// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using ClassicalSharp.Physics;
using OpenTK;

namespace ClassicalSharp {
	
	/// <summary> Shared helper class for respawning an entity. </summary>
	public static class Respawn {

		public static float HighestFreeY( Game game, ref AABB bb ) {
			int minX = Utils.Floor( bb.Min.X ), maxX = Utils.Floor( bb.Max.X );
			int minY = Utils.Floor( bb.Min.Y ), maxY = Utils.Floor( bb.Max.Y );
			int minZ = Utils.Floor( bb.Min.Z ), maxZ = Utils.Floor( bb.Max.Z );
			
			BlockInfo info = game.BlockInfo;
			float spawnY = float.NegativeInfinity;
			AABB blockBB = default(AABB);
			
			for( int y = minY; y <= maxY; y++ )
				for( int z = minZ; z <= maxZ; z++ )
					for ( int x = minX; x <= maxX; x++ )
			{
				byte block = game.World.GetPhysicsBlock( x, y, z );
				blockBB.Min = new Vector3( x, y, z ) + info.MinBB[block];
				blockBB.Max = new Vector3( x, y, z ) + info.MaxBB[block];
				
				if( info.Collide[block] != CollideType.Solid ) continue;
				if( !bb.Intersects( blockBB ) ) continue;				
				spawnY = Math.Max( spawnY, blockBB.Max.Y );
			}
			return spawnY;
		}
	}
}