import XCTest

final class StubURLProtocolTests: XCTestCase {

    private func makeSession() -> URLSession {
        let cfg = URLSessionConfiguration.ephemeral
        cfg.protocolClasses = [StubURLProtocol.self]
        return URLSession(configuration: cfg)
    }

    override func tearDown() {
        StubURLProtocol.reset()
        super.tearDown()
    }

    func testReplaysCannedResponseAndCapturesRequest() async throws {
        var stub = StubURLProtocol.Stub()
        stub.statusCode = 201
        stub.body = Data(#"{"ok":true}"#.utf8)
        StubURLProtocol.setStub(stub)

        var request = URLRequest(url: URL(string: "https://example.com/things")!)
        request.httpMethod = "POST"
        request.httpBody = Data(#"{"name":"x"}"#.utf8)

        let (data, response) = try await makeSession().data(for: request)

        XCTAssertEqual((response as? HTTPURLResponse)?.statusCode, 201)
        XCTAssertEqual(String(data: data, encoding: .utf8), #"{"ok":true}"#)
        XCTAssertEqual(StubURLProtocol.requestCount, 1)
        XCTAssertEqual(StubURLProtocol.capturedRequests.first?.httpMethod, "POST")
        XCTAssertEqual(StubURLProtocol.lastCapturedBody, Data(#"{"name":"x"}"#.utf8))
    }

    func testReplaysError() async {
        var stub = StubURLProtocol.Stub()
        stub.error = URLError(.notConnectedToInternet)
        StubURLProtocol.setStub(stub)

        do {
            _ = try await makeSession().data(for: URLRequest(url: URL(string: "https://example.com")!))
            XCTFail("expected throw")
        } catch {
            XCTAssertEqual((error as? URLError)?.code, .notConnectedToInternet)
        }
    }
}