import XCTest
@testable import ReynaCLIHostCore

final class ProtocolTests: XCTestCase {

    func testServiceHealthReturnsOKWithSameIdAndProtocolVersion() throws {
        let req = Request(id: "x", operation: "service.health", arguments: Args())
        let resp = dispatch(request: req)

        XCTAssertEqual(resp.id, "x", "response must echo same id")
        XCTAssertTrue(resp.ok, "service.health should be ok:true")
        XCTAssertNotNil(resp.result, "result must be present on success")
        XCTAssertEqual(resp.result?.operation, "service.health")
        XCTAssertFalse(resp.result?.protocol_version.isEmpty ?? true, "protocol_version must be nonempty")
        XCTAssertNil(resp.error, "error must be nil on success")
    }

    func testServiceHealthDecodedFromJSON() throws {
        let json = #"{"id":"abc-123","operation":"service.health","arguments":{}}"#
        let data = json.data(using: .utf8)!
        let decoder = JSONDecoder()
        let req = try decoder.decode(Request.self, from: data)

        let resp = dispatch(request: req)

        XCTAssertEqual(resp.id, "abc-123")
        XCTAssertTrue(resp.ok)
        XCTAssertEqual(resp.result?.operation, "service.health")
        XCTAssertFalse(resp.result?.protocol_version.isEmpty ?? true)
    }

    func testUnknownOperationReturnsError() throws {
        let req = Request(id: "y", operation: "does.not.exist", arguments: Args())
        let resp = dispatch(request: req)

        XCTAssertEqual(resp.id, "y")
        XCTAssertFalse(resp.ok, "unknown operation must return ok:false")
        XCTAssertNil(resp.result, "result must be nil on failure")
        XCTAssertNotNil(resp.error)
        XCTAssertEqual(resp.error?.code, "unknown_operation")
    }

    func testUnknownOperationJSONRoundTrip() throws {
        let json = #"{"id":"1","operation":"foo.bar","arguments":{}}"#
        let req = try JSONDecoder().decode(Request.self, from: json.data(using: .utf8)!)
        let resp = dispatch(request: req)
        let encoded = try JSONEncoder().encode(resp)
        let decoded = try JSONDecoder().decode(Response.self, from: encoded)

        XCTAssertEqual(decoded.id, "1")
        XCTAssertFalse(decoded.ok)
        XCTAssertEqual(decoded.error?.code, "unknown_operation")
    }

    func testDispatchIsDeterministic() throws {
        let req = Request(id: "same", operation: "service.health", arguments: Args())
        let r1 = dispatch(request: req)
        let r2 = dispatch(request: req)
        XCTAssertEqual(r1.id, r2.id)
        XCTAssertEqual(r1.ok, r2.ok)
        XCTAssertEqual(r1.result?.protocol_version, r2.result?.protocol_version)
    }
}