using System;
using System.Collections.Generic;
using ActiveProtect.Simulation;
using ActiveProtect.Utility;

namespace ActiveProtect.Models
{

    /// <summary>
    /// 表示仿真中的导弹
    /// </summary>
    public class MissileBase : SimulationElement
    {        
        /// <summary>
        /// 当前飞行时间(秒)
        /// </summary>
        public double FlightTime { get; protected set; }
        
        /// <summary>
        /// 当前飞行距离(米)
        /// </summary>
        public double FlightDistance { get; protected set; }
                
        /// <summary>
        /// 当前发动机燃烧时间(秒)
        /// </summary>
        public double EngineBurnTime { get; protected set; }

        /// <summary>
        /// 是否有制导
        /// </summary>
        public bool HasGuidance { get; protected set; }
        
        /// <summary>
        /// 失去制导的时间(秒)
        /// </summary>
        protected double LostGuidanceTime { get; set; } = 0;
        
        /// <summary>
        /// 最后已知的速度向量
        /// </summary>
        protected Vector3D LastKnownVelocity = Vector3D.Zero;

        /// <summary>
        /// 制导加速度
        /// </summary>
        protected Vector3D GuidanceAcceleration { get; set; }

        /// <summary>
        /// 推力加速度
        /// </summary>
        protected Vector3D ThrustAcceleration { get; set; }

        /// <summary>
        /// 导弹固定配置参数
        /// </summary>
        public readonly MissileProperties MissileProperties;

        /// <summary>
        /// 构造函数
        /// </summary>
        public MissileBase(MissileProperties properties, ISimulationManager manager)
            : base(properties.Id, properties.InitialPosition, properties.InitialOrientation, properties.InitialSpeed, manager)
        {
            MissileProperties = properties;
            SimulationManager = manager;

            IsActive = false;
            HasGuidance = false;
            FlightTime = 0;
            FlightDistance = 0;
            EngineBurnTime = 0;
            GuidanceAcceleration = Vector3D.Zero;
            ThrustAcceleration = Vector3D.Zero;
        }

        /// <summary>
        /// 更新导弹状态
        /// </summary>
        public override void Update(double deltaTime)
        {
            if (IsActive)
            {
                // 更新导弹运动状态
                UpdateMotionState(deltaTime);
            }
        }

        protected virtual void UpdateMotionState(double deltaTime)
        {

            //Vector3D acceleration = CalculateAcceleration(Velocity);

            Vector3D acceleration = GuidanceAcceleration;

            if (HasGuidance)
            {
                // 制导条件下，使用四阶龙格-库塔方法更新导弹的位置和速度
                (Position, Velocity) = MotionAlgorithm.RungeKutta4(deltaTime, Position, Velocity, acceleration);
            }
            else
            {
                // 无制导条件下，使用运动学方程更新导弹的位置和速度
                (Position, Velocity) = MotionAlgorithm.CalculateBallisticMotion(Position, Velocity, acceleration, deltaTime);
            }

            

            // 限制速度不超过最大速度
            if (Velocity.Magnitude() > MissileProperties.MaxSpeed)
            {
                Velocity = Velocity.Normalize() * MissileProperties.MaxSpeed;
            }

            Speed = Velocity.Magnitude();
            Orientation = Orientation.FromVector(Velocity);

            // 添加高斯噪声(测试用，用于测试运动中概率的影响)
            // Position = MotionAlgorithm.AddRandomPerturbation(Position);
            // Velocity = MotionAlgorithm.AddRandomPerturbation(Velocity);

            FlightTime += deltaTime;
            FlightDistance += Speed * deltaTime;
            //DistanceToTarget = Vector3D.Distance(Position, SimulationManager.GetEntityById(MissileProperties.TargetId).Position);
        }

        /// <summary>
        /// 计算导弹的加速度
        /// </summary>
        private Vector3D CalculateAcceleration(Vector3D velocity)
        {
            // 计算空气阻力的影响
            Vector3D dragAcceleration = velocity.Normalize() * -1 * CalculateDrag(velocity.Magnitude()) / MissileProperties.Mass;
            
            Vector3D totalAcceleration = GuidanceAcceleration + ThrustAcceleration + dragAcceleration;

            Console.WriteLine($"导弹 {Id} 的加速度: {totalAcceleration}, 制导加速度: {GuidanceAcceleration}, 推力加速度: {ThrustAcceleration}, 空气阻力加速度: {dragAcceleration}");
            if (totalAcceleration.Magnitude() > MissileProperties.MaxAcceleration)
            {
                totalAcceleration = totalAcceleration.Normalize() * MissileProperties.MaxAcceleration;
            }

            return totalAcceleration;
        }

        /// <summary>
        /// 计算空气阻力
        /// </summary>
        private static double CalculateDrag(double speed)
        {
            const double dragCoefficient = 0.1; // 减小阻力系数
            const double airDensity = 1.225; // 海平面空气密度，kg/m^3
            const double referenceArea = 0.01; // 减小导弹的参考面积，m^2

            return 0.5 * dragCoefficient * airDensity * referenceArea * speed * speed;
        }

        /// <summary>
        /// 检查是否应该自毁
        /// </summary>
        protected bool ShouldSelfDestruct()
        {
            if (FlightTime >= MissileProperties.MaxFlightTime)
            {
                Console.WriteLine($"导弹 {Id} 超出最大飞行时间 ({FlightTime:F2}/{MissileProperties.MaxFlightTime:F2})，准备自毁");
                return true;
            }
            if (FlightDistance >= MissileProperties.MaxFlightDistance)
            {
                Console.WriteLine($"导弹 {Id} 超出最大飞行距离 ({FlightDistance:F2}/{MissileProperties.MaxFlightDistance:F2})，准备自毁");
                return true;
            }
            if (Position.Y <= -1.0) // 数字略小于0
            {
                Console.WriteLine($"导弹 {Id} 高度小于等于0 ({Position.Y:F2})，准备自毁");
                return true;
            }
            return false;
        }

        /// <summary>
        /// 更新发动机燃烧时间
        /// </summary>
        // private void UpdateEngineBurnTime(double deltaTime)
        // {
        //     if (CurrentStage == FlightStage.Acceleration && EngineBurnTime < MaxEngineBurnTime)
        //     {
        //         EngineBurnTime += deltaTime;
        //     }
        // }

        /// <summary>
        /// 导弹爆炸
        /// </summary>
        protected virtual void Explode()
        {
            Deactivate();
        }

        public override void Activate()
        {
            base.Activate();
            SimulationManager.SubscribeToEvent<TargetHitEvent>(OnTargetHitEvent);
        }

        public override void Deactivate()
        {
            base.Deactivate();
            SimulationManager.UnsubscribeFromEvent<TargetHitEvent>(OnTargetHitEvent);
        }

        /// <summary>
        /// 处理目标被击中事件
        /// </summary>
        private void OnTargetHitEvent(TargetHitEvent eventData)
        {
            if (eventData.MissileId == Id)
            {
                Explode();
            }
        }

        /// <summary>
        /// 导弹自毁
        /// </summary>
        public void SelfDestruct()
        {
            if (IsActive)
            {
                string reason = FlightTime >= MissileProperties.MaxFlightTime ? "超出最大飞行时间" :
                                FlightDistance >= MissileProperties.MaxFlightDistance ? "超出最大飞行距离" :
                                Position.Y <= 0 ? "高度小于等于0" :
                                !HasGuidance ? "失去引导" : "未知原因";
                
                Console.WriteLine($"导弹 {Id} 自毁。原因: {reason}");
                Deactivate();
            }
        }

        /// <summary>
        /// 获取导弹状态
        /// </summary>
        public override string GetStatus()
        {
            MissileRunningState missileRunningState = GetRunningState();
            return $"导弹 {missileRunningState.Id}:\n" +
                   $"  位置: {missileRunningState.Position}\n" +
                   $"  速度: {missileRunningState.Speed:F2} m/s\n" +
                   $"  速度分量: {missileRunningState.Velocity}\n" +
                   $"  朝向: {missileRunningState.Orientation}\n" +
                   $"  飞行时间: {missileRunningState.FlightTime:F2}/{MissileProperties.MaxFlightTime:F2}\n" +
                   $"  飞行距离: {missileRunningState.FlightDistance:F2}/{MissileProperties.MaxFlightDistance:F2}\n" +
                   $"  发动机工作时间: {missileRunningState.EngineBurnTime:F2}/{MissileProperties.MaxEngineBurnTime:F2}\n" +
                   $"  有引导: {(missileRunningState.HasGuidance ? "是" : "否")}\n" +
                   $"  失去引导时间: {missileRunningState.LostGuidanceTime:F2}\n";
        }

        /// <summary>
        /// 更新导弹的制导状态
        /// </summary>
        protected virtual void UpdateGuidanceStatus()
        {
            // 基类中的默认实现
        }

        public MissileRunningState GetRunningState()
        {
            return new MissileRunningState
            {
                Id = Id,
                Type = MissileProperties.Type,
                Position = Position,
                Velocity = Velocity,
                Orientation = Orientation,
                Speed = Speed,
                FlightTime = FlightTime,
                FlightDistance = FlightDistance,
                HasGuidance = HasGuidance,
                LostGuidanceTime = LostGuidanceTime,
                EngineBurnTime = EngineBurnTime,
                IsActive = IsActive
            };
        }
    }

    /// <summary>
    /// 表示导弹的运行状态信息
    /// </summary>
    public struct MissileRunningState
    {
        /// <summary>
        /// 导弹ID
        /// </summary>
        public string Id { get; set; }

        /// <summary>
        /// 导弹类型
        /// </summary>
        public MissileType Type { get; set; }

        /// <summary>
        /// 当前位置
        /// </summary>
        public Vector3D Position { get; set; }

        /// <summary>
        /// 当前速度向量
        /// </summary>
        public Vector3D Velocity { get; set; }

        /// <summary>
        /// 当前朝向
        /// </summary>
        public Orientation Orientation { get; set; }

        /// <summary>
        /// 当前速度(米/秒)
        /// </summary>
        public double Speed { get; set; }

        /// <summary>
        /// 当前飞行时间(秒)
        /// </summary>
        public double FlightTime { get; set; }

        /// <summary>
        /// 当前飞行距离(米)
        /// </summary>
        public double FlightDistance { get; set; }

        /// <summary>
        /// 是否有制导
        /// </summary>
        public bool HasGuidance { get; set; }

        /// <summary>
        /// 失去制导时间(秒)
        /// </summary>
        public double LostGuidanceTime { get; set; }

        /// <summary>
        /// 当前发动机燃烧时间(秒)
        /// </summary>
        public double EngineBurnTime { get; set; }

        /// <summary>
        /// 是否处于活动状态
        /// </summary>
        public bool IsActive { get; set; }
    }
}