import {
	CONFIG_DIR_NAME,
	type ExtensionAPI,
	type ExtensionCommandContext,
} from "@earendil-works/pi-coding-agent";
import { homedir } from "node:os";
import { ConfigStore } from "./config";
import { createChiBaseModule } from "./identity";
import { ChiRegistry } from "./registry";
import { createChiSettingsUI } from "./settings-ui";

export interface ExtensionFactoryOptions {
	homeDir?: string;
}

export function createChiBaseExtension(
	pi: ExtensionAPI,
	options: ExtensionFactoryOptions = {},
): void {
	let currentRegistry: ChiRegistry | undefined;

	pi.on("session_start", async (_event, ctx) => {
		const config = new ConfigStore({
			homeDir: options.homeDir ?? homedir(),
			cwd: ctx.cwd,
			configDirName: CONFIG_DIR_NAME,
			projectTrusted: ctx.isProjectTrusted(),
		});
		const registry = new ChiRegistry({ config });
		currentRegistry = registry;
		registry.register(createChiBaseModule());
		pi.events.emit("chi:discover", registry);
		await registry.initializeAll();
		for (const id of registry.getDuplicateModuleIds()) {
			ctx.ui.notify(
				"Two identical Chi modules are active: " + id
					+ ". Install the Chi bundle OR individual modules, never both — and a global"
					+ " install may be clashing with a local one. Remove one of the installations"
					+ " (pi list, then pi remove <source>).",
				"error",
			);
		}
	});

	pi.on("before_agent_start", async (event) => {
		const sections = currentRegistry?.renderPromptSections();
		if (!sections) return;
		return { systemPrompt: event.systemPrompt + "\n\n" + sections };
	});

	pi.registerCommand("chi", {
		description: "View and edit Chi settings",
		handler: async (_args: string, ctx: ExtensionCommandContext) => {
			if (ctx.mode !== "tui") {
				ctx.ui.notify("/chi requires TUI mode", "error");
				return;
			}
			const registry = currentRegistry;
			if (!registry) {
				ctx.ui.notify("Chi Base is not ready", "error");
				return;
			}

			await ctx.ui.custom((tui, theme, _keybindings, done) =>
				createChiSettingsUI({
					registry,
					projectTrusted: ctx.isProjectTrusted(),
					theme: { bold: (value) => theme.bold(value) },
					notify: (message, type) => ctx.ui.notify(message, type),
					requestRender: () => tui.requestRender(),
					done: () => done(undefined),
				}),
			);
		},
	});
}

export default createChiBaseExtension;