encapsulate file storage, also handle Pastebin rate limits in JSON validator

13 files changed, 306 insertions, 212 deletions

diff --git a/src/SMAPI.Web/Controllers/JsonValidatorController.cs b/src/SMAPI.Web/Controllers/JsonValidatorController.cs
index 40599abc..830fe839 100644
--- a/src/SMAPI.Web/Controllers/JsonValidatorController.cs
+++ b/src/SMAPI.Web/Controllers/JsonValidatorController.cs
@@ -9,8 +9,7 @@ using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using Newtonsoft.Json.Schema;
 using StardewModdingAPI.Web.Framework;
-using StardewModdingAPI.Web.Framework.Clients.Pastebin;
-using StardewModdingAPI.Web.Framework.Compression;
+using StardewModdingAPI.Web.Framework.Storage;
 using StardewModdingAPI.Web.ViewModels.JsonValidator;
 
 namespace StardewModdingAPI.Web.Controllers
@@ -21,11 +20,8 @@ namespace StardewModdingAPI.Web.Controllers
         /*********
         ** Fields
         *********/
-        /// <summary>The underlying Pastebin client.</summary>
-        private readonly IPastebinClient Pastebin;
-
-        /// <summary>The underlying text compression helper.</summary>
-        private readonly IGzipHelper GzipHelper;
+        /// <summary>Provides access to raw data storage.</summary>
+        private readonly IStorageProvider Storage;
 
         /// <summary>The supported JSON schemas (names indexed by ID).</summary>
         private readonly IDictionary<string, string> SchemaFormats = new Dictionary<string, string>
@@ -49,12 +45,10 @@ namespace StardewModdingAPI.Web.Controllers
         ** Constructor
         ***/
         /// <summary>Construct an instance.</summary>
-        /// <param name="pastebin">The Pastebin API client.</param>
-        /// <param name="gzipHelper">The underlying text compression helper.</param>
-        public JsonValidatorController(IPastebinClient pastebin, IGzipHelper gzipHelper)
+        /// <param name="storage">Provides access to raw data storage.</param>
+        public JsonValidatorController(IStorageProvider storage)
         {
-            this.Pastebin = pastebin;
-            this.GzipHelper = gzipHelper;
+            this.Storage = storage;
         }
 
         /***
@@ -62,7 +56,7 @@ namespace StardewModdingAPI.Web.Controllers
         ***/
         /// <summary>Render the schema validator UI.</summary>
         /// <param name="schemaName">The schema name with which to validate the JSON.</param>
-        /// <param name="id">The paste ID.</param>
+        /// <param name="id">The stored file ID.</param>
         [HttpGet]
         [Route("json")]
         [Route("json/{schemaName}")]
@@ -76,16 +70,16 @@ namespace StardewModdingAPI.Web.Controllers
                 return this.View("Index", result);
 
             // fetch raw JSON
-            PasteInfo paste = await this.GetAsync(id);
-            if (string.IsNullOrWhiteSpace(paste.Content))
+            StoredFileInfo file = await this.Storage.GetAsync(id);
+            if (string.IsNullOrWhiteSpace(file.Content))
                 return this.View("Index", result.SetUploadError("The JSON file seems to be empty."));
-            result.SetContent(paste.Content);
+            result.SetContent(file.Content, expiry: file.Expiry, uploadWarning: file.Warning);
 
             // parse JSON
             JToken parsed;
             try
             {
-                parsed = JToken.Parse(paste.Content, new JsonLoadSettings
+                parsed = JToken.Parse(file.Content, new JsonLoadSettings
                 {
                     DuplicatePropertyNameHandling = DuplicatePropertyNameHandling.Error,
                     CommentHandling = CommentHandling.Load
@@ -97,7 +91,7 @@ namespace StardewModdingAPI.Web.Controllers
             }
 
             // format JSON
-            result.SetContent(parsed.ToString(Formatting.Indented));
+            result.SetContent(parsed.ToString(Formatting.Indented), expiry: file.Expiry, uploadWarning: file.Warning);
 
             // skip if no schema selected
             if (schemaName == "none")
@@ -132,23 +126,20 @@ namespace StardewModdingAPI.Web.Controllers
         public async Task<ActionResult> PostAsync(JsonValidatorRequestModel request)
         {
             if (request == null)
-                return this.View("Index", new JsonValidatorModel(null, null, this.SchemaFormats).SetUploadError("The request seems to be invalid."));
+                return this.View("Index", this.GetModel(null, null).SetUploadError("The request seems to be invalid."));
 
             // normalize schema name
             string schemaName = this.NormalizeSchemaName(request.SchemaName);
 
-            // get raw log text
+            // get raw text
             string input = request.Content;
             if (string.IsNullOrWhiteSpace(input))
-                return this.View("Index", new JsonValidatorModel(null, schemaName, this.SchemaFormats).SetUploadError("The JSON file seems to be empty."));
-
-            // upload log
-            input = this.GzipHelper.CompressString(input);
-            SavePasteResult result = await this.Pastebin.PostAsync($"JSON validator {DateTime.UtcNow:s}", input);
+                return this.View("Index", this.GetModel(null, schemaName).SetUploadError("The JSON file seems to be empty."));
 
-            // handle errors
-            if (!result.Success)
-                return this.View("Index", new JsonValidatorModel(result.ID, schemaName, this.SchemaFormats).SetUploadError($"Pastebin error: {result.Error ?? "unknown error"}"));
+            // upload file
+            var result = await this.Storage.SaveAsync(title: $"JSON validator {DateTime.UtcNow:s}", content: input, compress: true);
+            if (!result.Succeeded)
+                return this.View("Index", this.GetModel(result.ID, schemaName).SetUploadError(result.UploadError));
 
             // redirect to view
             return this.Redirect(this.Url.PlainAction("Index", "JsonValidator", new { schemaName = schemaName, id = result.ID }));
@@ -158,13 +149,12 @@ namespace StardewModdingAPI.Web.Controllers
         /*********
         ** Private methods
         *********/
-        /// <summary>Fetch raw text from Pastebin.</summary>
-        /// <param name="id">The Pastebin paste ID.</param>
-        private async Task<PasteInfo> GetAsync(string id)
+        /// <summary>Build a JSON validator model.</summary>
+        /// <param name="pasteID">The stored file ID.</param>
+        /// <param name="schemaName">The schema name with which the JSON was validated.</param>
+        private JsonValidatorModel GetModel(string pasteID, string schemaName)
         {
-            PasteInfo response = await this.Pastebin.GetAsync(id);
-            response.Content = this.GzipHelper.DecompressString(response.Content);
-            return response;
+            return new JsonValidatorModel(pasteID, schemaName, this.SchemaFormats);
         }
 
         /// <summary>Get a normalized schema name, or the <see cref="DefaultSchemaID"/> if blank.</summary>
diff --git a/src/SMAPI.Web/Controllers/LogParserController.cs b/src/SMAPI.Web/Controllers/LogParserController.cs
index 318b34d0..e270ae0a 100644
--- a/src/SMAPI.Web/Controllers/LogParserController.cs
+++ b/src/SMAPI.Web/Controllers/LogParserController.cs
@@ -1,22 +1,12 @@
 using System;
-using System.IO;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
-using Amazon;
-using Amazon.Runtime;
-using Amazon.S3;
-using Amazon.S3.Model;
-using Amazon.S3.Transfer;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.Options;
 using StardewModdingAPI.Toolkit.Utilities;
 using StardewModdingAPI.Web.Framework;
-using StardewModdingAPI.Web.Framework.Clients.Pastebin;
-using StardewModdingAPI.Web.Framework.Compression;
-using StardewModdingAPI.Web.Framework.ConfigModels;
 using StardewModdingAPI.Web.Framework.LogParsing;
 using StardewModdingAPI.Web.Framework.LogParsing.Models;
+using StardewModdingAPI.Web.Framework.Storage;
 using StardewModdingAPI.Web.ViewModels;
 
 namespace StardewModdingAPI.Web.Controllers
@@ -27,14 +17,8 @@ namespace StardewModdingAPI.Web.Controllers
         /*********
         ** Fields
         *********/
-        /// <summary>The API client settings.</summary>
-        private readonly ApiClientsConfig ClientsConfig;
-
-        /// <summary>The underlying Pastebin client.</summary>
-        private readonly IPastebinClient Pastebin;
-
-        /// <summary>The underlying text compression helper.</summary>
-        private readonly IGzipHelper GzipHelper;
+        /// <summary>Provides access to raw data storage.</summary>
+        private readonly IStorageProvider Storage;
 
 
         /*********
@@ -44,21 +28,17 @@ namespace StardewModdingAPI.Web.Controllers
         ** Constructor
         ***/
         /// <summary>Construct an instance.</summary>
-        /// <param name="clientsConfig">The API client settings.</param>
-        /// <param name="pastebin">The Pastebin API client.</param>
-        /// <param name="gzipHelper">The underlying text compression helper.</param>
-        public LogParserController(IOptions<ApiClientsConfig> clientsConfig, IPastebinClient pastebin, IGzipHelper gzipHelper)
+        /// <param name="storage">Provides access to raw data storage.</param>
+        public LogParserController(IStorageProvider storage)
         {
-            this.ClientsConfig = clientsConfig.Value;
-            this.Pastebin = pastebin;
-            this.GzipHelper = gzipHelper;
+            this.Storage = storage;
         }
 
         /***
         ** Web UI
         ***/
         /// <summary>Render the log parser UI.</summary>
-        /// <param name="id">The paste ID.</param>
+        /// <param name="id">The stored file ID.</param>
         /// <param name="raw">Whether to display the raw unparsed log.</param>
         [HttpGet]
         [Route("log")]
@@ -70,12 +50,12 @@ namespace StardewModdingAPI.Web.Controllers
                 return this.View("Index", this.GetModel(id));
 
             // log page
-            PasteInfo paste = await this.GetAsync(id);
-            ParsedLog log = paste.Success
-                ? new LogParser().Parse(paste.Content)
-                : new ParsedLog { IsValid = false, Error = paste.Error };
+            StoredFileInfo file = await this.Storage.GetAsync(id);
+            ParsedLog log = file.Success
+                ? new LogParser().Parse(file.Content)
+                : new ParsedLog { IsValid = false, Error = file.Error };
 
-            return this.View("Index", this.GetModel(id, uploadWarning: paste.Warning, expiry: paste.Expiry).SetResult(log, raw));
+            return this.View("Index", this.GetModel(id, uploadWarning: file.Warning, expiry: file.Expiry).SetResult(log, raw));
         }
 
         /***
@@ -92,8 +72,7 @@ namespace StardewModdingAPI.Web.Controllers
                 return this.View("Index", this.GetModel(null, uploadError: "The log file seems to be empty."));
 
             // upload log
-            input = this.GzipHelper.CompressString(input);
-            var uploadResult = await this.TrySaveLog(input);
+            UploadResult uploadResult = await this.Storage.SaveAsync(title: $"SMAPI log {DateTime.UtcNow:s}", content: input, compress: true);
             if (!uploadResult.Succeeded)
                 return this.View("Index", this.GetModel(null, uploadError: uploadResult.UploadError));
 
@@ -105,106 +84,8 @@ namespace StardewModdingAPI.Web.Controllers
         /*********
         ** Private methods
         *********/
-        /// <summary>Fetch raw text from Pastebin.</summary>
-        /// <param name="id">The Pastebin paste ID.</param>
-        private async Task<PasteInfo> GetAsync(string id)
-        {
-            // get from Amazon S3
-            if (Guid.TryParseExact(id, "N", out Guid _))
-            {
-                var credentials = new BasicAWSCredentials(accessKey: this.ClientsConfig.AmazonAccessKey, secretKey: this.ClientsConfig.AmazonSecretKey);
-
-                using (IAmazonS3 s3 = new AmazonS3Client(credentials, RegionEndpoint.GetBySystemName(this.ClientsConfig.AmazonRegion)))
-                {
-                    try
-                    {
-                        using (GetObjectResponse response = await s3.GetObjectAsync(this.ClientsConfig.AmazonLogBucket, $"logs/{id}"))
-                        using (Stream responseStream = response.ResponseStream)
-                        using (StreamReader reader = new StreamReader(responseStream))
-                        {
-                            DateTime expiry = response.Expiration.ExpiryDateUtc;
-                            string pastebinError = response.Metadata["x-amz-meta-pastebin-error"];
-                            string content = this.GzipHelper.DecompressString(reader.ReadToEnd());
-
-                            return new PasteInfo
-                            {
-                                Success = true,
-                                Content = content,
-                                Expiry = expiry,
-                                Warning = pastebinError
-                            };
-                        }
-                    }
-                    catch (AmazonServiceException ex)
-                    {
-                        return ex.ErrorCode == "NoSuchKey"
-                            ? new PasteInfo { Error = "There's no log with that ID." }
-                            : new PasteInfo { Error = $"Could not fetch that log from AWS S3 ({ex.ErrorCode}: {ex.Message})." };
-                    }
-                }
-            }
-
-            // get from PasteBin
-            else
-            {
-                PasteInfo response = await this.Pastebin.GetAsync(id);
-                response.Content = this.GzipHelper.DecompressString(response.Content);
-                return response;
-            }
-        }
-
-        /// <summary>Save a log to Pastebin or Amazon S3, if available.</summary>
-        /// <param name="content">The content to upload.</param>
-        /// <returns>Returns metadata about the save attempt.</returns>
-        private async Task<UploadResult> TrySaveLog(string content)
-        {
-            // save to PasteBin
-            string uploadError;
-            {
-                SavePasteResult result = await this.Pastebin.PostAsync($"SMAPI log {DateTime.UtcNow:s}", content);
-                if (result.Success)
-                    return new UploadResult(true, result.ID, null);
-
-                uploadError = $"Pastebin error: {result.Error ?? "unknown error"}";
-            }
-
-            // fallback to S3
-            try
-            {
-                var credentials = new BasicAWSCredentials(accessKey: this.ClientsConfig.AmazonAccessKey, secretKey: this.ClientsConfig.AmazonSecretKey);
-
-                using (Stream stream = new MemoryStream(Encoding.UTF8.GetBytes(content)))
-                using (IAmazonS3 s3 = new AmazonS3Client(credentials, RegionEndpoint.GetBySystemName(this.ClientsConfig.AmazonRegion)))
-                using (TransferUtility uploader = new TransferUtility(s3))
-                {
-                    string id = Guid.NewGuid().ToString("N");
-
-                    var uploadRequest = new TransferUtilityUploadRequest
-                    {
-                        BucketName = this.ClientsConfig.AmazonLogBucket,
-                        Key = $"logs/{id}",
-                        InputStream = stream,
-                        Metadata =
-                        {
-                            // note: AWS will lowercase keys and prefix 'x-amz-meta-'
-                            ["smapi-uploaded"] = DateTime.UtcNow.ToString("O"),
-                            ["pastebin-error"] = uploadError
-                        }
-                    };
-
-                    await uploader.UploadAsync(uploadRequest);
-
-                    return new UploadResult(true, id, uploadError);
-                }
-            }
-            catch (Exception ex)
-            {
-                return new UploadResult(false, null, $"{uploadError}\n{ex.Message}");
-            }
-        }
-
         /// <summary>Build a log parser model.</summary>
-        /// <param name="pasteID">The paste ID.</param>
+        /// <param name="pasteID">The stored file ID.</param>
         /// <param name="expiry">When the uploaded file will no longer be available.</param>
         /// <param name="uploadWarning">A non-blocking warning while uploading the log.</param>
         /// <param name="uploadError">An error which occurred while uploading the log.</param>
@@ -243,36 +124,5 @@ namespace StardewModdingAPI.Web.Controllers
                     return null;
             }
         }
-
-        /// <summary>The result of an attempt to upload a file.</summary>
-        private class UploadResult
-        {
-            /*********
-            ** Accessors
-            *********/
-            /// <summary>Whether the file upload succeeded.</summary>
-            public bool Succeeded { get; }
-
-            /// <summary>The file ID, if applicable.</summary>
-            public string ID { get; }
-
-            /// <summary>The upload error, if any.</summary>
-            public string UploadError { get; }
-
-
-            /*********
-            ** Public methods
-            *********/
-            /// <summary>Construct an instance.</summary>
-            /// <param name="succeeded">Whether the file upload succeeded.</param>
-            /// <param name="id">The file ID, if applicable.</param>
-            /// <param name="uploadError">The upload error, if any.</param>
-            public UploadResult(bool succeeded, string id, string uploadError)
-            {
-                this.Succeeded = succeeded;
-                this.ID = id;
-                this.UploadError = uploadError;
-            }
-        }
     }
 }
diff --git a/src/SMAPI.Web/Framework/Clients/Pastebin/PasteInfo.cs b/src/SMAPI.Web/Framework/Clients/Pastebin/PasteInfo.cs
index bb2de356..1ef3ef12 100644
--- a/src/SMAPI.Web/Framework/Clients/Pastebin/PasteInfo.cs
+++ b/src/SMAPI.Web/Framework/Clients/Pastebin/PasteInfo.cs
@@ -11,12 +11,6 @@ namespace StardewModdingAPI.Web.Framework.Clients.Pastebin
         /// <summary>The fetched paste content (if <see cref="Success"/> is <c>true</c>).</summary>
         public string Content { get; set; }
 
-        /// <summary>When the file will no longer be available.</summary>
-        public DateTime? Expiry { get; set; }
-
-        /// <summary>The error message if saving succeeded, but a non-blocking issue was encountered.</summary>
-        public string Warning { get; set; }
-
         /// <summary>The error message if saving failed.</summary>
         public string Error { get; set; }
     }
diff --git a/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs b/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs
index 7119ef03..1e020840 100644
--- a/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs
+++ b/src/SMAPI.Web/Framework/ConfigModels/ApiClientsConfig.cs
@@ -26,7 +26,7 @@ namespace StardewModdingAPI.Web.Framework.ConfigModels
         public string AmazonRegion { get; set; }
 
         /// <summary>The AWS bucket in which to store temporary uploaded logs.</summary>
-        public string AmazonLogBucket { get; set; }
+        public string AmazonTempBucket { get; set; }
 
 
         /****
diff --git a/src/SMAPI.Web/Framework/Storage/IStorageProvider.cs b/src/SMAPI.Web/Framework/Storage/IStorageProvider.cs
new file mode 100644
index 00000000..e222a235
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Storage/IStorageProvider.cs
@@ -0,0 +1,19 @@
+using System.Threading.Tasks;
+
+namespace StardewModdingAPI.Web.Framework.Storage
+{
+    /// <summary>Provides access to raw data storage.</summary>
+    internal interface IStorageProvider
+    {
+        /// <summary>Save a text file to Pastebin or Amazon S3, if available.</summary>
+        /// <param name="title">The display title, if applicable.</param>
+        /// <param name="content">The content to upload.</param>
+        /// <param name="compress">Whether to gzip the text.</param>
+        /// <returns>Returns metadata about the save attempt.</returns>
+        Task<UploadResult> SaveAsync(string title, string content, bool compress = true);
+
+        /// <summary>Fetch raw text from storage.</summary>
+        /// <param name="id">The storage ID returned by <see cref="SaveAsync"/>.</param>
+        Task<StoredFileInfo> GetAsync(string id);
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Storage/StorageProvider.cs b/src/SMAPI.Web/Framework/Storage/StorageProvider.cs
new file mode 100644
index 00000000..bbb6e06b
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Storage/StorageProvider.cs
@@ -0,0 +1,147 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Threading.Tasks;
+using Amazon;
+using Amazon.Runtime;
+using Amazon.S3;
+using Amazon.S3.Model;
+using Amazon.S3.Transfer;
+using Microsoft.Extensions.Options;
+using StardewModdingAPI.Web.Framework.Clients.Pastebin;
+using StardewModdingAPI.Web.Framework.Compression;
+using StardewModdingAPI.Web.Framework.ConfigModels;
+
+namespace StardewModdingAPI.Web.Framework.Storage
+{
+    /// <summary>Provides access to raw data storage.</summary>
+    internal class StorageProvider : IStorageProvider
+    {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>The API client settings.</summary>
+        private readonly ApiClientsConfig ClientsConfig;
+
+        /// <summary>The underlying Pastebin client.</summary>
+        private readonly IPastebinClient Pastebin;
+
+        /// <summary>The underlying text compression helper.</summary>
+        private readonly IGzipHelper GzipHelper;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="clientsConfig">The API client settings.</param>
+        /// <param name="pastebin">The underlying Pastebin client.</param>
+        /// <param name="gzipHelper">The underlying text compression helper.</param>
+        public StorageProvider(IOptions<ApiClientsConfig> clientsConfig, IPastebinClient pastebin, IGzipHelper gzipHelper)
+        {
+            this.ClientsConfig = clientsConfig.Value;
+            this.Pastebin = pastebin;
+            this.GzipHelper = gzipHelper;
+        }
+
+        /// <summary>Save a text file to Pastebin or Amazon S3, if available.</summary>
+        /// <param name="title">The display title, if applicable.</param>
+        /// <param name="content">The content to upload.</param>
+        /// <param name="compress">Whether to gzip the text.</param>
+        /// <returns>Returns metadata about the save attempt.</returns>
+        public async Task<UploadResult> SaveAsync(string title, string content, bool compress = true)
+        {
+            // save to PasteBin
+            string uploadError;
+            {
+                SavePasteResult result = await this.Pastebin.PostAsync(title, content);
+                if (result.Success)
+                    return new UploadResult(true, result.ID, null);
+
+                uploadError = $"Pastebin error: {result.Error ?? "unknown error"}";
+            }
+
+            // fallback to S3
+            try
+            {
+                var credentials = new BasicAWSCredentials(accessKey: this.ClientsConfig.AmazonAccessKey, secretKey: this.ClientsConfig.AmazonSecretKey);
+                using Stream stream = new MemoryStream(Encoding.UTF8.GetBytes(content));
+                using IAmazonS3 s3 = new AmazonS3Client(credentials, RegionEndpoint.GetBySystemName(this.ClientsConfig.AmazonRegion));
+                using TransferUtility uploader = new TransferUtility(s3);
+
+                string id = Guid.NewGuid().ToString("N");
+
+                var uploadRequest = new TransferUtilityUploadRequest
+                {
+                    BucketName = this.ClientsConfig.AmazonTempBucket,
+                    Key = $"uploads/{id}",
+                    InputStream = stream,
+                    Metadata =
+                    {
+                        // note: AWS will lowercase keys and prefix 'x-amz-meta-'
+                        ["smapi-uploaded"] = DateTime.UtcNow.ToString("O"),
+                        ["pastebin-error"] = uploadError
+                    }
+                };
+
+                await uploader.UploadAsync(uploadRequest);
+
+                return new UploadResult(true, id, uploadError);
+            }
+            catch (Exception ex)
+            {
+                return new UploadResult(false, null, $"{uploadError}\n{ex.Message}");
+            }
+        }
+
+        /// <summary>Fetch raw text from storage.</summary>
+        /// <param name="id">The storage ID returned by <see cref="SaveAsync"/>.</param>
+        public async Task<StoredFileInfo> GetAsync(string id)
+        {
+            // get from Amazon S3
+            if (Guid.TryParseExact(id, "N", out Guid _))
+            {
+                var credentials = new BasicAWSCredentials(accessKey: this.ClientsConfig.AmazonAccessKey, secretKey: this.ClientsConfig.AmazonSecretKey);
+                using IAmazonS3 s3 = new AmazonS3Client(credentials, RegionEndpoint.GetBySystemName(this.ClientsConfig.AmazonRegion));
+
+                try
+                {
+                    using GetObjectResponse response = await s3.GetObjectAsync(this.ClientsConfig.AmazonTempBucket, $"uploads/{id}");
+                    using Stream responseStream = response.ResponseStream;
+                    using StreamReader reader = new StreamReader(responseStream);
+
+                    DateTime expiry = response.Expiration.ExpiryDateUtc;
+                    string pastebinError = response.Metadata["x-amz-meta-pastebin-error"];
+                    string content = this.GzipHelper.DecompressString(reader.ReadToEnd());
+
+                    return new StoredFileInfo
+                    {
+                        Success = true,
+                        Content = content,
+                        Expiry = expiry,
+                        Warning = pastebinError
+                    };
+                }
+                catch (AmazonServiceException ex)
+                {
+                    return ex.ErrorCode == "NoSuchKey"
+                        ? new StoredFileInfo { Error = "There's no file with that ID." }
+                        : new StoredFileInfo { Error = $"Could not fetch that file from AWS S3 ({ex.ErrorCode}: {ex.Message})." };
+                }
+            }
+
+            // get from PasteBin
+            else
+            {
+                PasteInfo response = await this.Pastebin.GetAsync(id);
+                response.Content = this.GzipHelper.DecompressString(response.Content);
+                return new StoredFileInfo
+                {
+                    Success = response.Success,
+                    Content = response.Content,
+                    Error = response.Error
+                };
+            }
+        }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Storage/StoredFileInfo.cs b/src/SMAPI.Web/Framework/Storage/StoredFileInfo.cs
new file mode 100644
index 00000000..30676c88
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Storage/StoredFileInfo.cs
@@ -0,0 +1,23 @@
+using System;
+
+namespace StardewModdingAPI.Web.Framework.Storage
+{
+    /// <summary>The response for a get-file request.</summary>
+    internal class StoredFileInfo
+    {
+        /// <summary>Whether the file was successfully fetched.</summary>
+        public bool Success { get; set; }
+
+        /// <summary>The fetched file content (if <see cref="Success"/> is <c>true</c>).</summary>
+        public string Content { get; set; }
+
+        /// <summary>When the file will no longer be available.</summary>
+        public DateTime? Expiry { get; set; }
+
+        /// <summary>The error message if saving succeeded, but a non-blocking issue was encountered.</summary>
+        public string Warning { get; set; }
+
+        /// <summary>The error message if saving failed.</summary>
+        public string Error { get; set; }
+    }
+}
diff --git a/src/SMAPI.Web/Framework/Storage/UploadResult.cs b/src/SMAPI.Web/Framework/Storage/UploadResult.cs
new file mode 100644
index 00000000..483c1769
--- /dev/null
+++ b/src/SMAPI.Web/Framework/Storage/UploadResult.cs
@@ -0,0 +1,33 @@
+namespace StardewModdingAPI.Web.Framework.Storage
+{
+    /// <summary>The result of an attempt to upload a file.</summary>
+    internal class UploadResult
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>Whether the file upload succeeded.</summary>
+        public bool Succeeded { get; }
+
+        /// <summary>The file ID, if applicable.</summary>
+        public string ID { get; }
+
+        /// <summary>The upload error, if any.</summary>
+        public string UploadError { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="succeeded">Whether the file upload succeeded.</param>
+        /// <param name="id">The file ID, if applicable.</param>
+        /// <param name="uploadError">The upload error, if any.</param>
+        public UploadResult(bool succeeded, string id, string uploadError)
+        {
+            this.Succeeded = succeeded;
+            this.ID = id;
+            this.UploadError = uploadError;
+        }
+    }
+}
diff --git a/src/SMAPI.Web/Startup.cs b/src/SMAPI.Web/Startup.cs
index 53823771..31b5e61d 100644
--- a/src/SMAPI.Web/Startup.cs
+++ b/src/SMAPI.Web/Startup.cs
@@ -7,6 +7,7 @@ using Microsoft.AspNetCore.Rewrite;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
 using MongoDB.Bson.Serialization;
 using MongoDB.Driver;
 using Newtonsoft.Json;
@@ -24,6 +25,7 @@ using StardewModdingAPI.Web.Framework.Clients.Pastebin;
 using StardewModdingAPI.Web.Framework.Compression;
 using StardewModdingAPI.Web.Framework.ConfigModels;
 using StardewModdingAPI.Web.Framework.RewriteRules;
+using StardewModdingAPI.Web.Framework.Storage;
 
 namespace StardewModdingAPI.Web
 {
@@ -158,7 +160,13 @@ namespace StardewModdingAPI.Web
             }
 
             // init helpers
-            services.AddSingleton<IGzipHelper>(new GzipHelper());
+            services
+                .AddSingleton<IGzipHelper>(new GzipHelper())
+                .AddSingleton<IStorageProvider>(serv => new StorageProvider(
+                    serv.GetRequiredService<IOptions<ApiClientsConfig>>(),
+                    serv.GetRequiredService<IPastebinClient>(),
+                    serv.GetRequiredService<IGzipHelper>()
+                ));
         }
 
         /// <summary>The method called by the runtime to configure the HTTP request pipeline.</summary>
diff --git a/src/SMAPI.Web/ViewModels/JsonValidator/JsonValidatorModel.cs b/src/SMAPI.Web/ViewModels/JsonValidator/JsonValidatorModel.cs
index 5b18331f..c0dd7184 100644
--- a/src/SMAPI.Web/ViewModels/JsonValidator/JsonValidatorModel.cs
+++ b/src/SMAPI.Web/ViewModels/JsonValidator/JsonValidatorModel.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -24,7 +25,13 @@ namespace StardewModdingAPI.Web.ViewModels.JsonValidator
         /// <summary>The schema validation errors, if any.</summary>
         public JsonValidatorErrorModel[] Errors { get; set; } = new JsonValidatorErrorModel[0];
 
-        /// <summary>An error which occurred while uploading the JSON to Pastebin.</summary>
+        /// <summary>A non-blocking warning while uploading the file.</summary>
+        public string UploadWarning { get; set; }
+
+        /// <summary>When the uploaded file will no longer be available.</summary>
+        public DateTime? Expiry { get; set; }
+
+        /// <summary>An error which occurred while uploading the JSON.</summary>
         public string UploadError { get; set; }
 
         /// <summary>An error which occurred while parsing the JSON.</summary>
@@ -41,7 +48,7 @@ namespace StardewModdingAPI.Web.ViewModels.JsonValidator
         public JsonValidatorModel() { }
 
         /// <summary>Construct an instance.</summary>
-        /// <param name="pasteID">The paste ID.</param>
+        /// <param name="pasteID">The stored file ID.</param>
         /// <param name="schemaName">The schema name with which the JSON was validated.</param>
         /// <param name="schemaFormats">The supported JSON schemas (names indexed by ID).</param>
         public JsonValidatorModel(string pasteID, string schemaName, IDictionary<string, string> schemaFormats)
@@ -53,14 +60,18 @@ namespace StardewModdingAPI.Web.ViewModels.JsonValidator
 
         /// <summary>Set the validated content.</summary>
         /// <param name="content">The validated content.</param>
-        public JsonValidatorModel SetContent(string content)
+        /// <param name="expiry">When the uploaded file will no longer be available.</param>
+        /// <param name="uploadWarning">A non-blocking warning while uploading the log.</param>
+        public JsonValidatorModel SetContent(string content, DateTime? expiry, string uploadWarning = null)
         {
             this.Content = content;
+            this.Expiry = expiry;
+            this.UploadWarning = uploadWarning;
 
             return this;
         }
 
-        /// <summary>Set the error which occurred while uploading the log to Pastebin.</summary>
+        /// <summary>Set the error which occurred while uploading the JSON.</summary>
         /// <param name="error">The error message.</param>
         public JsonValidatorModel SetUploadError(string error)
         {
diff --git a/src/SMAPI.Web/Views/JsonValidator/Index.cshtml b/src/SMAPI.Web/Views/JsonValidator/Index.cshtml
index de6b06a2..a5a134ac 100644
--- a/src/SMAPI.Web/Views/JsonValidator/Index.cshtml
+++ b/src/SMAPI.Web/Views/JsonValidator/Index.cshtml
@@ -1,3 +1,4 @@
+@using Humanizer
 @using StardewModdingAPI.Web.Framework
 @using StardewModdingAPI.Web.ViewModels.JsonValidator
 @model JsonValidatorModel
@@ -26,7 +27,7 @@
     {
         <meta name="robots" content="noindex" />
     }
-    <link rel="stylesheet" href="~/Content/css/json-validator.css" />
+    <link rel="stylesheet" href="~/Content/css/json-validator.css?r=20191203" />
     <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/tmont/sunlight@1.22.0/src/themes/sunlight.default.min.css" />
 
     <script src="https://cdn.jsdelivr.net/npm/jquery@3.3.1/dist/jquery.min.js" crossorigin="anonymous"></script>
@@ -67,6 +68,18 @@ else if (Model.PasteID != null)
     </div>
 }
 
+@* save warnings *@
+@if (Model.UploadWarning != null || Model.Expiry != null)
+{
+    <div class="save-metadata" v-pre>
+        @if (Model.Expiry != null)
+        {
+            <text>This log will expire in @((DateTime.UtcNow - Model.Expiry.Value).Humanize()). </text>
+        }
+        <!--@Model.UploadWarning-->
+    </div>
+}
+
 @* upload new file *@
 @if (Model.Content == null)
 {
diff --git a/src/SMAPI.Web/appsettings.json b/src/SMAPI.Web/appsettings.json
index f81587ef..b3567469 100644
--- a/src/SMAPI.Web/appsettings.json
+++ b/src/SMAPI.Web/appsettings.json
@@ -26,7 +26,7 @@
         "AmazonAccessKey": null,
         "AmazonSecretKey": null,
         "AmazonRegion": "us-east-1",
-        "AmazonLogBucket": "smapi-log-parser",
+        "AmazonTempBucket": "smapi-web-temp",
 
         "ChucklefishBaseUrl": "https://community.playstarbound.com",
         "ChucklefishModPageUrlFormat": "resources/{0}",
diff --git a/src/SMAPI.Web/wwwroot/Content/css/json-validator.css b/src/SMAPI.Web/wwwroot/Content/css/json-validator.css
index cd117694..18195098 100644
--- a/src/SMAPI.Web/wwwroot/Content/css/json-validator.css
+++ b/src/SMAPI.Web/wwwroot/Content/css/json-validator.css
@@ -41,6 +41,12 @@
     background: #FCC;
 }
 
+.save-metadata {
+    margin-top: 1em;
+    font-size: 0.8em;
+    opacity: 0.3;
+}
+
 /*********
 ** Validation results
 *********/