import {
	afterAll,
	beforeAll,
	beforeEach,
	describe,
	expect,
	it,
	mock,
} from "bun:test";
import type { Server } from "bun";

// Mock the storage service before importing image service
const mockUploadImage = mock(() => Promise.resolve());
mock.module("../../src/server/services/storage.service", () => ({
	uploadImage: mockUploadImage,
}));

const { fetchImageFromUrl } = await import(
	"../../src/server/services/image.service.ts"
);

// 1x1 transparent PNG (smallest valid PNG)
const TINY_PNG = new Uint8Array([
	0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49,
	0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06,
	0x00, 0x00, 0x00, 0x1f, 0x15, 0xc4, 0x89, 0x00, 0x00, 0x00, 0x0a, 0x49, 0x44,
	0x41, 0x54, 0x78, 0x9c, 0x62, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01, 0xe2, 0x21,
	0xbc, 0x33, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60,
	0x82,
]);

let server: Server;
let baseUrl: string;

beforeAll(() => {
	server = Bun.serve({
		port: 0,
		fetch(req) {
			const url = new URL(req.url);
			if (url.pathname === "/image.png") {
				return new Response(TINY_PNG, {
					headers: { "Content-Type": "image/png" },
				});
			}
			if (url.pathname === "/page.html") {
				return new Response("<html></html>", {
					headers: { "Content-Type": "text/html" },
				});
			}
			return new Response("Not found", { status: 404 });
		},
	});
	baseUrl = `http://localhost:${server.port}`;
});

afterAll(() => {
	server.stop(true);
});

describe("Image Service", () => {
	beforeEach(() => {
		mockUploadImage.mockClear();
	});

	describe("fetchImageFromUrl", () => {
		it("fetches a valid image URL and uploads to storage", async () => {
			const imageUrl = `${baseUrl}/image.png`;
			const result = await fetchImageFromUrl(imageUrl);

			expect(result.filename).toMatch(/^\d+-[\w-]+\.png$/);
			expect(result.sourceUrl).toBe(imageUrl);

			// Verify uploadImage was called with correct args
			expect(mockUploadImage).toHaveBeenCalledTimes(1);
			const [buffer, filename, contentType] = mockUploadImage.mock
				.calls[0] as unknown[];
			expect(buffer).toBeInstanceOf(Buffer);
			expect(filename).toBe(result.filename);
			expect(contentType).toBe("image/png");
		});

		it("rejects non-image content type", async () => {
			await expect(fetchImageFromUrl(`${baseUrl}/page.html`)).rejects.toThrow(
				"Invalid content type",
			);
		});

		it("rejects invalid URL format", async () => {
			await expect(fetchImageFromUrl("not-a-url")).rejects.toThrow(
				"Invalid URL format",
			);
		});

		it("rejects non-HTTP protocols", async () => {
			await expect(
				fetchImageFromUrl("ftp://example.com/image.png"),
			).rejects.toThrow("URL must use HTTP or HTTPS");
		});

		it("rejects 404 responses", async () => {
			await expect(fetchImageFromUrl(`${baseUrl}/missing.jpg`)).rejects.toThrow(
				"HTTP 404",
			);
		});
	});
});
