using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;

namespace Microsoft.Xna.Framework.Graphics
{
    [DebuggerDisplay("{ParameterClass} {ParameterType} {Name} : {Semantic}")]
	public class EffectParameter
	{
        /// <summary>
        /// The next state key used when an effect parameter
        /// is updated by any of the 'set' methods.
        /// </summary>
        internal static ulong NextStateKey { get; private set; }

        internal EffectParameter(   EffectParameterClass class_, 
                                    EffectParameterType type, 
                                    string name, 
                                    int rowCount, 
                                    int columnCount,
                                    string semantic, 
                                    EffectAnnotationCollection annotations,
                                    EffectParameterCollection elements,
                                    EffectParameterCollection structMembers,
                                    object data )
		{
            ParameterClass = class_;
            ParameterType = type;

            Name = name;
            Semantic = semantic;
            Annotations = annotations;

            RowCount = rowCount;
			ColumnCount = columnCount;

            Elements = elements;
            StructureMembers = structMembers;

            Data = data;
            StateKey = unchecked(NextStateKey++);
		}

        internal EffectParameter(EffectParameter cloneSource)
        {
            // Share all the immutable types.
            ParameterClass = cloneSource.ParameterClass;
            ParameterType = cloneSource.ParameterType;
            Name = cloneSource.Name;
            Semantic = cloneSource.Semantic;
            Annotations = cloneSource.Annotations;
            RowCount = cloneSource.RowCount;
            ColumnCount = cloneSource.ColumnCount;

            // Clone the mutable types.
            Elements = cloneSource.Elements.Clone();
            StructureMembers = cloneSource.StructureMembers.Clone();

            // The data is mutable, so we have to clone it.
            var array = cloneSource.Data as Array;
            if (array != null)
                Data = array.Clone();
            StateKey = unchecked(NextStateKey++);
        }

		public string Name { get; private set; }

        public string Semantic { get; private set; }

		public EffectParameterClass ParameterClass { get; private set; }

		public EffectParameterType ParameterType { get; private set; }

		public int RowCount { get; private set; }

        public int ColumnCount { get; private set; }

        public EffectParameterCollection Elements { get; private set; }

        public EffectParameterCollection StructureMembers { get; private set; }

        public EffectAnnotationCollection Annotations { get; private set; }


        // TODO: Using object adds alot of boxing/unboxing overhead
        // and garbage generation.  We should consider a templated
        // type implementation to fix this!

        internal object Data { get; private set; }

        /// <summary>
        /// The current state key which is used to detect
		/// if the parameter value has been changed.
        /// </summary>
        internal ulong StateKey { get; private set; }


        public bool GetValueBoolean ()
		{
            if (ParameterClass != EffectParameterClass.Scalar || ParameterType != EffectParameterType.Bool)
                throw new InvalidCastException();

#if DIRECTX
            return ((int[])Data)[0] != 0;
#else
            // MojoShader encodes even booleans into a float.
            return ((float[])Data)[0] != 0.0f;
#endif
        }

		public bool[] GetValueBooleanArray ()
		{
			throw new NotImplementedException();
		}

		public int GetValueInt32 ()
		{
            if (ParameterClass != EffectParameterClass.Scalar || ParameterType != EffectParameterType.Int32)
                throw new InvalidCastException();

#if DIRECTX
            return ((int[])Data)[0];
#else
            // MojoShader encodes integers into a float.
            return (int)((float[])Data)[0];
#endif
        }

		public int[] GetValueInt32Array ()
		{
			throw new NotImplementedException();
		}

		public Matrix GetValueMatrix ()
		{
            if (ParameterClass != EffectParameterClass.Matrix || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

            if (RowCount != 4 || ColumnCount != 4)
                throw new InvalidCastException();

            var floatData = (float[])Data;

            return new Matrix(  floatData[0], floatData[4], floatData[8], floatData[12],
                                floatData[1], floatData[5], floatData[9], floatData[13],
                                floatData[2], floatData[6], floatData[10], floatData[14],
                                floatData[3], floatData[7], floatData[11], floatData[15]);
		}

		public Matrix[] GetValueMatrixArray (int count)
		{
			throw new NotImplementedException();
		}

		public Quaternion GetValueQuaternion ()
		{
			throw new NotImplementedException();
		}

		public Quaternion[] GetValueQuaternionArray ()
		{
			throw new NotImplementedException();
		}

		public Single GetValueSingle ()
		{
            // TODO: Should this fetch int and bool as a float?
            if (ParameterClass != EffectParameterClass.Scalar || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

			return ((float[])Data)[0];
		}

		public Single[] GetValueSingleArray ()
		{
			if (Elements != null && Elements.Count > 0)
            {
                var ret = new Single[RowCount * ColumnCount * Elements.Count];
				for (int i=0; i<Elements.Count; i++)
                {
                    var elmArray = Elements[i].GetValueSingleArray();
                    for (var j = 0; j < elmArray.Length; j++)
						ret[RowCount*ColumnCount*i+j] = elmArray[j];
				}
				return ret;
			}
			
			switch(ParameterClass) 
            {
			case EffectParameterClass.Scalar:
				return new Single[] { GetValueSingle () };
            case EffectParameterClass.Vector:
			case EffectParameterClass.Matrix:
                    if (Data is Matrix)
                        return Matrix.ToFloatArray((Matrix)Data);
                    else
                        return (float[])Data;
			default:
				throw new NotImplementedException();
			}
		}

		public string GetValueString ()
		{
            if (ParameterClass != EffectParameterClass.Object || ParameterType != EffectParameterType.String)
                throw new InvalidCastException();

		    return ((string[])Data)[0];
		}

		public Texture2D GetValueTexture2D ()
		{
            if (ParameterClass != EffectParameterClass.Object || ParameterType != EffectParameterType.Texture2D)
                throw new InvalidCastException();

			return (Texture2D)Data;
		}

#if !GLES
	    public Texture3D GetValueTexture3D ()
	    {
            if (ParameterClass != EffectParameterClass.Object || ParameterType != EffectParameterType.Texture3D)
                throw new InvalidCastException();

            return (Texture3D)Data;
	    }
#endif

		public TextureCube GetValueTextureCube ()
		{
			throw new NotImplementedException();
		}

		public Vector2 GetValueVector2 ()
		{
            if (ParameterClass != EffectParameterClass.Vector || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

            var vecInfo = (float[])Data;
			return new Vector2(vecInfo[0],vecInfo[1]);
		}

		public Vector2[] GetValueVector2Array ()
		{
			throw new NotImplementedException();
		}

		public Vector3 GetValueVector3 ()
		{
            if (ParameterClass != EffectParameterClass.Vector || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

            var vecInfo = (float[])Data;
			return new Vector3(vecInfo[0],vecInfo[1],vecInfo[2]);
		}

		public Vector3[] GetValueVector3Array ()
		{
			throw new NotImplementedException();
		}

		public Vector4 GetValueVector4 ()
		{
            if (ParameterClass != EffectParameterClass.Vector || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

            var vecInfo = (float[])Data;
			return new Vector4(vecInfo[0],vecInfo[1],vecInfo[2],vecInfo[3]);
		}

		public Vector4[] GetValueVector4Array ()
		{
			throw new NotImplementedException();
		}

		public void SetValue (bool value)
		{
            if (ParameterClass != EffectParameterClass.Scalar || ParameterType != EffectParameterType.Bool)
                throw new InvalidCastException();

#if DIRECTX
            // We store the bool as an integer as that
            // is what the constant buffers expect.
            ((int[])Data)[0] = value ? 1 : 0;
#else
            // MojoShader encodes even booleans into a float.
            ((float[])Data)[0] = value ? 1 : 0;
#endif
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (bool[] value)
		{
			throw new NotImplementedException();
		}

		public void SetValue (int value)
		{
            if (ParameterClass != EffectParameterClass.Scalar || ParameterType != EffectParameterType.Int32)
                throw new InvalidCastException();

#if DIRECTX
            ((int[])Data)[0] = value;
#else
            // MojoShader encodes integers into a float.
            ((float[])Data)[0] = value;
#endif
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (int[] value)
		{
			throw new NotImplementedException();
		}

        public void SetValue(Matrix value)
        {
            // HLSL expects matrices to be transposed by default.
            // These unrolled loops do the transpose during assignment.
            if (RowCount == 4 && ColumnCount == 4)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M21;
                fData[2] = value.M31;
                fData[3] = value.M41;

                fData[4] = value.M12;
                fData[5] = value.M22;
                fData[6] = value.M32;
                fData[7] = value.M42;

                fData[8] = value.M13;
                fData[9] = value.M23;
                fData[10] = value.M33;
                fData[11] = value.M43;

                fData[12] = value.M14;
                fData[13] = value.M24;
                fData[14] = value.M34;
                fData[15] = value.M44;
            }
            else if (RowCount == 4 && ColumnCount == 3)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M21;
                fData[2] = value.M31;
                fData[3] = value.M41;

                fData[4] = value.M12;
                fData[5] = value.M22;
                fData[6] = value.M32;
                fData[7] = value.M42;

                fData[8] = value.M13;
                fData[9] = value.M23;
                fData[10] = value.M33;
                fData[11] = value.M43;
            }
            else if (RowCount == 3 && ColumnCount == 4)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M21;
                fData[2] = value.M31;

                fData[3] = value.M12;
                fData[4] = value.M22;
                fData[5] = value.M32;

                fData[6] = value.M13;
                fData[7] = value.M23;
                fData[8] = value.M33;

                fData[9] = value.M14;
                fData[10] = value.M24;
                fData[11] = value.M34;
            }
            else if (RowCount == 3 && ColumnCount == 3)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M21;
                fData[2] = value.M31;

                fData[3] = value.M12;
                fData[4] = value.M22;
                fData[5] = value.M32;

                fData[6] = value.M13;
                fData[7] = value.M23;
                fData[8] = value.M33;
            }

            StateKey = unchecked(NextStateKey++);
        }

		public void SetValueTranspose(Matrix value)
		{
            // HLSL expects matrices to be transposed by default, so copying them straight
            // from the in-memory version effectively transposes them back to row-major.
            if (RowCount == 4 && ColumnCount == 4)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M12;
                fData[2] = value.M13;
                fData[3] = value.M14;

                fData[4] = value.M21;
                fData[5] = value.M22;
                fData[6] = value.M23;
                fData[7] = value.M24;

                fData[8] = value.M31;
                fData[9] = value.M32;
                fData[10] = value.M33;
                fData[11] = value.M34;

                fData[12] = value.M41;
                fData[13] = value.M42;
                fData[14] = value.M43;
                fData[15] = value.M44;
            }
            else if (RowCount == 4 && ColumnCount == 3)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M12;
                fData[2] = value.M13;

                fData[3] = value.M21;
                fData[4] = value.M22;
                fData[5] = value.M23;

                fData[6] = value.M31;
                fData[7] = value.M32;
                fData[8] = value.M33;

                fData[9] = value.M41;
                fData[10] = value.M42;
                fData[11] = value.M43;
            }
            else if (RowCount == 3 && ColumnCount == 4)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M12;
                fData[2] = value.M13;
                fData[3] = value.M14;

                fData[4] = value.M21;
                fData[5] = value.M22;
                fData[6] = value.M23;
                fData[7] = value.M24;

                fData[8] = value.M31;
                fData[9] = value.M32;
                fData[10] = value.M33;
                fData[11] = value.M34;
            }
            else if (RowCount == 3 && ColumnCount == 3)
            {
                var fData = (float[])Data;

                fData[0] = value.M11;
                fData[1] = value.M12;
                fData[2] = value.M13;

                fData[3] = value.M21;
                fData[4] = value.M22;
                fData[5] = value.M23;

                fData[6] = value.M31;
                fData[7] = value.M32;
                fData[8] = value.M33;
            }

			StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Matrix[] value)
		{
            for (var i = 0; i < value.Length; i++)
				Elements[i].SetValue (value[i]);

            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Quaternion value)
		{
			throw new NotImplementedException();
		}

		public void SetValue (Quaternion[] value)
		{
			throw new NotImplementedException();
		}

		public void SetValue (Single value)
		{
            if (ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();
#if PSM
            if(Data == null) {
                return;
            }
#endif
			((float[])Data)[0] = value;
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Single[] value)
		{
			for (var i=0; i<value.Length; i++)
				Elements[i].SetValue (value[i]);

            StateKey = unchecked(NextStateKey++);
		}
		
		public void SetValue (string value)
		{
			throw new NotImplementedException();
		}

		public void SetValue (Texture value)
		{
            if (this.ParameterType != EffectParameterType.Texture && 
                this.ParameterType != EffectParameterType.Texture1D &&
                this.ParameterType != EffectParameterType.Texture2D &&
                this.ParameterType != EffectParameterType.Texture3D &&
                this.ParameterType != EffectParameterType.TextureCube) 
            {
                throw new InvalidCastException();
            }

			Data = value;
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Vector2 value)
		{
            if (ParameterClass != EffectParameterClass.Vector || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

            var fData = (float[])Data;
            fData[0] = value.X;
            fData[1] = value.Y;
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Vector2[] value)
		{
            for (var i = 0; i < value.Length; i++)
				Elements[i].SetValue (value[i]);
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Vector3 value)
		{
            if (ParameterClass != EffectParameterClass.Vector || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

            var fData = (float[])Data;
            fData[0] = value.X;
            fData[1] = value.Y;
            fData[2] = value.Z;
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Vector3[] value)
		{
            for (var i = 0; i < value.Length; i++)
				Elements[i].SetValue (value[i]);
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Vector4 value)
		{
            if (ParameterClass != EffectParameterClass.Vector || ParameterType != EffectParameterType.Single)
                throw new InvalidCastException();

			var fData = (float[])Data;
            fData[0] = value.X;
            fData[1] = value.Y;
            fData[2] = value.Z;
            fData[3] = value.W;
            StateKey = unchecked(NextStateKey++);
		}

		public void SetValue (Vector4[] value)
		{
            for (var i = 0; i < value.Length; i++)
				Elements[i].SetValue (value[i]);
            StateKey = unchecked(NextStateKey++);
		}
	}
}