#region Copyright & License Information
/*
 * Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
 * This file is part of OpenRA, which is free software. It is made
 * available to you under the terms of the GNU General Public License
 * as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version. For more
 * information, see COPYING.
 */
#endregion

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using OpenRA.FileSystem;

namespace OpenRA.Graphics
{
	public static class VoxelProvider
	{
		static Dictionary<string, Dictionary<string, Voxel>> units;

		public static void Initialize(VoxelLoader loader, IReadOnlyFileSystem fileSystem, List<MiniYamlNode> sequences)
		{
			units = new Dictionary<string, Dictionary<string, Voxel>>();
			foreach (var s in sequences)
				LoadVoxelsForUnit(loader, s.Key, s.Value);

			loader.RefreshBuffer();
		}

		static Voxel LoadVoxel(VoxelLoader voxelLoader, string unit, MiniYaml info)
		{
			var vxl = unit;
			var hva = unit;
			if (info.Value != null)
			{
				var fields = info.Value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
				if (fields.Length >= 1)
					vxl = hva = fields[0].Trim();

				if (fields.Length >= 2)
					hva = fields[1].Trim();
			}

			return voxelLoader.Load(vxl, hva);
		}

		static void LoadVoxelsForUnit(VoxelLoader loader, string unit, MiniYaml sequences)
		{
			Game.ModData.LoadScreen.Display();
			try
			{
				var seq = sequences.ToDictionary(my => LoadVoxel(loader, unit, my));
				units.Add(unit, seq);
			}
			catch (FileNotFoundException) { } // Do nothing; we can crash later if we actually wanted art
		}

		public static Voxel GetVoxel(string unitName, string voxelName)
		{
			try { return units[unitName][voxelName]; }
			catch (KeyNotFoundException)
			{
				if (units.ContainsKey(unitName))
					throw new InvalidOperationException(
						"Unit `{0}` does not have a voxel `{1}`".F(unitName, voxelName));
				else
					throw new InvalidOperationException(
						"Unit `{0}` does not have any voxels defined.".F(unitName));
			}
		}

		public static bool HasVoxel(string unit, string seq)
		{
			if (!units.ContainsKey(unit))
				throw new InvalidOperationException(
					"Unit `{0}` does not have any voxels defined.".F(unit));

			return units[unit].ContainsKey(seq);
		}
	}
}