using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System;

namespace Wing.Gizmos
{
    public delegate Vector3 GizmosValueChangedHandler(Vector3 before);

    public class GizmosBase : MonoBehaviour
    {
        public event Action<EGizmosAxisType> AxisSelectedEvent;
        public GameObject _lastSelected;
        public float scale = 1.0f;
        private Vector3 _lastMousePt;
        private bool dirty = false;
        private float _distanceFactor = 1.0f;
        protected Dictionary<GameObject, EGizmosAxisType> _axisMap = new Dictionary<GameObject, EGizmosAxisType>();
        // Use this for initialization
        void Awake()
        {
            transform.localScale = Vector3.zero;
            OnInit();
        }

        protected void ConstructAxis(string axisRoot, EGizmosAxisType type)
        {
            Transform go = transform.Find(axisRoot);
            for (int i = 0; i < go.childCount; ++i)
            {
                GameObject obj = go.GetChild(i).gameObject;
                obj.AddComponent<GizmosAxis>();
                MeshRenderer r = obj.GetComponent<MeshRenderer>();
                SetColor(r.material, type, false);
                _axisMap[obj] = type;
            }
        }

        private void SetColor(Material mat, EGizmosAxisType type, bool highlight)
        {
            if (!highlight)
            {
                float lightness = 1.0f;
                if (type == EGizmosAxisType.X)
                {
                    mat.color = new Color(lightness, 0.0f, 0.0f, 0.5f);
                }
                else if (type == EGizmosAxisType.Y)
                {
                    mat.color = new Color(0.0f, lightness, 0.0f, 0.5f);
                }
                else if (type == EGizmosAxisType.Z)
                {
                    mat.color = new Color(0.0f, 0.0f, lightness, 0.5f);
                }
                else if (type == EGizmosAxisType.LockX)
                {
                    mat.color = new Color(lightness, 0.0f, 0.0f, 0.5f);
                }
                else if (type == EGizmosAxisType.LockY)
                {
                    mat.color = new Color(0.0f, lightness, 0.0f, 0.5f);
                }
                else if (type == EGizmosAxisType.LockZ)
                {
                    mat.color = new Color(0.0f, 0.0f, lightness, 0.5f);
                }
                else
                {
                    mat.color = new Color(lightness, lightness, lightness, 1.0f);
                }
            }
            else
            {
                mat.color = new Color(1.0f, 1.0f, 0.0f, 1.0f);
            }

        }

        // Update is called once per frame
        void Update()
        {
            Vector3 diff = transform.position - Camera.main.transform.position;
            float d = diff.magnitude * scale * 0.05f;
            _distanceFactor = ComputeScaleFactor(d);
            transform.localScale = new Vector3(d, d, d);
        }

        protected virtual float ComputeScaleFactor(float d)
        {
            return d * 1.4f;
        }

        private void ChangeColor(GameObject go, bool highlight)
        {
            Transform root = go.transform.parent;
            for (int i = 0; i < root.childCount; ++i)
            {
                GameObject childGO = root.GetChild(i).gameObject;
                MeshRenderer r = childGO.GetComponent<MeshRenderer>();
                EGizmosAxisType type = _axisMap[childGO];
                SetColor(r.material, type, highlight);
            }
        }

        public void OnMouseEnter(GameObject go)
        {
            if(_lastSelected != null)
            {
                ChangeColor(_lastSelected, false);
            }
            ChangeColor(go, true);
            //Debug.Log("OnMouseEnter");
            _lastSelected = go;
            OnAxisSelected(_axisMap[go]);
        }

        public void OnMouseExit(GameObject go)
        {
            //ChangeColor(go, false);
            //            Debug.Log("OnMouse Exit");
        }

        public void OnMouseDown(GameObject go)
        {
            _lastMousePt = Input.mousePosition;
            //            Debug.Log("OnMouseDown");
            OnAxisSelected(_axisMap[go]);
        }

        public void OnMouseUp(GameObject go)
        {
            OnDragEnd(go);
            dirty = false;
        }

        public void OnMouseDrag(GameObject go)
        {
            Vector3 mousePt = Input.mousePosition;
            Vector3 diff = mousePt - _lastMousePt;
            if (diff.x + diff.y == 0)
            {
                return;
            }
            dirty = true;
            EGizmosAxisType type = _axisMap[go];
            float dx = 0;
            float dy = 0;
            float dz = 0;
            float scensitivity = 0.02f;

            Vector3 ogrinPos = transform.position;
            Vector3 start = Camera.main.WorldToScreenPoint(ogrinPos);
            start.z = 0;

            if (type != EGizmosAxisType.CENTER)
            {
                Vector3 end = Camera.main.WorldToScreenPoint(ogrinPos + transform.right * 2);
                end.z = 0;
                Vector3 axisDir = end - start;
                axisDir.Normalize();
                dx = (axisDir.x * diff.x + axisDir.y * diff.y) * scensitivity;


                end = Camera.main.WorldToScreenPoint(ogrinPos + transform.up * 2);
                end.z = 0;
                axisDir = end - start;
                axisDir.Normalize();
                dy = (axisDir.x * diff.x + axisDir.y * diff.y) * scensitivity;

                end = Camera.main.WorldToScreenPoint(ogrinPos + transform.forward * 2);
                end.z = 0;
                axisDir = end - start;
                axisDir.Normalize();
                dz = (axisDir.x * diff.x + axisDir.y * diff.y) * scensitivity;
            }
            else
            {
                Vector3 end = start + Vector3.one;
                end.z = 0;
                Vector3 axisDir = end - start;
                axisDir.Normalize();
                dx = dy = dz = (axisDir.x * diff.x + axisDir.y * diff.y) * scensitivity;
            }


            Vector3 axisMask = Vector3.zero;
            switch (type)
            {
                case EGizmosAxisType.X:
                    axisMask.x = 1;
                    break;
                case EGizmosAxisType.Y:
                    axisMask.y = 1;
                    break;
                case EGizmosAxisType.Z:
                    axisMask.z = 1;
                    break;
                case EGizmosAxisType.LockX:
                    axisMask.y = 1;
                    axisMask.z = 1;
                    break;
                case EGizmosAxisType.LockY:
                    axisMask.x = 1;
                    axisMask.z = 1;
                    break;
                case EGizmosAxisType.LockZ:
                    axisMask.x = 1;
                    axisMask.y = 1;
                    break;
                case EGizmosAxisType.CENTER:
                    axisMask.x = 1;
                    axisMask.y = 1;
                    axisMask.z = 1;
                    break;
            }


            dx = dx * axisMask.x * _distanceFactor;
            dy = dy * axisMask.y * _distanceFactor;
            dz = dz * axisMask.z * _distanceFactor;
            OnDragDelta(go, dx, dy, dz);
            _lastMousePt = mousePt;
        }

        protected virtual void OnInit() { }

        protected virtual void OnDragDelta(GameObject go,float dx, float dy, float dz) { }
        protected virtual void OnDragEnd(GameObject go) { }

        protected virtual void OnAxisSelected(EGizmosAxisType type)
        {
            if(AxisSelectedEvent != null)
            {
                AxisSelectedEvent(type);
            }
        }
    }
}