// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using System.Drawing;
using ClassicalSharp.Entities;
using ClassicalSharp.GraphicsAPI;
using ClassicalSharp.Gui.Widgets;
#if ANDROID
using Android.Graphics;
#endif

namespace ClassicalSharp.Gui.Screens {
	public class FpsScreen : Screen, IGameComponent {
		
		Font font, posFont;
		StringBuffer text;
		
		public FpsScreen( Game game ) : base( game ) {
			text = new StringBuffer( 128 );
		}

		public void Init( Game game ) { }
		public void Ready( Game game) { Init(); }
		public void Reset( Game game ) { }
		public void OnNewMap( Game game ) { }
		public void OnNewMapLoaded( Game game ) { }
		
		TextWidget fpsText, hackStates;
		TextAtlas posAtlas;
		public override void Render( double delta ) {
			UpdateFPS( delta );
			if( game.HideGui || !game.ShowFPS ) return;
			
			gfx.Texturing = true;
			fpsText.Render( delta );
			if( !game.ClassicMode && game.Gui.activeScreen == null ) {
				UpdateHackState( false );
				DrawPosition();
				hackStates.Render( delta );
			}
			gfx.Texturing = false;
		}
		
		double accumulator;
		int frames, totalSeconds;
		
		void UpdateFPS( double delta ) {
			frames++;
			accumulator += delta;
			if( accumulator < 1 ) return;
			
			int index = 0;
			totalSeconds++;
			int fps = (int)(frames / accumulator);
			
			text.Clear()
				.AppendNum( ref index, fps ).Append( ref index, " fps, " );
			if( game.ClassicMode ) {
				text.AppendNum( ref index, game.ChunkUpdates ).Append( ref index, " chunk updates" );
			} else {
				text.AppendNum( ref index, game.ChunkUpdates ).Append( ref index, " chunks/s, " )
					.AppendNum( ref index, game.Vertices ).Append( ref index, " vertices" );
			}
			
			string textString = text.ToString();
			fpsText.SetText( textString );
			accumulator = 0;
			frames = 0;
			game.ChunkUpdates = 0;
		}
		
		string Q( int value ) { return value == 1 ? "" : "s"; }
		
		public override void Init() {
			font = new Font( game.FontName, 14 );
			posFont = new Font( game.FontName, 14, FontStyle.Italic );
			game.Events.ChatFontChanged += ChatFontChanged;
			
			fpsText = new ChatTextWidget( game, font );
			fpsText.XOffset = 2;
			fpsText.YOffset = 2;
			fpsText.ReducePadding = true;
			fpsText.Init();
			
			string msg = text.Length > 0 ? text.ToString() : "FPS: no data yet";
			fpsText.SetText( msg );
			posAtlas = new TextAtlas( game );
			posAtlas.Pack( "0123456789-, ()", posFont, "Feet pos: " );
			posAtlas.tex.Y = (short)(fpsText.Height + 2);
			
			hackStates = new ChatTextWidget( game, posFont );
			hackStates.XOffset = 2;
			hackStates.YOffset = fpsText.Height + posAtlas.tex.Height + 2;
			hackStates.ReducePadding = true;
			hackStates.Init();
			UpdateHackState( true );
		}
		
		public override void Dispose() {
			font.Dispose();
			posFont.Dispose();
			fpsText.Dispose();
			
			posAtlas.Dispose();
			hackStates.Dispose();
			game.Events.ChatFontChanged -= ChatFontChanged;
		}
		
		void ChatFontChanged( object sender, EventArgs e ) { Recreate(); }
		
		public override void OnResize( int width, int height ) { }
		
		void DrawPosition() {
			int index = 0;
			Texture tex = posAtlas.tex;
			tex.X1 = 2; tex.Width = (short)posAtlas.offset;
			IGraphicsApi.Make2DQuad( ref tex, FastColour.WhitePacked, 
			                        game.ModelCache.vertices, ref index );
			
			Vector3I pos = Vector3I.Floor( game.LocalPlayer.Position );
			posAtlas.curX = posAtlas.offset + 2;
			VertexP3fT2fC4b[] vertices = game.ModelCache.vertices;
			
			posAtlas.Add( 13, vertices, ref index );
			posAtlas.AddInt( pos.X, vertices, ref index );
			posAtlas.Add( 11, vertices, ref index );
			posAtlas.AddInt( pos.Y, vertices, ref index );
			posAtlas.Add( 11, vertices, ref index );
			posAtlas.AddInt( pos.Z, vertices, ref index );
			posAtlas.Add( 14, vertices, ref index );
			
			gfx.BindTexture( posAtlas.tex.ID );
			gfx.UpdateDynamicIndexedVb( DrawMode.Triangles,
			                           game.ModelCache.vb, game.ModelCache.vertices, index );
		}
		
		bool speeding, halfSpeeding, noclip, fly;
		int lastFov;
		void UpdateHackState( bool force ) {
			HacksComponent hacks = game.LocalPlayer.Hacks;
			if( force || hacks.Speeding != speeding || hacks.HalfSpeeding != halfSpeeding || hacks.Noclip != noclip ||
			   hacks.Flying != fly || game.Fov != lastFov ) {
				speeding = hacks.Speeding; halfSpeeding = hacks.HalfSpeeding; noclip = hacks.Noclip; fly = hacks.Flying;
				lastFov = game.Fov;
				int index = 0;
				text.Clear();
				
				if( game.Fov != game.DefaultFov ) text.Append( ref index, "Zoom fov " )
					.AppendNum( ref index, lastFov ).Append( ref index, "  " );
				if( fly ) text.Append( ref index, "Fly ON   " );
				
				bool speed = (speeding || halfSpeeding) &&
					(hacks.CanSpeed || hacks.MaxSpeedMultiplier > 1);
				if( speed ) text.Append( ref index, "Speed ON   " );
				if( noclip ) text.Append( ref index, "Noclip ON   " );
				hackStates.SetText( text.ToString() );
			}
		}
	}
}