// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

using ICSharpCode.AvalonEdit;
using ICSharpCode.AvalonEdit.Rendering;
using ICSharpCode.AvalonEdit.Search;
using ICSharpCode.Core;
using ICSharpCode.Core.Presentation;
using ICSharpCode.SharpDevelop.Gui.OptionPanels;
using ICSharpCode.SharpDevelop.Project;

namespace ICSharpCode.SharpDevelop.Gui
{
	/// <summary>
	/// This class displays the errors and warnings which the compiler outputs and
	/// allows the user to jump to the source of the warning / error
	/// </summary>
	public class CompilerMessageView : AbstractPadContent, IClipboardHandler
	{
		static CompilerMessageView instance;
		
		/// <summary>
		/// Gets the instance of the CompilerMessageView. This property is thread-safe, but
		/// most instance methods of the CompilerMessageView aren't.
		/// </summary>
		public static CompilerMessageView Instance {
			get {
				if (instance == null)
					WorkbenchSingleton.SafeThreadCall(InitializeInstance);
				return instance;
			}
		}
		
		static void InitializeInstance()
		{
			WorkbenchSingleton.Workbench.GetPad(typeof(CompilerMessageView)).CreatePad();
		}
		
		#region MessageViewLinkElementGenerator
		enum LinkType { CSharp, NUnit, Cpp }
		
		class MessageViewLinkElementGenerator : LinkElementGenerator
		{
			LinkType type;
			
			public MessageViewLinkElementGenerator(LinkType type)
				: base(GetRegex(type))
			{
				this.type = type;
				RequireControlModifierForClick = false;
			}
			
			protected override Uri GetUriFromMatch(Match match)
			{
				return new Uri(match.Groups[1].Value.Trim());
			}
			
			public override VisualLineElement ConstructElement(int offset)
			{
				int matchOffset;
				Match m = GetMatch(offset, out matchOffset);
				if (m.Success && matchOffset == offset) {
					Uri uri = GetUriFromMatch(m);
					if (uri == null)
						return null;
					VisualLineMessageViewLinkText linkText = new VisualLineMessageViewLinkText(CurrentContext.VisualLine, m.Length);
					linkText.NavigateUri = uri;
					linkText.RequireControlModifierForClick = this.RequireControlModifierForClick;
					linkText.Line = int.Parse(m.Groups[2].Value);
					if (type == LinkType.CSharp)
						linkText.Column = int.Parse(m.Groups[3].Value);
					return linkText;
				} else {
					return null;
				}
			}
			
			static Regex GetRegex(LinkType type)
			{
				switch (type) {
					case CompilerMessageView.LinkType.CSharp:
						return new Regex(@"\b(\w:[/\\].*?)\((\d+),(\d+)\)");
					case CompilerMessageView.LinkType.NUnit:
						return new Regex(@"\b(\w:[/\\].*?):line\s(\d+)?\r?$");
					case CompilerMessageView.LinkType.Cpp:
						return new Regex(@"\b(\w:[/\\].*?)\((\d+)\)");
					default:
						throw new Exception("Invalid value for LinkType");
				}
			}
			
			public static void RegisterGenerators(TextView textView)
			{
				textView.ElementGenerators.Add(new MessageViewLinkElementGenerator(LinkType.CSharp));
				textView.ElementGenerators.Add(new MessageViewLinkElementGenerator(LinkType.NUnit));
				textView.ElementGenerators.Add(new MessageViewLinkElementGenerator(LinkType.Cpp));
			}
		}
		
		class VisualLineMessageViewLinkText : VisualLineLinkText
		{
			/// <summary>
			/// Creates a visual line text element with the specified length.
			/// It uses the <see cref="ITextRunConstructionContext.VisualLine"/> and its
			/// <see cref="VisualLineElement.RelativeTextOffset"/> to find the actual text string.
			/// </summary>
			public VisualLineMessageViewLinkText(VisualLine parentVisualLine, int length) : base(parentVisualLine, length)
			{
				this.RequireControlModifierForClick = false;
			}
			
			public int Line { get; set; }
			public int Column { get; set; }
			
			protected override void OnMouseDown(System.Windows.Input.MouseButtonEventArgs e)
			{
				if (e.ChangedButton == MouseButton.Left && !e.Handled && LinkIsClickable() && NavigateUri.IsFile) {
					FileService.JumpToFilePosition(NavigateUri.LocalPath, Line, Column);
					e.Handled = true;
				}
			}
			
			protected override VisualLineText CreateInstance(int length)
			{
				return new VisualLineMessageViewLinkText(ParentVisualLine, length) {
					NavigateUri = this.NavigateUri,
					Line = this.Line,
					Column = this.Column,
					TargetName = this.TargetName,
					RequireControlModifierForClick = this.RequireControlModifierForClick
				};
			}
		}
		#endregion
		
		TextEditor textEditor = new TextEditor();
		DockPanel panel = new DockPanel();
		ToolBar toolStrip;
		
		List<MessageViewCategory> messageCategories = new List<MessageViewCategory>();
		
		int selectedCategory = 0;
		public int SelectedCategoryIndex {
			get {
				return selectedCategory;
			}
			set {
				WorkbenchSingleton.AssertMainThread();
				if (selectedCategory != value) {
					selectedCategory = value;
					DisplayActiveCategory();
					OnSelectedCategoryIndexChanged(EventArgs.Empty);
				}
			}
		}
		
		void DisplayActiveCategory()
		{
			WorkbenchSingleton.DebugAssertMainThread();
			if (selectedCategory < 0) {
				textEditor.Text = "";
			} else {
				lock (messageCategories[selectedCategory].SyncRoot) {
					// accessing a categories' text takes its lock - but we have to take locks in the same
					// order as in the Append calls to prevent a deadlock
					EnqueueAppend(new AppendCall(messageCategories[selectedCategory], messageCategories[selectedCategory].Text, true));
				}
			}
		}
		
		public bool WordWrap {
			get {
				return properties.Get("WordWrap", true);
			}
			set {
				properties.Set("WordWrap", value);
			}
		}
		
		public MessageViewCategory SelectedMessageViewCategory {
			get {
				if (selectedCategory >= 0) {
					return messageCategories[selectedCategory];
				}
				return null;
			}
		}
		
		// The compiler message view properties.
		Properties properties  = null;
		
		public List<MessageViewCategory> MessageCategories {
			get {
				return messageCategories;
			}
		}
		
		public override object Control {
			get {
				return panel;
			}
		}
		
		public CompilerMessageView()
		{
			instance = this;
			
			AddCategory(TaskService.BuildMessageViewCategory);
			
			textEditor.IsReadOnly = true;
			
			textEditor.ContextMenu = MenuService.CreateContextMenu(this, "/SharpDevelop/Pads/CompilerMessageView/ContextMenu");
			
			properties = (Properties)PropertyService.Get(OutputWindowOptionsPanel.OutputWindowsProperty, new Properties());
			
			var font = FontSelectionPanel.ParseFont(properties.Get("DefaultFont", Core.WinForms.WinFormsResourceService.DefaultMonospacedFont.ToString()).ToString());
			
			textEditor.FontFamily = new FontFamily(font.FontFamily.Name);
			textEditor.FontSize = Math.Round(font.Size * 96.0 / 72.0);
			properties.PropertyChanged += new PropertyChangedEventHandler(PropertyChanged);
			
			MessageViewLinkElementGenerator.RegisterGenerators(textEditor.TextArea.TextView);
			textEditor.TextArea.TextView.ElementGenerators.OfType<LinkElementGenerator>().ForEach(x => x.RequireControlModifierForClick = false);
			
			toolStrip = ToolBarService.CreateToolBar(panel, this, "/SharpDevelop/Pads/CompilerMessageView/Toolbar");
			toolStrip.SetValue(DockPanel.DockProperty, Dock.Top);
			
			panel.Children.Add(toolStrip);
			panel.Children.Add(textEditor);
			
			SetWordWrap();
			DisplayActiveCategory();
			ProjectService.SolutionLoaded += SolutionLoaded;
			
			textEditor.TextArea.DefaultInputHandler.NestedInputHandlers.Add(new SearchInputHandler(textEditor.TextArea));
		}

		void SolutionLoaded(object sender, SolutionEventArgs e)
		{
			foreach (MessageViewCategory category in messageCategories) {
				category.ClearText();
			}
		}
		
		void SetWordWrap()
		{
			bool wordWrap = this.WordWrap;
			textEditor.WordWrap = wordWrap;
		}
		
		#region Category handling
		/// <summary>
		/// Adds a category to the compiler message view. This method is thread-safe.
		/// </summary>
		public void AddCategory(MessageViewCategory category)
		{
			if (WorkbenchSingleton.InvokeRequired) {
				WorkbenchSingleton.SafeThreadAsyncCall((Action<MessageViewCategory>)AddCategory, category);
				return;
			}
			messageCategories.Add(category);
			category.TextSet      += new TextEventHandler(CategoryTextSet);
			category.TextAppended += new TextEventHandler(CategoryTextAppended);
			
			OnMessageCategoryAdded(EventArgs.Empty);
		}
		
		void CategoryTextSet(object sender, TextEventArgs e)
		{
			EnqueueAppend(new AppendCall((MessageViewCategory)sender, e.Text, true));
		}
		
		struct AppendCall
		{
			internal readonly MessageViewCategory Category;
			internal readonly string Text;
			internal readonly bool ClearCategory;
			
			public AppendCall(MessageViewCategory category, string text, bool clearCategory)
			{
				this.Category = category;
				this.Text = text;
				this.ClearCategory = clearCategory;
			}
		}
		
		readonly object appendLock = new object();
		List<AppendCall> appendCalls = new List<AppendCall>();
		
		void CategoryTextAppended(object sender, TextEventArgs e)
		{
			EnqueueAppend(new AppendCall((MessageViewCategory)sender, e.Text, false));
		}
		
		void EnqueueAppend(AppendCall appendCall)
		{
			bool waitForMainThread;
			lock (appendLock) {
				appendCalls.Add(appendCall);
				if (appendCalls.Count == 1)
					WorkbenchSingleton.SafeThreadAsyncCall(ProcessAppendText);
				waitForMainThread = appendCalls.Count > 2000;
			}
			if (waitForMainThread && WorkbenchSingleton.InvokeRequired) {
				int sleepLength = 20;
				do {
					Thread.Sleep(sleepLength);
					sleepLength += 20;
					lock (appendLock)
						waitForMainThread = appendCalls.Count > 2000;
					//if (waitForMainThread) LoggingService.Debug("Extending sleep (" + sleepLength + ")");
				} while (waitForMainThread);
			}
		}
		
		void ProcessAppendText()
		{
			List<AppendCall> appendCalls;
			lock (appendLock) {
				appendCalls = this.appendCalls;
				this.appendCalls = new List<AppendCall>();
			}
			Debug.Assert(appendCalls.Count > 0);
			if (appendCalls.Count == 0)
				return;
			
			MessageViewCategory newCategory = appendCalls[appendCalls.Count - 1].Category;
			if (messageCategories[SelectedCategoryIndex] != newCategory) {
				SelectCategory(newCategory.Category);
				return;
			}
			
			bool clear;
			string text;
			if (appendCalls.Count == 1) {
				//LoggingService.Debug("CompilerMessageView: Single append.");
				clear = appendCalls[0].ClearCategory;
				text = appendCalls[0].Text;
			} else {
				if (LoggingService.IsDebugEnabled) {
					LoggingService.Debug("CompilerMessageView: Combined " + appendCalls.Count + " appends.");
				}
				
				clear = false;
				StringBuilder b = new StringBuilder();
				foreach (AppendCall append in appendCalls) {
					if (append.Category == newCategory) {
						if (append.ClearCategory) {
							b.Length = 0;
							clear = true;
						}
						b.Append(append.Text);
					}
				}
				text = b.ToString();
			}
			
			if (clear)
				textEditor.Text = text;
			else
				textEditor.AppendText(text);
			
			textEditor.ScrollToEnd();
		}
		
		public void SelectCategory(string categoryName)
		{
			for (int i = 0; i < messageCategories.Count; ++i) {
				MessageViewCategory category = (MessageViewCategory)messageCategories[i];
				if (category.Category == categoryName) {
					SelectedCategoryIndex = i;
					break;
				}
			}
		}
		
		void SelectCategory(string categoryName, string text)
		{
			for (int i = 0; i < messageCategories.Count; ++i) {
				MessageViewCategory category = (MessageViewCategory)messageCategories[i];
				if (category.Category == categoryName) {
					selectedCategory = i;
					textEditor.Text = StringParser.Parse(text);
					OnSelectedCategoryIndexChanged(EventArgs.Empty);
					break;
				}
			}
		}
		
		public MessageViewCategory GetCategory(string categoryName)
		{
			foreach (MessageViewCategory category in messageCategories) {
				if (category.Category == categoryName) {
					return category;
				}
			}
			return null;
		}
		#endregion
		
		/// <summary>
		/// Changes wordwrap settings if that property has changed.
		/// </summary>
		void PropertyChanged(object sender, PropertyChangedEventArgs e)
		{
			if (e.Key == "WordWrap") {
				SetWordWrap();
			}
			if (e.Key == "DefaultFont") {
				var font = FontSelectionPanel.ParseFont(properties.Get("DefaultFont", Core.WinForms.WinFormsResourceService.DefaultMonospacedFont.ToString()).ToString());
				
				textEditor.FontFamily = new FontFamily(font.FontFamily.Name);
				textEditor.FontSize = Math.Round(font.Size * 96.0 / 72.0);
			}
		}
		
		protected virtual void OnMessageCategoryAdded(EventArgs e)
		{
			if (MessageCategoryAdded != null) {
				MessageCategoryAdded(this, e);
			}
		}
		
		protected virtual void OnSelectedCategoryIndexChanged(EventArgs e)
		{
			if (SelectedCategoryIndexChanged != null) {
				SelectedCategoryIndexChanged(this, e);
			}
		}
		
		public event EventHandler MessageCategoryAdded;
		public event EventHandler SelectedCategoryIndexChanged;
		
		#region ICSharpCode.SharpDevelop.Gui.IClipboardHandler interface implementation
		public bool EnableCut {
			get {
				return false;
			}
		}
		
		public bool EnableCopy {
			get {
				return textEditor.SelectionLength > 0;
			}
		}
		
		public bool EnablePaste {
			get {
				return false;
			}
		}
		
		public bool EnableDelete {
			get {
				return false;
			}
		}
		
		public bool EnableSelectAll {
			get {
				return textEditor.Document.TextLength > 0;
			}
		}
		
		public void Cut()
		{
		}
		
		public void Copy()
		{
			textEditor.Copy();
		}
		
		public void Paste()
		{
		}
		
		public void Delete()
		{
		}
		
		public void SelectAll()
		{
			textEditor.SelectAll();
		}
		#endregion
	}
}