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

using System;

namespace ICSharpCode.Editor
{
	/// <summary>
	/// A document representing a source code file for refactoring.
	/// Line and column counting starts at 1.
	/// Offset counting starts at 0.
	/// </summary>
	public interface IDocument : ITextSource, IServiceProvider
	{
		/// <summary>
		/// Gets/Sets the text of the whole document..
		/// </summary>
		new string Text { get; set; } // hides TextBuffer.Text to add the setter
		
		/// <summary>
		/// This event is called directly before a change is applied to the document.
		/// </summary>
		/// <remarks>
		/// It is invalid to modify the document within this event handler.
		/// Aborting the change (by throwing an exception) is likely to cause corruption of data structures
		/// that listen to the Changing and Changed events.
		/// </remarks>
		event EventHandler<TextChangeEventArgs> TextChanging;
		
		/// <summary>
		/// This event is called directly after a change is applied to the document.
		/// </summary>
		/// <remarks>
		/// It is invalid to modify the document within this event handler.
		/// Aborting the event handler (by throwing an exception) is likely to cause corruption of data structures
		/// that listen to the Changing and Changed events.
		/// </remarks>
		event EventHandler<TextChangeEventArgs> TextChanged;
		
		/// <summary>
		/// This event is called after a group of changes is completed.
		/// </summary>
		/// <seealso cref="EndUndoableAction"/>
		event EventHandler ChangeCompleted;
		
		/// <summary>
		/// Gets the number of lines in the document.
		/// </summary>
		int LineCount { get; }
		
		/// <summary>
		/// Gets the document line with the specified number.
		/// </summary>
		/// <param name="lineNumber">The number of the line to retrieve. The first line has number 1.</param>
		IDocumentLine GetLineByNumber(int lineNumber);
		
		/// <summary>
		/// Gets the document line that contains the specified offset.
		/// </summary>
		IDocumentLine GetLineByOffset(int offset);
		
		/// <summary>
		/// Gets the offset from a text location.
		/// </summary>
		/// <seealso cref="GetLocation"/>
		int GetOffset(int line, int column);
		
		/// <summary>
		/// Gets the offset from a text location.
		/// </summary>
		/// <seealso cref="GetLocation"/>
		int GetOffset(TextLocation location);
		
		/// <summary>
		/// Gets the location from an offset.
		/// </summary>
		/// <seealso cref="GetOffset(TextLocation)"/>
		TextLocation GetLocation(int offset);
		
		/// <summary>
		/// Inserts text.
		/// </summary>
		/// <param name="offset">The offset at which the text is inserted.</param>
		/// <param name="text">The new text.</param>
		/// <remarks>
		/// Anchors positioned exactly at the insertion offset will move according to their movement type.
		/// For AnchorMovementType.Default, they will move behind the inserted text.
		/// The caret will also move behind the inserted text.
		/// </remarks>
		void Insert(int offset, string text);
		
		/// <summary>
		/// Inserts text.
		/// </summary>
		/// <param name="offset">The offset at which the text is inserted.</param>
		/// <param name="text">The new text.</param>
		/// <param name="defaultAnchorMovementType">
		/// Anchors positioned exactly at the insertion offset will move according to the anchor's movement type.
		/// For AnchorMovementType.Default, they will move according to the movement type specified by this parameter.
		/// The caret will also move according to the <paramref name="defaultAnchorMovementType"/> parameter.
		/// </param>
		void Insert(int offset, string text, AnchorMovementType defaultAnchorMovementType);
		
		/// <summary>
		/// Removes text.
		/// </summary>
		/// <param name="offset">Starting offset of the text to be removed.</param>
		/// <param name="length">Length of the text to be removed.</param>
		void Remove(int offset, int length);
		
		/// <summary>
		/// Replaces text.
		/// </summary>
		/// <param name="offset">The starting offset of the text to be replaced.</param>
		/// <param name="length">The length of the text to be replaced.</param>
		/// <param name="newText">The new text.</param>
		void Replace(int offset, int length, string newText);
		
		/// <summary>
		/// Make the document combine the following actions into a single
		/// action for undo purposes.
		/// </summary>
		void StartUndoableAction();
		
		/// <summary>
		/// Ends the undoable action started with <see cref="StartUndoableAction"/>.
		/// </summary>
		void EndUndoableAction();
		
		/// <summary>
		/// Creates an undo group. Dispose the returned value to close the undo group.
		/// </summary>
		/// <returns>An object that closes the undo group when Dispose() is called.</returns>
		IDisposable OpenUndoGroup();
		
		/// <summary>
		/// Creates a new <see cref="ITextAnchor"/> at the specified offset.
		/// </summary>
		/// <inheritdoc cref="ITextAnchor" select="remarks|example"/>
		ITextAnchor CreateAnchor(int offset);
	}
}