/**
 * Company Context Extension
 *
 * WHAT: On session start, loads config/company.json (the single source of
 *       truth). If `remoteConfigUrl` is set, tries to fetch a fresh config
 *       from there with a short timeout and falls back silently to the local
 *       file on any error. Renders a short corporate context from
 *       `company-context.md` and injects it into the system prompt. Also
 *       registers the `/kit-config` command for debugging effective values.
 *
 * CONFIGURE: Edit config/company.json (gitHost, trackerUrl, docsUrl, repoMap,
 *       rules, remoteConfigUrl). Edit the wording in company-context.md —
 *       non-programmers can safely change text between the {{placeholders}}.
 *
 * DISABLE: Remove/rename this file from the package `extensions/` folder,
 *       or exclude it via the package manifest / settings.
 */

import * as path from "node:path";
import { fileURLToPath } from "node:url";
import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import {
	readLocalConfig,
	fetchRemoteConfig,
	loadTemplate,
	renderContext,
	DEFAULT_CONFIG,
	type CompanyConfig,
} from "./lib/company-config.ts";

const HERE = path.dirname(fileURLToPath(import.meta.url));
const CONFIG_PATH = path.join(HERE, "..", "config", "company.json");
const TEMPLATE_PATH = path.join(HERE, "company-context.md");

export default function companyContextExtension(pi: ExtensionAPI) {
	const template = loadTemplate(TEMPLATE_PATH);

	// Effective config and where it came from. Refreshed on every session start.
	let effective: CompanyConfig = { ...DEFAULT_CONFIG };
	let source: "local" | "remote" = "local";
	// Rendered once per session; injected by before_agent_start.
	let rendered: string | null = null;

	pi.on("session_start", async (_event, ctx) => {
		effective = readLocalConfig(CONFIG_PATH);
		source = "local";

		if (effective.remoteConfigUrl) {
			const remote = await fetchRemoteConfig(effective.remoteConfigUrl);
			if (remote) {
				// Remote wins, but keep the local remoteConfigUrl so a bad remote
				// value can't orphan future refreshes.
				effective = { ...remote, remoteConfigUrl: effective.remoteConfigUrl };
				source = "remote";
			}
		}

		const { text, truncated } = renderContext(template, effective);
		rendered = text;

		if (ctx.hasUI) {
			if (truncated) {
				ctx.ui.notify(
					`pi-kit: корпоративный контекст обрезан до ${text.split("\n").length} строк (лимит) — часть правил не попала в контекст.`,
					"warning",
				);
			} else {
				ctx.ui.notify(`pi-kit: корпоративный контекст загружен (источник: ${source})`, "info");
			}
		}
	});

	pi.on("before_agent_start", async (event) => {
		// session_start may not have fired (rare); render on demand as a fallback.
		const context = rendered ?? renderContext(template, effective).text;
		if (!context) return undefined;
		return { systemPrompt: `${event.systemPrompt}\n\n${context}` };
	});

	pi.registerCommand("kit-config", {
		description: "Показать действующие корпоративные значения pi-kit и их источник",
		handler: async (_args, ctx) => {
			const origin =
				source === "remote"
					? `remote (${effective.remoteConfigUrl})`
					: `local (${CONFIG_PATH})`;
			const lines = [
				`Источник: ${origin}`,
				"",
				`gitHost:    ${effective.gitHost}`,
				`trackerUrl: ${effective.trackerUrl}`,
				`docsUrl:    ${effective.docsUrl}`,
				`repoMap:    ${effective.repoMap}`,
				`remoteConfigUrl: ${effective.remoteConfigUrl ?? "(не задан)"}`,
				"rules:",
				...(effective.rules.length > 0 ? effective.rules.map((r) => `  - ${r}`) : ["  (нет)"]),
			];

			if (ctx.hasUI) {
				await ctx.ui.select("Действующая конфигурация pi-kit", lines);
			} else {
				ctx.ui.notify(lines.join("\n"), "info");
			}
		},
	});
}