/**
 * search-tools extension — tier-aware activation of pi's built-in search tools.
 *
 * pi registers seven built-in tools but activates only read/bash/edit/write
 * (findings §2); grep/find/ls sit in the registry and are never activated.
 * Claude Code ships no Grep/Glob/LS on any tier (bash covers search — Haiku
 * included), so frontier/workhorse/cheap stay lean; only One Code's sub-Haiku
 * `tiny` tier, whose prompt steers to "the search tools", gets them in the
 * request. Tier resolution is the same call the system-prompt extension makes,
 * so prompt text and tool surface stay in step, including on a mid-session model
 * change.
 */

import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { resolveModelTier } from "../lib/model-tier.ts";
import { withSearchTools } from "./tools.ts";

export default function searchToolsExtension(pi: ExtensionAPI) {
	const apply = (model: Parameters<typeof resolveModelTier>[0]) => {
		const tier = resolveModelTier(model);
		const active = pi.getActiveTools();
		const next = withSearchTools(active, tier);
		if (next.join(" ") !== active.join(" ")) pi.setActiveTools(next);
	};

	pi.on("session_start", (_event, ctx) => apply(ctx.model));
	pi.on("model_select", (event) => apply(event.model));
}