using UnityEngine;

namespace UnityEditor.Graphs.Material
{
	[Title("Art/Colorize Node")]
	class ColorizeNode : Function1Input, IGeneratesFunction
	{
		[SerializeField]
		private Color m_Color = Color.blue;
		[SerializeField]
		private float m_Colorization = 0.0f;
		[SerializeField]
		private float m_Brightness = 1.0f;
		[SerializeField]
		private float m_Contrast = 1.0f;

		public override void Init()
		{
			name = "ColorizeNode";
			base.Init();
		}

		protected override string GetFunctionName() {return ""; }
		
		protected override string GetFunctionCallBody (string inputValue)
		{
			return  "unity_colorize_"+precision+"("+inputValue+", "+precision+"4("+m_Color.r+", "+m_Color.g+", "+m_Color.b+", "+m_Color.a+"), "+m_Colorization+", "+m_Brightness+", "+m_Contrast+")";
		}

		public void GenerateNodeFunction(ShaderGenerator visitor, GenerationMode generationMode)
		{
			var outputString = new ShaderGenerator ();

			foreach (var thePrecisision in m_PrecisionNames)
			{
				outputString.AddShaderChunk ("inline " + thePrecisision + "4 unity_colorize_" + thePrecisision + " (" + thePrecisision + "4 arg1, " + thePrecisision + "4 color, " + thePrecisision + " amount, " + thePrecisision + " brightness, " + thePrecisision + " contrast)", false);
				outputString.AddShaderChunk ("{", false);
				outputString.Indent ();
				outputString.AddShaderChunk (thePrecisision + "4 x = lerp(arg1, arg1 * color, amount);", false);
				outputString.AddShaderChunk ("x *= brightness;", false);
				outputString.AddShaderChunk ("x = pow(x, contrast);", false);
				outputString.AddShaderChunk ("return x;", false);
				outputString.Deindent ();
				outputString.AddShaderChunk ("}", false);
			}

			visitor.AddShaderChunk (outputString.GetShaderString (0), true);
		}

		static float Slider (string title, float value, float from, float to)
		{
			GUILayout.BeginHorizontal ();
			GUILayout.Label (title);
			value = GUILayout.HorizontalSlider(value, from, to, GUILayout.Width(64));
			GUILayout.EndHorizontal ();
			return value;
		}

		public override void NodeUI (Graphs.GraphGUI host) 
		{
			base.NodeUI(host);

			EditorGUI.BeginChangeCheck ();
			m_Color = EditorGUILayout.ColorField("Tint", m_Color);
			m_Colorization = Slider ("Colorization", m_Colorization, 0f, 1f);
			m_Brightness = Slider ("Brightness", m_Brightness, 0f, 2f);
			m_Contrast = Slider ("Contrast", m_Contrast, 0.3f, 4f);
			if (EditorGUI.EndChangeCheck ())
				RegeneratePreviewShaders ();
		}		
	}
}