import XCTest
import Foundation
import ForgeCameraARRI
import ForgeOffload
@testable import ForgeSim

/// CAP-level sim tests: raw TCP client speaking binary CAP frames.
final class ArriSimTests: XCTestCase {

    var sim: ArriSimulator!

    override func setUp() async throws {
        sim = ArriSimulator(password: "arri")
        try await sim.start(port: 0)
    }

    override func tearDown() async throws {
        try? await sim.stop()
        sim = nil
    }

    /// Minimal blocking CAP test client.
    final class TestClient {
        let fd: Int32
        var buffer = Data()
        var msgId: UInt16 = 100

        init?(port: Int) {
            fd = socket(AF_INET, Int32(SOCK_STREAM.rawValue), 0)
            guard fd >= 0 else { return nil }
            var tv = timeval(tv_sec: 2, tv_usec: 0)
            setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, socklen_t(MemoryLayout<timeval>.size))
            var addr = sockaddr_in()
            addr.sin_family = sa_family_t(AF_INET)
            addr.sin_port = in_port_t(UInt16(port).bigEndian)
            _ = inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr)
            let rc = withUnsafePointer(to: &addr) { ptr in
                ptr.withMemoryRebound(to: sockaddr.self, capacity: 1) { sa in
                    connect(fd, sa, socklen_t(MemoryLayout<sockaddr_in>.size))
                }
            }
            guard rc == 0 else {
                close(fd)
                return nil
            }
        }

        deinit {
            close(fd)
        }

        func send(_ cmd: CAP.Command, payload: Data = Data()) -> UInt16 {
            msgId &+= 1
            let frame = CAP.Frame(
                msgType: CAP.MsgType.command.rawValue,
                msgId: msgId,
                cmdCode: cmd.rawValue,
                payload: payload)
            let data = CAP.encode(frame)
            _ = data.withUnsafeBytes { write(fd, $0.baseAddress, $0.count) }
            return msgId
        }

        func readFrame() -> CAP.Frame? {
            var chunk = [UInt8](repeating: 0, count: 8192)
            for _ in 0..<40 {
                if let f = try? CAP.decodeFirst(&buffer), f != nil {
                    return f
                }
                let n = read(fd, &chunk, chunk.count)
                if n > 0 {
                    buffer.append(contentsOf: chunk[0..<n])
                } else if n == 0 {
                    return nil
                }
            }
            return try? CAP.decodeFirst(&buffer) ?? nil
        }

        /// Read frames until predicate matches (skips events/other replies).
        func readUntil(_ predicate: (CAP.Frame) -> Bool) -> CAP.Frame? {
            for _ in 0..<50 {
                guard let f = readFrame() else { return nil }
                if predicate(f) { return f }
            }
            return nil
        }

        func authenticate(password: String) -> Bool {
            // Welcome arrives unsolicited.
            guard readUntil({ $0.cmdCode == CAP.Command.welcome.rawValue }) != nil else { return false }
            let chalId = send(.requestPwdChallenge)
            guard let chalReply = readUntil({ $0.msgId == chalId }),
                  let (challenge, _) = CAP.readString(chalReply.payload, at: 0) else { return false }
            var pw = Data()
            CAP.putString(MD5.hexString(Data((challenge + password).utf8)), into: &pw)
            let pwId = send(.password, payload: pw)
            guard let pwReply = readUntil({ $0.msgId == pwId }),
                  pwReply.cmdCode == CAP.Result.ok.rawValue else { return false }
            return true
        }
    }

    func testWelcomeOnConnect() async throws {
        let port = await sim.boundPort!
        let client = try XCTUnwrap(TestClient(port: port))
        let welcome = client.readUntil { $0.cmdCode == CAP.Command.welcome.rawValue }
        XCTAssertNotNil(welcome)
        let (version, _) = CAP.readString(welcome!.payload, at: 0) ?? ("", 0)
        XCTAssertTrue(version.contains("CAP"))
    }

    func testAuthFlow() async throws {
        let port = await sim.boundPort!
        let client = try XCTUnwrap(TestClient(port: port))
        XCTAssertTrue(client.authenticate(password: "arri"))
    }

    func testWrongPassword() async throws {
        let port = await sim.boundPort!
        let client = try XCTUnwrap(TestClient(port: port))
        XCTAssertFalse(client.authenticate(password: "nope"))
    }

    func testUnauthenticatedGetRejected() async throws {
        let port = await sim.boundPort!
        let client = try XCTUnwrap(TestClient(port: port))
        _ = client.readUntil { $0.cmdCode == CAP.Command.welcome.rawValue }
        var payload = Data()
        CAP.putU16(CAP.Variable.exposureIndex.rawValue, into: &payload)
        let id = client.send(.getVariable, payload: payload)
        let reply = client.readUntil { $0.msgId == id }
        XCTAssertEqual(reply?.cmdCode, CAP.Result.notAuthorized.rawValue)
    }

    func testGetVariable() async throws {
        await sim.setMetadata(ei: 1280, colorTemp: 3200, tint: -2, fps: 25, timecode: "01:02:03:04")
        let port = await sim.boundPort!
        let client = try XCTUnwrap(TestClient(port: port))
        XCTAssertTrue(client.authenticate(password: "arri"))

        var payload = Data()
        CAP.putU16(CAP.Variable.exposureIndex.rawValue, into: &payload)
        let id = client.send(.getVariable, payload: payload)
        let reply = client.readUntil { $0.msgId == id }
        XCTAssertEqual(reply?.cmdCode, CAP.Result.ok.rawValue)
        XCTAssertEqual(CAP.readU16(reply!.payload, at: 0), CAP.Variable.exposureIndex.rawValue)
        XCTAssertEqual(CAP.readU32(reply!.payload, at: 2), 1280)
    }

    func testSetCDLStored() async throws {
        let port = await sim.boundPort!
        let client = try XCTUnwrap(TestClient(port: port))
        XCTAssertTrue(client.authenticate(password: "arri"))

        var payload = Data()
        CAP.putU16(CAP.Variable.cdlValues.rawValue, into: &payload)
        payload.append(CAP.encodeCDLBlob(
            slope: (1.5, 1, 1), offset: (0, 0, 0), power: (1, 1, 1), saturation: 0.8))
        let id = client.send(.setVariable, payload: payload)
        let reply = client.readUntil { $0.msgId == id }
        XCTAssertEqual(reply?.cmdCode, CAP.Result.ok.rawValue)

        let stored = await sim.lastCDL
        XCTAssertEqual(stored?[0] ?? 0, 1.5, accuracy: 1e-5)
        XCTAssertEqual(stored?[9] ?? 0, 0.8, accuracy: 1e-5)
    }

    func testSubscriptionPushesEvents() async throws {
        let port = await sim.boundPort!
        let client = try XCTUnwrap(TestClient(port: port))
        XCTAssertTrue(client.authenticate(password: "arri"))

        var payload = Data()
        CAP.putU16(CAP.Variable.cameraState.rawValue, into: &payload)
        let id = client.send(.requestVariables, payload: payload)
        _ = client.readUntil { $0.msgId == id }

        await sim.setRecording(true)
        let event = client.readUntil { frame in
            frame.msgType == CAP.MsgType.event.rawValue
                && CAP.readU16(frame.payload, at: 0) == CAP.Variable.cameraState.rawValue
                && CAP.CameraStateBits(rawValue: CAP.readU16(frame.payload, at: 2) ?? 0).contains(.recording)
        }
        XCTAssertNotNil(event)
    }
}