FictionArchive/FictionArchive.Service.FileService/Controllers/S3ProxyController.cs

using System.Web;
using Amazon.S3;
using Amazon.S3.Model;
using FictionArchive.Service.FileService.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;

namespace FictionArchive.Service.FileService.Controllers
{
    [Route("api/{*path}")]
    [ApiController]
    [Authorize]
    public class S3ProxyController : ControllerBase
    {
        private readonly AmazonS3Client _amazonS3Client;
        private readonly S3Configuration _s3Configuration;

        public S3ProxyController(AmazonS3Client amazonS3Client, IOptions<S3Configuration> s3Configuration)
        {
            _amazonS3Client = amazonS3Client;
            _s3Configuration = s3Configuration.Value;
        }

        [HttpGet]
        public async Task<IActionResult> Get(string path)
        {
            var decodedPath = HttpUtility.UrlDecode(path);

            try
            {
                var s3Response = await _amazonS3Client.GetObjectAsync(new GetObjectRequest()
                {
                    BucketName = _s3Configuration.Bucket,
                    Key = decodedPath
                });
                
                Response.Headers.CacheControl = "public, max-age=604800"; // 7 days
                Response.Headers.LastModified = s3Response.LastModified?.ToString("R");

                if (!string.IsNullOrEmpty(s3Response.ETag))
                {
                    Response.Headers.ETag = s3Response.ETag;
                }

                return File(s3Response.ResponseStream, s3Response.Headers.ContentType);
            }
            catch (AmazonS3Exception e)
            {
                if (e.Message == "Key not found")
                {
                    return NotFound();
                }
                throw;
            }
        }
    }
}