"use client";

/**
 * Chat helpers and types shared by the chat UI. The record shapes themselves
 * live in `lib/schemas.ts` (zod, shared with backup/sync); this module
 * re-exports them so UI code has one import.
 */

import type { ChatAttachment, ChatMessage, ChatScope, ChatSource } from "./schemas";

export type { ChatAttachment, ChatMessage, ChatScope, ChatSource };

export type ChatError = { message: string; kind?: string };

export type ChatModelChoice = {
  name: string;
  badge: "text" | "vision" | "both";
  available: boolean | null;
};

/** Last model choice, remembered across visits. */
const MODEL_KEY = "freezmo.chat.model.v1";

export function readStoredChatModel(): string | null {
  try {
    const value = window.localStorage.getItem(MODEL_KEY);
    return value && value.trim() ? value : null;
  } catch {
    return null;
  }
}

export function storeChatModel(model: string): void {
  try {
    window.localStorage.setItem(MODEL_KEY, model);
  } catch {
    /* private mode */
  }
}

export function chatMessageId(prefix: string): string {
  const rand =
    typeof crypto !== "undefined" && "randomUUID" in crypto
      ? crypto.randomUUID().slice(0, 8)
      : Math.random().toString(36).slice(2, 10);
  return `${prefix}_${Date.now().toString(36)}_${rand}`;
}

/** Auto title from the first user turn (markdown stripped, one line). */
export function titleFromMessage(content: string): string {
  const line = content
    .replace(/[#*`>_]/g, "")
    .replace(/\s+/g, " ")
    .trim();
  if (!line) return "";
  return line.length > 60 ? `${line.slice(0, 57)}…` : line;
}

/** Case/diacritic-insensitive search over titles and message text. */
export function conversationMatches(title: string, messages: ChatMessage[], query: string): boolean {
  const needle = fold(query);
  if (!needle) return true;
  if (fold(title).includes(needle)) return true;
  return messages.some((message) => fold(message.content).includes(needle));
}

function fold(value: string): string {
  return value
    .toLowerCase()
    .normalize("NFKD")
    .replace(/[\u0300-\u036f]/g, "");
}