import { afterEach, describe, expect, it, vi } from "bun:test";
import { Agent, type AgentMessage } from "@oh-my-pi/pi-agent-core";
import type { Message, SimpleStreamOptions } from "@oh-my-pi/pi-ai";
import { Settings } from "@oh-my-pi/pi-coding-agent/config/settings";
import { AgentSession } from "@oh-my-pi/pi-coding-agent/session/agent-session";
import { SessionManager } from "@oh-my-pi/pi-coding-agent/session/session-manager";

function createAgent(): Agent {
	return new Agent({
		initialState: {
			systemPrompt: "system prompt",
			messages: [],
			tools: [],
		},
	});
}

describe("AgentSession message pipeline", () => {
	const sessions: AgentSession[] = [];

	afterEach(async () => {
		vi.restoreAllMocks();
		for (const session of sessions.splice(0)) {
			await session.dispose();
		}
	});

	it("applies transformContext before convertToLlm", async () => {
		const inputMessages: AgentMessage[] = [{ role: "user", content: "hello", timestamp: Date.now() }];
		const transformedMessages: AgentMessage[] = [
			...inputMessages,
			{ role: "user", content: "injected context", timestamp: Date.now() },
		];
		const convertedMessages: Message[] = [
			{
				role: "user",
				content: [{ type: "text", text: "converted" }],
				attribution: "user",
				timestamp: Date.now(),
			},
		];
		const transformContext = vi.fn(async (messages: AgentMessage[], signal?: AbortSignal) => {
			expect(signal).toBe(abortController.signal);
			return [...messages, ...transformedMessages.slice(messages.length)];
		});
		const convertToLlm = vi.fn(async (_messages: AgentMessage[]) => {
			return convertedMessages;
		});
		const abortController = new AbortController();
		const session = new AgentSession({
			agent: createAgent(),
			sessionManager: SessionManager.inMemory(),
			settings: Settings.isolated({ "compaction.enabled": false }),
			modelRegistry: {} as never,
			transformContext,
			convertToLlm,
		});
		sessions.push(session);

		const result = await session.convertMessagesToLlm(inputMessages, abortController.signal);

		expect(transformContext).toHaveBeenCalledWith(inputMessages, abortController.signal);
		expect(convertToLlm).toHaveBeenCalledWith(transformedMessages);
		expect(result).toEqual(convertedMessages);
	});

	it("composes session payload hooks into direct side-request options", async () => {
		const sessionOnPayload = vi.fn(async (payload: unknown) => ({
			...(payload as Record<string, unknown>),
			session: true,
		}));
		const requestOnPayload = vi.fn(async () => undefined);
		const session = new AgentSession({
			agent: createAgent(),
			sessionManager: SessionManager.inMemory(),
			settings: Settings.isolated({ "compaction.enabled": false }),
			modelRegistry: {} as never,
			onPayload: sessionOnPayload,
		});
		sessions.push(session);
		const options: SimpleStreamOptions = {
			apiKey: "key",
			onPayload: requestOnPayload,
		};

		const prepared = session.prepareSimpleStreamOptions(options);
		const result = await prepared.onPayload?.({ original: true });

		expect(sessionOnPayload).toHaveBeenCalledWith({ original: true }, undefined);
		expect(requestOnPayload).toHaveBeenCalledWith({ original: true, session: true }, undefined);
		expect(result).toEqual({ original: true, session: true });
	});
});