[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.Core/Entities/Guilds/IGuild.cs

@@ -1251,5 +1251,21 @@ namespace Discord
         /// </returns>
         Task<IReadOnlyCollection<IApplicationCommand>> BulkOverwriteApplicationCommandsAsync(ApplicationCommandProperties[] properties,
             RequestOptions options = null);
+
+        /// <summary>
+        ///     Gets the welcome screen of the guild. Returns <see langword="null"/> if the welcome channel is not set.
+        /// </summary>
+        /// <returns>
+        ///     A task that represents the asynchronous creation operation. The task result contains a <see cref="WelcomeScreen"/>.
+        /// </returns>
+        Task<WelcomeScreen> GetWelcomeScreenAsync(RequestOptions options = null);
+
+        /// <summary>
+        ///     Modifies the welcome screen of the guild. Returns <see langword="null"/> if welcome screen is removed.
+        /// </summary>
+        /// <returns>
+        ///     A task that represents the asynchronous creation operation. The task result contains a <see cref="WelcomeScreen"/>.
+        /// </returns>
+        Task<WelcomeScreen> ModifyWelcomeScreenAsync(bool enabled, WelcomeScreenChannelProperties[] channels, string description = null, RequestOptions options = null);
     }
 }

src/Discord.Net.Core/Entities/Guilds/WelcomeScreen.cs

@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+using System.Collections.Immutable;
+
+namespace Discord;
+
+public class WelcomeScreen
+{
+    /// <summary>
+    ///     Gets the server description shown in the welcome screen. <see langword="null"/> if not set.
+    /// </summary>
+    public string Description { get; }
+
+    /// <summary>
+    ///     Gets the channels shown in the welcome screen, up to 5 channels.
+    /// </summary>
+    public IReadOnlyCollection<WelcomeScreenChannel> Channels { get; }
+
+    internal WelcomeScreen(string description, IReadOnlyCollection<WelcomeScreenChannel> channels)
+    {
+        Description = description;
+
+        Channels = channels.ToImmutableArray();
+    }
+}

src/Discord.Net.Core/Entities/Guilds/WelcomeScreenChannel.cs

@@ -0,0 +1,41 @@
+using System;
+
+namespace Discord;
+
+public class WelcomeScreenChannel : ISnowflakeEntity
+{
+    /// <summary>
+    /// 	Gets the channel's id.
+    /// </summary>
+    public ulong Id { get; }
+
+    /// <summary>
+    /// 	Gets the description shown for the channel.
+    /// </summary>
+    public string Description { get; }
+
+    /// <summary>
+    ///     Gets the emoji for this channel. <see cref="Emoji"/> if it is unicode emoji, <see cref="Emote"/> if it is a custom one and <see langword="null"/> if none is set.
+    /// </summary>
+    /// <remarks>
+    ///     If the emoji is <see cref="Emote"/> only the <see cref="Emote.Id"/> will be populated.
+    ///     Use <see cref="IGuild.GetEmoteAsync"/> to get the emoji.
+    /// </remarks>
+    public IEmote Emoji { get; }
+
+    /// <inheritdoc/>
+    public DateTimeOffset CreatedAt => SnowflakeUtils.FromSnowflake(Id);
+
+    internal WelcomeScreenChannel(ulong id, string description, string emojiName = null, ulong? emoteId = null)
+    {
+        Id = id;
+        Description = description;
+
+        if (emoteId.HasValue && emoteId.Value != 0)
+            Emoji = new Emote(emoteId.Value, emojiName, false);
+        else if (emojiName != null)
+            Emoji = new Emoji(emojiName);
+        else
+            Emoji = null;
+    }
+}

src/Discord.Net.Core/Entities/Guilds/WelcomeScreenChannelProperties.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Xml.Linq;
+
+namespace Discord;
+
+public class WelcomeScreenChannelProperties : ISnowflakeEntity
+{
+    /// <summary>
+    /// 	Gets or sets the channel's id.
+    /// </summary>
+    public ulong Id { get; set; }
+
+    /// <summary>
+    /// 	Gets or sets the description shown for the channel.
+    /// </summary>
+    public string Description { get; set; }
+
+    /// <summary>
+    ///     Gets or sets the emoji for this channel. <see cref="Emoji"/> if it is unicode emoji, <see cref="Emote"/> if it is a custom one and <see langword="null"/> if none is set.
+    /// </summary>
+    /// <remarks>
+    ///     If the emoji is <see cref="Emote"/> only the <see cref="Emote.Id"/> will be populated.
+    ///     Use <see cref="IGuild.GetEmoteAsync"/> to get the emoji.
+    /// </remarks>
+    public IEmote Emoji { get; set; }
+
+    /// <inheritdoc/>
+    public DateTimeOffset CreatedAt => SnowflakeUtils.FromSnowflake(Id);
+
+    /// <summary>
+    ///     Initializes a new instance of <see cref="WelcomeScreenChannelProperties"/>.
+    /// </summary>
+    /// <param name="id">Id if a channel.</param>
+    /// <param name="description">Description for the channel in the welcome screen.</param>
+    /// <param name="emoji">The emoji for the channel in the welcome screen.</param>
+    public WelcomeScreenChannelProperties(ulong id, string description, IEmote emoji = null)
+    {
+        Id = id;
+        Description = description;
+        Emoji = emoji;
+    }
+
+    /// <summary>
+    ///     Initializes a new instance of <see cref="WelcomeScreenChannelProperties"/>.
+    /// </summary>
+    public WelcomeScreenChannelProperties() { }
+    /// <summary>
+    ///     Initializes a new instance of <see cref="WelcomeScreenChannelProperties"/>.
+    /// </summary>
+    /// <param name="channel">A welcome screen channel to modify.</param>
+    /// <returns>A new instance of <see cref="WelcomeScreenChannelProperties"/>.</returns>
+    public static WelcomeScreenChannelProperties FromWelcomeScreenChannel(WelcomeScreenChannel channel)
+        => new (channel.Id, channel.Description, channel.Emoji);
+}

src/Discord.Net.Core/Entities/Invites/IInvite.cs

@@ -60,6 +60,7 @@ namespace Discord
         ///     A guild object representing the guild that the invite points to.
         /// </returns>
         IGuild Guild { get; }
+
         /// <summary>
         ///     Gets the ID of the guild this invite is linked to.
         /// </summary>

src/Discord.Net.Core/Entities/Invites/InviteGuild.cs

@@ -0,0 +1,156 @@
+using System;
+
+namespace Discord;
+
+public class InviteGuild : ISnowflakeEntity
+{
+    /// <inheritdoc />
+    public DateTimeOffset CreatedAt => SnowflakeUtils.FromSnowflake(Id);
+
+    /// <inheritdoc/>
+    public ulong Id { get; private set; }
+
+    /// <summary>
+    ///     Gets the name of this guild.
+    /// </summary>
+    /// <returns>
+    ///     A string containing the name of this guild.
+    /// </returns>
+    public string Name { get; private set; }
+
+    /// <summary>
+    ///     Gets the description for the guild.
+    /// </summary>
+    /// <returns>
+    ///     The description for the guild; <see langword="null" /> if none is set.
+    /// </returns>
+    public string Description { get; private set; }
+
+    /// <summary>
+    ///     Gets the ID of this guild's splash image.
+    /// </summary>
+    /// <returns>
+    ///     An identifier for the splash image; <see langword="null" /> if none is set.
+    /// </returns>
+    public string SplashId { get; private set; }
+
+    /// <summary>
+    ///     Gets the URL of this guild's splash image.
+    /// </summary>
+    /// <returns>
+    ///     A URL pointing to the guild's splash image; <see langword="null" /> if none is set.
+    /// </returns>
+    public string SplashUrl => CDN.GetGuildSplashUrl(Id, SplashId);
+
+    /// <summary>
+    ///     Gets the identifier for this guilds banner image.
+    /// </summary>
+    /// <returns>
+    ///     An identifier for the banner image; <see langword="null" /> if none is set.
+    /// </returns>
+    public string BannerId { get; private set; }
+
+    /// <summary>
+    ///     Gets the URL of this guild's banner image.
+    /// </summary>
+    /// <returns>
+    ///     A URL pointing to the guild's banner image; <see langword="null" /> if none is set.
+    /// </returns>
+    public string BannerUrl => CDN.GetGuildBannerUrl(Id, BannerId, ImageFormat.Auto);
+
+    /// <summary>
+    ///     Gets the features for this guild.
+    /// </summary>
+    /// <returns>
+    ///     A flags enum containing all the features for the guild.
+    /// </returns>
+    public GuildFeatures Features { get; private set; }
+
+    /// <summary>
+    ///     Gets the ID of this guild's icon.
+    /// </summary>
+    /// <returns>
+    ///     An identifier for the splash image; <see langword="null" /> if none is set.
+    /// </returns>
+    public string IconId { get; private set; }
+
+    /// <summary>
+    ///     Gets the URL of this guild's icon.
+    /// </summary>
+    /// <returns>
+    ///     A URL pointing to the guild's icon; <see langword="null" /> if none is set.
+    /// </returns>
+    public string IconUrl => CDN.GetGuildIconUrl(Id, IconId);
+    
+    /// <summary>
+    /// 
+    ///     Gets the level of requirements a user must fulfill before being allowed to post messages in this guild.
+    /// </summary>
+    /// <returns>
+    ///     The level of requirements.
+    /// </returns>
+    public VerificationLevel VerificationLevel { get; private set; }
+
+    /// <summary>
+    ///     Gets the code for this guild's vanity invite URL.
+    /// </summary>
+    /// <returns>
+    ///     A string containing the vanity invite code for this guild; <see langword="null" /> if none is set.
+    /// </returns>
+    public string VanityURLCode { get; private set; }
+
+    /// <summary>
+    ///     Gets the number of premium subscribers of this guild.
+    /// </summary>
+    /// <remarks>
+    ///     This is the number of users who have boosted this guild.
+    /// </remarks>
+    /// <returns>
+    ///     The number of premium subscribers of this guild; 
+    /// </returns>
+    public int PremiumSubscriptionCount { get; private set; }
+
+    /// <summary>
+    ///     Gets the NSFW level of this guild.
+    /// </summary>
+    /// <returns>
+    ///     The NSFW level of this guild.
+    /// </returns>
+    public NsfwLevel NsfwLevel { get; private set; }
+
+    /// <summary>
+    ///     Gets the Welcome Screen of this guild
+    /// </summary>
+    /// <returns>
+    ///     The welcome screen of this guild. <see langword="null" /> if none is set.
+    /// </returns>
+    public WelcomeScreen WelcomeScreen { get; private set; }
+
+    internal InviteGuild(
+        ulong id, 
+        string name, 
+        string description, 
+        string splashId, 
+        string bannerId, 
+        GuildFeatures features, 
+        string iconId, 
+        VerificationLevel verificationLevel, 
+        string vanityURLCode, 
+        int premiumSubscriptionCount, 
+        NsfwLevel nsfwLevel, 
+        WelcomeScreen welcomeScreen)
+    {
+        Id = id;
+        Name = name;
+        Description = description;
+        SplashId = splashId;
+        BannerId = bannerId;
+        Features = features;
+        IconId = iconId;
+        VerificationLevel = verificationLevel;
+        VanityURLCode = vanityURLCode;
+        PremiumSubscriptionCount = premiumSubscriptionCount;
+        NsfwLevel = nsfwLevel;
+        WelcomeScreen = welcomeScreen;
+    }
+}