using UnityEngine;
using System.Collections;

namespace WPM {
    public partial class WorldMapGlobe : MonoBehaviour {
        const string SPHERE_FOW_NAME = "SphereFoWLayer";
        GameObject sphereFoWLayer;
        Material[] sphereFoWMaterials;
        RenderTexture rtFoW;
        Material fowDrawMat;

        #region Fog of War handling

        void CreateFogOfWarLayer() {

            if (!gameObject.activeInHierarchy)
                return;

            // Sphere FoW layer
            Transform t = transform.Find(SPHERE_FOW_NAME);
            if (t != null) {
                Renderer r = t.gameObject.GetComponent<Renderer>();
                if (r == null || r.sharedMaterial == null) {
                    DestroyImmediate(t.gameObject);
                    t = null;
                }
            }

            if (t == null) {
                sphereFoWLayer = Instantiate(Resources.Load<GameObject>("Prefabs/SphereFoWLayer"));
                sphereFoWLayer.hideFlags = HideFlags.DontSave;
                sphereFoWLayer.name = SPHERE_FOW_NAME;
                sphereFoWLayer.transform.SetParent(transform, false);
                sphereFoWLayer.layer = gameObject.layer;
                sphereFoWLayer.transform.localPosition = Misc.Vector3zero;
            } else {
                sphereFoWLayer = t.gameObject;
                sphereFoWLayer.SetActive(true);
            }

            // Material
            if (sphereFoWMaterials == null || sphereFoWMaterials.Length != 3) {
                sphereFoWMaterials = new Material[3];
                sphereFoWMaterials[0] = Instantiate(Resources.Load<Material>("Materials/SphereFoW")) as Material;
                sphereFoWMaterials[1] = Instantiate(Resources.Load<Material>("Materials/SphereFoWPass1")) as Material;
                sphereFoWMaterials[2] = Instantiate(Resources.Load<Material>("Materials/SphereFoWPass2")) as Material;
            }
            sphereFoWLayer.GetComponent<Renderer>().sharedMaterials = sphereFoWMaterials;

            CheckFoWTexture();
        }

        void CheckFoWTexture() {
            if (sphereFoWMaterials == null) return;
            int res = (int)Mathf.Pow(2, _fogOfWarResolution);
            if (rtFoW != null && rtFoW.width != res) {
                rtFoW.Release();
                DestroyImmediate(rtFoW);
            }
            if (rtFoW == null) {
                RenderTextureFormat rtFormat = SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.RHalf) ? RenderTextureFormat.RHalf : RenderTextureFormat.ARGB32;
                rtFoW = new RenderTexture(res, res / 2, 0, rtFormat);
                SetFowAlpha(Misc.Vector2zero, 1, 2, 1);
            }
        }


        void DestroyFogOfWarLayer() {
            if (sphereFoWLayer != null) {
                DestroyImmediate(sphereFoWLayer);
            }
            if (rtFoW != null) {
                RenderTexture.active = null;
                rtFoW.Release();
                DestroyImmediate(rtFoW);
                rtFoW = null;
            }
            if (fowDrawMat != null) {
                DestroyImmediate(fowDrawMat);
                fowDrawMat = null;
            }
            if (sphereFoWMaterials != null) {
                for (int k = 0; k < sphereFoWMaterials.Length; k++) {
                    DestroyImmediate(sphereFoWMaterials[k]);
                }
                sphereFoWMaterials = null;
            }
        }


        void DrawFogOfWar() {
            if (_showFogOfWar) {
                CreateFogOfWarLayer();
                if (sphereFoWMaterials != null) {
                    for (int k = 0; k < sphereFoWMaterials.Length; k++) {
                        Material mat = sphereFoWMaterials[k];
                        mat.SetFloat(ShaderParams.Alpha, _fogOfWarAlpha);
                        mat.SetColor(ShaderParams.Color, _fogOfWarColor1);
                        mat.SetColor(ShaderParams.Color2, _fogOfWarColor2);
                        mat.SetFloat(ShaderParams.FoWElevation, _fogOfWarElevation);
                        mat.SetFloat(ShaderParams.FoWNoise, _fogOfWarNoise);
                    }
                }
            } else {
                DestroyFogOfWarLayer();
            }
        }

        void SetFowAlpha(Vector2 uv, float alpha, float radius, float strength) {

            if (fowDrawMat == null) {
                fowDrawMat = new Material(Shader.Find("World Political Map/FogOfWarPainter"));
            }
            fowDrawMat.SetVector(ShaderParams.FoWPaintData, new Vector4(uv.x, uv.y, radius * radius, alpha));
            fowDrawMat.SetFloat(ShaderParams.FoWPaintStrength, strength);
            RenderTexture rt = RenderTexture.GetTemporary(rtFoW.width, rtFoW.height, 0, rtFoW.format);
            Graphics.Blit(rtFoW, rt, fowDrawMat);
            rtFoW.DiscardContents();
            Graphics.Blit(rt, rtFoW);
            RenderTexture.ReleaseTemporary(rt);

            if (sphereFoWMaterials != null) {
                for (int k = 0; k < sphereFoWMaterials.Length; k++) {
                    sphereFoWMaterials[k].SetTexture(ShaderParams.FoWMaskTex, rtFoW);
                }
            }

        }


        #endregion







    }
}