using System;
using System.ComponentModel;
using System.Globalization;
using System.Resources;
using System.Collections.Generic;

namespace CKAN.GUI
{
    // Thanks and credit to this guy: https://stackoverflow.com/q/1952638/2422988

    internal class SingleAssemblyComponentResourceManager : ComponentResourceManager
    {
        public SingleAssemblyComponentResourceManager(Type t) : base(t)
        {
            contextTypeInfo = t;
        }

        protected override ResourceSet? InternalGetResourceSet(CultureInfo culture,
            bool createIfNotExists, bool tryParents)
        {
            if (!myResourceSets.TryGetValue(culture, out ResourceSet? rs) && createIfNotExists && MainAssembly != null)
            {
                // Lazy-load default language (without caring about duplicate assignment in race conditions, no harm done)
                neutralResourcesCulture ??= GetNeutralResourcesLanguage(MainAssembly);

                // If we're asking for the default language, then ask for the
                // invariant (non-specific) resources.
                if (neutralResourcesCulture.Equals(culture))
                {
                    culture = CultureInfo.InvariantCulture;
                }
                string resourceFileName = GetResourceFileName(culture);

                var store = MainAssembly.GetManifestResourceStream(contextTypeInfo, resourceFileName);

                // If we found the appropriate resources in the local assembly
                if (store != null)
                {
                    rs = new ResourceSet(store);
                    // Save for later
                    myResourceSets.Add(culture, rs);
                }
                else
                {
                    rs = base.InternalGetResourceSet(culture, createIfNotExists, tryParents);
                }
            }
            return rs;
        }

        private readonly Type contextTypeInfo;
        private CultureInfo? neutralResourcesCulture;
        private readonly Dictionary<CultureInfo, ResourceSet> myResourceSets = new Dictionary<CultureInfo, ResourceSet>();
    }
}