calendar

import { type ChatMessage, type PromptPreprocessorController } from "@lmstudio/sdk";
import { parseIcsFile, filterByRange, formatEvent } from "./ical";
import { fetchMacOSEvents } from "./macos";

// PromptPreprocessorController has no getPluginConfig — use defaults.
// injectTodayIntoPrompt config only affects tool calls; preprocessor always injects.
// To disable injection, users can toggle it off by removing the preprocessor (not supported without config access).

export async function promptPreprocessor(
  ctl: PromptPreprocessorController,
  userMessage: ChatMessage,
): Promise<string | ChatMessage> {
  // Only inject on first message of a session to avoid repetition
  const history = await ctl.pullHistory();
  if (history.length !== 0) return userMessage;

  try {
    const today = new Date();
    today.setHours(0, 0, 0, 0);
    const endOfDay = new Date(today);
    endOfDay.setHours(23, 59, 59, 999);

    // Default to macOS; ICS path unknown without config access
    const events = fetchMacOSEvents(today, endOfDay);

    const summary = events.length === 0
      ? "No events scheduled today."
      : `Today's events (${today.toDateString()}):\n${events.map(e => "  • " + formatEvent(e)).join("\n")}`;

    const injection = `[Calendar context: ${summary}]`;
    return `${injection}\n\n${userMessage.getText()}`;
  } catch {
    // Silently skip if Calendar.app unavailable or on non-macOS
    return userMessage;
  }
}