using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Aiwaz.Contracts;
using SlimDX;
using Aiwaz.Resources.Attributes;
using System.Collections.ObjectModel;

namespace Aiwaz.Resources.Prefab
{
    [CreationParameters("Unity-sized one-sided quad")]
    public class QuadParams : ICreationParams
    {
        public float Width;
        public float Height;
        public bool IsTwoSided;

        public QuadParams()
        {
            Width = 1.0f;
            Height = 1.0f;
            IsTwoSided = false;
        }
    }

    [AiwazResource("Quad", "A simple 2d non-uniform Quad")]
    public class Quad : Resource
    {
        public struct CommonQuadVertex
        {
            public CommonQuadVertex(SlimDX.Vector3 pos,
                                    SlimDX.Vector3 normal,
                                    SlimDX.Vector2 tex)
            {
                this.Pos = pos;
                this.Normal = normal;
                this.Tex = tex;
            }
            public SlimDX.Vector3 Pos;
            public SlimDX.Vector3 Normal;
            public SlimDX.Vector2 Tex;
        };

        public GeometryBuffer GeometryBuffer { get; protected set; }

        public Quad(QuadParams parameters)
        {
            this.creationParams = parameters;
            float width = parameters.Width * 0.5f;
	        float height = parameters.Height * 0.5f;

            CommonQuadVertex[] quadOneSidedVertices = new CommonQuadVertex[]
	        {
		        new CommonQuadVertex( new SlimDX.Vector3( -width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 0.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 1.0f, 1.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( -width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 0.0f, 1.0f ) ),

		        new CommonQuadVertex( new SlimDX.Vector3( -width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 0.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 1.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 1.0f, 1.0f ) ),
	        };

            CommonQuadVertex[] quadTwoSidedVertices = new CommonQuadVertex[]
	        {
		        new CommonQuadVertex( new SlimDX.Vector3( -width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 0.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 1.0f, 1.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( -width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 0.0f, 1.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( -width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 0.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 1.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, -1.0f), new SlimDX.Vector2( 1.0f, 1.0f ) ),

		        new CommonQuadVertex( new SlimDX.Vector3( -width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, 1.0f), new SlimDX.Vector2( 1.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, 1.0f), new SlimDX.Vector2( 0.0f, 1.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( -width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, 1.0f), new SlimDX.Vector2( 1.0f, 1.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( -width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, 1.0f), new SlimDX.Vector2( 1.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, 1.0f), new SlimDX.Vector2( 0.0f, 0.0f ) ),
		        new CommonQuadVertex( new SlimDX.Vector3( width, -height, 0.0f ),	new SlimDX.Vector3(0.0f, 0.0f, 1.0f), new SlimDX.Vector2( 0.0f, 1.0f ) ),
	        };
            
            var vertexElements = new VertexElement[]
            {
                new VertexElement(VertexElement.Format.Position),
                new VertexElement(VertexElement.Format.Normal),
                new VertexElement(VertexElement.Format.Texture2D)
            };

            var oneSidedIndices = new uint[] { 0,1,2, 3,4,5 };
            var twoSidedIndices = new uint[] { 0, 1, 2, 3, 4, 5, 11, 10, 9, 8, 7, 6 };

            this.GeometryBuffer = GeometryBuffer.Create<CommonQuadVertex>(
                parameters.IsTwoSided ? twoSidedIndices : oneSidedIndices,
                parameters.IsTwoSided ? quadTwoSidedVertices : quadOneSidedVertices,
                vertexElements,
                false);
        }

        private ICreationParams creationParams;
        public override ICreationParams CreationParams
        {
            get { return creationParams; }
        }

        private ObservableCollection<IResource> children;
        [ReadOnly]
        public override ObservableCollection<IResource> Children
        {
            get
            {
                if (children == null)
                {
                    children = new ObservableCollection<IResource>();
                    children.Add(GeometryBuffer);
                }
                return children;
            }
        }
    }
}