//
// SearchEntry.cs
//
// Author:
//   Aaron Bockover <abockover@novell.com>
//   Gabriel Burt <gburt@novell.com>
//
// Copyright 2007-2010 Novell, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using Gtk;

namespace MonoDevelop.Components
{
	[System.ComponentModel.ToolboxItem(true)]
	public class SearchEntry : EventBox
	{
		private HBox box;
		private Entry entry;
		private HoverImageButton filter_button;
		private HoverImageButton clear_button;

		private Menu menu;
		private int active_filter_id = -1;

		private uint changed_timeout_id = 0;

		private string empty_message;
		private bool ready = false;

		private event EventHandler filter_changed;
		private event EventHandler entry_changed;

		public event EventHandler Changed {
			add { entry_changed += value; }
			remove { entry_changed -= value; }
		}

		public event EventHandler Activated {
			add { entry.Activated += value; }
			remove { entry.Activated -= value; }
		}

		public event EventHandler FilterChanged {
			add { filter_changed += value; }
			remove { filter_changed -= value; }
		}
		
		bool forceFilterButtonVisible;
		public bool ForceFilterButtonVisible {
			get {
				return forceFilterButtonVisible; 
			}
			set {
				forceFilterButtonVisible = value;
				ShowHideButtons ();
			}
		}
		
		public Menu Menu {
			get { return menu; }
			set { menu = value; menu.Deactivated += OnMenuDeactivated; }
		}

		public Entry Entry {
			get { return this.entry; }
		}

		public SearchEntry ()
		{
			AppPaintable = true;
			
			BuildWidget ();
			BuildMenu ();
			
			NoShowAll = true;
		}
		public Gdk.Pixbuf FilterButtonPixbuf {
			get {
				return filter_button.Pixbuf;
			}
			set {
				filter_button.Pixbuf = value;
			}
		}
		
		private void BuildWidget ()
		{
			box = new HBox ();
			entry = new FramelessEntry (this);
			filter_button = new HoverImageButton (IconSize.Menu, new string[] { Stock.Find });
			clear_button = new HoverImageButton (IconSize.Menu, new string[] { Stock.Clear });
			
			box.PackStart (filter_button, false, false, 0);
			box.PackStart (entry, true, true, 0);
			box.PackStart (clear_button, false, false, 0);
			Add (box);
			box.ShowAll ();
			
			entry.StyleSet += OnInnerEntryStyleSet;
			entry.StateChanged += OnInnerEntryStateChanged;
			entry.FocusInEvent += OnInnerEntryFocusEvent;
			entry.FocusOutEvent += OnInnerEntryFocusEvent;
			entry.Changed += OnInnerEntryChanged;
			
			filter_button.Image.Xpad = 2;
			clear_button.Image.Xpad = 2;
			filter_button.CanFocus = false;
			clear_button.CanFocus = false;
			
			filter_button.ButtonReleaseEvent += OnButtonReleaseEvent;
			clear_button.ButtonReleaseEvent += OnButtonReleaseEvent;
			clear_button.Clicked += OnClearButtonClicked;
			
			filter_button.Visible = false;
			clear_button.Visible = false;
			
		}

		Gtk.EventBox statusLabelEventBox;
		public Gtk.EventBox AddLabelWidget (Gtk.Label label)
		{
			box.Remove (clear_button);
			statusLabelEventBox = new Gtk.EventBox ();
			statusLabelEventBox.Child = label;
			box.PackStart (statusLabelEventBox, false, false, 0);
			box.PackStart (clear_button, false, false, 0);
			UpdateStyle ();
			box.ShowAll ();
			return statusLabelEventBox;
		}

		private void BuildMenu ()
		{
			menu = new Menu ();
			menu.Deactivated += OnMenuDeactivated;
		}

		public void PopupFilterMenu ()
		{
			ShowMenu (0);
		}
		
		void ShowMenu (uint time)
		{
			OnRequestMenu (EventArgs.Empty);
			if (menu.Children.Length > 0) {
				menu.Popup (null, null, OnPositionMenu, 0, time);
				menu.ShowAll ();
			}
		}

		private void ShowHideButtons ()
		{
			clear_button.Visible = entry.Text.Length > 0;
			filter_button.Visible = ForceFilterButtonVisible || (menu != null && menu.Children.Length > 0);
		}

		private void OnPositionMenu (Menu menu, out int x, out int y, out bool push_in)
		{
			int origin_x, origin_y, tmp;
			
			filter_button.GdkWindow.GetOrigin (out origin_x, out tmp);
			GdkWindow.GetOrigin (out tmp, out origin_y);
			
			x = origin_x + filter_button.Allocation.X;
			y = origin_y + SizeRequest ().Height;
			push_in = true;
		}

		private void OnMenuDeactivated (object o, EventArgs args)
		{
			filter_button.QueueDraw ();
		}

		private bool toggling = false;
		public bool IsCheckMenu { get; set; }
		private void OnMenuItemToggled (object o, EventArgs args)
		{
			if (IsCheckMenu || toggling || !(o is FilterMenuItem)) {
				return;
			}
			
			toggling = true;
			FilterMenuItem item = (FilterMenuItem)o;
			
			foreach (MenuItem child_item in menu) {
				if (!(child_item is FilterMenuItem)) {
					continue;
				}
				
				FilterMenuItem filter_child = (FilterMenuItem)child_item;
				if (filter_child != item) {
					filter_child.Active = false;
				}
			}
			
			item.Active = true;
			ActiveFilterID = item.ID;
			toggling = false;
		}

		private void OnInnerEntryChanged (object o, EventArgs args)
		{
			ShowHideButtons ();
			
			if (changed_timeout_id > 0) {
				GLib.Source.Remove (changed_timeout_id);
			}
			
			if (Ready)
				changed_timeout_id = GLib.Timeout.Add (25, OnChangedTimeout);
		}

		private bool OnChangedTimeout ()
		{
			OnChanged ();
			return false;
		}

		private void UpdateStyle ()
		{
			Gdk.Color color = entry.Style.Base (entry.State);
			filter_button.ModifyBg (entry.State, color);
			clear_button.ModifyBg (entry.State, color);
			if (statusLabelEventBox != null)
				statusLabelEventBox.ModifyBg (entry.State, color);
			box.BorderWidth = (uint)entry.Style.XThickness;
		}

		private void OnInnerEntryStyleSet (object o, StyleSetArgs args)
		{
			UpdateStyle ();
		}

		private void OnInnerEntryStateChanged (object o, EventArgs args)
		{
			UpdateStyle ();
		}

		private void OnInnerEntryFocusEvent (object o, EventArgs args)
		{
			QueueDraw ();
		}

		private void OnButtonReleaseEvent (object o, ButtonReleaseEventArgs args)
		{
			if (args.Event.Button != 1) {
				return;
			}
			
			entry.HasFocus = true;
			
			if (o == filter_button) {
				ShowMenu (args.Event.Time);
			}
		}
		
		protected virtual void OnRequestMenu (EventArgs e)
		{
			EventHandler handler = this.RequestMenu;
			if (handler != null)
				handler (this, e);
		}
		
		public event EventHandler RequestMenu;
		
		public void GrabFocusEntry ()
		{
			this.entry.GrabFocus ();
		}
		private void OnClearButtonClicked (object o, EventArgs args)
		{
			active_filter_id = 0;
			entry.Text = String.Empty;
		}

		protected override bool OnKeyPressEvent (Gdk.EventKey evnt)
		{
			if (evnt.Key == Gdk.Key.Escape) {
				active_filter_id = 0;
				entry.Text = String.Empty;
				return true;
			}
			return base.OnKeyPressEvent (evnt);
		}

		protected override bool OnExposeEvent (Gdk.EventExpose evnt)
		{
			Style.PaintFlatBox (entry.Style, GdkWindow, State, ShadowType.None,
				evnt.Area, this, "entry_bg", 0, 0, Allocation.Width, Allocation.Height);
			PropagateExpose (Child, evnt);
			Style.PaintShadow (entry.Style, GdkWindow, StateType.Normal, ShadowType.In,
				evnt.Area, entry, "entry", 0, 0, Allocation.Width, Allocation.Height);
			return true;
		}

		protected override void OnShown ()
		{
			base.OnShown ();
			ShowHideButtons ();
		}

		protected virtual void OnChanged ()
		{
			if (!Ready) {
				return;
			}
			
			EventHandler handler = entry_changed;
			if (handler != null) {
				handler (this, EventArgs.Empty);
			}
		}

		protected virtual void OnFilterChanged ()
		{
			EventHandler handler = filter_changed;
			if (handler != null) {
				handler (this, EventArgs.Empty);
			}
			
			if (IsQueryAvailable) {
				OnInnerEntryChanged (this, EventArgs.Empty);
			}
		}

		public CheckMenuItem AddFilterOption (int id, string label)
		{
			if (id < 0) {
				throw new ArgumentException ("id", "must be >= 0");
			}
			
			FilterMenuItem item = new FilterMenuItem (id, label);
			
			item.Toggled += OnMenuItemToggled;
			menu.Append (item);
			
			if (ActiveFilterID < 0) {
				item.Toggle ();
			}
			
			filter_button.Visible = true;
			return item;
		}

		public void AddFilterSeparator ()
		{
			menu.Append (new SeparatorMenuItem ());
		}

		public void RemoveFilterOption (int id)
		{
			FilterMenuItem item = FindFilterMenuItem (id);
			if (item != null) {
				menu.Remove (item);
			}
		}

		public void ActivateFilter (int id)
		{
			FilterMenuItem item = FindFilterMenuItem (id);
			if (item != null) {
				item.Toggle ();
			}
		}

		private FilterMenuItem FindFilterMenuItem (int id)
		{
			foreach (MenuItem item in menu) {
				if (item is FilterMenuItem && ((FilterMenuItem)item).ID == id) {
					return (FilterMenuItem)item;
				}
			}
			
			return null;
		}

		public string GetLabelForFilterID (int id)
		{
			FilterMenuItem item = FindFilterMenuItem (id);
			if (item == null) {
				return null;
			}
			
			return item.Label;
		}

		public void CancelSearch ()
		{
			entry.Text = String.Empty;
			ActivateFilter (0);
		}

		public int ActiveFilterID {
			get { return active_filter_id; }
			set {
				if (value == active_filter_id) {
					return;
				}
				
				active_filter_id = value;
				OnFilterChanged ();
			}
		}

		public string EmptyMessage {
			get { return entry.Sensitive ? empty_message : String.Empty; }
			set {
				empty_message = value;
				entry.QueueDraw ();
			}
		}

		public string Query {
			get { return entry.Text.Trim (); }
			set { entry.Text = value.Trim (); }
		}

		public bool IsQueryAvailable {
			get { return Query != null && Query != String.Empty; }
		}

		public bool Ready {
			get { return ready; }
			set { ready = value; }
		}

		public new bool HasFocus {
			get { return entry.HasFocus; }
			set { entry.HasFocus = true; }
		}


		public Entry InnerEntry {
			get { return entry; }
		}

		protected override void OnStateChanged (Gtk.StateType previous_state)
		{
			base.OnStateChanged (previous_state);
			
			entry.Sensitive = State != StateType.Insensitive;
			filter_button.Sensitive = State != StateType.Insensitive;
			clear_button.Sensitive = State != StateType.Insensitive;
		}

		private class FilterMenuItem : CheckMenuItem
		{
			private int id;
			private string label;

			public FilterMenuItem (int id, string label) : base(label)
			{
				this.id = id;
				this.label = label;
				DrawAsRadio = true;
			}

			public int ID {
				get { return id; }
			}

			public string Label {
				get { return label; }
			}
			/*
            // FIXME: Remove when restored to CheckMenuItem
            private bool active;
            public bool Active {
                get { return active; }
                set { active = value; }
            }*/

			public new event EventHandler Toggled;
			protected override void OnActivated ()
			{
				base.OnActivated ();
				if (Toggled != null) {
					Toggled (this, EventArgs.Empty);
				}
			}
			
		}

		private class FramelessEntry : Entry
		{
			private Gdk.Window text_window;
			private SearchEntry parent;
			private Pango.Layout layout;
			private Gdk.GC text_gc;

			public FramelessEntry (SearchEntry parent) : base()
			{
				this.parent = parent;
				HasFrame = false;
				
				parent.StyleSet += OnParentStyleSet;
				WidthChars = 1;
			}

			private void OnParentStyleSet (object o, EventArgs args)
			{
				RefreshGC ();
				QueueDraw ();
			}

			private void RefreshGC ()
			{
				text_gc = null;
			}
			
			protected override void OnDestroyed ()
			{
				parent.StyleSet -= OnParentStyleSet;
				base.OnDestroyed ();
			}
			
			public static Gdk.Color ColorBlend (Gdk.Color a, Gdk.Color b)
			{
				// at some point, might be nice to allow any blend?
				double blend = 0.5;
				
				if (blend < 0.0 || blend > 1.0) {
					throw new ApplicationException ("blend < 0.0 || blend > 1.0");
				}
				
				double blendRatio = 1.0 - blend;
				
				int aR = a.Red >> 8;
				int aG = a.Green >> 8;
				int aB = a.Blue >> 8;
				
				int bR = b.Red >> 8;
				int bG = b.Green >> 8;
				int bB = b.Blue >> 8;
				
				double mR = aR + bR;
				double mG = aG + bG;
				double mB = aB + bB;
				
				double blR = mR * blendRatio;
				double blG = mG * blendRatio;
				double blB = mB * blendRatio;
				
				Gdk.Color color = new Gdk.Color ((byte)blR, (byte)blG, (byte)blB);
				Gdk.Colormap.System.AllocColor (ref color, true, true);
				return color;
			}

			protected override bool OnExposeEvent (Gdk.EventExpose evnt)
			{
				// The Entry's GdkWindow is the top level window onto which
				// the frame is drawn; the actual text entry is drawn into a
				// separate window, so we can ensure that for themes that don't
				// respect HasFrame, we never ever allow the base frame drawing
				// to happen
				if (evnt.Window == GdkWindow) {
					return true;
				}
				
				bool ret = base.OnExposeEvent (evnt);
				
				if (text_gc == null) {
					text_gc = new Gdk.GC (evnt.Window);
					text_gc.Copy (Style.TextGC (StateType.Normal));
					Gdk.Color color_a = parent.Style.Base (StateType.Normal);
					Gdk.Color color_b = parent.Style.Text (StateType.Normal);
					text_gc.RgbFgColor = ColorBlend (color_a, color_b);
				}
				
				if (Text.Length > 0 || HasFocus || parent.EmptyMessage == null) {
					return ret;
				}
				
				if (layout == null) {
					layout = new Pango.Layout (PangoContext);
					layout.FontDescription = PangoContext.FontDescription.Copy ();
				}
				
				int width, height;
				layout.SetMarkup (parent.EmptyMessage);
				layout.GetPixelSize (out width, out height);
				evnt.Window.DrawLayout (text_gc, 2, (SizeRequest ().Height - height) / 2, layout);
				
				return ret;
			}
		}
	}
}
