using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;

namespace MbUnit.ReSharperRunner
{
    public class PlugInAssemblyResolver
    {
        public Assembly ResolveAssembly(object sender, ResolveEventArgs args)
        {
            return ResolveAssembly(args.Name);
        }

        private static Assembly ResolveAssembly(string assemblyName)
        {
            string[] fileNames = GetFilenames(assemblyName);
            List<string> paths = new List<string>();
            paths.Add(Environment.CurrentDirectory);
            paths.Add(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location));
            foreach (string path in paths)
            {
                foreach (string fileName in fileNames)
                {
                    string assemblyFile = Path.Combine(path, fileName);
                    if (File.Exists(assemblyFile))
                    {
                        return Assembly.LoadFrom(assemblyFile);
                    }
                }
            }
            return null;
        }

        private static string[] GetFilenames(string name)
        {
            List<string> fileNames = new List<string>();
            string[] nameSegments = name.Split(new char[] {','});
            fileNames.Add(Path.GetFileName(nameSegments[0]));
            fileNames.Add(Path.GetFileName(nameSegments[0]) + ".dll");
            fileNames.Add(Path.GetFileNameWithoutExtension(nameSegments[0]) + ".dll");
            fileNames.Add(Path.GetFileNameWithoutExtension(nameSegments[0]) + ".exe");
            fileNames.Add(Path.GetFileName(nameSegments[0]) + ".exe");
            fileNames.Add(nameSegments[0]);
            return fileNames.ToArray();
        }
    }
}