// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using System.Collections.Generic;
using ClassicalSharp.Events;
using ClassicalSharp.GraphicsAPI;

namespace ClassicalSharp.Model {

	public class ModelCache : IDisposable {
		
		Game game;
		IGraphicsApi api;
		public ModelCache( Game window ) {
			this.game = window;
			api = game.Graphics;
		}
		
		#if FALSE
		public CustomModel[] CustomModels = new CustomModel[256];
		#endif
		public List<CachedModel> Models = new List<CachedModel>();
		public List<CachedTexture> Textures = new List<CachedTexture>();
		internal int vb;
		internal VertexP3fT2fC4b[] vertices;


		public void InitCache() {
			vertices = new VertexP3fT2fC4b[24 * 12];
			vb = api.CreateDynamicVb( VertexFormat.P3fT2fC4b, vertices.Length );
			RegisterDefaultModels();
			game.Events.TextureChanged += TextureChanged;
		}
		
		public void Register( string modelName, string texName, IModel instance ) {
			CachedModel model = new CachedModel();
			model.Name = modelName;
			model.Instance = instance;
			Models.Add( model );
			
			instance.data = model;
			instance.texIndex = GetTextureIndex( texName );
		}
		
		public void RegisterTextures( params string[] texNames ) {
			for( int i = 0; i < texNames.Length; i++ ) {
				CachedTexture texture = new CachedTexture();
				texture.Name = texNames[i];
				Textures.Add( texture );
			}
		}
		
		public int GetTextureIndex( string texName ) {
			for( int i = 0; i < Textures.Count; i++ ) {
				if( Textures[i].Name == texName ) return i;
			}
			return -1;
		}

		
		public IModel Get( string modelName ) {
			if( modelName == "block" ) return Models[0].Instance;
			byte blockId;
			if( Byte.TryParse( modelName, out blockId ) )
				modelName = "block";

			for( int i = 0; i < Models.Count; i++ ) {
				CachedModel m = Models[i];
				if( m.Name != modelName ) continue;
				if( m.Initalised ) return m.Instance;
				
				InitModel( ref m );
				Models[i] = m;
				return m.Instance;
			}
			return Models[0].Instance;
		}
		
		public void Dispose() {
			game.Events.TextureChanged -= TextureChanged;
			for( int i = 0; i < Models.Count; i++ )
				Models[i].Instance.Dispose();
			
			for( int i = 0; i < Textures.Count; i++ ) {
				CachedTexture tex = Textures[i];
				api.DeleteTexture( ref tex.TexID );
				Textures[i] = tex;
			}
			api.DeleteDynamicVb( vb );
		}
		
		void InitModel( ref CachedModel m ) {
			m.Instance.CreateParts();
			m.Initalised = true;
		}
		
		void RegisterDefaultModels() {
			RegisterTextures( "char.png", "chicken.png", "creeper.png", "pig.png", "sheep.png",
			                 "sheep_fur.png", "skeleton.png", "spider.png", "zombie.png" );
			
			Register( "humanoid", "char.png", new HumanoidModel( game ) );
			CachedModel human = Models[0];
			InitModel( ref human );
			Models[0] = human;
			
			Register( "chicken", "chicken.png", new ChickenModel( game ) );
			Register( "creeper", "creeper.png", new CreeperModel( game ) );
			Register( "pig", "pig.png", new PigModel( game ) );
			Register( "sheep", "sheep.png", new SheepModel( game ) );
			Register( "skeleton", "skeleton.png", new SkeletonModel( game ) );
			Register( "spider", "spider.png", new SpiderModel( game ) );
			Register( "zombie", "zombie.png", new ZombieModel( game ) );
			
			Register( "block", null, new BlockModel( game ) );
			Register( "chibi", "char.png", new ChibiModel( game ) );
			Register( "giant", "char.png", new GiantModel( game ) );
		}

		void TextureChanged( object sender, TextureEventArgs e ) {
			for( int i = 0; i < Textures.Count; i++ ) {
				CachedTexture tex = Textures[i];
				if( tex.Name != e.Name ) continue;
				
				game.UpdateTexture( ref tex.TexID, e.Name, e.Data, e.Name == "char.png" );
				Textures[i] = tex; break;
			}
		}
	}
	
	public struct CachedModel {
		public string Name;
		public IModel Instance;
		public bool Initalised;
	}
	
	public struct CachedTexture {
		public string Name;
		public int TexID;
	}
}