[Feature] add missing invite guild properties & welcome screen support (#2510)

* added models

* working getter for welcome screen

* <see langword="null"/>

* more changes

* modify welcome screen support

* fix some typos & remove `using` added by VS

* Working-ish state

* Resolve some reviews

* change access modifier

* forgot to add docs

* revert to InviteGuild & extend it

* resolve some reviews

* Apply suggestions from code review

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

Co-authored-by: Cenk Ergen <57065323+Cenngo@users.noreply.github.com>
Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

src/Discord.Net.Rest/API/Common/Guild.cs

@@ -83,5 +83,8 @@ namespace Discord.API
         public Sticker[] Stickers { get; set; }
         [JsonProperty("premium_progress_bar_enabled")]
         public Optional<bool> IsBoostProgressBarEnabled { get; set; }
+
+        [JsonProperty("welcome_screen")]
+        public Optional<WelcomeScreen> WelcomeScreen { get; set; }
     }
 }

src/Discord.Net.Rest/API/Common/InviteGuild.cs

@@ -6,9 +6,41 @@ namespace Discord.API
     {
         [JsonProperty("id")]
         public ulong Id { get; set; }
+
         [JsonProperty("name")]
         public string Name { get; set; }
-        [JsonProperty("splash_hash")]
-        public string SplashHash { get; set; }
+
+        [JsonProperty("splash")]
+        public Optional<string> Splash { get; set; }
+
+        [JsonProperty("banner")]
+        public Optional<string> BannerHash { get; set; }
+
+        [JsonProperty("description")]
+        public Optional<string> Description { get; set; }
+
+        [JsonProperty("icon")]
+        public Optional<string> IconHash { get; set; }
+
+        [JsonProperty("features")]
+        public GuildFeatures Features { get; set; }
+
+        [JsonProperty("verification_level")]
+        public VerificationLevel VerificationLevel { get; set; }
+
+        [JsonProperty("vanity_url_code")]
+        public Optional<string> VanityUrlCode { get; set; }
+
+        [JsonProperty("premium_subscription_count")]
+        public Optional<int> PremiumSubscriptionCount { get; set; }
+
+        [JsonProperty("nsfw")]
+        public Optional<bool?> Nsfw { get; set; }
+
+        [JsonProperty("nsfw_level")]
+        public NsfwLevel NsfwLevel { get; set; }
+
+        [JsonProperty("welcome_screen")]
+        public Optional<WelcomeScreen> WelcomeScreen { get; set; }
     }
 }

src/Discord.Net.Rest/API/Common/WelcomeScreen.cs

@@ -0,0 +1,12 @@
+using Newtonsoft.Json;
+
+namespace Discord.API;
+
+internal class WelcomeScreen
+{
+    [JsonProperty("description")]
+    public Optional<string> Description { get; set; }
+
+    [JsonProperty("welcome_channels")]
+    public WelcomeScreenChannel[] WelcomeChannels { get; set; }
+}

src/Discord.Net.Rest/API/Common/WelcomeScreenChannel.cs

@@ -0,0 +1,18 @@
+using Newtonsoft.Json;
+
+namespace Discord.API;
+
+internal class WelcomeScreenChannel
+{
+    [JsonProperty("channel_id")]
+    public ulong ChannelId { get; set; }
+
+    [JsonProperty("description")]
+    public string Description { get; set; }
+
+    [JsonProperty("emoji_id")]
+    public Optional<ulong?> EmojiId { get; set; }
+
+    [JsonProperty("emoji_name")]
+    public Optional<string> EmojiName{ get; set; }
+}

src/Discord.Net.Rest/API/Rest/ModifyGuildWelcomeScreenParams.cs

@@ -0,0 +1,15 @@
+using Newtonsoft.Json;
+
+namespace Discord.API.Rest;
+
+internal class ModifyGuildWelcomeScreenParams
+{
+    [JsonProperty("enabled")]
+    public Optional<bool> Enabled { get; set; }
+
+    [JsonProperty("welcome_channels")]
+    public Optional<WelcomeScreenChannel[]> WelcomeChannels { get; set; }
+
+    [JsonProperty("description")]
+    public Optional<string> Description { get; set; }
+}