//
// System.Web.UI.WebControls.ListControl.cs
//
// Authors:
//   Gaurav Vaish (gvaish@iitk.ac.in)
//   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
//
// (C) Gaurav Vaish (2002)
// (C) 2003 Andreas Nahr
//

using System;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Web;
using System.Web.UI;
using System.Web.Util;

namespace System.Web.UI.WebControls
{
	[DefaultEvent("SelectedIndexChanged")]
	#if !NET_2_0
	[DefaultProperty("DataSource")]
	#endif
	[Designer ("System.Web.UI.Design.WebControls.ListControlDesigner, " + Consts.AssemblySystem_Design, typeof (IDesigner))]
	[DataBindingHandler("System.Web.UI.Design.ListControlDataBindingHandler, " + Consts.AssemblySystem_Design)]
	[ParseChildren(true, "Items")]
	public abstract class ListControl : 
		#if NET_2_0
			DataBoundControl
		#else
			WebControl
		#endif
	{
		private static readonly object SelectedIndexChangedEvent = new object();

		#if !NET_2_0
		private object             dataSource;
		#endif
		
		private ListItemCollection items;

		private int cachedSelectedIndex = -1;
		private string cachedSelectedValue;

		#if !NET_2_0
		public ListControl(): base(HtmlTextWriterTag.Select)
		{
		}
		#else
		protected override HtmlTextWriterTag TagKey {
			get { return HtmlTextWriterTag.Select; }
		}
		#endif

		[WebCategory ("Action")]
		[WebSysDescription ("Raised when the selected index entry has changed.")]
		public event EventHandler SelectedIndexChanged
		{
			add
			{
				Events.AddHandler(SelectedIndexChangedEvent, value);
			}
			remove
			{
				Events.RemoveHandler(SelectedIndexChangedEvent, value);
			}
		}

		[DefaultValue (false), WebCategory ("Behavior")]
		[WebSysDescription ("The control automatically posts back after changing the text.")]
		public virtual bool AutoPostBack
		{
			get
			{
				object o = ViewState["AutoPostBack"];
				if(o!=null)
					return (bool)o;
				return false;
			}
			set
			{
				ViewState["AutoPostBack"] = value;
			}
		}

		#if !NET_2_0
		[DefaultValue (""), WebCategory ("Data")]
		[WebSysDescription ("The name of the table that is used for binding when a DataSource is specified.")]
		public virtual string DataMember
		{
			get
			{
				object o = ViewState["DataMember"];
				if(o!=null)
					return (string)o;
				return String.Empty;
			}
			set
			{
				ViewState["DataMember"] = value;
			}
		}


		[DefaultValue (null), Bindable (true), WebCategory ("Data")]
		[DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
		[WebSysDescription ("The DataSource that is used for data-binding.")]
		public virtual object DataSource
		{
			get
			{
				return dataSource;
			}
			set
			{
				if(value == null || value is IListSource || value is IEnumerable) {
					dataSource = value;
					return;
				}
				throw new ArgumentException(HttpRuntime.FormatResourceString(ID, "Invalid DataSource Type"));
			}
		}
		#endif

		[DefaultValue (""), WebCategory ("Data")]
		[WebSysDescription ("The field in the datatable that provides the text entry.")]
		public virtual string DataTextField
		{
			get
			{
				object o = ViewState["DataTextField"];
				if(o!=null)
					return (string)o;
				return String.Empty;
			}
			set
			{
				ViewState["DataTextField"] = value;
			}
		}

		[DefaultValue (""), WebCategory ("Data")]
		[WebSysDescription ("Specifies a formatting rule for the texts that are returned.")]
		public virtual string DataTextFormatString
		{
			get
			{
				object o = ViewState["DataTextFormatString"];
				if(o!=null)
					return (string)o;
				return String.Empty;
			}
			set
			{
				ViewState["DataTextFormatString"] = value;
			}
		}

		[DefaultValue (""), WebCategory ("Data")]
		[WebSysDescription ("The field in the datatable that provides the entry value.")]
		public virtual string DataValueField
		{
			get
			{
				object o = ViewState["DataValueField"];
				if(o!=null)
					return (string)o;
				return String.Empty;
			}
			set
			{
				ViewState["DataValueField"] = value;
			}
		}

		[DefaultValue (null), MergableProperty (false), WebCategory ("Misc")]
		[PersistenceMode (PersistenceMode.InnerDefaultProperty)]
		[WebSysDescription ("A collection of all items contained in this list.")]
		public virtual ListItemCollection Items
		{
			get
			{
				if(items==null)
				{
					items = new ListItemCollection();
					if(IsTrackingViewState)
					{
						items.TrackViewState();
					}
				}
				return items;
			}
		}

		[DefaultValue (0), Bindable (true), WebCategory ("Misc")]
		[Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
		[WebSysDescription ("The index number of the currently selected ListItem.")]
		public virtual int SelectedIndex
		{
			get {
				ListItemCollection items = Items;
				int last = items.Count;
				for (int i = 0; i < last; i++) {
					if (items [i].Selected)
						return i;
				}
				return -1;
			}
			set {
				if (Items.Count == 0)
				{
					cachedSelectedIndex = value;
					return;
				}
				if ((value < -1) || (value >= Items.Count))
					throw new ArgumentOutOfRangeException ();

				ClearSelection ();
				if (value != -1)
					Items [value].Selected = true;
			}
		}

		[DefaultValue (null), WebCategory ("Misc")]
		[Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
		[WebSysDescription ("The currently selected ListItem.")]
		public virtual ListItem SelectedItem
		{
			get
			{
				int idx = SelectedIndex;
				if (idx < 0)
					return null;

				return Items [idx];
			}
		}

#if NET_1_1
		[DefaultValue (""), Bindable (true), WebCategory ("Misc")]
		[Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
		[WebSysDescription ("The value of the currently selected ListItem.")]
		public virtual string SelectedValue {
			get {
				int idx = SelectedIndex;
				if (idx == -1)
					return "";

				return Items [idx].Value;
			}

			set {
				ListItem item = null;

				if (value != null) {
					if (Items.Count > 0) {
						item = Items.FindByValue (value);
						if (item == null)
							throw new ArgumentOutOfRangeException ("value");
					} else {
						cachedSelectedValue = value;
						return;
					}
				}

				ClearSelection ();
				if (item != null)
					item.Selected = true;
			}
		}
#endif
		
		internal virtual ArrayList SelectedIndices
		{
			get
			{
				ArrayList si = new ArrayList();
				for(int i=0; i < Items.Count; i++)
				{
					if(Items[i].Selected)
						si.Add(i);
				}
				return si;
			}
		}

		internal void Select(ArrayList indices)
		{
			ClearSelection();
			foreach(object intObj in indices)
			{
				int index = (int)intObj;
				if(index >= 0 && index < Items.Count)
					Items[index].Selected = true;
			}
		}

		public virtual void ClearSelection()
		{
			for(int i=0; i < Items.Count; i++)
			{
				Items[i].Selected = false;
			}
		}

		protected override void LoadViewState(object savedState)
		{
			//Order: BaseClass, Items (Collection), Indices
			if(savedState != null && savedState is Triplet)
			{
				Triplet state = (Triplet)savedState;
				base.LoadViewState(state.First);
				Items.LoadViewState(state.Second);
				object indices = state.Third;
				if(indices != null)
				{
					Select((ArrayList)indices);
				}
			}
		}

		#if NET_2_0
		protected override void PerformDataBinding ()
		{
			base.PerformDataBinding ();
			IEnumerable ds = GetResolvedDataSource ();
		#else
		protected override void OnDataBinding(EventArgs e)
		{
			base.OnDataBinding(e);
			IEnumerable ds = DataSourceHelper.GetResolvedDataSource (DataSource, DataMember);
		#endif
			if(ds != null) {
				string dtf = DataTextField;
				string dvf = DataValueField;
				string dtfs = DataTextFormatString;
				if (dtfs.Length == 0)
					dtfs = "{0}";

				Items.Clear();

				bool dontUseProperties = (dtf.Length == 0 && dvf.Length == 0);

				foreach (object current in ds) {
					ListItem li = new ListItem();
					if (dontUseProperties){
						li.Text  = String.Format (dtfs, current);
						li.Value = current.ToString ();
						Items.Add (li);
						continue;
					}

					object o;
					if (dtf.Length > 0) {
						o = DataBinder.GetPropertyValue (current, dtf, dtfs);
						li.Text = o.ToString ();
					}

					if (dvf.Length > 0) {
						o = DataBinder.GetPropertyValue (current, dvf, null);
						li.Value = o.ToString ();
					}

					Items.Add(li);
				}
			}

			if (cachedSelectedValue != null) {
				int index = Items.FindByValueInternal (cachedSelectedValue);
				if (index == -1)
					throw new ArgumentOutOfRangeException("value");

				if (cachedSelectedIndex != -1 && cachedSelectedIndex != index)
					throw new ArgumentException(HttpRuntime.FormatResourceString(
						"Attributes_mutually_exclusive", "Selected Index", "Selected Value"));

				SelectedIndex = index;
				cachedSelectedIndex = -1;
				cachedSelectedValue = null;
				return;
			}

			if (cachedSelectedIndex != -1) {
				SelectedIndex = cachedSelectedIndex;
				cachedSelectedIndex = -1;
			}
		}

		protected virtual void OnSelectedIndexChanged(EventArgs e)
		{
			if(Events!=null)
				{
					EventHandler eh = (EventHandler)(Events[SelectedIndexChangedEvent]);
					if(eh!=null)
						eh(this, e);
				}
		}

		protected override void OnPreRender (EventArgs e)
		{
			base.OnPreRender(e);
		}

		protected override object SaveViewState()
		{
			//Order: BaseClass, Items (Collection), Indices
			object vs = base.SaveViewState();
			object itemSvs = Items.SaveViewState();
			object indices = null;
			if (SaveSelectedIndicesViewState)
				indices = SelectedIndices;

			if (vs != null || itemSvs != null || indices != null)
				return new Triplet(vs, itemSvs, indices);

			return null;
		}

		protected override void TrackViewState()
		{
			base.TrackViewState();
			Items.TrackViewState();
		}

		private bool SaveSelectedIndicesViewState {
			get {
				if (Events[SelectedIndexChangedEvent] == null && Enabled && Visible) {
					Type t = GetType();
					// If I am a derivative, let it take of storing the selected indices.
					if (t == typeof(DropDownList) || t == typeof(ListBox) ||
					    t == typeof(CheckBoxList) || t == typeof(RadioButtonList))
						return false;
				}
				return true;
			}
		}
	}
}