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

namespace BF
{
    [RequireComponent(typeof(MaskableGraphic))]
    [DisallowMultipleComponent]
    [ExecuteInEditMode]
    public class UIDynamicBrightEffect : BaseMeshEffect
    {
        [SerializeField]
        [Range(0, 3)]
        float brightness = 1.0f;
        public float Brightness
        {
            get { return brightness; }
            set { brightness = value; SetDirty(); }
        }

        public bool Brighting { get { return Math.Abs(brightness - 1.0f) > 0 && IsActive(); } }

        public Material effectmat;

        static List<UIVertex> Vertexs = new List<UIVertex>();
        const string SHADER_NAME = "BF/UI/UIDynamicBright";

        protected override void OnEnable()
        {
            if (effectmat == null)
            {
                var shader = Shader.Find(SHADER_NAME);
                effectmat = new Material(shader);
            }
            graphic.material = effectmat;
        }

        protected override void OnDisable()
        {
            graphic.material = BFMain.Instance.RenderMgr.UIDefaultMat;
        }

        public override void ModifyMesh(VertexHelper vh)
        {
            if (!IsActive())
            {
                return;
            }

            vh.GetUIVertexStream(Vertexs);
            vh.Clear();
            for (int i = 0; i < Vertexs.Count; i++)
            {
                UIVertex vertex = new UIVertex();
                vertex.color = Vertexs[i].color;
                vertex.position = Vertexs[i].position;
                vertex.uv0 = Vertexs[i].uv0;
                vertex.uv2 = new Vector2(brightness, 0f);
                Vertexs[i] = vertex;
            }
            vh.AddUIVertexTriangleStream(Vertexs);
            Vertexs.Clear();
        }

        public void SetMarterial(Material material)
        {
            effectmat = material;
        }

        public void SetBright(float brightness = 1.25f)
        {
            Brightness = Math.Max(0f, brightness);
        }

        void SetDirty()
        {
            if (graphic)
            {
                graphic.SetVerticesDirty();
            }
        }
    }
}