Packages can be loaded/unloaded. IUnloadableService interface added whose method Unload, if service implements it, will be called when the module is unloaded.

NadekoBot.Core/Modules/CustomReactions/Extensions/Extensions.cs

@@ -0,0 +1,148 @@
+using AngleSharp;
+using AngleSharp.Dom.Html;
+using Discord;
+using Discord.WebSocket;
+using NadekoBot.Extensions;
+using NadekoBot.Modules.CustomReactions.Services;
+using NadekoBot.Services.Database.Models;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using NadekoBot.Common;
+using NadekoBot.Common.Replacements;
+
+namespace NadekoBot.Modules.CustomReactions.Extensions
+{
+    public static class Extensions
+    {
+        private static readonly Regex imgRegex = new Regex("%(img|image):(?<tag>.*?)%", RegexOptions.Compiled);
+
+        private static readonly NadekoRandom rng = new NadekoRandom();
+
+        public static Dictionary<Regex, Func<Match, Task<string>>> regexPlaceholders = new Dictionary<Regex, Func<Match, Task<string>>>()
+        {
+            { imgRegex, async (match) => {
+                var tag = match.Groups["tag"].ToString();
+                if(string.IsNullOrWhiteSpace(tag))
+                    return "";
+
+                var fullQueryLink = $"http://imgur.com/search?q={ tag }";
+                var config = Configuration.Default.WithDefaultLoader();
+                var document = await BrowsingContext.New(config).OpenAsync(fullQueryLink);
+
+                var elems = document.QuerySelectorAll("a.image-list-link").ToArray();
+
+                if (!elems.Any())
+                    return "";
+
+                var img = (elems.ElementAtOrDefault(new NadekoRandom().Next(0, elems.Length))?.Children?.FirstOrDefault() as IHtmlImageElement);
+
+                if (img?.Source == null)
+                    return "";
+
+                return " " + img.Source.Replace("b.", ".") + " ";
+            } }
+        };
+
+        private static string ResolveTriggerString(this string str, IUserMessage ctx, DiscordSocketClient client)
+        {
+            var rep = new ReplacementBuilder()
+                .WithUser(ctx.Author)
+                .WithClient(client)
+                .Build();
+
+            str = rep.Replace(str.ToLowerInvariant());
+
+            return str;
+        }
+
+        private static async Task<string> ResolveResponseStringAsync(this string str, IUserMessage ctx, DiscordSocketClient client, string resolvedTrigger, bool containsAnywhere)
+        {
+            var substringIndex = resolvedTrigger.Length;
+            if (containsAnywhere)
+            {
+                var pos = ctx.Content.GetWordPosition(resolvedTrigger);
+                if (pos == WordPosition.Start)
+                    substringIndex += 1;
+                else if (pos == WordPosition.End)
+                    substringIndex = ctx.Content.Length;
+                else if (pos == WordPosition.Middle)
+                    substringIndex += ctx.Content.IndexOf(resolvedTrigger);
+            }
+
+            var rep = new ReplacementBuilder()
+                .WithDefault(ctx.Author, ctx.Channel, (ctx.Channel as ITextChannel)?.Guild, client)
+                .WithOverride("%target%", () => ctx.Content.Substring(substringIndex).Trim())
+                .Build();
+
+            str = rep.Replace(str);
+
+            foreach (var ph in regexPlaceholders)
+            {
+                str = await ph.Key.ReplaceAsync(str, ph.Value);
+            }
+            return str;
+        }
+
+        public static string TriggerWithContext(this CustomReaction cr, IUserMessage ctx, DiscordSocketClient client)
+            => cr.Trigger.ResolveTriggerString(ctx, client);
+
+        public static Task<string > ResponseWithContextAsync(this CustomReaction cr, IUserMessage ctx, DiscordSocketClient client, bool containsAnywhere)
+            => cr.Response.ResolveResponseStringAsync(ctx, client, cr.Trigger.ResolveTriggerString(ctx, client), containsAnywhere);
+
+        public static async Task<IUserMessage> Send(this CustomReaction cr, IUserMessage ctx, DiscordSocketClient client, CustomReactionsService crs)
+        {
+            var channel = cr.DmResponse ? await ctx.Author.GetOrCreateDMChannelAsync() : ctx.Channel;
+
+            crs.ReactionStats.AddOrUpdate(cr.Trigger, 1, (k, old) => ++old);
+
+            if (CREmbed.TryParse(cr.Response, out CREmbed crembed))
+            {
+                var trigger = cr.Trigger.ResolveTriggerString(ctx, client);
+                var substringIndex = trigger.Length;
+                if (cr.ContainsAnywhere)
+                {
+                    var pos = ctx.Content.GetWordPosition(trigger);
+                    if (pos == WordPosition.Start)
+                        substringIndex += 1;
+                    else if (pos == WordPosition.End)
+                        substringIndex = ctx.Content.Length;
+                    else if (pos == WordPosition.Middle)
+                        substringIndex += ctx.Content.IndexOf(trigger);
+                }
+
+                var rep = new ReplacementBuilder()
+                    .WithDefault(ctx.Author, ctx.Channel, (ctx.Channel as ITextChannel)?.Guild, client)
+                    .WithOverride("%target%", () => ctx.Content.Substring(substringIndex).Trim())
+                    .Build();
+
+                rep.Replace(crembed);
+
+                return await channel.EmbedAsync(crembed.ToEmbed(), crembed.PlainText?.SanitizeMentions() ?? "");
+            }
+            return await channel.SendMessageAsync((await cr.ResponseWithContextAsync(ctx, client, cr.ContainsAnywhere)).SanitizeMentions());
+        }
+
+        public static WordPosition GetWordPosition(this string str, string word)
+        {
+            if (str.StartsWith(word + " "))
+                return WordPosition.Start;
+            else if (str.EndsWith(" " + word))
+                return WordPosition.End;
+            else if (str.Contains(" " + word + " "))
+                return WordPosition.Middle;
+            else
+                return WordPosition.None;
+        }
+    }
+
+    public enum WordPosition
+    {
+        None,
+        Start,
+        Middle,
+        End,
+    }
+}