using Unity.Entities;
using Unity.Mathematics;
using Unity.Transforms;
using Unity.Collections;
using Unity.Physics;
using UnityEngine;
using EE2Clone.Components;
using EE2Clone.NetCode;

namespace EE2Clone.Hybrid
{
    /// <summary>
    /// Processes right-click context commands: move, attack, gather, build/repair.
    /// Sends the appropriate RPC to the server based on what was right-clicked.
    /// Client-side MonoBehaviour.
    /// </summary>
    public class CommandDispatcher : MonoBehaviour
    {
        private Camera _mainCamera;

        private void Start()
        {
            _mainCamera = Camera.main;
        }

        private void Update()
        {
            var input = RTSInputActions.Instance;
            if (input == null || _mainCamera == null) return;

            if (input.RightClickPressed)
                HandleRightClick(input.MousePosition);

            if (input.StopPressed)
                HandleStop();
        }

        private void HandleRightClick(Vector2 screenPos)
        {
            var selection = SelectionManager.Instance;
            if (selection == null || selection.SelectedEntities.Count == 0) return;

            var world = World.DefaultGameObjectInjectionWorld;
            if (world == null || !world.IsCreated) return;

            var em = world.EntityManager;
            var ray = _mainCamera.ScreenPointToRay(new Vector3(screenPos.x, screenPos.y, 0));

            // Raycast to find what was clicked
            var physicsWorldQuery = em.CreateEntityQuery(typeof(PhysicsWorldSingleton));
            if (physicsWorldQuery.IsEmpty) return;

            var physicsWorld = physicsWorldQuery.GetSingleton<PhysicsWorldSingleton>();
            var rayInput = new RaycastInput
            {
                Start = ray.origin,
                End = ray.origin + ray.direction * 500f,
                Filter = new CollisionFilter
                {
                    BelongsTo = ~0u,
                    CollidesWith = ~0u,
                    GroupIndex = 0
                }
            };

            Entity hitEntity = Entity.Null;
            float3 hitPosition = float3.zero;

            if (physicsWorld.CastRay(rayInput, out var hit))
            {
                hitEntity = physicsWorld.Bodies[hit.RigidBodyIndex].Entity;
                hitPosition = hit.Position;
            }
            else
            {
                // No hit — use ground plane intersection
                if (ray.direction.y != 0)
                {
                    float t = -ray.origin.y / ray.direction.y;
                    if (t > 0)
                        hitPosition = new float3(ray.origin.x + ray.direction.x * t, 0, ray.origin.z + ray.direction.z * t);
                }
                return; // Only move command if no entity hit
            }

            // Determine command type based on what was clicked
            if (hitEntity != Entity.Null && em.Exists(hitEntity))
            {
                if (em.HasComponent<ResourceNodeTag>(hitEntity))
                {
                    // Gather command for citizens
                    SendGatherCommands(hitEntity);
                    return;
                }

                if (em.HasComponent<UnitTag>(hitEntity) || em.HasComponent<BuildingTag>(hitEntity))
                {
                    if (em.HasComponent<OwnerPlayer>(hitEntity))
                    {
                        var owner = em.GetComponentData<OwnerPlayer>(hitEntity);
                        // TODO: compare with local player id
                        // For now, treat as enemy → attack
                        SendAttackCommands(hitEntity);
                        return;
                    }
                }

                if (em.HasComponent<BuildingTag>(hitEntity) && em.HasComponent<UnderConstructionTag>(hitEntity))
                {
                    // Build/repair command for citizens
                    SendBuildRepairCommands(hitEntity);
                    return;
                }
            }

            // Default: move command
            SendMoveCommands(hitPosition);
        }

        private void SendMoveCommands(float3 position)
        {
            var world = World.DefaultGameObjectInjectionWorld;
            if (world == null) return;
            var em = world.EntityManager;

            foreach (var unit in SelectionManager.Instance.SelectedEntities)
            {
                if (!em.Exists(unit) || !em.HasComponent<UnitTag>(unit)) continue;

                var rpcEntity = em.CreateEntity();
                em.AddComponentData(rpcEntity, new MoveCommandRpc
                {
                    UnitEntity = unit,
                    TargetPosition = position
                });
                em.AddComponent<SendRpcCommandRequest>(rpcEntity);
            }
        }

        private void SendAttackCommands(Entity target)
        {
            var world = World.DefaultGameObjectInjectionWorld;
            if (world == null) return;
            var em = world.EntityManager;

            foreach (var unit in SelectionManager.Instance.SelectedEntities)
            {
                if (!em.Exists(unit) || !em.HasComponent<UnitTag>(unit)) continue;

                var rpcEntity = em.CreateEntity();
                em.AddComponentData(rpcEntity, new AttackCommandRpc
                {
                    AttackerEntity = unit,
                    TargetEntity = target
                });
                em.AddComponent<SendRpcCommandRequest>(rpcEntity);
            }
        }

        private void SendGatherCommands(Entity resourceNode)
        {
            var world = World.DefaultGameObjectInjectionWorld;
            if (world == null) return;
            var em = world.EntityManager;

            foreach (var unit in SelectionManager.Instance.SelectedEntities)
            {
                if (!em.Exists(unit) || !em.HasComponent<CitizenTag>(unit)) continue;

                var rpcEntity = em.CreateEntity();
                em.AddComponentData(rpcEntity, new GatherCommandRpc
                {
                    CitizenEntity = unit,
                    ResourceNodeEntity = resourceNode
                });
                em.AddComponent<SendRpcCommandRequest>(rpcEntity);
            }
        }

        private void SendBuildRepairCommands(Entity building)
        {
            var world = World.DefaultGameObjectInjectionWorld;
            if (world == null) return;
            var em = world.EntityManager;

            foreach (var unit in SelectionManager.Instance.SelectedEntities)
            {
                if (!em.Exists(unit) || !em.HasComponent<CitizenTag>(unit)) continue;

                var rpcEntity = em.CreateEntity();
                em.AddComponentData(rpcEntity, new BuildRepairCommandRpc
                {
                    CitizenEntity = unit,
                    BuildingEntity = building
                });
                em.AddComponent<SendRpcCommandRequest>(rpcEntity);
            }
        }

        private void HandleStop()
        {
            var world = World.DefaultGameObjectInjectionWorld;
            if (world == null) return;
            var em = world.EntityManager;

            foreach (var unit in SelectionManager.Instance.SelectedEntities)
            {
                if (!em.Exists(unit) || !em.HasComponent<UnitTag>(unit)) continue;

                var rpcEntity = em.CreateEntity();
                em.AddComponentData(rpcEntity, new StopCommandRpc
                {
                    UnitEntity = unit
                });
                em.AddComponent<SendRpcCommandRequest>(rpcEntity);
            }
        }
    }
}