import Flutter
import UIKit
import UnityLibrary

/// Unity插件类，用于注册Flutter与Unity之间的通信桥梁
public class UnityPlugin: NSObject, FlutterPlugin {
    
    // Unity框架引用
    private weak var unityFramework: UnityFramework?
    private weak var flutterViewController: FlutterViewController?
    
    // 单例实例
    static var instance: UnityPlugin?
    
    // 注册插件方法
    public static func register(with registrar: FlutterPluginRegistrar) {
        let channel = FlutterMethodChannel(
            name: "com.example.ar_tourism_flutter_unity.unity",
            binaryMessenger: registrar.messenger()
        )
        
        // 创建插件实例并保存单例引用
        let instance = UnityPlugin(registrar: registrar)
        self.instance = instance
        
        // 设置方法调用处理器
        registrar.addMethodCallDelegate(instance, channel: channel)
    }
    
    init(registrar: FlutterPluginRegistrar) {
        super.init()
        
        // 尝试获取AppDelegate中的Unity框架引用
        if let appDelegate = UIApplication.shared.delegate as? AppDelegate {
            self.unityFramework = appDelegate.unityFramework
        }
        
        // 尝试获取FlutterViewController
        if let rootViewController = UIApplication.shared.keyWindow?.rootViewController as? FlutterViewController {
            self.flutterViewController = rootViewController
        } else if let rootVC = UIApplication.shared.keyWindow?.rootViewController {
            // 如果根视图控制器不是FlutterViewController，尝试在子视图控制器中查找
            self.flutterViewController = findFlutterViewController(rootVC)
        }
    }
    
    // 递归查找FlutterViewController
    private func findFlutterViewController(_ viewController: UIViewController) -> FlutterViewController? {
        if let flutterVC = viewController as? FlutterViewController {
            return flutterVC
        }
        
        if let navigationController = viewController as? UINavigationController {
            for childVC in navigationController.viewControllers {
                if let flutterVC = findFlutterViewController(childVC) {
                    return flutterVC
                }
            }
        }
        
        if let tabBarController = viewController as? UITabBarController {
            for childVC in tabBarController.viewControllers ?? [] {
                if let flutterVC = findFlutterViewController(childVC) {
                    return flutterVC
                }
            }
        }
        
        for childVC in viewController.children {
            if let flutterVC = findFlutterViewController(childVC) {
                return flutterVC
            }
        }
        
        if let presentedVC = viewController.presentedViewController {
            return findFlutterViewController(presentedVC)
        }
        
        return nil
    }
    
    // 处理Flutter调用的方法
    public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
        switch call.method {
        case "initializeUnity":
            initializeUnity(result: result)
            
        case "checkAndRequestPermissions":
            checkAndRequestPermissions(result: result)
            
        case "start_unity":
            startUnity(call: call, result: result)
            
        case "closeUnity":
            closeUnity(result: result)
            
        case "sendMessageToUnity":
            sendMessageToUnity(call: call, result: result)
            
        default:
            result(FlutterMethodNotImplemented)
        }
    }
    
    // 初始化Unity
    private func initializeUnity(result: @escaping FlutterResult) {
        if unityFramework == nil {
            if let appDelegate = UIApplication.shared.delegate as? AppDelegate {
                appDelegate.initUnityFramework()
                self.unityFramework = appDelegate.unityFramework
            }
        }
        
        result(unityFramework != nil)
    }
    
    // 检查并请求权限
    private func checkAndRequestPermissions(result: @escaping FlutterResult) {
        // iOS中通常在Info.plist中已声明所需权限，这里简单返回true
        // 如果有特定权限检查需求，可以在这里添加相应代码
        result(true)
    }
    
    // 启动Unity
    private func startUnity(call: FlutterMethodCall, result: @escaping FlutterResult) {
        guard let args = call.arguments as? [String: Any] else {
            result(FlutterError(code: "INVALID_ARGUMENTS", message: "参数无效", details: nil))
            return
        }
        
        let token = args["token"] as? String ?? ""
        let sceneName = args["sceneName"] as? String ?? "Main"
        let returnToHome = args["returnToHome"] as? Bool ?? true
        
        print("启动Unity: token=\(token), sceneName=\(sceneName), returnToHome=\(returnToHome)")
        
        // 确保Unity已初始化
        if unityFramework == nil {
            initializeUnity(result: { success in
                if success as? Bool == true {
                    self.loadUnityScene(sceneName: sceneName, token: token)
                    result(true)
                } else {
                    result(FlutterError(code: "UNITY_INIT_FAILED", message: "Unity初始化失败", details: nil))
                }
            })
        } else {
            loadUnityScene(sceneName: sceneName, token: token)
            result(true)
        }
    }
    
    // 加载Unity场景
    private func loadUnityScene(sceneName: String, token: String) {
        // 向Unity发送加载场景的消息
        if let unityFramework = unityFramework {
            // 设置一些全局参数
            unityFramework.sendMessageToGO(
                withName: "GameManager",
                functionName: "SetToken", 
                message: token
            )
            
            // 加载指定场景
            unityFramework.sendMessageToGO(
                withName: "GameManager",
                functionName: "LoadScene", 
                message: sceneName
            )
        }
    }
    
    // 关闭Unity
    private func closeUnity(result: @escaping FlutterResult) {
        if let unityFramework = unityFramework {
            unityFramework.pause(true)
        }
        result(true)
    }
    
    // 向Unity发送消息
    private func sendMessageToUnity(call: FlutterMethodCall, result: @escaping FlutterResult) {
        guard let args = call.arguments as? [String: Any],
              let gameObject = args["gameObject"] as? String,
              let methodName = args["methodName"] as? String,
              let message = args["message"] as? String else {
            result(FlutterError(code: "INVALID_ARGUMENTS", message: "参数无效", details: nil))
            return
        }
        
        if let unityFramework = unityFramework {
            unityFramework.sendMessageToGO(
                withName: gameObject,
                functionName: methodName, 
                message: message
            )
            result(true)
        } else {
            result(FlutterError(code: "UNITY_NOT_INITIALIZED", message: "Unity未初始化", details: nil))
        }
    }
    
    // 接收从Unity发送的消息并转发到Flutter
    public func receiveUnityMessage(_ message: String) {
        let channel = FlutterMethodChannel(
            name: "com.example.ar_tourism_flutter_unity.unity",
            binaryMessenger: flutterViewController as! FlutterBinaryMessenger
        )
        
        channel.invokeMethod("onUnityMessage", arguments: message)
    }
    
    // 处理Unity返回事件
    public func handleUnityBackPressed() {
        let channel = FlutterMethodChannel(
            name: "com.example.ar_tourism_flutter_unity.unity",
            binaryMessenger: flutterViewController as! FlutterBinaryMessenger
        )
        
        channel.invokeMethod("onUnityBackPressed", arguments: nil)
    }
    
    // 处理Unity关闭事件
    public func handleUnityClosed() {
        let channel = FlutterMethodChannel(
            name: "com.example.ar_tourism_flutter_unity.unity",
            binaryMessenger: flutterViewController as! FlutterBinaryMessenger
        )
        
        channel.invokeMethod("onUnityClosed", arguments: nil)
    }
}