using Amazon.Runtime;
using Amazon.S3;
using Amazon.S3.Transfer;
using Amazon;
using Amazon.S3.Model;
using Dapper;
using Microsoft.AspNetCore.JsonPatch;
using MisIngredientesVue.Core.Exceptions;
using MisIngredientesVue.Core.Extensions;
using MisIngredientesVue.Core.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MisIngredientesVue.Core.Services
{
    public interface IFileStorageService
    {
        Task SaveFile(string id, string folder, byte[] contents);
        Task<byte[]> LoadFile(string id, string folder);
        Task<bool> FileExists(string id, string folder);
    }

    public class FileStorageService : IFileStorageService
    {
        AmazonS3Client _s3Client;

        public FileStorageService() {
            _s3Client = new AmazonS3Client("AKIAIIQHM2OQTAIIL62A", "jPlXrQqtAVQgwM5VSyS613BhwHNG6mC8PJwzcbfn", Amazon.RegionEndpoint.USEast1);
        }

        public async Task SaveFile(string id, string folder, byte[] contents)
        {
            using (var memStream = new MemoryStream(contents))
            { 
                memStream.Position = 0;
                var fileTransferUtility = new TransferUtility(_s3Client);
                await fileTransferUtility.UploadAsync(memStream, folder, id);
            }
                
        }

        public async Task<bool> FileExists(string id, string folder)
        {
            try
            {
                var response = await _s3Client.GetObjectMetadataAsync(new GetObjectMetadataRequest()
                {
                    BucketName = folder,
                    Key = id
                });

                return true;
            }

            catch (Amazon.S3.AmazonS3Exception ex)
            {
                if (ex.StatusCode == System.Net.HttpStatusCode.NotFound)
                    return false;

                //status wasn't not found, so throw the exception
                throw;
            }
        }

        public async Task<byte[]> LoadFile(string id, string folder)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                byte[] buffer = new byte[16 * 1024];

                var fileTransferUtility = new TransferUtility(_s3Client);
                var stream = await fileTransferUtility.OpenStreamAsync(folder, id);

                int read;
                while ((read = stream.Read(buffer, 0, buffer.Length)) > 0)
                {
                    ms.Write(buffer, 0, read);
                }
                return ms.ToArray();
            }

        }
    }
}