Send scheduled Reminder/Alerts by email in SharePoint

using System;
using System.Collections.Generic;
using System.Text;
using Mullivan.Serialization;
using System.Xml.Serialization;
using System.Runtime.InteropServices;
using System.Web.UI;
using System.Web;
using Microsoft.SharePoint;
using Microsoft.SharePoint.WebControls;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;

namespace Mullivan.SharePoint.WebParts
{
    [Guid("89f69852-4044-4979-8ccd-35f177b7b0b2")]
    [XmlRoot(Namespace = "PagesNavigationWebPart")]
    public class PagesNavigationWebPart : Microsoft.SharePoint.WebPartPages.WebPart
    {
        private Dictionary<string, NavLink> _mainLinks;
        private string _errorMessage;

        public PagesNavigationWebPart()
            : base()
        {
            this.DisplayField = "Title";
        }

        public string DisplayField
        {
            get;
            set;
        }

        public string ContentSourceField
        {
            get;
            set;
        }

        protected override void OnLoad(EventArgs e)
        {
            _errorMessage = null;

            try
            {
                _mainLinks = this.GetNavLinks();
            }
            catch (Exception ex)
            {
                _errorMessage = ex.ToString() + Environment.NewLine + Environment.NewLine;
                _errorMessage += "Link Configuration" + Environment.NewLine;
            }
            base.OnLoad(e);
        }

        protected override void OnPreRender(EventArgs e)
        {
            ClientScriptManager csm = this.Page.ClientScript;
            Type lnType = this.GetType();
            //Register our Javascript file
            if (!csm.IsClientScriptIncludeRegistered(@"Mullivan.SharePoint.WebParts.JS.LibraryNavigation.js"))
            {
                string url = csm.GetWebResourceUrl(lnType, @"Mullivan.SharePoint.WebParts.JS.LibraryNavigation.js");
                csm.RegisterClientScriptInclude(lnType, "Mullivan.SharePoint.WebParts.JS.LibraryNavigation.js", ResolveClientUrl(url));
            }

            RegisterStyleSheet(ResolveUrl(csm.GetWebResourceUrl(lnType, @"Mullivan.SharePoint.WebParts.CSS.LibraryNavigation.css")));

            base.OnPreRender(e);
        }

        protected override void Render(HtmlTextWriter writer)
        {
            if (!string.IsNullOrEmpty(_errorMessage))
            {
                writer.Write(HttpUtility.HtmlEncode(_errorMessage).Replace("\n", "<br/>"));
                return;
            }

            ClientScriptManager csm = this.Page.ClientScript;
            Type lnType = this.GetType();
            StringBuilder sbSubMenus = new StringBuilder();
            string libNavLeftUrl = ResolveUrl(csm.GetWebResourceUrl(lnType, "Mullivan.SharePoint.WebParts.Images.LibNav_Left.jpg"));
            string libNavMidUrl = ResolveUrl(csm.GetWebResourceUrl(lnType, "Mullivan.SharePoint.WebParts.Images.LibNav_Mid.jpg"));
            string libNavRightUrl = ResolveUrl(csm.GetWebResourceUrl(lnType, "Mullivan.SharePoint.WebParts.Images.LibNav_Right.jpg"));
            string libNavOverUrl = ResolveUrl(csm.GetWebResourceUrl(lnType, "Mullivan.SharePoint.WebParts.Images.LibNav_Over.jpg"));
            string libNavSubItemMidUrl = ResolveUrl(csm.GetWebResourceUrl(lnType, "Mullivan.SharePoint.WebParts.Images.LibNav_SubItem_Mid.jpg"));
            string libNavSubItemOverUrl = ResolveUrl(csm.GetWebResourceUrl(lnType, "Mullivan.SharePoint.WebParts.Images.LibNav_SubItem_Over.jpg"));

            RegisterPreloadImage("preload_libNavOver", libNavOverUrl);
            RegisterPreloadImage("preload_libNavSubItemOver", libNavSubItemOverUrl);

            writer.WriteLine("<div class=\"lnwp_Container\">");
            writer.WriteLine("<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\">");
            //create td with middle background image
            writer.WriteLine(string.Format("<tr style=\"background-image:url('{0}')\">", libNavMidUrl));
            writer.WriteLine("<td>");
            writer.WriteLine(string.Format("<div class=\"lnwp_LeftImage\" style=\"background-image:url('{0}')\" />", libNavLeftUrl));
            writer.WriteLine("</td>");

            foreach (string key in _mainLinks.Keys)
            {
                NavLink navLink = _mainLinks[key];
                string containerName = "LPNW_Container_" + Guid.NewGuid().ToString().Replace("-", "");
                string menuName = "LPNW_Menu_" + Guid.NewGuid().ToString().Replace("-", "");
                //Generate Title Text
                writer.WriteLine(
                    string.Format(
                    "<td style=\"cursor:pointer\"  onmouseover=\"LPNW_SwapImage(this, '{0}');LPNW_MenuShowMenu(this, '{2}', '{3}',0,-8,'{4}');\" onmouseout=\"LPNW_SwapImage(this, '{1}');LPNW_MenuStartTimeout(10);\">"
                    , libNavOverUrl
                    , libNavMidUrl
                    , containerName
                    , menuName
                    , navLink.Title
                    , navLink.Url));
                AppendCenteredText(writer, "&nbsp;" + navLink.Title + "&nbsp;");
                writer.WriteLine("</td>");//Generate Title Text
                writer.WriteLine("<td>");
                AppendCenteredText(writer, "<span class=\"lnwp_Spacer\">|</span>");
                writer.WriteLine("</td>");


                sbSubMenus.AppendLine(string.Format("<div style=\"position:absolute;z-index:2;width:200px;display:none\" id=\"{0}\">", containerName));
                sbSubMenus.AppendLine(string.Format("<table id=\"{0}\" class=\"lnwp_MenuTable\" onmouseout=\"LPNW_MenuStartTimeout(10);\" onmouseover=\"LPNW_MenuResetTimeout();\" cellpadding=\"0\" cellspacing=\"0\">"
                    , menuName));

                if (string.IsNullOrEmpty(navLink.ErrorMessage))
                {
                    foreach (NavLink subItem in navLink.SubLinks)
                    {
                        sbSubMenus.AppendLine(string.Format("<tr style=\"background-image:url('{0}')\" onmouseover=\"LPNW_SwapImage(this, '{1}');LPNW_MenuOverMenuItem('{2}');\" onmouseout=\"LPNW_SwapImage(this,'{0}');\" >"
                            , libNavSubItemMidUrl
                            , libNavSubItemOverUrl
                            , menuName));
                        sbSubMenus.AppendLine(string.Format("<td nowrap=\"nowrap\" style=\"padding-left:4px;text-align:left;vertical-align:middle;height:20px;cursor:pointer;\" onclick=\"LPNW_NavigateTo('{0}');\">", subItem.Url));
                        sbSubMenus.AppendLine(string.Format("<a href=\"{0}\">", subItem.Url));
                        sbSubMenus.AppendLine(subItem.Title);
                        sbSubMenus.AppendLine("</a>");
                        sbSubMenus.AppendLine("</td>");
                        sbSubMenus.AppendLine("</tr>");
                    }
                }
                else
                {
                    sbSubMenus.AppendLine(string.Format("<tr style=\"background-color:white\" >"));
                    sbSubMenus.AppendLine(string.Format("<td style=\"color:red;padding-left:4px;text-align:left;vertical-align:top;\">"));
                    sbSubMenus.AppendLine(HttpUtility.HtmlEncode(navLink.ErrorMessage).Replace("\n", "<br/>"));
                    sbSubMenus.AppendLine("</td>");
                    sbSubMenus.AppendLine("</tr>");
                }

                sbSubMenus.AppendLine("</table>");
                sbSubMenus.AppendLine("</div>");
            }

            //Generate Title Text
            writer.WriteLine("<td width=\"99%\" class=\"lnwp_td_Title\">");
            AppendCenteredText(writer, this.Title);
            writer.WriteLine("</td>");

            //create td with right background image
            writer.WriteLine("<td>");
            writer.WriteLine(string.Format("<div class=\"lnwp_RightImage\" style=\"background-image:url('{0}')\" />", libNavRightUrl));
            writer.WriteLine("</td>");
            writer.WriteLine("</tr>");
            writer.WriteLine("</table>");
            writer.Write(sbSubMenus.ToString());
            writer.WriteLine("</div>");
            base.Render(writer);
        }

        private void RegisterPreloadImage(string name, string libNavOverUrl)
        {
            ClientScriptManager csm = this.Page.ClientScript;
            Type lnType = this.GetType();

            string strPreLoad = @"
<script type=""text/javascript"">
    var image = new Image();
    image.src = '{0}';
</script>
";
            strPreLoad = string.Format(strPreLoad, libNavOverUrl);
            csm.RegisterStartupScript(lnType, name, strPreLoad);
        }

        private void AppendCenteredText(HtmlTextWriter writer, string html)
        {
            writer.WriteLine("<table  border=\"0\" cellpadding=\"0\" cellspacing=\"0\">");
            writer.WriteLine("<tr>");
            writer.WriteLine("<td nowrap=\"nowrap\" style=\"height:32px;vertical-align:middle;\">");
            writer.WriteLine(html);
            writer.WriteLine("</td>");
            writer.WriteLine("</tr>");
            writer.WriteLine("</table>");
        }

        private Dictionary<string, NavLink> GetNavLinks()
        {
            Dictionary<string, NavLink> navLinks = new Dictionary<string, NavLink>();

            SPWeb web = SPContext.Current.Web;

            string listName = "Pages";
            SPList list = web.Lists[listName];

            if (list == null)
                throw new Exception(string.Format("List {0} could not be found.", listName));

            //Set Defaults
            if (string.IsNullOrEmpty(this.DisplayField))
                this.DisplayField = "Title";

            SPField spField = null;

            if (!string.IsNullOrEmpty(this.ContentSourceField))
                spField = list.Fields.GetFieldByInternalName(this.ContentSourceField);
            else
            {
                foreach (SPField f in list.Fields)
                {
                    if (f.Title.ToLower().Contains("content source"))
                    {
                        spField = f;
                        break;
                    }
                }
            }

            if (spField == null)
                throw new Exception("Content Source field could not be found.");

            SPQuery query = new SPQuery();

            query.ViewAttributes = "Scope=\"Recursive\"";
            query.ViewFields = string.Format(
                "<FieldRef Name=\"EncodedAbsUrl\" /><FieldRef Name=\"{0}\" /><FieldRef Name=\"{1}\" />"
                , spField.InternalName, this.DisplayField);

            query.Query = string.Format(@"<Where><IsNotNull><FieldRef Name='{0}' /></IsNotNull></Where>
<OrderBy><FieldRef Name='{0}' /><FieldRef Name='{1}' /></OrderBy>"
                ,spField.InternalName, this.DisplayField);

            SPField displayField = list.Fields.GetField(this.DisplayField);
            if (displayField == null)
                displayField = list.Fields.GetFieldByInternalName(this.DisplayField);

            SPListItemCollection items = list.GetItems(query);
            foreach (SPListItem item in items)
            {
                NavLink subLink = new NavLink();
                if (displayField != null)
                {
                    object objDisplay = item[displayField.Id];
                    if (objDisplay != null)
                        subLink.Title = objDisplay.ToString();
                    else
                        subLink.Title = "[not set]";
                }
                else
                    subLink.Title = "Column not found";
                
                subLink.Url = item["EncodedAbsUrl"].ToString();

                string tabName = item[spField.InternalName].ToString();

                if (navLinks.ContainsKey(tabName))
                    navLinks[tabName].SubLinks.Add(subLink);
                else
                {
                    NavLink tab = new NavLink();
                    tab.Title = tabName;
                    tab.SubLinks.Add(subLink);
                    navLinks.Add(tabName, tab);
                }
            }

            return navLinks;
        }

        private void RegisterStyleSheet(string cssUrl)
        {
            HtmlHead header = FindControl<HtmlHead>(this.Page.Master.Controls);

            if (header != null)
            {
                Literal literal = new Literal();
                literal.Text = string.Format("<link href=\"{0}\" type=\"text/css\" rel=\"stylesheet\"/>", cssUrl);
                header.Controls.Add(literal);
            }
        }

        private T FindControl<T>(ControlCollection controlCollection)
            where T : Control
        {
            foreach (Control c in controlCollection)
            {
                if (c.GetType() == typeof(T))
                    return (T)c;
                else
                {
                    T child = FindControl<T>(c.Controls);
                    if (child != null)
                        return child;
                }
            }
            return null;
        }

    }
}