Extending WordPress with C# Plugins

/*
 * Content Watchdog Wordpress C# Plugin
 * 
 * Author: 
 *  Miloslav Beno (miloslav@devsense.com)
 * 
 * Copyright (c) 2012 DEVSENSE s.r.o
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Devsense.Text;

namespace Devsense.WordPress.Plugins.ContentWatchdog
{   
    
    /// <summary>
    /// Main class of ContentWatchdog plugin for monitoring content of posts and pages
    /// </summary>
    public class ContentWatchdog
    {
        #region Constants
        private const string optionfPrefix = "content_watch_dog_";

        private const string badWordsOption     = optionfPrefix + "bad_words";
        private const string emailOption        = optionfPrefix + "email";
        private const string watchContentOption = optionfPrefix + "watching";
        private const string matchWholeWordOption = optionfPrefix + "matchWholeWord";

        private const string badWordFoundArg = "badWordFound";
        #endregion

        #region Fields and Properties

        private static StringSearch badWordsSearch;
        private dynamic wp;

        /// <summary>
        /// Collection of words to be monitored in posts and pages by the plugin
        /// </summary>
        public StringSearch BadWordsSearch
        {
            get 
            {
                if (badWordsSearch == null)
                    InitStringSearch();

                return badWordsSearch; 
            }
        }

        /// <summary>
        /// String of comma separated words to be monitored by the plugin
        /// </summary>
        public string BadWordsString
        {
            get { return wp.get_site_option(badWordsOption) as string; }
            set {
                if (value != null)
                {
                    string trimed = value.Trim();
                    wp.update_site_option(badWordsOption, value);
                    InitStringSearch();
                }
            }
        }

        /// <summary>
        /// Email address where notification email will be sent in case of post/page was
        /// submitted with bad word.
        /// </summary>
        /// <remarks>Default email is email of administrator</remarks>
        public string Email
        {
            get
            {
                string recipient = wp.get_site_option(emailOption) as string;

                //Check if email is not set
                if (String.IsNullOrEmpty(recipient))
                {
                    //return administrator email
                    return wp.get_site_option("admin_email") as string;
                }

                return recipient;
            }
            set { wp.update_site_option(emailOption, value); }
        }

        /// <summary>
        /// Indicates whether content monitoring is enabled
        /// </summary>
        public bool WatchContent
        {
            get { return !String.IsNullOrEmpty(wp.get_site_option(watchContentOption) as string); }
            set { wp.update_site_option(watchContentOption, value ? "1" : String.Empty); }
        }


        /// <summary>
        /// Indicates whether content monitoring is enabled
        /// </summary>
        public bool MatchWholeWord
        {
            get { return !String.IsNullOrEmpty(wp.get_site_option(matchWholeWordOption) as string); }
            set { wp.update_site_option(matchWholeWordOption, value ? "1" : String.Empty); }
        }

        /// <summary>
        /// Bad word was detected during saving the post
        /// </summary>
        public bool BadWordFound
        {
            get { return (wp._GET[badWordFoundArg] as string) != null; }
        }

        #endregion

        #region Construction

        /// <summary>
        /// Initialize new instance of the ContentWatchdog plugin
        /// </summary>
        public ContentWatchdog()
        {
            wp = PHP.Core.ScriptContext.CurrentContext.Globals;
           
            if (wp.is_multisite())
                wp.add_action("network_admin_menu", new Action(AddAdminPage), 10, 0);
            else
                wp.add_action("admin_menu", new Action(AddAdminPage), 10, 0);

            if (WatchContent)
            {
                wp.add_action("save_post", new Action<int, dynamic>(CheckPost), 10, 2);
                wp.add_action("all_admin_notices", new Action(ShowNotification), 10, 0);
            }
        }

        #endregion

        #region Methods

        /// <summary>
        /// Initialize StringSearch tree structure
        /// </summary>
        private void InitStringSearch()
        {
            var badWordsCol = BadWordsString.Split(',').Select(p => p.Trim()).ToArray();
            badWordsSearch = new StringSearch(badWordsCol, MatchWholeWord);
        }

        /// <summary>
        /// Adds admin page into admin section
        /// </summary>
        private void AddAdminPage() 
        {
            if (wp.is_multisite())
                wp.add_submenu_page("settings.php", Strings.PluginName, Strings.PluginName, 10, "content-watch-dog", new Action(AdminPageOutput));
            else
                wp.add_options_page(Strings.PluginName, Strings.PluginName, 10, "content-watch-dog", new Action(AdminPageOutput));
        }

        /// <summary>
        /// Outputs admin page
        /// </summary>
        /// <param name="s"></param>
        private void AdminPageOutput()
        {
            InitPropertiesFromForm();

            var template = new AdminPage{Model = this};
            template.Execute(); //Sends AdminPage to output stream
        }

        /// <summary>
        /// Initialize properties from submitted user form
        /// </summary>
        private void InitPropertiesFromForm()
        {
            var request = System.Web.HttpContext.Current.Request;
            if (request.Form.Count > 0)
            {
                //Update properties
                Email = wp.is_email(request.Form["Email"]) as string;
                WatchContent = request.Form["WatchContent"] != null ;
                MatchWholeWord = request.Form["MatchWholeWord"] != null;
                BadWordsString = wp.esc_html(request.Form["BadWordsString"]) as string;
            }
        }

        /// <summary>
        /// Checks post/page for occurrence of bad word
        /// </summary>
        /// <param name="postId">Identificator of post/page</param>
        /// <param name="post">Object representing the post/page</param>
        private void CheckPost(int postId, dynamic post) 
        {
            // Don't check it if it's not a post or page
            if (post.post_type != "post" && post.post_type != "page")
                return;

            //Don't check it if it's not published or it's password protected
            if (post.post_status != "publish" || !String.IsNullOrEmpty(post.post_password))
                return;

            if (BadWordsSearch.ContainsAny(post.post_title) || BadWordsSearch.ContainsAny(post.post_content))
            {
                //bad word was found
                string post_permalink = wp.get_permalink(postId);

                NotifyUser();
		        MailNotify(post_permalink, post.post_type);
            }
        }

        /// <summary>
        /// Sends a notification email to address in Email property
        /// </summary>
        /// <param name="postUrl">URL of the post</param>
        /// <param name="postType">Type of the post</param>
        private void MailNotify(string postUrl, string postType)
        {
            string subject = String.Format(Strings.MessageSubject, wp.get_site_url());
            string message = String.Format(Strings.MessageBody, postType, postUrl);

        	wp.wp_mail(Email, subject, message);
        }

        /// <summary>
        /// Sets notification argument into URL query string so user is notified after saving the post
        /// </summary>
        private void NotifyUser()
        {
            Func<string, int, string> redirect_post = (location, postId) => { return wp.add_query_arg(badWordFoundArg, "1", location); };

            wp.add_filter("redirect_post_location", redirect_post, 10, 2);
        }

        /// <summary>
        /// Displays warning notification that bad word was found
        /// </summary>
        private void ShowNotification()
        {
            if (BadWordFound)
                wp.notice = Strings.BadWordFoundWarning;
        }


        #endregion

    }
}