using System.Collections.Generic;

using RobocraftX.Blocks;
using RobocraftX.Common;
using RobocraftX.GUI.Hotbar.Colours;
using Svelto.DataStructures;
using Svelto.ECS;

using GamecraftModdingAPI.Engines;

namespace GamecraftModdingAPI.Blocks
{
	/// <summary>
	/// Engine for executing general block actions
	/// </summary>
	public class BlockEngine : IApiEngine
	{
		public string Name { get; } = "GamecraftModdingAPIBlockGameEngine";

		public EntitiesDB entitiesDB { set; private get; }

		public bool isRemovable => false;

		public void Dispose()
		{
		}

		public void Ready()
		{
		}

		public Block[] GetConnectedBlocks(EGID blockID)
		{
			if (!BlockExists(blockID)) return new Block[0];
			Stack<uint> cubeStack = new Stack<uint>();
			FasterList<uint> cubesToProcess = new FasterList<uint>();
			ConnectedCubesUtility.TreeTraversal.GetConnectedCubes(entitiesDB, blockID.entityID, cubeStack, cubesToProcess, (in GridConnectionsEntityStruct g) => { return false; });
			var ret = new Block[cubesToProcess.count];
			for (int i = 0; i < cubesToProcess.count; i++)
				ret[i] = new Block(cubesToProcess[i]);
			return ret;
		}

		public void SetBlockColorFromPalette(ref ColourParameterEntityStruct color)
		{
			ref var paletteEntry = ref entitiesDB.QueryEntity<PaletteEntryEntityStruct>(color.indexInPalette,
				CommonExclusiveGroups.COLOUR_PALETTE_GROUP);
			color.paletteColour = paletteEntry.Colour;
		}

		/// <summary>
		/// Get a struct of a block. Can be used to set properties.
		/// Returns a default value if not found.
		/// </summary>
		/// <param name="blockID">The block's ID</param>
		/// <typeparam name="T">The struct to query</typeparam>
		/// <returns>An editable reference to the struct</returns>
		public ref T GetBlockInfo<T>(EGID blockID) where T : struct, IEntityComponent
		{
			if (entitiesDB.Exists<T>(blockID))
				return ref entitiesDB.QueryEntity<T>(blockID);
			T[] structHolder = new T[1]; //Create something that can be referenced
			return ref structHolder[0]; //Gets a default value automatically
		}

		/// <summary>
		/// Get a struct of a block. Can be used to set properties.
		/// Returns a default value if not found.
		/// </summary>
		/// <param name="blockID">The block's ID</param>
		/// <param name="exists">Whether the specified struct exists for the block</param>
		/// <typeparam name="T">The struct to query</typeparam>
		/// <returns>An editable reference to the struct</returns>
		public ref T GetBlockInfo<T>(EGID blockID, out bool exists) where T : struct, IEntityComponent
		{
			exists = entitiesDB.Exists<T>(blockID);
			if (exists)
				return ref entitiesDB.QueryEntity<T>(blockID);
			T[] structHolder = new T[1];
			//ref T defRef = ref structHolder[0];
			return ref structHolder[0];
		}

		public bool BlockExists(EGID id)
		{
			return entitiesDB.Exists<DBEntityStruct>(id);
		}

		public bool GetBlockInfoExists<T>(EGID blockID) where T : struct, IEntityComponent
		{
			return entitiesDB.Exists<T>(blockID);
		}

#if DEBUG
		public EntitiesDB GetEntitiesDB()
		{
			return entitiesDB;
		}
#endif
	}
}