Added IMessage.Tags

src/Discord.Net.Rest/Entities/Messages/MessageHelper.cs

@@ -2,7 +2,6 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
-using System.Globalization;
 using System.Linq;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
@@ -11,8 +10,6 @@ namespace Discord.Rest
 {
     internal static class MessageHelper
     {
-        private static readonly Regex _emojiRegex = new Regex(@"<:(.+?):(\d+?)>", RegexOptions.Compiled);
-
         public static async Task ModifyAsync(IMessage msg, BaseDiscordClient client, Action<ModifyMessageParams> func,
             RequestOptions options)
         {
@@ -37,17 +34,94 @@ namespace Discord.Rest
             await client.ApiClient.RemovePinAsync(msg.ChannelId, msg.Id, options);
         }
 
-        public static ImmutableArray<Emoji> GetEmojis(string text)
+        public static ImmutableArray<ITag> ParseTags(string text, IMessageChannel channel, IGuild guild, ImmutableArray<IUser> userMentions)
         {
-            var matches = _emojiRegex.Matches(text);
-            var builder = ImmutableArray.CreateBuilder<Emoji>(matches.Count);
-            foreach (var match in matches.OfType<Match>())
+            var tags = new SortedList<int, ITag>();
+            
+            int index = 0;
+            while (true)
             {
+                index = text.IndexOf('<', index);
+                if (index == -1) break;
+                int endIndex = text.IndexOf('>', index + 1);
+                if (endIndex == -1) break;
+                string content = text.Substring(index, endIndex - index + 1);
+
                 ulong id;
-                if (ulong.TryParse(match.Groups[2].Value, NumberStyles.None, CultureInfo.InvariantCulture, out id))
-                    builder.Add(new Emoji(id, match.Groups[1].Value, match.Index, match.Length));
+                if (MentionUtils.TryParseUser(content, out id))
+                {
+                    IUser mentionedUser = null;
+                    foreach (var mention in userMentions)
+                    {
+                        if (mention.Id == id)
+                        {
+                            mentionedUser = channel?.GetUserAsync(id, CacheMode.CacheOnly).GetAwaiter().GetResult();
+                            if (mentionedUser == null)
+                                mentionedUser = mention;
+                            break;
+                        }
+                    }
+                    tags.Add(index, new Tag<IUser>(TagType.UserMention, index, content.Length, id, mentionedUser));
+                }
+                else if (MentionUtils.TryParseChannel(content, out id))
+                {
+                    IChannel mentionedChannel = null;
+                    if (guild != null)
+                        mentionedChannel = guild.GetChannelAsync(id, CacheMode.CacheOnly).GetAwaiter().GetResult();
+                    tags.Add(index, new Tag<IChannel>(TagType.ChannelMention, index, content.Length, id, mentionedChannel));
+                }
+                else if (MentionUtils.TryParseRole(content, out id))
+                {
+                    IRole mentionedRole = null;
+                    if (guild != null)
+                        mentionedRole = guild.GetRole(id);
+                    tags.Add(index, new Tag<IRole>(TagType.RoleMention, index, content.Length, id, mentionedRole));
+                }
+                else
+                {
+                    Emoji emoji;
+                    if (Emoji.TryParse(content, out emoji))
+                        tags.Add(index, new Tag<Emoji>(TagType.Emoji, index, content.Length, id, emoji));
+                }
+                index = endIndex + 1;
             }
-            return builder.ToImmutable();
+
+            index = 0;
+            while (true)
+            {
+                index = text.IndexOf("@everyone", index);
+                if (index == -1) break;
+
+                tags.Add(index, new Tag<object>(TagType.EveryoneMention, index, "@everyone".Length, 0, null));
+                index++;
+            }
+
+            index = 0;
+            while (true)
+            {
+                index = text.IndexOf("@here", index);
+                if (index == -1) break;
+
+                tags.Add(index, new Tag<object>(TagType.HereMention, index, "@here".Length, 0, null));
+                index++;
+            }
+
+            return tags.Values.ToImmutableArray();
+        }
+        public static ImmutableArray<ulong> FilterTagsByKey(TagType type, ImmutableArray<ITag> tags)
+        {
+            return tags
+                .Where(x => x.Type == type)
+                .Select(x => x.Key)
+                .ToImmutableArray();
+        }
+        public static ImmutableArray<T> FilterTagsByValue<T>(TagType type, ImmutableArray<ITag> tags)
+        {
+            return tags
+                .Where(x => x.Type == type)
+                .Select(x => (T)x.Value)
+                .Where(x => x != null)
+                .ToImmutableArray();
         }
     }
 }