using FairyGUI;
using UnityEngine;

namespace ET
{
    public class MapUnitOperationComponentAwakeSystem: AwakeSystem<MapUnitOperationComponent>
    {
        public override void Awake(MapUnitOperationComponent self)
        {
            self.Awake();
        }
    }
    
    public class MapUnitOperationComponentDestroySystem: DestroySystem<MapUnitOperationComponent>
    {
        public override void Destroy(MapUnitOperationComponent self)
        {
            self.Destroy();
        }
    }

    [FriendClass(typeof(MapUnitOperationComponent))]
    [FriendClass(typeof(CameraComponent))]
    public static class MapUnitOperationComponentSystem
    {
        public static void Awake(this MapUnitOperationComponent self)
        {
            self.CameraComp = self.ZoneScene().CurrentScene().GetComponent<CameraComponent>();
            self.MapComp = self.CameraComp.MapComp;
            
            // 操作事件
            Stage.inst.onTouchBegin.Add(self.OnTouchBegin);
            Stage.inst.onTouchMove.Add(self.OnTouchMove);
            Stage.inst.onTouchEnd.Add(self.OnTouchEnd);
        }

        public static void Edit(this MapUnitOperationComponent self, Transform unitRoot, SpriteRenderer unitSR)
        {
            self.CurEditUnitRoot = unitRoot;
            self.CurEditUnitSR = unitSR;
            
            self.CurEditUnitSize = self.MapComp.GetSizeBySpriteCollider(self.CurEditUnitSR);
            self.MapComp.ShowGrid();
            self.MapComp.ShowIndicator();
        }
        
        public static void OnTouchBegin(this MapUnitOperationComponent self, EventContext context)
        {
            if (!Stage.isTouchOnUI)
            {
                self.MovePos.Set(context.inputEvent.x, Screen.height - context.inputEvent.y);
                self.UpdateUnitPos(self.MovePos);
                self.IsTouchDown = true;
            }
        }

        public static void OnTouchMove(this MapUnitOperationComponent self, EventContext context)
        {
            if (self.IsTouchDown)
            {
                self.InputPos.Set(context.inputEvent.x, context.inputEvent.y);
                self.MovePos.Set(context.inputEvent.x, Screen.height - context.inputEvent.y);
                self.CheckToMoveCamera(self.InputPos);
                self.UpdateUnitPos(self.MovePos);

            }
        }
        
        public static void OnTouchEnd(this MapUnitOperationComponent self, EventContext context)
        {
            self.IsTouchDown = false;
        }
        
        // 移动到屏幕边界时需要判断是否移动相机看到更边上的地图
        public static void CheckToMoveCamera(this MapUnitOperationComponent self, Vector2 gesturePos)
        {
            var sprRender = self.CurEditUnitSR;
            Bounds bounds = sprRender.sprite.bounds;
            var size = bounds.size;

            var unitPos = self.CurEditUnitRoot.position;
            var cameraPos = self.CameraComp.GetCameraPos();
            
            self.DeltaPos.Set(0, 0, 0);

            float topOffset = (unitPos.y + size.y) - (cameraPos.y + self.CameraComp.CameraHalfHeight);
            float bottomOffset = (cameraPos.y - self.CameraComp.CameraHalfHeight) - (unitPos.y - size.y / 4) ;
            float moveDelta = self.CameraMoveSpeed;

            if (topOffset > 0 || bottomOffset > 0)
            {
                if (topOffset > bottomOffset)
                {
                    self.DeltaPos.y = moveDelta;
            
                } else if (topOffset < bottomOffset)
                {
                    self.DeltaPos.y = -moveDelta;
                }
            }

            if ((unitPos.x + size.x) >= (cameraPos.x + self.CameraComp.CameraHalfWidth))
            {
                self.DeltaPos.x = moveDelta;
            } else if ((unitPos.x - size.x) <= (cameraPos.x - self.CameraComp.CameraHalfWidth))
            {
                self.DeltaPos.x = -moveDelta;
            }
            
            Vector3 targetCameraPos = self.CameraComp.GetCameraPos() + self.DeltaPos;
            self.CameraComp.SetCameraPosClamped(targetCameraPos);
        }
        
        public static void UpdateUnitPos(this MapUnitOperationComponent self, Vector2 screenPos)
        {
            Vector3 worldPos = self.CameraComp.ScreenToWorldPoint(screenPos);
            worldPos.z = 0;
            var sprRender = self.CurEditUnitSR;
            var sprite = sprRender.sprite;
            Bounds bounds = sprite.bounds;
            Vector4 border = sprite.border;

            worldPos = self.MapComp.AlignPlacePosition(worldPos, self.CurEditUnitSize);
            self.CurEditUnitRoot.position = worldPos;
            
            self.UnitMinPos = sprRender.transform.TransformPoint(bounds.center - new Vector3(bounds.extents.x - border.x / sprite.pixelsPerUnit, bounds.extents.y - border.y / sprite.pixelsPerUnit));
            self.UnitMaxPos = sprRender.transform.TransformPoint(bounds.center + new Vector3(bounds.extents.x - border.z / sprite.pixelsPerUnit, bounds.extents.y - border.w / sprite.pixelsPerUnit));
            self.UnitMidPos = (self.UnitMaxPos + self.UnitMinPos) / 2;
            self.MapComp.UpdateIndicator(worldPos, self.CurEditUnitSize);
            
            self.UnitPosUpdate?.Invoke();
        }

        public static bool IsPlaceValid(this MapUnitOperationComponent self)
        {
            return self.MapComp.IsPlaceValid(self.CurEditUnitRoot.position, self.CurEditUnitSize);
        }

        public static Vector2 GetMidLeftPos(this MapUnitOperationComponent self)
        {
            var midPos = self.UnitMidPos;
            Vector2 midLeft = new Vector2(self.UnitMinPos.x , midPos.y);
            midLeft = self.CameraComp.WorldToScreenPoint(midLeft);

            return midLeft;
        }
        
        public static Vector2 GetMidRightPos(this MapUnitOperationComponent self)
        {
            var midPos = self.UnitMidPos;
            Vector2 midRight = new Vector2(self.UnitMaxPos.x , midPos.y);
            midRight = self.CameraComp.WorldToScreenPoint(midRight);

            return midRight;
        }
        
        public static void Destroy(this MapUnitOperationComponent self)
        {
            // 操作事件
            Stage.inst.onTouchBegin.Remove(self.OnTouchBegin);
            Stage.inst.onTouchMove.Remove(self.OnTouchMove);
            Stage.inst.onTouchEnd.Remove(self.OnTouchEnd);
            
            self.MapComp.HideGrid();
            self.MapComp.HideIndicator();
        }
    }
}