import { beforeEach, describe, expect, it, vi } from "vitest";
import { ObjectId } from "mongodb";
import type { Workspace } from "$lib/types/Workspace";

const mocks = vi.hoisted(() => ({
	workspaceFindOne: vi.fn(),
	sessionFindOne: vi.fn(),
	findUser: vi.fn(),
	config: {
		USE_USER_TOKEN: "false",
		OPENAI_API_KEY: "hf_inference_service_must_not_clone",
		HF_TOKEN: "hf_jobs_service_must_not_clone",
	},
}));

vi.mock("$lib/server/database", () => ({
	collections: {
		workspaces: { findOne: mocks.workspaceFindOne },
		sessions: { findOne: mocks.sessionFindOne },
	},
}));
vi.mock("$lib/server/config", () => ({ config: mocks.config }));
vi.mock("$lib/server/auth", () => ({ findUser: mocks.findUser }));

import { AGENT_PROXY_MAX_BODY_BYTES, issueAgentProxyCredential } from "./llmProxy";
import { GET, HEAD, POST } from "../../../routes/api/agent/git/[...path]/+server";

const NOW = new Date("2026-08-20T00:00:00.000Z");
const OWNER_HF_TOKEN = "hf_owner_oauth_server_side_only";

function workspace(
	tokenHash: string,
	repo: Workspace["repo"] = { kind: "hf", repoType: "space", ref: "owner/private-app" }
): Workspace {
	return {
		_id: new ObjectId(),
		conversationId: new ObjectId(),
		userId: new ObjectId(),
		sessionId: "owner-session",
		repo,
		branch: "main",
		flavor: "cpu-basic",
		model: "moonshotai/Kimi-K2.7-Code",
		thinkingLevel: "medium",
		policy: "auto",
		sandbox: {
			status: "provisioning",
			id: "job-agent-git-proxy",
			namespace: "service-owner",
			baseUrl: "https://job-agent-git-proxy--49983.hf.jobs",
			nonce: "nonce-git-proxy",
			image: "hf.co/spaces/example/runtime",
			flavor: "cpu-basic",
		},
		llmProxy: {
			tokenHash,
			createdAt: NOW,
			expiresAt: new Date("2100-01-01T00:00:00Z"),
			allowedModels: ["moonshotai/Kimi-K2.7-Code"],
		},
		spend: { accruedUsd: 0 },
		createdAt: NOW,
		updatedAt: NOW,
	};
}

async function arrange(repo?: Workspace["repo"]) {
	const credential = await issueAgentProxyCredential(["moonshotai/Kimi-K2.7-Code"]);
	const value = workspace(credential.tokenHash, repo);
	mocks.workspaceFindOne.mockResolvedValue(value);
	mocks.sessionFindOne.mockResolvedValue({ sessionId: "owner-session" });
	mocks.findUser.mockResolvedValue({
		user: null,
		invalidateSession: false,
		oauth: { token: { value: OWNER_HF_TOKEN, expiresAt: new Date(Date.now() + 60_000) } },
	});
	return { credential, workspace: value };
}

function infoRequest(token: string, method = "GET", suffix = "") {
	return new Request(
		`https://chat.example/api/agent/git/repository.git/info/refs?service=git-upload-pack${suffix}`,
		{
			method,
			headers: {
				accept: "application/x-git-upload-pack-advertisement",
				authorization: "Bearer attacker-controlled",
				cookie: "browser=session",
				"git-protocol": "version=2",
				"x-agent-session": token,
			},
		}
	);
}

function uploadRequest(token: string, body: BodyInit, headers: Record<string, string> = {}) {
	return new Request("https://chat.example/api/agent/git/repository.git/git-upload-pack", {
		method: "POST",
		headers: {
			"content-type": "application/x-git-upload-pack-request",
			"x-agent-session": token,
			...headers,
		},
		body,
	});
}

beforeEach(() => {
	vi.restoreAllMocks();
	mocks.workspaceFindOne.mockReset();
	mocks.sessionFindOne.mockReset();
	mocks.findUser.mockReset();
	vi.stubGlobal("fetch", vi.fn());
});

describe("agent Hugging Face Git smart-HTTP proxy", () => {
	it("derives the exact Space repo and attaches owner OAuth server-side even when inference user tokens are disabled", async () => {
		const { credential } = await arrange();
		vi.mocked(fetch).mockResolvedValue(
			new Response("001e# service=git-upload-pack\n0000", {
				status: 200,
				headers: {
					"content-type": "application/x-git-upload-pack-advertisement",
					"set-cookie": "hub=secret",
					location: "https://evil.example/",
					"x-reflected-auth": OWNER_HF_TOKEN,
				},
			})
		);

		const response = await GET({
			request: infoRequest(credential.token),
			params: { path: "repository.git/info/refs" },
		} as never);

		expect(response.status).toBe(200);
		expect(fetch).toHaveBeenCalledOnce();
		const [url, init] = vi.mocked(fetch).mock.calls[0];
		expect(String(url)).toBe(
			"https://huggingface.co/spaces/owner/private-app.git/info/refs?service=git-upload-pack"
		);
		const upstreamHeaders = new Headers(init?.headers);
		expect(upstreamHeaders.get("authorization")).toBe(`Bearer ${OWNER_HF_TOKEN}`);
		expect(upstreamHeaders.get("git-protocol")).toBe("version=2");
		expect(upstreamHeaders.get("x-agent-session")).toBeNull();
		expect(upstreamHeaders.get("cookie")).toBeNull();
		expect(init?.redirect).toBe("manual");
		expect(response.headers.get("set-cookie")).toBeNull();
		expect(response.headers.get("location")).toBeNull();
		expect(response.headers.get("x-reflected-auth")).toBeNull();
		expect(response.headers.get("cache-control")).toBe("no-store");
		expect(await response.text()).not.toContain(OWNER_HF_TOKEN);
		expect(mocks.config.USE_USER_TOKEN).toBe("false");
	});

	it.each([
		[
			"model",
			"owner/source",
			"https://huggingface.co/owner/source.git/info/refs?service=git-upload-pack",
		],
		[
			"dataset",
			"owner/source",
			"https://huggingface.co/datasets/owner/source.git/info/refs?service=git-upload-pack",
		],
	] as const)(
		"confines a %s checkout to its persisted repo type and ref",
		async (repoType, ref, expected) => {
			const { credential } = await arrange({ kind: "hf", repoType, ref });
			vi.mocked(fetch).mockResolvedValue(
				new Response("advertisement", {
					headers: { "content-type": "application/x-git-upload-pack-advertisement" },
				})
			);
			const response = await GET({
				request: infoRequest(credential.token),
				params: { path: "repository.git/info/refs" },
			} as never);
			expect(response.status).toBe(200);
			expect(String(vi.mocked(fetch).mock.calls[0][0])).toBe(expected);
		}
	);

	it("uses anonymous Hub access for a public repo instead of falling back to service credentials", async () => {
		const { credential } = await arrange();
		mocks.sessionFindOne.mockResolvedValue(null);
		vi.mocked(fetch).mockResolvedValue(
			new Response("advertisement", {
				headers: { "content-type": "application/x-git-upload-pack-advertisement" },
			})
		);

		const response = await GET({
			request: infoRequest(credential.token),
			params: { path: "repository.git/info/refs" },
		} as never);

		expect(response.status).toBe(200);
		const headers = new Headers(vi.mocked(fetch).mock.calls[0][1]?.headers);
		expect(headers.get("authorization")).toBeNull();
		expect(JSON.stringify([...headers])).not.toContain(mocks.config.OPENAI_API_KEY);
		expect(JSON.stringify([...headers])).not.toContain(mocks.config.HF_TOKEN);
	});

	it("streams upload-pack bytes while forwarding only the allowlisted request headers", async () => {
		const { credential } = await arrange({ kind: "hf", repoType: "dataset", ref: "owner/data" });
		const result = Uint8Array.from([0, 1, 2, 3, 255]);
		vi.mocked(fetch).mockResolvedValue(
			new Response(result, {
				headers: { "content-type": "application/x-git-upload-pack-result" },
			})
		);
		const requestBody = Buffer.from("000eversion 2\n0000");

		const response = await POST({
			request: uploadRequest(credential.token, requestBody),
			params: { path: "repository.git/git-upload-pack" },
		} as never);

		expect(response.status).toBe(200);
		expect(new Uint8Array(await response.arrayBuffer())).toEqual(result);
		const [url, init] = vi.mocked(fetch).mock.calls[0];
		expect(String(url)).toBe("https://huggingface.co/datasets/owner/data.git/git-upload-pack");
		expect(new Uint8Array(init?.body as ArrayBuffer)).toEqual(new Uint8Array(requestBody));
		expect(new Headers(init?.headers).get("authorization")).toBe(`Bearer ${OWNER_HF_TOKEN}`);
	});

	it("supports HEAD only for the exact upload-pack advertisement", async () => {
		const { credential } = await arrange();
		vi.mocked(fetch).mockResolvedValue(
			new Response(null, {
				headers: { "content-type": "application/x-git-upload-pack-advertisement" },
			})
		);
		const response = await HEAD({
			request: infoRequest(credential.token, "HEAD"),
			params: { path: "repository.git/info/refs" },
		} as never);
		expect(response.status).toBe(200);
		expect(vi.mocked(fetch).mock.calls[0][1]?.method).toBe("HEAD");
		expect(await response.text()).toBe("");
	});

	it.each([
		"other.git/info/refs",
		"repository.git/git-receive-pack",
		"repository.git/info/lfs/objects/batch",
		"repository.git/../../owner/other.git/info/refs",
		"models/expensive-model",
	])(
		"rejects cross-repo or operation escalation path %s before any upstream request",
		async (path) => {
			const { credential } = await arrange();
			const response = await GET({
				request: infoRequest(credential.token),
				params: { path },
			} as never);
			expect(response.status).toBe(404);
			expect(fetch).not.toHaveBeenCalled();
		}
	);

	it("rejects extra query controls, non-HF workspaces, and invalid persisted refs", async () => {
		let arranged = await arrange();
		let response = await GET({
			request: infoRequest(arranged.credential.token, "GET", "&repo=attacker/other"),
			params: { path: "repository.git/info/refs" },
		} as never);
		expect(response.status).toBe(404);

		arranged = await arrange({ kind: "git", ref: "https://example.com/public.git" });
		response = await GET({
			request: infoRequest(arranged.credential.token),
			params: { path: "repository.git/info/refs" },
		} as never);
		expect(response.status).toBe(403);

		arranged = await arrange({
			kind: "hf",
			repoType: "space",
			ref: "owner/valid" as string,
		});
		arranged.workspace.repo = {
			kind: "hf",
			repoType: "space",
			ref: "owner/../../other",
		};
		response = await GET({
			request: infoRequest(arranged.credential.token),
			params: { path: "repository.git/info/refs" },
		} as never);
		expect(response.status).toBe(403);
		expect(fetch).not.toHaveBeenCalled();
	});

	it("rejects unsupported methods and upload-pack media types", async () => {
		const { credential } = await arrange();
		let response = await GET({
			request: infoRequest(credential.token, "DELETE"),
			params: { path: "repository.git/info/refs" },
		} as never);
		expect(response.status).toBe(405);

		response = await POST({
			request: uploadRequest(credential.token, "payload", { "content-type": "application/json" }),
			params: { path: "repository.git/git-upload-pack" },
		} as never);
		expect(response.status).toBe(415);
		expect(fetch).not.toHaveBeenCalled();
	});

	it("enforces both declared and streamed 8 MiB upload-pack request limits", async () => {
		const { credential } = await arrange();
		let response = await POST({
			request: uploadRequest(credential.token, "x", {
				"content-length": String(AGENT_PROXY_MAX_BODY_BYTES + 1),
			}),
			params: { path: "repository.git/git-upload-pack" },
		} as never);
		expect(response.status).toBe(413);

		response = await POST({
			request: uploadRequest(credential.token, Buffer.alloc(AGENT_PROXY_MAX_BODY_BYTES + 1)),
			params: { path: "repository.git/git-upload-pack" },
		} as never);
		expect(response.status).toBe(413);
		expect(fetch).not.toHaveBeenCalled();
	});

	it("never reflects upstream errors, redirects, cookies, or the raw owner credential", async () => {
		const { credential } = await arrange();
		vi.mocked(fetch).mockResolvedValue(
			new Response(`denied: ${OWNER_HF_TOKEN}`, {
				status: 401,
				headers: {
					location: `https://example.com/?token=${OWNER_HF_TOKEN}`,
					"set-cookie": `token=${OWNER_HF_TOKEN}`,
					"www-authenticate": `Bearer token=${OWNER_HF_TOKEN}`,
				},
			})
		);
		const response = await GET({
			request: infoRequest(credential.token),
			params: { path: "repository.git/info/refs" },
		} as never);
		const serialized = `${JSON.stringify([...response.headers])}\n${await response.text()}`;
		expect(response.status).toBe(403);
		expect(serialized).toContain("Reconnect Hugging Face");
		expect(serialized).not.toContain(OWNER_HF_TOKEN);
		expect(response.headers.get("location")).toBeNull();
		expect(response.headers.get("set-cookie")).toBeNull();
		expect(response.headers.get("www-authenticate")).toBeNull();
	});

	it("returns an actionable non-challenge error when a private repo has no owner OAuth", async () => {
		const { credential } = await arrange();
		mocks.sessionFindOne.mockResolvedValue(null);
		vi.mocked(fetch).mockResolvedValue(
			new Response("private upstream detail", {
				status: 401,
				headers: { "www-authenticate": "Basic realm=private" },
			})
		);

		const response = await GET({
			request: infoRequest(credential.token),
			params: { path: "repository.git/info/refs" },
		} as never);

		expect(response.status).toBe(403);
		expect(await response.text()).toBe("Sign in with Hugging Face to access this repository\n");
		expect(response.headers.get("www-authenticate")).toBeNull();
	});
});