using System;
using System.Collections.Generic;
using Mono.Cecil;

namespace ModTool.Shared
{
	
	public class AssemblyResolver : DefaultAssemblyResolver
	{
		private Dictionary<string, AssemblyDefinition> cache;

		private ReaderParameters parameters;

		public AssemblyResolver()
		{
			cache = new Dictionary<string, AssemblyDefinition>();

			parameters = new ReaderParameters()
			{
				AssemblyResolver = this,
				InMemory = true
			};
		}

		public override AssemblyDefinition Resolve(AssemblyNameReference name)
		{
			AssemblyDefinition assemblyDefinition;

			if (cache.TryGetValue(name.Name, out assemblyDefinition))
				return assemblyDefinition;

			foreach (var assembly in AppDomain.CurrentDomain.GetAssemblies())
			{
				if(assembly.GetName().Name == name.Name)
				{
					string location = assembly.Location;

					assemblyDefinition = GetAssembly(location, parameters);

					cache.Add(name.Name, assemblyDefinition);

					return assemblyDefinition;
				}
			}

			return base.Resolve(name);
		}

		protected virtual AssemblyDefinition GetAssembly(string location, ReaderParameters parameters)
		{
			return ModuleDefinition.ReadModule(location, parameters).Assembly;
		}

		protected override void Dispose(bool disposing)
		{
			foreach (var assembly in cache.Values)
				assembly.Dispose();

			cache.Clear();

			base.Dispose(disposing);
		}
	}
	
}