// 
// LogView.cs
//  
// Author:
//       Lluis Sanchez Gual <lluis@novell.com>
// 
// Copyright (c) 2010 Novell, Inc (http://www.novell.com)
// 
// 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 MonoDevelop.Ide.Gui.Pads;
using Gtk;
using Pango;
using System.Collections.Generic;
using MonoDevelop.Core;
using MonoDevelop.Core.ProgressMonitoring;
using MonoDevelop.Core.Execution;
using System.IO;

namespace MonoDevelop.Ide.Gui.Components
{
	public class LogView: Gtk.ScrolledWindow
	{
		Gtk.TextBuffer buffer;
		Gtk.TextView textEditorControl;
		TextMark endMark;
		FontDescription customFont;
		
		TextTag tag;
		TextTag bold;
		TextTag errorTag;
		TextTag consoleLogTag;
		int ident = 0;
		List<TextTag> tags = new List<TextTag> ();
		Stack<string> indents = new Stack<string> ();

		Queue<QueuedUpdate> updates = new Queue<QueuedUpdate> ();
		QueuedTextWrite lastTextWrite;
		GLib.TimeoutHandler outputDispatcher;
		bool outputDispatcherRunning = false;
		
		const int MAX_BUFFER_LENGTH = 200 * 1024; 

		public LogView ()
		{
			buffer = new Gtk.TextBuffer (new Gtk.TextTagTable ());
			textEditorControl = new Gtk.TextView (buffer);
			textEditorControl.Editable = false;
			
			ShadowType = ShadowType.None;
			Add (textEditorControl);

			bold = new TextTag ("bold");
			bold.Weight = Pango.Weight.Bold;
			buffer.TagTable.Add (bold);
			
			errorTag = new TextTag ("error");
			errorTag.Foreground = "red";
			errorTag.Weight = Pango.Weight.Bold;
			buffer.TagTable.Add (errorTag);
			
			consoleLogTag = new TextTag ("consoleLog");
			consoleLogTag.Foreground = "darkgrey";
			buffer.TagTable.Add (consoleLogTag);
			
			tag = new TextTag ("0");
			tag.LeftMargin = 10;
			buffer.TagTable.Add (tag);
			tags.Add (tag);
			
			endMark = buffer.CreateMark ("end-mark", buffer.EndIter, false);

			UpdateCustomFont (IdeApp.Preferences.CustomOutputPadFont);
			IdeApp.Preferences.CustomOutputPadFontChanged += HandleCustomFontChanged;
			
			outputDispatcher = new GLib.TimeoutHandler (outputDispatchHandler);
		}
		
		public LogViewProgressMonitor GetProgressMonitor ()
		{
			return new LogViewProgressMonitor (this);
		}

		public void Clear ()
		{
			lock (updates) {
				updates.Clear ();
				lastTextWrite = null;
				outputDispatcherRunning = false;
			}

			buffer.Clear();
		}
		
		void HandleCustomFontChanged (object sender, PropertyChangedEventArgs e)
		{
			UpdateCustomFont ((string)e.NewValue);
		}
		
		void UpdateCustomFont (string name)
		{
			if (customFont != null) {
				customFont.Dispose ();
				customFont = null;
			}
			if (!string.IsNullOrEmpty (name)) {
				customFont = Pango.FontDescription.FromString (name);
			}
			textEditorControl.ModifyFont (customFont);
		}
		
		//mechanism to to batch copy text when large amounts are being dumped
		bool outputDispatchHandler ()
		{
			lock (updates) {
				lastTextWrite = null;
				if (updates.Count == 0) {
					outputDispatcherRunning = false;
					return false;
				} else if (!outputDispatcherRunning) {
					updates.Clear ();
					return false;
				} else {
					while (updates.Count > 0) {
						QueuedUpdate up = updates.Dequeue ();
						up.Execute (this);
					}
				}
			}
			return true;
		}

		void addQueuedUpdate (QueuedUpdate update)
		{
			lock (updates) {
				updates.Enqueue (update);
				if (!outputDispatcherRunning) {
					GLib.Timeout.Add (50, outputDispatcher);
					outputDispatcherRunning = true;
				}
				lastTextWrite = update as QueuedTextWrite;
			}
		}

		protected void UnsafeBeginTask (string name, int totalWork)
		{
			if (name != null && name.Length > 0) {
				Indent ();
				indents.Push (name);
			} else
				indents.Push (null);

			if (name != null) {
				UnsafeAddText (Environment.NewLine + name + Environment.NewLine, bold);
			}
		}
		
		public void BeginTask (string name, int totalWork)
		{
			QueuedBeginTask bt = new QueuedBeginTask (name, totalWork);
			addQueuedUpdate (bt);
		}
		
		public void EndTask ()
		{
			QueuedEndTask et = new QueuedEndTask ();
			addQueuedUpdate (et);
		}
		
		protected void UnsafeEndTask ()
		{
			if (indents.Count > 0 && indents.Pop () != null)
				Unindent ();
		}
		
		public void WriteText (string text)
		{
			//raw text has an extra optimisation here, as we can append it to existing updates
			lock (updates) {
				if (lastTextWrite != null) {
					if (lastTextWrite.Tag == null) {
						lastTextWrite.Write (text);
						return;
					}
				}
			}
			QueuedTextWrite qtw = new QueuedTextWrite (text, null);
			addQueuedUpdate (qtw);
		}
		
		public void WriteConsoleLogText (string text)
		{
			lock (updates) {
				if (lastTextWrite != null && lastTextWrite.Tag == consoleLogTag) {
					lastTextWrite.Write (text);
					return;
				}
			}
			QueuedTextWrite w = new QueuedTextWrite (text, consoleLogTag);
			addQueuedUpdate (w);
		}
		
		public void WriteError (string text)
		{
			QueuedTextWrite w = new QueuedTextWrite (text, errorTag);
			addQueuedUpdate (w);
		}
		
		protected void UnsafeAddText (string text, TextTag extraTag)
		{
			//don't allow the pad to hold more than MAX_BUFFER_LENGTH chars
			int overrun = (buffer.CharCount + text.Length) - MAX_BUFFER_LENGTH;
			if (overrun > 0) {
				TextIter start = buffer.StartIter;
				TextIter end = buffer.GetIterAtOffset (overrun);
				buffer.Delete (ref start, ref end);
			}
			
			TextIter it = buffer.EndIter;
			ScrolledWindow window = textEditorControl.Parent as ScrolledWindow;
			bool scrollToEnd = true;
			if (window != null) {
				scrollToEnd = window.Vadjustment.Value >= window.Vadjustment.Upper - 2 * window.Vadjustment.PageSize;
			}
			if (extraTag != null)
				buffer.InsertWithTags (ref it, text, tag, extraTag);
			else
				buffer.InsertWithTags (ref it, text, tag);
			
			if (scrollToEnd) {
				it.LineOffset = 0;
				buffer.MoveMark (endMark, it);
				textEditorControl.ScrollToMark (endMark, 0, false, 0, 0);
			}
		}
		
		void Indent ()
		{
			ident++;
			if (ident >= tags.Count) {
				tag = new TextTag (ident.ToString ());
				tag.LeftMargin = 10 + 15 * (ident - 1);
				buffer.TagTable.Add (tag);
				tags.Add (tag);
			} else {
				tag = tags [ident];
			}
		}
		
		void Unindent ()
		{
			if (ident >= 0) {
				ident--;
				tag = tags [ident];
			}
		}

		protected override void OnDestroyed ()
		{
			base.OnDestroyed ();
			
			lock (updates) {
				updates.Clear ();
				lastTextWrite = null;
			}
			IdeApp.Preferences.CustomOutputPadFontChanged -= HandleCustomFontChanged;
			if (customFont != null) {
				customFont.Dispose ();
				customFont = null;
			}
		}
		
		private abstract class QueuedUpdate
		{
			public abstract void Execute (LogView pad);
		}
		
		private class QueuedTextWrite : QueuedUpdate
		{
			private System.Text.StringBuilder Text;
			public TextTag Tag;
			public override void Execute (LogView pad)
			{
				pad.UnsafeAddText (Text.ToString (), Tag);
			}
			
			public QueuedTextWrite (string text, TextTag tag)
			{
				Text = new System.Text.StringBuilder (text);
				Tag = tag;
			}
			
			public void Write (string s)
			{
				Text.Append (s);
				if (Text.Length > MAX_BUFFER_LENGTH)
					Text.Remove (0, Text.Length - MAX_BUFFER_LENGTH);
			}
		}
		
		private class QueuedBeginTask : QueuedUpdate
		{
			public string Name;
			public int TotalWork;
			public override void Execute (LogView pad)
			{
				pad.UnsafeBeginTask (Name, TotalWork);
			}
			
			public QueuedBeginTask (string name, int totalWork)
			{
				TotalWork = totalWork;
				Name = name;
			}
		}
		
		private class QueuedEndTask : QueuedUpdate
		{
			public override void Execute (LogView pad)
			{
				pad.UnsafeEndTask ();
			}
		}
	}

	public class LogViewProgressMonitor : NullProgressMonitor, IConsole
	{
		LogView outputPad;
		event EventHandler stopRequested;
		
		LogTextWriter logger = new LogTextWriter ();
		LogTextWriter internalLogger = new LogTextWriter ();
		NotSupportedTextReader inputReader = new NotSupportedTextReader ();
		
		public LogView LogView {
			get { return this.outputPad; }
		}
		
		public LogViewProgressMonitor (LogView pad)
		{
			outputPad = pad;
			outputPad.Clear ();
			logger.TextWritten += outputPad.WriteText;
			internalLogger.TextWritten += outputPad.WriteConsoleLogText;
		}
		
		public override void BeginTask (string name, int totalWork)
		{
			if (outputPad == null) throw GetDisposedException ();
			outputPad.BeginTask (name, totalWork);
			base.BeginTask (name, totalWork);
		}
		
		public override void EndTask ()
		{
			if (outputPad == null) throw GetDisposedException ();
			outputPad.EndTask ();
			base.EndTask ();
		}
		
		protected override void OnCompleted ()
		{
			if (outputPad == null) throw GetDisposedException ();
			outputPad.WriteText ("\n");
			
			foreach (string msg in Messages)
				outputPad.WriteText (msg + "\n");
			
			foreach (string msg in Warnings)
				outputPad.WriteText (msg + "\n");
			
			foreach (ProgressError msg in Errors)
				outputPad.WriteError (msg.Message + "\n");
			
			base.OnCompleted ();
			
			outputPad = null;
		}
		
		Exception GetDisposedException ()
		{
			return new InvalidOperationException ("Output progress monitor already disposed.");
		}
		
		protected override void OnCancelRequested ()
		{
			base.OnCancelRequested ();
			if (stopRequested != null)
				stopRequested (this, null);
		}
		
		public override TextWriter Log {
			get { return logger; }
		}
		
		TextWriter IConsole.Log {
			get { return internalLogger; }
		}
		
		TextReader IConsole.In {
			get { return inputReader; }
		}
		
		TextWriter IConsole.Out {
			get { return logger; }
		}
		
		TextWriter IConsole.Error {
			get { return logger; }
		} 
		
		bool IConsole.CloseOnDispose {
			get { return false; }
		}
		
		event EventHandler IConsole.CancelRequested {
			add { stopRequested += value; }
			remove { stopRequested -= value; }
		}
	}

	
	class NotSupportedTextReader: TextReader
	{
		bool userWarned;
		
		void WarnUser ()
		{
			if (userWarned)
				return;
			userWarned = true;
			string title = GettextCatalog.GetString ("Console input not supported");
			string desc = GettextCatalog.GetString ("Console input is not supported when using the MonoDevelop output console. If your applications needs to read data from the standard input, please set the 'Run in External Console' option in the project options.");
			MessageService.ShowWarning (title, desc);
		}
		
		public override int Peek ()
		{
			WarnUser ();
			return -1;
		}
		
		public override int ReadBlock (char[] buffer, int index, int count)
		{
			WarnUser ();
			return base.ReadBlock(buffer, index, count);
		}
		
		public override int Read (char[] buffer, int index, int count)
		{
			WarnUser ();
			return base.Read(buffer, index, count);
		}
		
		public override int Read ()
		{
			WarnUser ();
			return base.Read();
		}
		
		public override string ReadLine ()
		{
			WarnUser ();
			return base.ReadLine();
		}
		
		public override string ReadToEnd ()
		{
			WarnUser ();
			return base.ReadToEnd();
		}
	}
}

