alerts

import {
  type ChatMessage,
  type PromptPreprocessorController,
} from "@lmstudio/sdk";
import { homedir } from "os";
import { join } from "path";
import { loadAlerts, getDueAlerts } from "./store";

// Uses default path — custom dataPath from config only applies to tool calls.
const DEFAULT_DATA_PATH = join(homedir(), ".lmstudio-alerts");

export async function promptPreprocessor(
  ctl: PromptPreprocessorController,
  userMessage: ChatMessage,
): Promise<string | ChatMessage> {
  const history = await ctl.pullHistory();

  // Only inject on the first message of a session
  if (history.length !== 0) return userMessage;

  try {
    const all = await loadAlerts(DEFAULT_DATA_PATH);
    const due = getDueAlerts(all);

    if (due.length === 0) return userMessage;

    const sorted = [...due].sort((a, b) => {
      const priority = { high: 0, normal: 1, low: 2 };
      return (priority[a.priority] - priority[b.priority]) ||
        new Date(a.dueAt).getTime() - new Date(b.dueAt).getTime();
    });

    const lines = sorted.map(a => {
      const overdue = new Date(a.dueAt) < new Date();
      const timeStr = new Date(a.dueAt).toLocaleString([], { dateStyle: "short", timeStyle: "short" });
      const flag = a.priority === "high" ? "[HIGH]" : a.priority === "normal" ? "[NORMAL]" : "[LOW]";
      const status = overdue ? `OVERDUE (was due ${timeStr})` : `due ${timeStr}`;
      return `  ${flag} [id:${a.id}] ${a.message} — ${status}`;
    });

    const alertBlock = `[ALERTS — ${due.length} pending reminder${due.length > 1 ? "s" : ""}:\n${lines.join("\n")}\nTo dismiss: alert(action="dismiss", id="<id>")]`;

    return `${alertBlock}\n\n${userMessage.getText()}`;
  } catch {
    return userMessage;
  }
}