using UnityEngine;
using System.Collections;
using Thousandto.Core.Base;
using PathUtils = UnityEngine.Gonbest.MagicCube.PathUtils;
using CoroutinePool = UnityEngine.Gonbest.MagicCube.CoroutinePool;
using StringUtils = UnityEngine.Gonbest.MagicCube.StringUtils;

public class VRShadow : MonoBehaviour {

    public Camera ShadowCamera;
    public Transform TargetShadowPlane;

    private RenderTexture RT;
    private Material ShadowMat;
    private Transform TargetTrans;
    private int Depth = 0;

    public void Initialize(Transform roleTrans, Transform plane, string shadowLayer = "ARLayer")
    {
        if (ShadowCamera != null) return;

        TargetTrans = roleTrans;
        var parent = plane.parent;

        //设置渲染阴影的材质球，替换shader
        ShadowMat = plane.GetComponent<Renderer>().material;
        ShadowMat.shader = FindShader();
        //创建阴影相机
        ShadowCamera = CreateShadowCamera(parent);
        ShadowCamera.cullingMask = 1 << LayerMask.NameToLayer(shadowLayer);
        //创建用于渲染阴影的RenderTexture
        RT = CreateRenderTexture();
        RT.name = "RenderTexture1";
        RT.antiAliasing = 1;
        ShadowCamera.targetTexture = RT;

        if (Depth > 0)
        {
            ShadowMat.EnableKeyword("_USE_DEPTH_ON_");
            ShadowMat.DisableKeyword("_USE_DEPTH_OFF_");
        }
        else
        {
            ShadowMat.EnableKeyword("_USE_DEPTH_OFF_");
            ShadowMat.DisableKeyword("_USE_DEPTH_ON_");
        }
    }

    private Shader FindShader()
    {
        string shaderAB = PathUtils.GetResourcePath("Shader/Ares/Special/VRShadow.unity3d");
        if(System.IO.File.Exists(shaderAB))
        {
            //var ab =AssetBundle.LoadFromFile(shaderAB);
            //if (ab != null)
            //{
            //    var shader = ab.LoadAsset<Shader>("Shader/Ares/Special/VRShadow");
            //    ab.Unload(false);

            //    UnityEngine.Debug.Log("shader load from bundle success");
            //    return shader;
            //}
            //UnityEngine.Debug.Log("shader load from bundle failed");
        }

        return ShaderEx.Find("Ares/Special/VRShadow");
    }

    private void Render()
    {
        if (ShadowCamera == null) return;

        Matrix4x4 proj = ShadowCamera.projectionMatrix;
        Matrix4x4 view = ShadowCamera.worldToCameraMatrix;

        proj = GL.GetGPUProjectionMatrix(ShadowCamera.projectionMatrix, true);

        ShadowMat.SetMatrix("_VRWorld2ShadowProj", proj * view);
        ShadowMat.SetTexture("_VRShadowMap", RT);
        ShadowMat.SetFloat("_VRShadowIntensity", 0.7f);

        ShadowCamera.transform.position = TargetTrans.position;
    }

    private Camera CreateShadowCamera(Transform parent)
    {
        GameObject go = new GameObject("VRShadowCamera");
        go.transform.parent = parent;
        go.transform.position = new Vector3(0, 3, 0);
        go.transform.rotation = Quaternion.Euler(15, 9, 0);
        go.transform.localScale = Vector3.one;

        Camera camera = go.AddComponent<Camera>();
        SetCameraParams(camera);
        //SetReplacementShader(camera);
        return camera;
    }

    private RenderTexture CreateRenderTexture()
    {
        var format = GetRenderTextureFormat();
        return RenderTexture.GetTemporary(512, 512, Depth, format);
    }

    private void SetCameraParams(Camera camera)
    {
        camera.clearFlags = CameraClearFlags.SolidColor;
        camera.backgroundColor = Color.black;
        camera.orthographic = true;
        camera.orthographicSize = 3.0f;
        camera.nearClipPlane = -100;
        camera.farClipPlane = 100;
        camera.depth = 2;
        camera.cullingMask = 1 << LayerMask.NameToLayer("Role");
    }

    private void SetReplacementShader(Camera camera)
    {
        //渲染对象显示在视口中是白色
        var _depthShader = ShaderEx.Find("Ares/SpecialEffect/MakeShadow");
        camera.SetReplacementShader(_depthShader, "RenderType");
    }

    private RenderTextureFormat GetRenderTextureFormat()
    {
        var texFormat = RenderTextureFormat.RGB565;
        if (SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.Depth))
        {
            Depth = 24;
            texFormat = RenderTextureFormat.Depth;
        }
        else if (SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.RGB565))
        {
            texFormat = RenderTextureFormat.RGB565;
        }
        else if (SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.ARGB4444))
        {
            texFormat = RenderTextureFormat.ARGB4444;
        }
        else if (SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.ARGB1555))
        {
            texFormat = RenderTextureFormat.ARGB1555;
        }
        else if (SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.ARGB32))
        {
            texFormat = RenderTextureFormat.ARGB32;
        }
        
        //UnityEngine.Debug.Log("VRShadow: RT format = " + texFormat);
        return texFormat;
    }

    // Update is called once per frame
    void Update () {
        Render();
    }

    //在编辑器中对脚本的值做改变会触发这个函数
    void OnValidate()
    {
        if (TargetShadowPlane == null) return;

        Initialize(TargetShadowPlane.parent, TargetShadowPlane);
    }
}