using System;
using System.Diagnostics;
using System.Xml;
using System.Data;
using System.IO;

namespace Msdn.Outlook.Calendaring
{
    /// <summary>
    /// A sample SharePoint task list calendar provider
    /// </summary>
    public class TaskListCalendarProvider : CalendarProvider
    {
        // Local variable that holds the site of the task
        // list to link, along with the name of the task
        // list.
        string _initData = "";

        /// <summary>
        /// Sets the value of the the _initData local variable
        /// </summary>
        /// <param name="initData"></param>
        public override void Configure(string initData)
        {
            _initData = initData;
        }

        /// <summary>
        /// Gets a list of events formatted so they can be
        /// displayed in Outlook
        /// </summary>
        /// <returns>Event collection</returns>
        public override EventCollection GetEvents()
        {
            EventCollection events = new EventCollection();

            DataSet dsTasks = GetTasks();

            if (dsTasks.Tables.Count > 1)
            {

                DataView dvTasks = new DataView(dsTasks.Tables["row"], "", "ows_StartDate", DataViewRowState.CurrentRows);

                DataTable dtTasks = dvTasks.ToTable();

                DateTime prevStartDate = DateTime.MinValue;
                int hours2add = 0;
                foreach (DataRow drTask in dtTasks.Rows)
                {
                    DateTime startDateTime = DateTime.Parse(drTask["ows_StartDate"].ToString());

                    if (startDateTime != prevStartDate)
                    {
                        hours2add = 0;
                        prevStartDate = startDateTime;
                    }
                    else
                    {
                        hours2add = hours2add + 1;
                    }
                    startDateTime = startDateTime.AddHours(hours2add);

                    DateTime endDateTime;
                    try
                    {
                        endDateTime = DateTime.Parse(drTask["ows_DueDate"].ToString());
                    }
                    catch
                    {
                        endDateTime = startDateTime;
                    }
                    if (endDateTime == startDateTime) endDateTime = startDateTime.AddMinutes(60);
                    Event e = new Event();
                    try
                    {
                        e.Author = drTask["ows_AssignedTo"].ToString().Split('#')[1];
                    }
                    catch
                    {
                        e.Author = "Unassigned";
                    }
                    try
                    {
                        e.Description = GetDescription(drTask);
                    }
                    catch
                    {
                        e.Description = "";
                    }
                    e.Location = " ** SharePoint Task List: " + _initData.Split(';')[1] + " at Site: " + _initData.Split(';')[0] + " **";
                    e.Start = startDateTime.ToUniversalTime();
                    e.End = endDateTime.ToUniversalTime();
                    e.Title = drTask["ows_Title"].ToString() + " (" + drTask["ows_AssignedTo"].ToString().Split('#')[1] + ")";
                    events.Add(e);
                }

            }

            return events;
        }

        /// <summary>
        /// Returns string to be displayed in the task description
        /// field in Outlook
        /// </summary>
        /// <param name="drTask">A datarow object containing source data for description</param>
        /// <returns>String value representing the description to display</returns>
        private string GetDescription(DataRow drTask)
        {
            string assignedTo = "Unassigned";
            string status = "Unknown";
            string estHours = "0";
            string description = "";
            string linkUrl = "";

            try
            {
                assignedTo = drTask["ows_AssignedTo"].ToString().Split('#')[1];
            }
            catch { }

            try
            {
                status = drTask["ows_Status"].ToString();
            }
            catch { }

            try
            {
                estHours = drTask["EstHours"].ToString();
            }
            catch { }

            try
            {
                description = drTask["ows_Body"].ToString().Replace("<div>", "").Replace("</div>", "");
            }
            catch { }

            try
            {
                linkUrl = _initData.Split(';')[0] + "/Lists/" + _initData.Split(';')[1] + "/DispForm.aspx?ID=" + drTask["ows_ID"].ToString();
                linkUrl = linkUrl.Replace(" ", "%20");
            }
            catch { }

            return string.Format("Assigned To: {0}\nStatus: {1}\nDescription: {2}\n\nLink to Task: {3}",
                assignedTo,
                status,
                description,
                linkUrl);
        }

        /// <summary>
        /// Return a dataset containing all items in the specified task list
        /// </summary>
        /// <returns>DataSet containing all items in attached SharePoint task list</returns>
        public DataSet GetTasks()
        {
            // Get handle to web service
            ListsService.Lists lsvc = new ListsService.Lists();

            // Assume current user has at least read permissions to 
            // source task list
            lsvc.Credentials = System.Net.CredentialCache.DefaultCredentials;

            string url = _initData.Split(';')[0] + "/_vti_bin/lists.asmx";
            string listName = _initData.Split(';')[1];

            lsvc.Url = url;

            XmlDocument xmlDoc = new XmlDocument();

            XmlNode ndQuery = xmlDoc.CreateNode(XmlNodeType.Element, "Query", "");
            XmlNode ndViewFields = xmlDoc.CreateNode(XmlNodeType.Element, "ViewFields", "<FieldRef Name='Assigned To'/>");
            XmlNode ndQueryOptions = xmlDoc.CreateNode(XmlNodeType.Element, "QueryOptions", "");

            DataSet dsTasks = new DataSet();

            ndQueryOptions.InnerXml = "<IncludeMandatoryColumns>FALSE</IncludeMandatoryColumns><DateInUtc>TRUE</DateInUtc>";

            // Retrieve the current task list from SharePoint
            XmlNode ndListItems = lsvc.GetListItems(listName, null, ndQuery, ndViewFields, "2000", ndQueryOptions, null);
            StringReader sr = new StringReader(ndListItems.OuterXml);
            dsTasks.ReadXml(sr);
            sr.Close();

            if (dsTasks == null || dsTasks.Tables.Count == 0)
                return null;
            else
                return dsTasks;

        }
    }
}