/**
 * quit-aliases — Extra ways to exit pi.
 *
 * Adds `/exit` as a slash command and makes the bare words
 * `exit`, `quit`, `:q` (case-insensitive, any time — even mid-stream)
 * trigger a clean shutdown, just like the built-in `/quit`.
 *
 * Triggers:
 *   /exit                  — slash command (shows up in `/` autocomplete)
 *   exit | quit | :q       — bare words (exact match, trimmed, case-insensitive)
 *
 * Both paths call ctx.shutdown(), pi's documented graceful shutdown
 * ("available in all contexts: event handlers, tools, commands, shortcuts").
 *
 * Install (global, auto-discovered, /reload hot-reloadable):
 *   ~/.pi/agent/extensions/quit-aliases/index.ts  → symlinked to this file
 *
 * Matching rules:
 *   - Bare words match only when the WHOLE input (trimmed, lowercased) equals
 *     one of the trigger words. `exit now` / `please quit` are NOT matched and
 *     are sent to the agent as normal messages.
 *   - Option B: works any time, including while the agent is generating
 *     (shutdown aborts the in-flight stream gracefully).
 *   - event.source === "extension" is skipped, so another extension's
 *     sendUserMessage("exit") cannot accidentally trigger an exit.
 *
 * `/quit` (built-in) is untouched and still works.
 */

import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";

const BARE_QUIT_WORDS = new Set(["exit", "quit", ":q"]);

export default function (pi: ExtensionAPI) {
	// /exit — slash-command alias for /quit. No built-in /exit exists, so this
	// registers cleanly (no /exit:1 / /exit:2 suffix). /quit stays built-in.
	pi.registerCommand("exit", {
		description: "Quit pi (alias for /quit)",
		handler: async (_args, ctx) => {
			ctx.shutdown();
		},
	});

	// Bare words exit / quit / :q. Fires after the slash-command check, so these
	// (no leading `/`) reach here. Returning "handled" skips the agent entirely.
	pi.on("input", (event, ctx) => {
		if (event.source === "extension") return { action: "continue" };

		const text = event.text.trim().toLowerCase();
		if (BARE_QUIT_WORDS.has(text)) {
			ctx.shutdown();
			return { action: "handled" };
		}

		return { action: "continue" };
	});
}