import { mkdtempSync, mkdirSync, rmSync, writeFileSync } from "fs";
import { tmpdir } from "os";
import { join } from "path";
import { afterEach, describe, expect, it, vi } from "vitest";
import { createCompactionRuntime } from "../src/compaction";
import { DEFERRED_REINJECT_CUSTOM_TYPE, deliverDeferredReinjectSteer, tryConsumeDeferredReinject } from "../src/reinject";
import { createDefaultSettings } from "../src/settings";
import { createInitialState, trackSkill } from "../src/state";

const tempDirs: string[] = [];

afterEach(() => {
	for (const dir of tempDirs.splice(0)) {
		rmSync(dir, { recursive: true, force: true });
	}
});

function tempSkillDir(name: string): { filePath: string; baseDir: string } {
	const root = mkdtempSync(join(tmpdir(), "pi-skill-reinject-mid-turn-"));
	tempDirs.push(root);
	const baseDir = join(root, name);
	mkdirSync(baseDir, { recursive: true });
	const filePath = join(baseDir, "SKILL.md");
	writeFileSync(filePath, `---\nname: ${name}\n---\n# body\n`, "utf8");
	return { filePath, baseDir };
}

describe("deliverDeferredReinjectSteer", () => {
	it("sends steer message and clears pending when skills resolve", () => {
		const { filePath, baseDir } = tempSkillDir("alpha");
		const runtime = createCompactionRuntime();
		const state = createInitialState();
		trackSkill(state, { name: "alpha", filePath, baseDir, source: "slash" });
		state.pendingReinject = ["alpha"];
		const sendMessage = vi.fn();
		const pi = { sendMessage } as never;
		const registered = [{ name: "alpha", filePath, baseDir }];

		const delivered = deliverDeferredReinjectSteer(
			pi,
			state,
			createDefaultSettings(),
			registered,
			runtime,
			"compact-1",
		);

		expect(delivered).toBe(true);
		expect(state.pendingReinject).toEqual([]);
		expect(runtime.deferredDeliveredForCompactionId).toBe("compact-1");
		expect(sendMessage).toHaveBeenCalledOnce();
		expect(sendMessage).toHaveBeenCalledWith(
			expect.objectContaining({
				customType: DEFERRED_REINJECT_CUSTOM_TYPE,
				display: true,
				content: expect.stringContaining('<skill name="alpha"'),
			}),
			{ deliverAs: "steer" },
		);
	});

	it("returns false without sendMessage when pending is empty", () => {
		const runtime = createCompactionRuntime();
		const state = createInitialState();
		const sendMessage = vi.fn();
		const pi = { sendMessage } as never;

		expect(
			deliverDeferredReinjectSteer(pi, state, createDefaultSettings(), [], runtime, "compact-1"),
		).toBe(false);
		expect(sendMessage).not.toHaveBeenCalled();
	});
});

describe("tryConsumeDeferredReinject after mid-turn steer", () => {
	it("skips before_agent_start inject when steer already delivered for compaction", () => {
		const { filePath, baseDir } = tempSkillDir("beta");
		const runtime = createCompactionRuntime();
		runtime.lastCompactionEntryId = "compact-2";
		runtime.deferredDeliveredForCompactionId = "compact-2";
		const state = createInitialState();
		trackSkill(state, { name: "beta", filePath, baseDir, source: "slash" });
		state.pendingReinject = ["beta"];

		expect(
			tryConsumeDeferredReinject(
				state,
				createDefaultSettings(),
				[{ name: "beta", filePath, baseDir }],
				undefined,
				runtime,
			),
		).toBeUndefined();
	});

	it("consumes pending on before_agent_start when steer did not run (idle path)", () => {
		const { filePath, baseDir } = tempSkillDir("gamma");
		const runtime = createCompactionRuntime();
		runtime.lastCompactionEntryId = "compact-3";
		const state = createInitialState();
		trackSkill(state, { name: "gamma", filePath, baseDir, source: "slash" });
		state.pendingReinject = ["gamma"];

		const result = tryConsumeDeferredReinject(
			state,
			createDefaultSettings(),
			[{ name: "gamma", filePath, baseDir }],
			undefined,
			runtime,
		);

		expect(result?.message.customType).toBe(DEFERRED_REINJECT_CUSTOM_TYPE);
		expect(state.pendingReinject).toEqual([]);
		expect(runtime.deferredDeliveredForCompactionId).toBeNull();
	});
});