using System;
using System.Reflection;
using UnityEngine.Graphing;

namespace UnityEngine.MaterialGraph
{
    [Title("Logic/If")]
    public class IfNode : CodeFunctionNode
    {
        public enum ComparisonOperationType
        {
            Equal = 0,
            NotEqual,
            GreaterThan,
            GreaterThanOrEqual,
            LessThan,
            LessThanOrEqual
        }

        [SerializeField]
        private ComparisonOperationType m_comparisonOperation = ComparisonOperationType.Equal;

        public ComparisonOperationType ComparisonOperation
        {
            get { return m_comparisonOperation; }
            set
            {
                if (m_comparisonOperation == value)
                    return;

                m_comparisonOperation = value;
                if (onModified != null)
                {
                    onModified(this, ModificationScope.Graph);
                }
            }
        }

        public IfNode()
        {
            name = "If";
        }

        protected override MethodInfo GetFunctionToConvert()
        {
            switch (ComparisonOperation)
            {
                case ComparisonOperationType.Equal:
                    return GetType().GetMethod("Unity_IfEqual", BindingFlags.Static | BindingFlags.NonPublic);
                case ComparisonOperationType.NotEqual:
                    return GetType().GetMethod("Unity_IfNotEqual", BindingFlags.Static | BindingFlags.NonPublic);
                case ComparisonOperationType.GreaterThan:
                    return GetType().GetMethod("Unity_IfGreaterThan", BindingFlags.Static | BindingFlags.NonPublic);
                case ComparisonOperationType.GreaterThanOrEqual:
                    return GetType().GetMethod("Unity_IfGreaterThanOrEqual", BindingFlags.Static | BindingFlags.NonPublic);
                case ComparisonOperationType.LessThan:
                    return GetType().GetMethod("Unity_IfLessThan", BindingFlags.Static | BindingFlags.NonPublic);
                case ComparisonOperationType.LessThanOrEqual:
                    return GetType().GetMethod("Unity_IfLessThanOrEqual", BindingFlags.Static | BindingFlags.NonPublic);
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

        const string functionTemplate = @"
{
    if({comparitor})
    {
        result = trueValue;
    }
    else
    {
        result = falseValue;
    }
}
";
        static string Unity_IfEqual(
            [Slot(0, Binding.None)] DynamicDimensionVector a,
            [Slot(1, Binding.None)] DynamicDimensionVector b,
            [Slot(2, Binding.None)] DynamicDimensionVector trueValue,
            [Slot(3, Binding.None)] DynamicDimensionVector falseValue,
            [Slot(4, Binding.None)] DynamicDimensionVector result)
        {
            return functionTemplate.Replace("{comparitor}", "a == b");
        }

        static string Unity_IfNotEqual(
            [Slot(0, Binding.None)] DynamicDimensionVector a,
            [Slot(1, Binding.None)] DynamicDimensionVector b,
            [Slot(2, Binding.None)] DynamicDimensionVector trueValue,
            [Slot(3, Binding.None)] DynamicDimensionVector falseValue,
            [Slot(4, Binding.None)] DynamicDimensionVector result)
        {
            return functionTemplate.Replace("{comparitor}", "a != b");
        }

        static string Unity_IfGreaterThan(
            [Slot(0, Binding.None)] DynamicDimensionVector a,
            [Slot(1, Binding.None)] DynamicDimensionVector b,
            [Slot(2, Binding.None)] DynamicDimensionVector trueValue,
            [Slot(3, Binding.None)] DynamicDimensionVector falseValue,
            [Slot(4, Binding.None)] DynamicDimensionVector result)
        {
            return functionTemplate.Replace("{comparitor}", "a > b");
        }

        static string Unity_IfGreaterThanOrEqual(
            [Slot(0, Binding.None)] DynamicDimensionVector a,
            [Slot(1, Binding.None)] DynamicDimensionVector b,
            [Slot(2, Binding.None)] DynamicDimensionVector trueValue,
            [Slot(3, Binding.None)] DynamicDimensionVector falseValue,
            [Slot(4, Binding.None)] DynamicDimensionVector result)
        {
            return functionTemplate.Replace("{comparitor}", "a >= b");
        }

        static string Unity_IfLessThan(
            [Slot(0, Binding.None)] DynamicDimensionVector a,
            [Slot(1, Binding.None)] DynamicDimensionVector b,
            [Slot(2, Binding.None)] DynamicDimensionVector trueValue,
            [Slot(3, Binding.None)] DynamicDimensionVector falseValue,
            [Slot(4, Binding.None)] DynamicDimensionVector result)
        {
            return functionTemplate.Replace("{comparitor}", "a < b");
        }

        static string Unity_IfLessThanOrEqual(
            [Slot(0, Binding.None)] DynamicDimensionVector a,
            [Slot(1, Binding.None)] DynamicDimensionVector b,
            [Slot(2, Binding.None)] DynamicDimensionVector trueValue,
            [Slot(3, Binding.None)] DynamicDimensionVector falseValue,
            [Slot(4, Binding.None)] DynamicDimensionVector result)
        {
            return functionTemplate.Replace("{comparitor}", "a <= b");
        }
    }
}