// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
// 
// 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 System.IO;
using System.Text;

namespace UyghurEditPP.Document
{
	/// <summary>
	/// A TextWriter implementation that directly inserts into a document.
	/// </summary>
	public class DocumentTextWriter : TextWriter
	{
		readonly IDocument document;
		int insertionOffset;

		/// <summary>
		/// Creates a new DocumentTextWriter that inserts into document, starting at insertionOffset.
		/// </summary>
		public DocumentTextWriter(IDocument document, int insertionOffset)
		{
			this.insertionOffset = insertionOffset;
			if (document == null)
				throw new ArgumentNullException("document");
			this.document = document;
			var line = document.GetLineByOffset(insertionOffset);
			if (line.DelimiterLength == 0)
				line = line.PreviousLine;
			if (line != null)
				this.NewLine = document.GetText(line.EndOffset, line.DelimiterLength);
		}

		/// <summary>
		/// Gets/Sets the current insertion offset.
		/// </summary>
		public int InsertionOffset {
			get { return insertionOffset; }
			set { insertionOffset = value; }
		}

		/// <inheritdoc/>
		public override void Write(char value)
		{
			document.Insert(insertionOffset, value.ToString());
			insertionOffset++;
		}

		/// <inheritdoc/>
		public override void Write(char[] buffer, int index, int count)
		{
			document.Insert(insertionOffset, new string(buffer, index, count));
			insertionOffset += count;
		}

		/// <inheritdoc/>
		public override void Write(string value)
		{
			document.Insert(insertionOffset, value);
			insertionOffset += value.Length;
		}

		/// <inheritdoc/>
		public override Encoding Encoding {
			get { return Encoding.UTF8; }
		}
	}
}
