Add importing and exporting function

PluralKit.Bot/Bot.cs

@@ -68,6 +68,8 @@ namespace PluralKit.Bot
                 .AddTransient<EmbedService>()
                 .AddTransient<ProxyService>()
                 .AddTransient<LogChannelService>()
+                .AddTransient<DataFileService>()
+                
                 .AddSingleton<WebhookCacheService>()
                 
                 .AddTransient<SystemStore>()

PluralKit.Bot/Commands/ImportExportCommands.cs

@@ -0,0 +1,85 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Text;
+using System.Threading.Tasks;
+using Discord.Commands;
+using Newtonsoft.Json;
+
+namespace PluralKit.Bot.Commands
+{
+    public class ImportExportCommands : ModuleBase<PKCommandContext>
+    {
+        public DataFileService DataFiles { get; set; }
+
+        [Command("import")]
+        [Remarks("import [fileurl]")]
+        public async Task Import([Remainder] string url = null)
+        {
+            if (url == null) url = Context.Message.Attachments.FirstOrDefault()?.Filename;
+            if (url == null) throw Errors.NoImportFilePassed;
+
+            await Context.BusyIndicator(async () =>
+            {
+                using (var client = new HttpClient())
+                {
+                    var response = await client.GetAsync(url);
+                    if (!response.IsSuccessStatusCode) throw Errors.InvalidImportFile;
+                    var str = await response.Content.ReadAsStringAsync();
+
+                    var data = TryDeserialize(str);
+                    if (!data.HasValue || !data.Value.Valid) throw Errors.InvalidImportFile;
+
+                    if (Context.SenderSystem != null && Context.SenderSystem.Hid != data.Value.Id)
+                    {
+                        // TODO: prompt "are you sure you want to import someone else's system?
+                    }
+
+                    // If passed system is null, it'll create a new one
+                    // (and that's okay!)
+                    var result = await DataFiles.ImportSystem(data.Value, Context.SenderSystem);
+                    
+                    if (Context.SenderSystem == null)
+                    {
+                        await Context.Channel.SendMessageAsync($"{Emojis.Success} PluralKit has created a system for you based on the given file. Your system ID is `{result.System.Hid}`. Type `pk;system` for more information.");
+                    }
+                    else
+                    {
+                        await Context.Channel.SendMessageAsync($"{Emojis.Success} Updated {result.ModifiedNames.Count} members, created {result.AddedNames.Count} members. Type `pk;system list` to check!");
+                    }
+                }
+            });
+        }
+
+        [Command("export")]
+        [Remarks("export")]
+        [MustHaveSystem]
+        public async Task Export()
+        {
+            await Context.BusyIndicator(async () =>
+            {
+                var data = await DataFiles.ExportSystem(Context.SenderSystem);
+                var json = JsonConvert.SerializeObject(data, Formatting.None);
+                
+                var stream = new MemoryStream(Encoding.UTF8.GetBytes(json));
+                await Context.Channel.SendFileAsync(stream, "system.json", $"{Emojis.Success} Here you go!");
+            });
+        }
+
+        private DataFileSystem? TryDeserialize(string json)
+        {
+            try
+            {
+                return JsonConvert.DeserializeObject<DataFileSystem>(json);
+            }
+            catch (JsonException e)
+            {
+                Console.WriteLine("uww");
+            }
+
+            return null;
+        }
+    }
+}

PluralKit.Bot/Errors.cs

@@ -60,7 +60,8 @@ namespace PluralKit.Bot {
 
         public static PKError InvalidTimeZone(string zoneStr) => new PKError($"Invalid time zone ID '{zoneStr}'. To find your time zone ID, use the following website: <https://xske.github.io/tz>");
         public static PKError TimezoneChangeCancelled => new PKError("Time zone change cancelled.");
-
         public static PKError AmbiguousTimeZone(string zoneStr, int count) => new PKError($"The time zone query '{zoneStr}' resulted in **{count}** different time zone regions. Try being more specific - e.g. pass an exact time zone specifier from the following website: <https://xske.github.io/tz>");
+        public static Exception NoImportFilePassed => new PKError("You must either pass an URL to a file as a command parameter, or as an attachment to the message containing the command.");
+        public static Exception InvalidImportFile => new PKError("Imported data file invalid. Make sure this is a .json file directly exported from PluralKit or Tupperbox.");
     }
 }