Open Source Extensible Enterprise n-tier Application Framework with Multilayered Architecture

using System;
using SiberTek.Xenta.Data;
using SiberTek.Xenta.Data.Providers;
using SiberTek.Xenta.Entities;
using SiberTek.Xenta.Entities.Collections;
using SiberTek.Xenta.Enums;
using SiberTek.Xenta.Events;
using SiberTek.Xenta.Exceptions;
using SiberTek.Xenta.Extensions;
using SiberTek.Xenta.Utils;

namespace SiberTek.Xenta.Managers
{
    /// <summary>
    /// Contains methods to manage forum posts
    /// </summary>
    public class ForumPostManager : IManager
    {
        #region Fields
        private static ForumPostManager _instance = null;
        private IForumPostDataProvider _dataProvider;
        private bool _initialized;
        #endregion

        #region Constructors
        private ForumPostManager()
        {
            _dataProvider = null;
            _initialized = false;
        }
        #endregion

        #region Events
        public event EntityEventHandler PostCreated;
        public event EntityEventHandler PostUpdated;
        public event EntityEventHandler PostDeleted;
        #endregion

        #region Properties
        public static ForumPostManager Instance
        {
            get
            {
                if(_instance == null)
                {
                    _instance = new ForumPostManager();
                }
                return _instance;
            }
        }

        private IForumPostDataProvider DataProvider
        {
            get
            {
                return _dataProvider;
            }
        }
        #endregion

        #region Methods
        public void Initialize()
        {
            if(!_initialized)
            {
                _dataProvider = DataAccessManager.GetProviderInstance<IForumPostDataProvider>("ForumPostDataProvider");

                ForumProfileManager.Instance.ProfileDeleted += OnForumProfileDeleted;
                ForumTopicManager.Instance.TopicDeleted += OnForumTopicDeleted;

                _initialized = true;
            }
        }

        public ForumPostInfo CreateForumPost(int parentPostID, int topicID, int authorID, string title, string text, bool isActive)
        {
            if(ForumTopicManager.Instance.GetForumTopic(topicID) == null)
            {
                throw new XentaException("Forum topic does not exist", (int)ForumError.TopicDoesNotExist);
            }
            if(UserManager.Instance.GetUser(authorID) == null)
            {
                throw new XentaException("User does not exist", (int)CoreError.UserDoesNotExist);
            }

            ForumPostInfo post = null;
            int postID;
            title = StringHelper.TrimToLength(title, 1000);
            text = StringHelper.TrimToLength(text, Int32.MaxValue);

            if(DataProvider.InsertForumPost(parentPostID, topicID, authorID, title, text, isActive, DateTime.UtcNow, DateTime.UtcNow, out postID))
            {
                post = GetForumPost(postID);

                FirePostCreated(post);

                MessageManager.Instance.SendForumPostNotification(postID);
            }
            return post;
        }

        public ForumPostInfo GetForumPost(int postID)
        {
            return DataMapper.Map(DataProvider.GetForumPost(postID));
        }

        public ForumPostInfoCollection GetForumPostsByParentPostID(int parentPostID)
        {
            return GetForumPostsByAuthorID(parentPostID, false);
        }

        public ForumPostInfoCollection GetForumPostsByParentPostID(int parentPostID, bool showHidden)
        {
            return GetAllForumPosts(String.Empty, null, parentPostID, null, null, null, showHidden);
        }

        public ForumPostInfoCollection GetForumPostsByAuthorID(int authorID)
        {
            return GetForumPostsByAuthorID(authorID, false);
        }

        public ForumPostInfoCollection GetForumPostsByAuthorID(int authorID, bool showHidden)
        {
            return GetAllForumPosts(String.Empty, null, null, authorID, null, null, showHidden);
        }

        public ForumPostInfoCollection GetForumPostsByTopicID(int topicID)
        {
            return GetForumPostsByTopicID(topicID, false);
        }

        public ForumPostInfoCollection GetForumPostsByTopicID(int topicID, bool showHidden)
        {
            return GetAllForumPosts(String.Empty, topicID, null, null, null, null, showHidden);
        }

        public ForumPostInfoCollection GetAllForumPosts(string searchTerm, int? topicID, int? parentPostID, int? authorID, DateTime? createdOnStart, DateTime? createdOnEnd, bool showHidden)
        {
            int totalCount = 0;
            return GetAllForumPosts(searchTerm, topicID, parentPostID, authorID, createdOnStart, createdOnEnd, showHidden, 0, Int32.MaxValue, out totalCount);
        }

        public ForumPostInfoCollection GetAllForumPosts(string searchTerm, int? topicID, int? parentPostID, int? authorID, DateTime? createdOnStart, DateTime? createdOnEnd, bool showHidden, int startIndex, int count, out int totalCount)
        {
            return DataMapper.Map(DataProvider.GetAllForumPosts(searchTerm, topicID, parentPostID, authorID, createdOnStart, createdOnEnd, showHidden, startIndex, count, out totalCount));
        }

        public ForumPostInfo UpdateForumPost(int postID, int parentPostID, int topicID, int authorID, string title, string text, bool isActive)
        {
            if(ForumTopicManager.Instance.GetForumTopic(topicID) == null)
            {
                throw new XentaException("Forum topic does not exist", (int)ForumError.TopicDoesNotExist);
            }
            if(UserManager.Instance.GetUser(authorID) == null)
            {
                throw new XentaException("User does not exist", (int)CoreError.UserDoesNotExist);
            }

            ForumPostInfo post = GetForumPost(postID);
            if(post == null)
            {
                throw new XentaException("Forum post does not exist", (int)ForumError.PostDoesNotExist);
            }

            title = StringHelper.TrimToLength(title, 1000);
            text = StringHelper.TrimToLength(text, Int32.MaxValue);

            if(DataProvider.UpdateForumPost(postID, parentPostID, topicID, authorID, title, text, isActive, post.CreatedOn, DateTime.UtcNow))
            {
                post = GetForumPost(postID);
                FirePostUpdated(post);
            }
            return post;
        }

        public void DeleteForumPost(int postID)
        {
            ForumPostInfo post = GetForumPost(postID);

            if(post != null)
            {
                FirePostDeleted(post);
                foreach(ForumPostInfo childPost in GetForumPostsByParentPostID(post.PostID))
                {
                    UpdateForumPost(childPost.PostID, post.ParentPostID, childPost.TopicID, childPost.AuthorID, childPost.Title, childPost.Text, childPost.IsActive);
                }
                DataProvider.DeleteForumPost(postID);
            }
        }
        #endregion

        #region Handlers
        private void OnForumProfileDeleted(object sender, EntityEventArgs e)
        {
            ForumProfileInfo profile = e.Entity as ForumProfileInfo;

            if(profile != null)
            {
                UserInfo guest = UserManager.Instance.GetGuestUser();

                foreach(ForumPostInfo post in profile.Posts)
                {
                    UpdateForumPost(post.PostID, post.ParentPostID, post.TopicID, guest.UserID, post.Title, post.Text, post.IsActive);
                }
            }
        }

        private void OnForumTopicDeleted(object sender, EntityEventArgs e)
        {
            ForumTopicInfo topic = e.Entity as ForumTopicInfo;

            if(topic != null)
            {
                foreach(ForumPostInfo post in topic.Posts)
                {
                    DeleteForumPost(post.PostID);
                }
            }
        }
        #endregion

        #region Utilties
        private void FirePostCreated(ForumPostInfo post)
        {
            if(PostCreated != null)
            {
                PostCreated(this, new EntityEventArgs(post));
            }
        }

        private void FirePostUpdated(ForumPostInfo post)
        {
            if(PostUpdated != null)
            {
                PostUpdated(this, new EntityEventArgs(post));
            }
        }

        private void FirePostDeleted(ForumPostInfo post)
        {
            if(PostDeleted != null)
            {
                PostDeleted(this, new EntityEventArgs(post));
            }
        }
        #endregion
    }
}