// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// This file is part of CodingEditor.
// Note:	This project is derived from Peter Project
//			(hosted on sourceforge and codeplex)
//
// Copyright (c) 2008-2009, CE Team
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

using System.Collections.Generic;
using System.Linq;
using ICSharpCode.TextEditor.Document;

namespace ICSharpCode.TextEditor.Src.Document.FoldingStrategy
{
    public class JSONFoldingStrategy : IFoldingStrategy
    {
        #region Methods

        /// <summary>
        /// Generates the foldings for our document.
        /// </summary>
        /// <param name="document">The current document.</param>
        /// <param name="fileName">The filename of the document.</param>
        /// <param name="parseInformation">Extra parse information, not used in this sample.</param>
        /// <returns>A list of FoldMarkers.</returns>
        public List<FoldMarker> GenerateFoldMarkers(IDocument document, string fileName, object parseInformation)
        {
            var list = new List<FoldMarker>();
            var startLines = new Stack<int>();

            // Create foldmarkers for the whole document, enumerate through every line.
            for (int i = 0; i < document.TotalNumberOfLines; i++)
            {
                var seg = document.GetLineSegment(i);
                int offs, end = seg.Length + seg.Offset;
                char c;
                for (
                    offs = seg.Offset;
                    offs < end;
                    offs++)
                {

                    c = document.GetCharAt(offs);
                    if (seg.Words.Any(w => w.IsDelimiter && w.Offset == offs - seg.Offset && w.Word == c.ToString()))
                    {
                        if (c == '{')
                        {
                            int offsetOfClosingBracket = SearchBracketForward(document, i, offs, '{', '}');
                            if (offsetOfClosingBracket > 0)
                            {
                                int length = offsetOfClosingBracket - offs + 1;
                                list.Add(new FoldMarker(document, offs, length, "{...}", false));
                            }
                        }
                        if (c == '[')
                        {
                            int offsetOfClosingBracket = SearchBracketForward(document, i, offs, '[', ']');
                            if (offsetOfClosingBracket > 0)
                            {
                                int length = offsetOfClosingBracket - offs + 1;
                                list.Add(new FoldMarker(document, offs, length, "[...]", false));
                            }
                        }
                    }
                }
            }

            return list;
        }


        private int SearchBracketForward(IDocument document, int currLine, int currOffset, char openBracket, char closingBracket)
        {
            // Create foldmarkers for the whole document, enumerate through every line.

            int brackets = 1, spaceCount = 0;
            for (int i = currLine; i < document.TotalNumberOfLines; i++)
            {
                var seg = document.GetLineSegment(i);
                int offs, end = seg.Length + seg.Offset;
                char c;
                for (
                    offs = i == currLine ? currOffset + 1 : seg.Offset;
                    offs < end;
                    offs++)
                {

                    c = document.GetCharAt(offs);
                    if (c == ' ' || c == '\t' || c == '\n' || c == '\r') spaceCount++;
                    if (seg.Words.Any(w => w.IsDelimiter && w.Offset == offs - seg.Offset && w.Word == c.ToString()))
                    {
                        if (c == openBracket)
                        {
                            ++brackets;
                        }
                        else if (c == closingBracket)
                        {
                            --brackets;
                            if (brackets == 0)
                            {
                                if (offs - spaceCount - 1 == currOffset)
                                {
                                    return -1;
                                }
                                return offs;
                            }
                        }
                    }
                }
            }
            return -1;
        }
        #endregion Methods
    }
}