import { existsSync, readFileSync } from "node:fs";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";
import type {
	ExtensionAPI,
	ExtensionContext,
} from "@earendil-works/pi-coding-agent";

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const PHRASES_PATH = resolve(__dirname, "PHRASES.md");

function loadPhrases(): string[] {
	if (!existsSync(PHRASES_PATH)) return ["Working..."];
	const raw = readFileSync(PHRASES_PATH, "utf-8");
	return raw
		.split("\n")
		.map((l) => l.trim())
		.filter((l) => l.length > 0 && !l.startsWith("#"));
}

function pickPhrase(phrases: string[]): string {
	return phrases[Math.floor(Math.random() * phrases.length)]!;
}

const SPINNER = ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"];

export default function (pi: ExtensionAPI) {
	let phrases = loadPhrases();
	let interval: ReturnType<typeof setInterval> | null = null;

	function clearTimer() {
		if (interval !== null) {
			clearInterval(interval);
			interval = null;
		}
	}

	function rotateMessage(ctx: ExtensionContext) {
		ctx.ui.setWorkingMessage(pickPhrase(phrases));
	}

	pi.on("session_start", async (_event, ctx) => {
		phrases = loadPhrases();
		ctx.ui.setWorkingIndicator({
			frames: [...SPINNER],
			intervalMs: 80,
		});
		ctx.ui.notify(`Loaded ${phrases.length} phrases`, "info");
	});

	pi.on("agent_start", async (_event, ctx) => {
		clearTimer();
		rotateMessage(ctx);
		interval = setInterval(() => rotateMessage(ctx), 3_000);
	});

	pi.on("agent_end", async (_event, ctx) => {
		clearTimer();
	});

	pi.on("session_shutdown", async () => {
		clearTimer();
	});

	pi.registerCommand("phrases", {
		description: "Reload phrases from PHRASES.md or list them",
		handler: async (args, ctx) => {
			if (args.trim() === "reload") {
				phrases = loadPhrases();
				ctx.ui.notify(`Reloaded ${phrases.length} phrases`, "info");
				return;
			}
			if (args.trim() === "list") {
				const samples = phrases
					.sort(() => Math.random() - 0.5)
					.slice(0, 8)
					.join("\n");
				ctx.ui.setEditorText(`${phrases.length} phrases loaded:\n\n${samples}`);
				return;
			}
			ctx.ui.notify("Usage: /phrases [reload|list]", "info");
		},
	});
}