using System;
using ActiveProtect.SimulationEnvironment;

namespace ActiveProtect.Models
{


    /// <summary>
    /// 红外指令制导导弹类
    /// </summary>
    public class InfraredCommandGuidedMissile : MissileBase
    {
        /// <summary>
        /// 红外指令制导导弹阶段
        /// </summary>
        private enum ICGM_Stage
        {
            Launch, // 发射阶段
            Cruise, // 巡航阶段
            Explode, // 爆炸阶段
            SelfDestruct // 自毁阶段
        }

        /// <summary>
        /// 当前阶段
        /// </summary>
        private ICGM_Stage currentStage;

        /// <summary>
        /// 红外热源辐射功率(瓦特)
        /// </summary>
        public double RadiationPower { get; set; }

        /// <summary>
        /// 红外指令导引系统
        /// </summary>
        private readonly InfraredCommandGuidanceSystem guidanceSystem;

        /// <summary>
        /// 红外测角仪
        /// </summary>
        private InfraredTracker infraredTracker;

        /// <summary>
        /// 构造函数
        /// </summary>
        public InfraredCommandGuidedMissile(MissileConfig config, ISimulationManager manager) : base(config, manager)
        {
            infraredTracker = null!;
            RadiationPower = 1000;

            // 初始化红外指令导引系统，包括自适应 PID 参数
            guidanceSystem = new InfraredCommandGuidanceSystem(
                maxAcceleration: config.MaxAcceleration,
                guidanceCoefficient: config.ProportionalNavigationCoefficient
            );

        }

        /// <summary>
        /// 更新导弹状态
        /// </summary>
        protected override void UpdateMotionState(double deltaTime)
        {   
            // 点亮红外热源
            LightInfraredSource();

            switch (currentStage)
            {
                case ICGM_Stage.Launch:
                    UpdateLaunchStage(deltaTime);
                    break;
                case ICGM_Stage.Cruise:
                    UpdateCruiseStage(deltaTime);
                    break;
                case ICGM_Stage.Explode:
                    UpdateExplodeStage(deltaTime);
                    break;
                case ICGM_Stage.SelfDestruct:
                    UpdateSelfDestructStage(deltaTime);
                    break;
            }

            base.UpdateMotionState(deltaTime);

        }

        /// <summary>
        /// 更新发射阶段
        /// </summary>
        /// <param name="deltaTime">时间步长</param>
        private void UpdateLaunchStage(double deltaTime)
        {
            // 发射阶段
            GuidanceAcceleration = Vector3D.Zero;
            if (FlightTime >= 0.1)
            {
                currentStage = ICGM_Stage.Cruise;
            }
        }
        /// <summary>
        /// 更新巡航阶段
        /// </summary>
        /// <param name="deltaTime">时间步长</param>
        private void UpdateCruiseStage(double deltaTime)
        {
            guidanceSystem.Update(deltaTime, Position, Velocity);
            GuidanceAcceleration = guidanceSystem.GetGuidanceAcceleration();
            if (DistanceToTarget <= ExplosionRadius)
            {
                currentStage = ICGM_Stage.Explode;
            }
            if(ShouldSelfDestruct())
            {
                currentStage = ICGM_Stage.SelfDestruct;
            }
        }

        /// <summary>
        /// 更新爆炸阶段
        /// </summary>
        /// <param name="deltaTime">时间步长</param>
        private void UpdateExplodeStage(double deltaTime)
        {
            // 爆炸阶段
            Explode();
        }

        /// <summary>
        /// 更新自毁阶段
        /// </summary>
        /// <param name="deltaTime">时间步长</param>
        private void UpdateSelfDestructStage(double deltaTime)
        {
            // 自毁阶段
            SelfDestruct();
        }


        /// <summary>
        /// 处理制导指令事件
        /// </summary>
        private void HandleGuidanceCommand(InfraredGuidanceCommandEvent evt)
        {
            if (evt.TargetMissileId == Id)
            {
                if (infraredTracker == null && evt.SenderId != null)
                {
                    if (SimulationManager.GetEntityById(evt.SenderId) is InfraredTracker tracker)
                    {
                        infraredTracker = tracker;
                    }
                }
                
                guidanceSystem.ReceiveGuidanceCommand(evt.TrackerToMissileVector, evt.TrackerToTargetVector);
            }
        }

        /// <summary>
        /// 点亮红外热源
        /// </summary>
        public void LightInfraredSource()
        {
            SimulationManager.PublishEvent(new InfraredGuidanceMissileLightEvent { RadiationPower = this.RadiationPower, SenderId = this.Id });
        }

        public override void Activate()
        {
            base.Activate();
            // 订阅红外指令制导事件
            SimulationManager.SubscribeToEvent<InfraredGuidanceCommandEvent>(HandleGuidanceCommand);
        }

        public override void Deactivate()
        {
            base.Deactivate();
            // 取消订阅红外指令制导事件
            SimulationManager.UnsubscribeFromEvent<InfraredGuidanceCommandEvent>(HandleGuidanceCommand);
        }

        /// <summary>
        /// 获取导弹状态
        /// </summary>
        public override string GetStatus()
        {
            return base.GetStatus() + $"\n  当前阶段：{currentStage}\n  导引系统状态: {guidanceSystem.GetStatus()}";
        }
    }
}