PluralKit/PluralKit.Bot/Commands/Avatars/ContextAvatarExt.cs
2021-08-27 11:03:47 -04:00

66 lines
2.1 KiB
C#

#nullable enable
using System;
using System.Linq;
using System.Threading.Tasks;
using Myriad.Extensions;
using Myriad.Types;
namespace PluralKit.Bot
{
public static class ContextAvatarExt
{
public static async Task<ParsedImage?> MatchImage(this Context ctx)
{
// If we have a user @mention/ID, use their avatar
if (await ctx.MatchUser() is { } user)
{
var url = user.AvatarUrl("png", 256);
return new ParsedImage { Url = url, Source = AvatarSource.User, SourceUser = user };
}
// If we have a positional argument, try to parse it as a URL
var arg = ctx.RemainderOrNull();
if (arg != null)
{
// Allow surrounding the URL with <angle brackets> to "de-embed"
if (arg.StartsWith("<") && arg.EndsWith(">"))
arg = arg.Substring(1, arg.Length - 2);
if (!Uri.TryCreate(arg, UriKind.Absolute, out var uri))
throw Errors.InvalidUrl(arg);
if (uri.Scheme != "http" && uri.Scheme != "https")
throw Errors.InvalidUrl(arg);
// ToString URL-decodes, which breaks URLs to spaces; AbsoluteUri doesn't
return new ParsedImage { Url = uri.AbsoluteUri, Source = AvatarSource.Url };
}
// If we have an attachment, use that
if (ctx.Message.Attachments.FirstOrDefault() is { } attachment)
{
var url = attachment.ProxyUrl;
return new ParsedImage { Url = url, Source = AvatarSource.Attachment };
}
// We should only get here if there are no arguments (which would get parsed as URL + throw if error)
// and if there are no attachments (which would have been caught just before)
return null;
}
}
public struct ParsedImage
{
public string Url;
public AvatarSource Source;
public User? SourceUser;
}
public enum AvatarSource
{
Url,
User,
Attachment
}
}