = value.replace(/\s+/g, " ").trim();
  if (!title || /[\d\p{P}\p{S}]/u.test(title)) return undefined;
  if (/\p{Script=Han}/u.test(title)) {
    const length = Array.from(title.replace(/\s/g, "")).length;
    return length >= 6 && length <= 14 ? title : undefined;
  }
  const words = title.split(" ").filter(Boolean);
  return words.length >= 3 && words.length <= 7 && title.length <= 64 ? title : undefined;
}

// AYANAM_SUGGESTIONS blocks are no longer produced anywhere, but stored answers from
// before the follow-up chips were removed still carry them, so they stay strippable
// rather than leaking a raw HTML comment into a replayed transcript.
function stripAgentReplyMetadata(value: string) {
  let title: string | undefined;
  const text = value
    .replace(/<!--AYANAM_SUGGESTIONS:\[[\s\S]*?\]-->/g, "")
    .replace(/<!--AYANAM_TITLE:([\s\S]*?)-->/g, (_, rawTitle: string) => {
      title = readTitle(rawTitle);
      return "";
    })
    .replace(/<!--AYANAM_[\s\S]*$/, "")
    .trim();

  return { text, title };
}

export function parseAgentReply(value: string, metadata?: ConsultationReplyMetadata) {
  const parsed = stripAgentReplyMetadata(value);
  return { text: parsed.text, title: metadata?.title ?? parsed.title };
}

export type SessionTitleOptions = {
  readonly entrypoint?: ConsultationEntrypoint | null;
  readonly theme?: ConsultationDomain;
  /** Wall clock. Only for minting a brand-new session. Re-titling an existing
   *  session must pass that session's created time; the default `new Date()`
   *  would stamp today's date onto old chats (BUG-699). */
  readonly at?: Date;
  readonly existingTitles?: readonly string[];
};

const DATED_CATEGORY_PREFIX = /^(?:生时校正|今日节奏)\s*·\s*\d{1,2}月\d{1,2}日/;
const DATED_CATEGORY_SUFFIX = /^\d{1,2}月\d{1,2}日\s*·\s*(?:生时校正|今日节奏)(?:\s+\d{2}:\d{2})?$/;

export function isGenericSessionTitle(title: string): boolean {
  const text = title.replace(/\s+/g, " ").trim();
  if (!text) return true;
  if (GENERIC_SESSION_TITLES.has(text)) return true;
  if (DATED_CATEGORY_PREFIX.test(text) || DATED_CATEGORY_SUFFIX.test(text)) return true;
  return /^(?:深入看今日|从今日问起|查看今日运势|生时校正|再次校正)/.test(text);
}

function clipTitle(value: string, maxChars = 14): string {
  const characters = Array.from(value);
  return characters.length > maxChars ? `${characters.slice(0, maxChars).join("")}…` : value;
}

// Daily rhythm only. Rectification titles are the result time, written by
// public.rectification_session_title when the case result changes (BUG-1001 / D3).
function datedSessionTitle(at: Date, category: string): string {
  const { month, day } = shanghaiDateParts(at);
  return `${category} · ${month}月${day}日`;
}

export function resolveSessionTitle(
  question: string,
  modelTitle?: string,
  options: SessionTitleOptions = {},
): string {
  const at = options.at ?? new Date(); // new sessions only; see SessionTitleOptions.at
  if (modelTitle && !isGenericSessionTitle(modelTitle)) {
    return clipTitle(modelTitle);
  }
  if (options.entrypoint === "daily_starlanguage" || isGeneralDailyFortuneQuestion(question)) {
    return datedSessionTitle(at, "今日节奏");
  }
  if (options.entrypoint === "birth_time_rectification") {
    return "生时校正";
  }
  const normalized = question.replace(/\s+/g, " ").trim().replace(/[？?！!。．，,；;：:]+$/u, "");
  if (!normalized) return "新对话";
  if (options.theme && options.theme !== "general") {
    const label = consultationDomainDefinition(options.theme).label;
    return `${label} · ${clipTitle(normalized, 10)}`;
  }
  return clipTitle(normalized);
}