using EnvelopeGenerator.Application.Common.Extensions;
using Microsoft.Extensions.Caching.Memory;

namespace EnvelopeGenerator.Application.Common.Extensions;

/// <summary>
/// 
/// </summary>
public static class MemoryCacheExtensions
{
    private static readonly Guid BaseId = Guid.NewGuid();

    /// <summary>
    /// 
    /// </summary>
    /// <typeparam name="TEnum"></typeparam>
    /// <param name="memoryCache"></param>
    /// <param name="key"></param>
    /// <param name="ignores"></param>
    /// <returns></returns>
    /// <exception cref="InvalidOperationException"></exception>
    public static IDictionary<string, int> GetEnumAsDictionary<TEnum>(this IMemoryCache memoryCache, string key = "", params object[] ignores)
        where TEnum : Enum
        => memoryCache.GetOrCreate(BaseId + typeof(TEnum).FullName + key, _ =>
        {
            var mergedIgnores = new List<TEnum>();

            foreach (var ignore in ignores)
            {
                if (ignore is IEnumerable<TEnum> ignoreList)
                    mergedIgnores.AddRange(ignoreList);
                else if (ignore is TEnum ignoreVal)
                    mergedIgnores.Add(ignoreVal);
            }

            return Enum.GetValues(typeof(TEnum))
                   .Cast<TEnum>()
                   .Where(e => !mergedIgnores.Contains(e))
                   .ToDictionary(e => e.ToString(), e => Convert.ToInt32(e));
        })
           ?? throw new InvalidOperationException($"Failed to cache or retrieve enum dictionary for type '{typeof(TEnum).FullName}'.");
}