using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Microsoft.SharePoint;

// Author:   William Cornwill
// Blog:     http://www.codejedi.net
// Date:     11th June 2007
// Licence:  Creative Commons Attribution 3.0 Unported (http://creativecommons.org/licenses/by/3.0/)
//           You are free to use, alter, remix and redistribute this works, as long as
//           this attribution remains unaltered. 

namespace CodeJedi.SharePoint.UserControls
{
    /// <summary>
    /// This is a MOSS version of the AdRotator control.  It obtains a handle to a picture library
    /// and then randomly chooses an image to render.
    /// </summary>
    [DefaultProperty("Text")]
    [ToolboxData("<{0}:MossAdRotator runat=server>")]
    public class MossAdRotator : AdRotator
    {
        #region Properties

        /// <summary>
        /// The name of the Picture Library that contains the images for the AdRotator
        /// </summary>
        [Bindable(true)]
        [Category("Behavior")]
        [DefaultValue("")]
        [Localizable(true)]
        public string AdsLibraryName
        {
            get { return adsLibraryName; }
            set { adsLibraryName = value; }
        }

        /// <summary>
        /// Indicates whether errors should be shown in the page.
        ///     if true, then any error messages will be displayed in the Alt Text of the image
        ///     if false, then the visibility of the AdRotator will be set to false
        /// </summary>
        [Bindable(false)]
        [Category("Behavior")]
        [DefaultValue(false)]
        public bool DisplayErrors
        {
            get { return displayErrors; }
            set { displayErrors = value; }
        }

        /// <summary>
        /// The display name of the SPField that contains the AlternativeText.
        /// </summary>
        [Bindable(true)]
        [Category("Behavior")]
        [DefaultValue("Description")]
        public string AlternativeTextFieldName
        {
            get { return alternativeTextFieldName; }
            set { alternativeTextFieldName = value; }
        }

        #endregion

        #region Privates

        private string adsLibraryName;
        private bool displayErrors;
        private string alternativeTextFieldName;

        /// <summary>
        /// Generates a random number between 0 and Max
        /// </summary>
        /// <param name="max">The maximum number to randomly generate</param>
        /// <returns>A random number</returns>
        private static int Randomiser(int max)
        {
            int index = 0;
            Random rand = new Random(); //no need for anything more complex!
            index = rand.Next(0, max);

            return index;
        }

        #endregion

        #region Overrides

        /// <summary>
        /// Event that obtains a random image from the nominated image library
        ///     - ImageUrl is Url of the image in the image library
        ///     - NavigateUrl is the Title of the image in the image library
        ///     - AlternativeText is the DisplayName of the image in the image library
        /// </summary>
        /// <param name="e"></param>
        protected override void OnAdCreated(AdCreatedEventArgs e)
        {
            try
            {
                SPWeb web = SPContext.Current.Web;
                SPList list = web.Lists[adsLibraryName];

                if (list == null)
                    throw new Exception("The Picture Library '" + adsLibraryName + "' could not be found.");

                int resourceIndex = Randomiser(list.ItemCount);
                SPListItem li = list.Items[resourceIndex];

                string webUrl = web.ServerRelativeUrl;
                if (webUrl != "/")
                {
                    webUrl = webUrl + "/";
                }
                e.ImageUrl = webUrl + li.Url;
                e.NavigateUrl = li.Title;
                try
                {
                    //Try and obtain the Alternative Text from the nominated field
                    e.AlternateText = li[alternativeTextFieldName].ToString();
                }
                catch (ArgumentException)
                {
                    //If the nominated field does not exist then use "" as Alternative Text
                    e.AlternateText = "";
                }
            }
            catch (Exception ex)
            {
                // If an exception occurs then output the message text to the Alternative Text of the image
                // if displayErrors is true, otherwise hide the entire control from rendering.
                if (displayErrors)
                {
                    e.AlternateText = ex.Message;
                }
                else
                {
                    this.Visible = false;
                }
            }
        }

        #endregion
    }
}