RedditScreener.cs

using System;
using System.Collections.Generic;

using RedditSharp;
using RedditSharp.Things;

namespace RedditScanner
{
    public class RedditScreener
    {
        private readonly string[] regexStrings = new string[]
        {
            "gdl",
            "game dev league",
            "game developers league",
            "game development league",
            "gamedev league",
            "discord.gg/gamedev"
        };

        private Reddit reddit;
        private List<Subreddit> subreddits;
        
        public RedditScreener(params string[] subreddits)
        {
            for(int i = 0; i < subreddits.Length; i++)
            {
                if (!subreddits[i].StartsWith("/r/")) subreddits[i] = "/r/" + subreddits[i];
            }

            reddit = new Reddit();
            this.subreddits = new List<Subreddit>();
            foreach (string subreddit in subreddits)
            {
                this.subreddits.Add(reddit.GetSubreddit(subreddit));
            }
        }

        public List<Post> Scan()
        {
            var posts = new List<Post>();

            foreach (var subreddit in subreddits)
            {
                posts = getPosts(subreddit);
            }

            return posts;
        }

        private List<Post> getPosts(Subreddit subreddit)
        {
            var ret = new List<Post>();
            var posts = subreddit.Search(DateTime.UtcNow.AddHours(-18), DateTime.UtcNow.AddHours(-6));
            foreach(Post post in posts)
            {
                if (checkPost(post))
                {
                    ret.Add(post);
                }
            }

            return ret;
        }

        private bool checkPost(Post post)
        {            
            foreach (var str in regexStrings)
            {
                if (post.Title.ToLower().Contains(str)) return true;
                if (post.SelfText.ToLower().Contains(str)) return true;
            }
            
            foreach(var comment in post.Comments)
            {
                foreach (var str in regexStrings) if (comment.Body.ToLower().Contains(str)) return true;
            }

            return false;
        }
    }
}