using System;
using System.IO;
using System.Threading.Tasks;
using GenHTTP.Api.Content.IO;
using GenHTTP.Api.Protocol;

namespace PRSServer
{
    public class ByteArrayResource : IResource
    {
        public ByteArrayResource(byte[] content, string? name, FlexibleContentType? contentType, DateTime? modified)
        {
            Content = content;
            Checksum = (ulong)content.GetHashCode();

            Name = name;
            ContentType = contentType ?? FlexibleContentType.Get(GenHTTP.Api.Protocol.ContentType.TextPlain);
            Modified = modified;
        }

        public byte[] Content { get; }

        private ulong Checksum { get; }

        public string? Name { get; }

        public DateTime? Modified { get; }

        public FlexibleContentType? ContentType { get; }

        public ulong? Length => (ulong)Content.Length;

        public ValueTask<Stream> GetContentAsync()
        {
            return new ValueTask<Stream>(new MemoryStream(Content, false));
        }

        public ValueTask<ulong> CalculateChecksumAsync()
        {
            return new ValueTask<ulong>(Checksum);
        }

        public ValueTask WriteAsync(Stream target, uint bufferSize)
        {
            return target.WriteAsync(Content.AsMemory());
        }
    }
}