import assert from "node:assert/strict";
import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";
import { test } from "node:test";
import {
	fauxAssistantMessage,
	fauxProvider,
	fauxToolCall,
	getCurrentTools,
	type FauxResponseFactory,
	type FauxResponseStep,
} from "@earendil-works/pi-ai";
import {
	DefaultResourceLoader,
	ModelRuntime,
	SessionManager,
	SettingsManager,
	createAgentSession,
	createCodemodeExtension,
} from "@selesai/code";

async function runNativeSession(config: Record<string, unknown> | undefined, responses: FauxResponseStep[], prompts: string[]): Promise<void> {
	const root = fs.mkdtempSync(path.join(os.tmpdir(), "pi-subagents-tool-activation-"));
	const cwd = path.join(root, "project");
	const agentDir = path.join(root, "agent");
	fs.mkdirSync(cwd);
	fs.mkdirSync(agentDir);
	if (config) {
		fs.mkdirSync(path.join(agentDir, "extensions", "subagent"), { recursive: true });
		fs.writeFileSync(path.join(agentDir, "extensions", "subagent", "config.json"), JSON.stringify(config));
	}
	const priorAgentDir = process.env.SELESAI_CODING_AGENT_DIR;
	const priorChild = process.env.SELESAI_SUBAGENT_CHILD;
	process.env.SELESAI_CODING_AGENT_DIR = agentDir;
	delete process.env.SELESAI_SUBAGENT_CHILD;
	let session: Awaited<ReturnType<typeof createAgentSession>>["session"] | undefined;
	try {
		const { default: registerSubagentExtension } = await import(`../../index.ts?native-activation=${Date.now()}`);
		const faux = fauxProvider({ provider: "tool-activation", models: [{ id: "local" }], tokensPerSecond: 100_000 });
		faux.setResponses(responses);
		const settingsManager = SettingsManager.inMemory({});
		const resourceLoader = new DefaultResourceLoader({
			cwd, agentDir, settingsManager,
			noExtensions: true, noSkills: true, noPromptTemplates: true, noThemes: true, noContextFiles: true,
			extensionFactories: [registerSubagentExtension, createCodemodeExtension({ inlineBudget: 0 }), (pi) => pi.registerProvider(faux.provider)],
		});
		await resourceLoader.reload();
		const modelRuntime = await ModelRuntime.create({ authPath: path.join(agentDir, "auth.json"), modelsPath: path.join(agentDir, "models.json"), allowModelNetwork: false });
		({ session } = await createAgentSession({
			cwd, agentDir, settingsManager, resourceLoader, modelRuntime,
			model: faux.getModel("local"), sessionManager: SessionManager.inMemory(cwd), noTools: "builtin",
		}));
		await session.bindExtensions({});
		session.setActiveToolsByName(["codemode"]);
		for (const prompt of prompts) await session.prompt(prompt);
	} finally {
		if (session) {
			await (session.extensionRunner as any).emit({ type: "session_shutdown", reason: "quit" });
			session.dispose();
		}
		if (priorAgentDir === undefined) delete process.env.SELESAI_CODING_AGENT_DIR; else process.env.SELESAI_CODING_AGENT_DIR = priorAgentDir;
		if (priorChild === undefined) delete process.env.SELESAI_SUBAGENT_CHILD; else process.env.SELESAI_SUBAGENT_CHILD = priorChild;
		fs.rmSync(root, { recursive: true, force: true });
	}
}

test("codemode invokes subagent management without loading direct schemas", { timeout: 30_000 }, async () => {
	let requests = 0;
	const checkTools = (context: Parameters<FauxResponseFactory>[0]) => {
		requests += 1;
		assert.deepEqual(getCurrentTools(context.messages).map((tool) => tool.name), ["codemode"]);
	};
	await runNativeSession(undefined, [
		(context) => {
			checkTools(context);
			return fauxAssistantMessage(fauxToolCall("codemode", { code: 'text(await tools.subagent({ action: "list", capabilities: true }));' }), { stopReason: "toolUse" });
		},
		(context) => {
			checkTools(context);
			const result = context.messages.findLast((message) => message.role === "toolResult" && message.toolName === "codemode");
			assert.ok(result && result.role === "toolResult");
			assert.equal(result.isError, false, "the nested management call must actually succeed");
			assert.match(JSON.stringify(result.content), /delegate|Executable agents/);
			return fauxAssistantMessage("Listed without activation.");
		},
		(context) => { checkTools(context); return fauxAssistantMessage("Still codemode-only."); },
	], ["Inspect installed agents without launching work.", "Continue."]);
	assert.equal(requests, 3);
});