import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { registerTlCommands } from "./commands.js";
import { hasLedger } from "./ledger.js";
import { TaskLedgerOverlay } from "./task-summary-overlay.js";
import { registerTlTools } from "./agent-tools.js";

/**
 * Main entry point for the Pi extension.
 *
 * Pi calls this default function once when the extension is loaded. The `pi`
 * object is Pi's extension API: we use it to register event handlers, tools,
 * commands, and UI changes.
 */
export default function taskLedgerExtension(pi: ExtensionAPI): void {
	const overlay = new TaskLedgerOverlay(pi);

	// Update the footer/status line and live overlay when a session starts or reloads.
	pi.on("session_start", async (_event, ctx) => {
		ctx.ui.setStatus("pi-tl", hasLedger(ctx) ? "tl" : "tl: no ledger");
		await overlay.refresh(ctx);
	});

	// Add TaskLedger guidance to the system prompt only for repositories that
	// already contain `.tl/`. If the repo is not initialized, we stay quiet.
	pi.on("before_agent_start", (event, ctx) => {
		if (!hasLedger(ctx)) return;
		return {
			systemPrompt:
				event.systemPrompt +
				"\n\ntask ledger is available in this repository via the `tl` CLI. Use `tl ready --json` before selecting queued work; inspect with `tl show <id>` and `tl history <id>`; claim with `tl claim <id>` before editing; add progress with `tl note`; finish with `tl close`, `tl block`, `tl pending`, `tl cancel`, or `tl release` as appropriate. Use `tl_bulk_create` only for approved batches of multiple new tasks.",
		};
	});

	pi.on("turn_end", async (_event, ctx) => {
		await overlay.refresh(ctx);
	});

	pi.on("session_compact", async (_event, ctx) => {
		await overlay.refresh(ctx);
	});

	pi.on("session_tree", async (_event, ctx) => {
		await overlay.refresh(ctx);
	});

	pi.on("session_shutdown", () => {
		overlay.dispose();
	});

	pi.registerShortcut("alt+t", {
		description: "Toggle Task Ledger overlay",
		handler: async (ctx) => overlay.toggle(ctx),
	});

	registerTlTools(pi);
	registerTlCommands(pi, async (ctx) => overlay.refresh(ctx));
}