using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.BL.Entities;
using Tango.MachineStudio.Common.Notifications;

namespace Tango.MachineStudio.DB.ViewModelspre { line-height: 125%; }
td.linenos .normal { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
span.linenos { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
td.linenos .special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
span.linenos.special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .ges { font-weight: bold; font-style: italic } /* Generic.EmphStrong */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
// 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.Diagnostics;
using System.Globalization;

namespace Tango.Scripting.Editors.Document
{
	/// <summary>
	/// Represents a line inside a <see cref="TextDocument"/>.
	/// </summary>
	/// <remarks>
	/// <para>
	/// The <see cref="TextDocument.Lines"/> collection contains one DocumentLine instance
	/// for every line in the document. This collection is read-only to user code and is automatically
	/// updated to reflect the current document content.
	/// </para>
	/// <para>
	/// Internally, the DocumentLine instances are arranged in a binary tree that allows for both efficient updates and lookup.
	/// Converting between offset and line number is possible in O(lg N) time,
	/// and the data structure also updates all offsets in O(lg N) whenever a line is inserted or removed.
	/// </para>
	/// </remarks>
	public sealed partial class DocumentLine : ISegment
	{
		#region Constructor
		#if DEBUG
		// Required for thread safety check which is done only in debug builds.
		// To save space, we don't store the document reference in release builds as we don't need it there.
		readonly TextDocument document;
		#endif
		
		internal bool isDeleted;
		
		internal DocumentLine(TextDocument document)
		{
			#if DEBUG
			Debug.Assert(document != null);
			this.document = document;
			#endif
		}
		
		[Conditional("DEBUG")]
		void DebugVerifyAccess()
		{
			#if DEBUG
			document.DebugVerifyAccess();
			#endif
		}
		#endregion
		
		#region Events
//		/// <summary>
//		/// Is raised when the line is deleted.
//		/// </summary>
//		public event EventHandler Deleted;
//
//		/// <summary>
//		/// Is raised when the line's text changes.
//		/// </summary>
//		public event EventHandler TextChanged;
//
//		/// <summary>
//		/// Raises the Deleted or TextChanged event.
//		/// </summary>
//		internal void RaiseChanged()
//		{
//			if (IsDeleted) {
//				if (Deleted != null)
//					Deleted(this, EventArgs.Empty);
//			} else {
//				if (TextChanged != null)
//					TextChanged(this, EventArgs.Empty);
//			}
//		}
		#endregion
		
		#region Properties stored in tree
		/// <summary>
		/// Gets if this line was deleted from the document.
		/// </summary>
		public bool IsDeleted {
			get {
				DebugVerifyAccess();
				return isDeleted;
			}
		}
		
		/// <summary>
		/// Gets the number of this line.
		/// Runtime: O(log n)
		/// </summary>
		/// <exception cref="InvalidOperationException">The line was deleted.</exception>
		public int LineNumber {
			get {
				if (IsDeleted)
					throw new InvalidOperationException();
				return DocumentLineTree.GetIndexFromNode(this) + 1;
			}
		}
		
		/// <summary>
		/// Gets the starting offset of the line in the document's text.
		/// Runtime: O(log n)
		/// </summary>
		/// <exception cref="InvalidOperationException">The line was deleted.</exception>
		public int Offset {
			get {
				if (IsDeleted)
					throw new InvalidOperationException();
				return DocumentLineTree.GetOffsetFromNode(this);
			}
		}
		
		/// <summary>
		/// Gets the end offset of the line in the document's text (the offset before the line delimiter).
		/// Runtime: O(log n)
		/// </summary>
		/// <exception cref="InvalidOperationException">The line was deleted.</exception>
		/// <remarks>EndOffset = <see cref="Offset"/> + <see cref="Length"/>.</remarks>
		public int EndOffset {
			get { return this.Offset + this.Length; }
		}
		#endregion
		
		#region Length
		int totalLength;
		byte delimiterLength;
		
		/// <summary>
		/// Gets the length of this line. The length does not include the line delimiter. O(1)
		/// </summary>
		/// <remarks>This property is still available even if the line was deleted;
		/// in that case, it contains the line's length before the deletion.</remarks>
		public int Length {
			get {
				DebugVerifyAccess();
				return totalLength - delimiterLength;
			}
		}
		
		/// <summary>
		/// Gets the length of this line, including the line delimiter. O(1)
		/// </summary>
		/// <remarks>This property is still available even if the line was deleted;
		/// in that case, it contains the line's length before the deletion.</remarks>
		public int TotalLength {
			get {
				DebugVerifyAccess();
				return totalLength;
			}
			internal set {
				// this is set by DocumentLineTree
				totalLength = value;
			}
		}
		
		/// <summary>
		/// <para>Gets the length of the line delimiter.</para>
		/// <para>The value is 1 for single <c>"\r"</c> or <c>"\n"</c>, 2 for the <c>"\r\n"</c> sequence;
		/// and 0 for the last line in the document.</para>
		/// </summary>
		/// <remarks>This property is still available even if the line was deleted;
		/// in that case, it contains the line delimiter's length before the deletion.</remarks>
		public int DelimiterLength {
			get {
				DebugVerifyAccess();
				return delimiterLength;
			}
			internal set {
				Debug.Assert(value >= 0 && value <= 2);
				delimiterLength = (byte)value;
			}
		}
		#endregion
		
		#region Previous / Next Line
		/// <summary>
		/// Gets the next line in the document.
		/// </summary>
		/// <returns>The line following this line, or null if this is the last line.</returns>
		public DocumentLine NextLine {
			get {
				DebugVerifyAccess();
				
				if (right != null) {
					return right.LeftMost;
				} else {
					DocumentLine node = this;
					DocumentLine oldNode;
					do {
						oldNode = node;
						node = node.parent;
						// we are on the way up from the right part, don't output node again
					} while (node != null && node.right == oldNode);
					return node;
				}
			}
		}
		
		/// <summary>
		/// Gets the previous line in the document.
		/// </summary>
		/// <returns>The line before this line, or null if this is the first line.</returns>
		public DocumentLine PreviousLine {
			get {
				DebugVerifyAccess();
				
				if (left != null) {
					return left.RightMost;
				} else {
					DocumentLine node = this;
					DocumentLine oldNode;
					do {
						oldNode = node;
						node = node.parent;
						// we are on the way up from the left part, don't output node again
					} while (node != null && node.left == oldNode);
					return node;
				}
			}
		}
		#endregion
		
		#region ToString
		/// <summary>
		/// Gets a string with debug output showing the line number and offset.
		/// Does not include the line's text.
		/// </summary>
		public override string ToString()
		{
			if (IsDeleted)
				return "[DocumentLine deleted]";
			else
				return string.Format(
					CultureInfo.InvariantCulture,
					"[DocumentLine Number={0} Offset={1} Length={2}]", LineNumber, Offset, Length);
		}
		#endregion
	}
}