refactor: move JsonModelExt to PluralKit.Core (in individual model/patch files)

PluralKit.API/Controllers/v1/JsonModelExt.cs

@@ -1,178 +0,0 @@
-using System;
-using System.Linq;
-
-using Newtonsoft.Json.Linq;
-
-using PluralKit.Core;
-
-namespace PluralKit.API
-{
-    public static class JsonModelExt
-    {
-        public static JObject ToJson(this PKSystem system, LookupContext ctx)
-        {
-            var o = new JObject();
-            o.Add("id", system.Hid);
-            o.Add("name", system.Name);
-            o.Add("description", system.DescriptionFor(ctx));
-            o.Add("tag", system.Tag);
-            o.Add("avatar_url", system.AvatarUrl.TryGetCleanCdnUrl());
-            o.Add("banner", system.DescriptionPrivacy.Get(ctx, system.BannerImage).TryGetCleanCdnUrl());
-            o.Add("created", system.Created.FormatExport());
-            o.Add("tz", system.UiTz);
-            o.Add("description_privacy", ctx == LookupContext.ByOwner ? system.DescriptionPrivacy.ToJsonString() : null);
-            o.Add("member_list_privacy", ctx == LookupContext.ByOwner ? system.MemberListPrivacy.ToJsonString() : null);
-            o.Add("front_privacy", ctx == LookupContext.ByOwner ? system.FrontPrivacy.ToJsonString() : null);
-            o.Add("front_history_privacy", ctx == LookupContext.ByOwner ? system.FrontHistoryPrivacy.ToJsonString() : null);
-            return o;
-        }
-
-        public static SystemPatch ToSystemPatch(JObject o)
-        {
-            var patch = new SystemPatch();
-            if (o.ContainsKey("name")) patch.Name = o.Value<string>("name").NullIfEmpty().BoundsCheckField(Limits.MaxSystemNameLength, "System name");
-            if (o.ContainsKey("description")) patch.Description = o.Value<string>("description").NullIfEmpty().BoundsCheckField(Limits.MaxDescriptionLength, "System description");
-            if (o.ContainsKey("tag")) patch.Tag = o.Value<string>("tag").NullIfEmpty().BoundsCheckField(Limits.MaxSystemTagLength, "System tag");
-            if (o.ContainsKey("avatar_url")) patch.AvatarUrl = o.Value<string>("avatar_url").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "System avatar URL");
-            if (o.ContainsKey("banner")) patch.BannerImage = o.Value<string>("banner").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "System banner URL");
-            if (o.ContainsKey("tz")) patch.UiTz = o.Value<string>("tz") ?? "UTC";
-            
-            if (o.ContainsKey("description_privacy")) patch.DescriptionPrivacy = o.Value<string>("description_privacy").ParsePrivacy("description");
-            if (o.ContainsKey("member_list_privacy")) patch.MemberListPrivacy = o.Value<string>("member_list_privacy").ParsePrivacy("member list");
-            if (o.ContainsKey("front_privacy")) patch.FrontPrivacy = o.Value<string>("front_privacy").ParsePrivacy("front");
-            if (o.ContainsKey("front_history_privacy")) patch.FrontHistoryPrivacy = o.Value<string>("front_history_privacy").ParsePrivacy("front history");
-            return patch;
-        }
-        
-        public static JObject ToJson(this PKMember member, LookupContext ctx)
-        {
-            var includePrivacy = ctx == LookupContext.ByOwner;
-            
-            var o = new JObject();
-            o.Add("id", member.Hid);
-            o.Add("name", member.NameFor(ctx));
-            // o.Add("color", member.ColorPrivacy.CanAccess(ctx) ? member.Color : null);
-            o.Add("color", member.Color);
-            o.Add("display_name", member.NamePrivacy.CanAccess(ctx) ? member.DisplayName : null);
-            o.Add("birthday", member.BirthdayFor(ctx)?.FormatExport());
-            o.Add("pronouns", member.PronounsFor(ctx));
-            o.Add("avatar_url", member.AvatarFor(ctx).TryGetCleanCdnUrl());
-            o.Add("banner", member.DescriptionPrivacy.Get(ctx, member.BannerImage).TryGetCleanCdnUrl());
-            o.Add("description", member.DescriptionFor(ctx));
-            
-            var tagArray = new JArray();
-            foreach (var tag in member.ProxyTags) 
-                tagArray.Add(new JObject {{"prefix", tag.Prefix}, {"suffix", tag.Suffix}});
-            o.Add("proxy_tags", tagArray);
-
-            o.Add("keep_proxy", member.KeepProxy);
-            
-            o.Add("privacy", includePrivacy ? (member.MemberVisibility.LevelName()) : null);
-
-            o.Add("visibility", includePrivacy ? (member.MemberVisibility.LevelName()) : null);
-            o.Add("name_privacy", includePrivacy ? (member.NamePrivacy.LevelName()) : null);
-            o.Add("description_privacy", includePrivacy ? (member.DescriptionPrivacy.LevelName()) : null);
-            o.Add("birthday_privacy", includePrivacy ? (member.BirthdayPrivacy.LevelName()) : null);
-            o.Add("pronoun_privacy", includePrivacy ? (member.PronounPrivacy.LevelName()) : null);
-            o.Add("avatar_privacy", includePrivacy ? (member.AvatarPrivacy.LevelName()) : null);
-            // o.Add("color_privacy", ctx == LookupContext.ByOwner ? (member.ColorPrivacy.LevelName()) : null);
-            o.Add("metadata_privacy", includePrivacy ? (member.MetadataPrivacy.LevelName()) : null);
-
-            o.Add("created", member.CreatedFor(ctx)?.FormatExport());
-
-            if (member.ProxyTags.Count > 0)
-            {
-                // Legacy compatibility only, TODO: remove at some point
-                o.Add("prefix", member.ProxyTags?.FirstOrDefault().Prefix);
-                o.Add("suffix", member.ProxyTags?.FirstOrDefault().Suffix);
-            }
-
-            return o;
-        }
-
-        public static MemberPatch ToMemberPatch(JObject o)
-        {
-            var patch = new MemberPatch();
-
-            if (o.ContainsKey("name") && o["name"].Type == JTokenType.Null) 
-                throw new JsonModelParseError("Member name can not be set to null.");
-            
-            if (o.ContainsKey("name")) patch.Name = o.Value<string>("name").BoundsCheckField(Limits.MaxMemberNameLength, "Member name");
-            if (o.ContainsKey("color")) patch.Color = o.Value<string>("color").NullIfEmpty()?.ToLower();
-            if (o.ContainsKey("display_name")) patch.DisplayName = o.Value<string>("display_name").NullIfEmpty().BoundsCheckField(Limits.MaxMemberNameLength, "Member display name");
-            if (o.ContainsKey("avatar_url")) patch.AvatarUrl = o.Value<string>("avatar_url").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "Member avatar URL");
-            if (o.ContainsKey("banner")) patch.BannerImage = o.Value<string>("banner").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "Member banner URL");
-
-            if (o.ContainsKey("birthday"))
-            {
-                var str = o.Value<string>("birthday").NullIfEmpty();
-                var res = DateTimeFormats.DateExportFormat.Parse(str);
-                if (res.Success) patch.Birthday = res.Value;
-                else if (str == null) patch.Birthday = null;
-                else throw new JsonModelParseError("Could not parse member birthday.");
-            }
-
-            if (o.ContainsKey("pronouns")) patch.Pronouns = o.Value<string>("pronouns").NullIfEmpty().BoundsCheckField(Limits.MaxPronounsLength, "Member pronouns");
-            if (o.ContainsKey("description")) patch.Description = o.Value<string>("description").NullIfEmpty().BoundsCheckField(Limits.MaxDescriptionLength, "Member descriptoin");
-            if (o.ContainsKey("keep_proxy")) patch.KeepProxy = o.Value<bool>("keep_proxy");
-
-            if (o.ContainsKey("prefix") || o.ContainsKey("suffix") && !o.ContainsKey("proxy_tags"))
-                patch.ProxyTags = new[] {new ProxyTag(o.Value<string>("prefix"), o.Value<string>("suffix"))};
-            else if (o.ContainsKey("proxy_tags"))
-            {
-                patch.ProxyTags = o.Value<JArray>("proxy_tags")
-                    .OfType<JObject>().Select(o => new ProxyTag(o.Value<string>("prefix"), o.Value<string>("suffix")))
-                    .ToArray();
-            }
-            if(o.ContainsKey("privacy")) //TODO: Deprecate this completely in api v2
-            {
-                var plevel = o.Value<string>("privacy").ParsePrivacy("member");
-                                
-                patch.Visibility = plevel;
-                patch.NamePrivacy = plevel;
-                patch.AvatarPrivacy = plevel;
-                patch.DescriptionPrivacy = plevel;
-                patch.BirthdayPrivacy = plevel;
-                patch.PronounPrivacy = plevel;
-                // member.ColorPrivacy = plevel;
-                patch.MetadataPrivacy = plevel;
-            }
-            else
-            {
-                if (o.ContainsKey("visibility")) patch.Visibility = o.Value<string>("visibility").ParsePrivacy("member");
-                if (o.ContainsKey("name_privacy")) patch.NamePrivacy = o.Value<string>("name_privacy").ParsePrivacy("member");
-                if (o.ContainsKey("description_privacy")) patch.DescriptionPrivacy = o.Value<string>("description_privacy").ParsePrivacy("member");
-                if (o.ContainsKey("avatar_privacy")) patch.AvatarPrivacy = o.Value<string>("avatar_privacy").ParsePrivacy("member");
-                if (o.ContainsKey("birthday_privacy")) patch.BirthdayPrivacy = o.Value<string>("birthday_privacy").ParsePrivacy("member");
-                if (o.ContainsKey("pronoun_privacy")) patch.PronounPrivacy = o.Value<string>("pronoun_privacy").ParsePrivacy("member");
-                // if (o.ContainsKey("color_privacy")) member.ColorPrivacy = o.Value<string>("color_privacy").ParsePrivacy("member");
-                if (o.ContainsKey("metadata_privacy")) patch.MetadataPrivacy = o.Value<string>("metadata_privacy").ParsePrivacy("member");
-            }
-
-            return patch;
-        }
-
-        private static string BoundsCheckField(this string input, int maxLength, string nameInError)
-        {
-            if (input != null && input.Length > maxLength)
-                throw new JsonModelParseError($"{nameInError} too long ({input.Length} > {maxLength}).");
-            return input;
-        }
-
-        private static string ToJsonString(this PrivacyLevel level) => level.LevelName();
-
-        private static PrivacyLevel ParsePrivacy(this string input, string errorName)
-        {
-            if (input == null) return PrivacyLevel.Public;
-            if (input == "") return PrivacyLevel.Private;
-            if (input == "private") return PrivacyLevel.Private;
-            if (input == "public") return PrivacyLevel.Public;
-            throw new JsonModelParseError($"Could not parse {errorName} privacy.");
-        }
-    }
-    
-    public class JsonModelParseError: Exception
-    {
-        public JsonModelParseError(string message): base(message) { }
-    }
-}

PluralKit.API/Controllers/v1/MemberController.cs

@@ -61,7 +61,7 @@ namespace PluralKit.API
             MemberPatch patch;
             try
             {
-                patch = JsonModelExt.ToMemberPatch(properties);
+                patch = MemberPatch.FromJSON(properties);
                 patch.CheckIsValid();
             }
             catch (JsonModelParseError e)
@@ -95,7 +95,7 @@ namespace PluralKit.API
             MemberPatch patch;
             try
             {
-                patch = JsonModelExt.ToMemberPatch(changes);
+                patch = MemberPatch.FromJSON(changes);
                 patch.CheckIsValid();
             }
             catch (JsonModelParseError e)

PluralKit.API/Controllers/v1/SystemController.cs

@@ -140,7 +140,7 @@ namespace PluralKit.API
             SystemPatch patch;
             try
             {
-                patch = JsonModelExt.ToSystemPatch(changes); 
+                patch = SystemPatch.FromJSON(changes);
                 patch.CheckIsValid();
             }
             catch (JsonModelParseError e)

PluralKit.Core/Models/PKMember.cs

@@ -1,12 +1,12 @@
 using System.Collections.Generic;
+using System.Linq;
 
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 
 using NodaTime;
 using NodaTime.Text;
 
-
-
 namespace PluralKit.Core {
     public readonly struct MemberId: INumericId<MemberId, int>
     {
@@ -101,5 +101,51 @@ namespace PluralKit.Core {
 
         public static int MessageCountFor(this PKMember member, LookupContext ctx) =>
             member.MetadataPrivacy.Get(ctx, member.MessageCount);
+
+        public static JObject ToJson(this PKMember member, LookupContext ctx)
+        {
+            var includePrivacy = ctx == LookupContext.ByOwner;
+            
+            var o = new JObject();
+            o.Add("id", member.Hid);
+            o.Add("name", member.NameFor(ctx));
+            // o.Add("color", member.ColorPrivacy.CanAccess(ctx) ? member.Color : null);
+            o.Add("color", member.Color);
+            o.Add("display_name", member.NamePrivacy.CanAccess(ctx) ? member.DisplayName : null);
+            o.Add("birthday", member.BirthdayFor(ctx)?.FormatExport());
+            o.Add("pronouns", member.PronounsFor(ctx));
+            o.Add("avatar_url", member.AvatarFor(ctx).TryGetCleanCdnUrl());
+            o.Add("banner", member.DescriptionPrivacy.Get(ctx, member.BannerImage).TryGetCleanCdnUrl());
+            o.Add("description", member.DescriptionFor(ctx));
+            
+            var tagArray = new JArray();
+            foreach (var tag in member.ProxyTags) 
+                tagArray.Add(new JObject {{"prefix", tag.Prefix}, {"suffix", tag.Suffix}});
+            o.Add("proxy_tags", tagArray);
+
+            o.Add("keep_proxy", member.KeepProxy);
+            
+            o.Add("privacy", includePrivacy ? (member.MemberVisibility.LevelName()) : null);
+
+            o.Add("visibility", includePrivacy ? (member.MemberVisibility.LevelName()) : null);
+            o.Add("name_privacy", includePrivacy ? (member.NamePrivacy.LevelName()) : null);
+            o.Add("description_privacy", includePrivacy ? (member.DescriptionPrivacy.LevelName()) : null);
+            o.Add("birthday_privacy", includePrivacy ? (member.BirthdayPrivacy.LevelName()) : null);
+            o.Add("pronoun_privacy", includePrivacy ? (member.PronounPrivacy.LevelName()) : null);
+            o.Add("avatar_privacy", includePrivacy ? (member.AvatarPrivacy.LevelName()) : null);
+            // o.Add("color_privacy", ctx == LookupContext.ByOwner ? (member.ColorPrivacy.LevelName()) : null);
+            o.Add("metadata_privacy", includePrivacy ? (member.MetadataPrivacy.LevelName()) : null);
+
+            o.Add("created", member.CreatedFor(ctx)?.FormatExport());
+
+            if (member.ProxyTags.Count > 0)
+            {
+                // Legacy compatibility only, TODO: remove at some point
+                o.Add("prefix", member.ProxyTags?.FirstOrDefault().Prefix);
+                o.Add("suffix", member.ProxyTags?.FirstOrDefault().Suffix);
+            }
+
+            return o;
+        }
     }
 }

PluralKit.Core/Models/PKSystem.cs

@@ -1,11 +1,10 @@
 using Dapper.Contrib.Extensions;
 
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 
 using NodaTime;
 
-
-
 namespace PluralKit.Core {
 
     public readonly struct SystemId: INumericId<SystemId, int>
@@ -34,7 +33,6 @@ namespace PluralKit.Core {
 
     public class PKSystem
     {
-        // Additions here should be mirrored in SystemStore::Save
         [Key] public SystemId Id { get; }
         public string Hid { get; }
         public string Name { get; }
@@ -63,5 +61,25 @@ namespace PluralKit.Core {
     {
         public static string DescriptionFor(this PKSystem system, LookupContext ctx) =>
             system.DescriptionPrivacy.Get(ctx, system.Description);
+
+        public static JObject ToJson(this PKSystem system, LookupContext ctx)
+        {
+            var o = new JObject();
+            o.Add("id", system.Hid);
+            o.Add("name", system.Name);
+            o.Add("description", system.DescriptionFor(ctx));
+            o.Add("tag", system.Tag);
+            o.Add("avatar_url", system.AvatarUrl.TryGetCleanCdnUrl());
+            o.Add("banner", system.DescriptionPrivacy.Get(ctx, system.BannerImage).TryGetCleanCdnUrl());
+            o.Add("created", system.Created.FormatExport());
+            // todo: change this to "timezone"
+            o.Add("tz", system.UiTz);
+            // todo: just don't include these if not ByOwner
+            o.Add("description_privacy", ctx == LookupContext.ByOwner ? system.DescriptionPrivacy.ToJsonString() : null);
+            o.Add("member_list_privacy", ctx == LookupContext.ByOwner ? system.MemberListPrivacy.ToJsonString() : null);
+            o.Add("front_privacy", ctx == LookupContext.ByOwner ? system.FrontPrivacy.ToJsonString() : null);
+            o.Add("front_history_privacy", ctx == LookupContext.ByOwner ? system.FrontHistoryPrivacy.ToJsonString() : null);
+            return o;
+        }
     }
 }

PluralKit.Core/Models/Patch/MemberPatch.cs

@@ -1,8 +1,11 @@
 #nullable enable
+using System.Linq;
 using System.Text.RegularExpressions;
 
 using NodaTime;
 
+using Newtonsoft.Json.Linq;
+
 namespace PluralKit.Core
 {
     public class MemberPatch: PatchObject
@@ -60,5 +63,70 @@ namespace PluralKit.Core
                 throw new InvalidPatchException("color");
         }
 
+#nullable disable
+
+        public static MemberPatch FromJSON(JObject o)
+        {
+            var patch = new MemberPatch();
+
+            if (o.ContainsKey("name") && o["name"].Type == JTokenType.Null) 
+                throw new JsonModelParseError("Member name can not be set to null.");
+            
+            if (o.ContainsKey("name")) patch.Name = o.Value<string>("name").BoundsCheckField(Limits.MaxMemberNameLength, "Member name");
+            if (o.ContainsKey("color")) patch.Color = o.Value<string>("color").NullIfEmpty()?.ToLower();
+            if (o.ContainsKey("display_name")) patch.DisplayName = o.Value<string>("display_name").NullIfEmpty().BoundsCheckField(Limits.MaxMemberNameLength, "Member display name");
+            if (o.ContainsKey("avatar_url")) patch.AvatarUrl = o.Value<string>("avatar_url").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "Member avatar URL");
+            if (o.ContainsKey("banner")) patch.BannerImage = o.Value<string>("banner").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "Member banner URL");
+
+            if (o.ContainsKey("birthday"))
+            {
+                var str = o.Value<string>("birthday").NullIfEmpty();
+                var res = DateTimeFormats.DateExportFormat.Parse(str);
+                if (res.Success) patch.Birthday = res.Value;
+                else if (str == null) patch.Birthday = null;
+                else throw new JsonModelParseError("Could not parse member birthday.");
+            }
+
+            if (o.ContainsKey("pronouns")) patch.Pronouns = o.Value<string>("pronouns").NullIfEmpty().BoundsCheckField(Limits.MaxPronounsLength, "Member pronouns");
+            if (o.ContainsKey("description")) patch.Description = o.Value<string>("description").NullIfEmpty().BoundsCheckField(Limits.MaxDescriptionLength, "Member descriptoin");
+            if (o.ContainsKey("keep_proxy")) patch.KeepProxy = o.Value<bool>("keep_proxy");
+
+            // legacy: used in old export files and APIv1
+            // todo: should we parse `proxy_tags` first?
+            if (o.ContainsKey("prefix") || o.ContainsKey("suffix") && !o.ContainsKey("proxy_tags"))
+                patch.ProxyTags = new[] {new ProxyTag(o.Value<string>("prefix"), o.Value<string>("suffix"))};
+            else if (o.ContainsKey("proxy_tags"))
+            {
+                patch.ProxyTags = o.Value<JArray>("proxy_tags")
+                    .OfType<JObject>().Select(o => new ProxyTag(o.Value<string>("prefix"), o.Value<string>("suffix")))
+                    .ToArray();
+            }
+            if(o.ContainsKey("privacy")) //TODO: Deprecate this completely in api v2
+            {
+                var plevel = o.Value<string>("privacy").ParsePrivacy("member");
+                                
+                patch.Visibility = plevel;
+                patch.NamePrivacy = plevel;
+                patch.AvatarPrivacy = plevel;
+                patch.DescriptionPrivacy = plevel;
+                patch.BirthdayPrivacy = plevel;
+                patch.PronounPrivacy = plevel;
+                // member.ColorPrivacy = plevel;
+                patch.MetadataPrivacy = plevel;
+            }
+            else
+            {
+                if (o.ContainsKey("visibility")) patch.Visibility = o.Value<string>("visibility").ParsePrivacy("member");
+                if (o.ContainsKey("name_privacy")) patch.NamePrivacy = o.Value<string>("name_privacy").ParsePrivacy("member");
+                if (o.ContainsKey("description_privacy")) patch.DescriptionPrivacy = o.Value<string>("description_privacy").ParsePrivacy("member");
+                if (o.ContainsKey("avatar_privacy")) patch.AvatarPrivacy = o.Value<string>("avatar_privacy").ParsePrivacy("member");
+                if (o.ContainsKey("birthday_privacy")) patch.BirthdayPrivacy = o.Value<string>("birthday_privacy").ParsePrivacy("member");
+                if (o.ContainsKey("pronoun_privacy")) patch.PronounPrivacy = o.Value<string>("pronoun_privacy").ParsePrivacy("member");
+                // if (o.ContainsKey("color_privacy")) member.ColorPrivacy = o.Value<string>("color_privacy").ParsePrivacy("member");
+                if (o.ContainsKey("metadata_privacy")) patch.MetadataPrivacy = o.Value<string>("metadata_privacy").ParsePrivacy("member");
+            }
+
+            return patch;
+        }
     }
 }

PluralKit.Core/Models/Patch/SystemPatch.cs

@@ -1,6 +1,8 @@
 #nullable enable
 using System.Text.RegularExpressions;
 
+using Newtonsoft.Json.Linq;
+
 namespace PluralKit.Core
 {
     public class SystemPatch: PatchObject
@@ -54,5 +56,25 @@ namespace PluralKit.Core
                 throw new InvalidPatchException("color");
         }
 
+        public static SystemPatch FromJSON(JObject o)
+        {
+            var patch = new SystemPatch();
+            if (o.ContainsKey("name")) patch.Name = o.Value<string>("name").NullIfEmpty().BoundsCheckField(Limits.MaxSystemNameLength, "System name");
+            if (o.ContainsKey("description")) patch.Description = o.Value<string>("description").NullIfEmpty().BoundsCheckField(Limits.MaxDescriptionLength, "System description");
+            if (o.ContainsKey("tag")) patch.Tag = o.Value<string>("tag").NullIfEmpty().BoundsCheckField(Limits.MaxSystemTagLength, "System tag");
+            if (o.ContainsKey("avatar_url")) patch.AvatarUrl = o.Value<string>("avatar_url").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "System avatar URL");
+            if (o.ContainsKey("banner")) patch.BannerImage = o.Value<string>("banner").NullIfEmpty().BoundsCheckField(Limits.MaxUriLength, "System banner URL");
+            if (o.ContainsKey("timezone")) patch.UiTz = o.Value<string>("tz") ?? "UTC";
+
+            // legacy: APIv1 uses "tz" instead of "timezone"
+            // todo: remove in APIv2
+            if (o.ContainsKey("tz")) patch.UiTz = o.Value<string>("tz") ?? "UTC";
+            
+            if (o.ContainsKey("description_privacy")) patch.DescriptionPrivacy = o.Value<string>("description_privacy").ParsePrivacy("description");
+            if (o.ContainsKey("member_list_privacy")) patch.MemberListPrivacy = o.Value<string>("member_list_privacy").ParsePrivacy("member list");
+            if (o.ContainsKey("front_privacy")) patch.FrontPrivacy = o.Value<string>("front_privacy").ParsePrivacy("front");
+            if (o.ContainsKey("front_history_privacy")) patch.FrontHistoryPrivacy = o.Value<string>("front_history_privacy").ParsePrivacy("front history");
+            return patch;
+        }
     }
 }

PluralKit.Core/Models/Privacy/PrivacyLevel.cs

@@ -38,5 +38,17 @@ namespace PluralKit.Core
             output = input;
             return true;
         }
+        
+        public static string ToJsonString(this PrivacyLevel level) => level.LevelName();
+
+        public static PrivacyLevel ParsePrivacy(this string input, string errorName)
+        {
+            if (input == null) return PrivacyLevel.Public;
+            if (input == "") return PrivacyLevel.Private;
+            if (input == "private") return PrivacyLevel.Private;
+            if (input == "public") return PrivacyLevel.Public;
+            throw new JsonModelParseError($"Could not parse {errorName} privacy.");
+        }
+
     }
 }

PluralKit.Core/Utils/JsonUtils.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace PluralKit.Core
+{
+    internal static class JsonUtils
+    {
+        public static string BoundsCheckField(this string input, int maxLength, string nameInError)
+        {
+            if (input != null && input.Length > maxLength)
+                throw new JsonModelParseError($"{nameInError} too long ({input.Length} > {maxLength}).");
+            return input;
+        }
+    }
+    
+    public class JsonModelParseError: Exception
+    {
+        public JsonModelParseError(string message): base(message) { }
+    }
+}