// (c) Copyright Ascensio System SIA 2010-2022
//
// This program is a free software product.
// You can redistribute it and/or modify it under the terms
// of the GNU Affero General Public License (AGPL) version 3 as published by the Free Software
// Foundation. In accordance with Section 7(a) of the GNU AGPL its Section 15 shall be amended
// to the effect that Ascensio System SIA expressly excludes the warranty of non-infringement of
// any third-party rights.
//
// This program is distributed WITHOUT ANY WARRANTY, without even the implied warranty
// of MERCHANTABILITY or FITNESS FOR A PARTICULAR  PURPOSE. For details, see
// the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
//
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//
// The  interactive user interfaces in modified source and object code versions of the Program must
// display Appropriate Legal Notices, as required under Section 5 of the GNU AGPL version 3.
//
// Pursuant to Section 7(b) of the License you must retain the original Product logo when
// distributing the program. Pursuant to Section 7(e) we decline to grant you any rights under
// trademark law for use of our trademarks.
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// All the Product's GUI elements, including illustrations and icon sets, as well as technical writing
// content are licensed under the terms of the Creative Commons Attribution-ShareAlike 4.0
// International. See the License terms at http://creativecommons.org/licenses/by-sa/4.0/legalcode

namespace Textile.States;

[FormatterState(@"^\s*<pre" + Globals.HtmlAttributesPattern + ">")]
public class PreFormatterState : FormatterState
{
    private bool _shouldExitNextTime;
    private int _fakeNestingDepth;

    public PreFormatterState(TextileFormatter f)
        : base(f)
    {
    }

    public override string Consume(string input, Match m)
    {
        if (!Regex.IsMatch(input, "</pre>"))
        {
            this.Formatter.ChangeState(this);
        }
        else
        {
            this.Formatter.ChangeState(new PassthroughFormatterState(this.Formatter));
        }
        return input;
    }

    public override bool ShouldNestState(FormatterState other)
    {
        return false;
    }

    public override void Enter()
    {
    }

    public override void Exit()
    {
    }

    public override void FormatLine(string input)
    {
        if (Regex.IsMatch(input, "<pre>"))
        {
            _fakeNestingDepth++;
        }

        Formatter.Output.WriteLine(input);
    }

    public override bool ShouldExit(string input)
    {
        if (_shouldExitNextTime)
        {
            return true;
        }

        if (Regex.IsMatch(input, @"</pre>"))
        {
            _fakeNestingDepth--;
        }

        if (_fakeNestingDepth <= 0)
        {
            _shouldExitNextTime = true;
        }

        return false;
    }

    public override bool ShouldFormatBlocks(string input)
    {
        return false;
    }

    public override bool ShouldParseForNewFormatterState(string input)
    {
        // Only allow a child formatting state for <code> tag.
        return Regex.IsMatch(input, @"^\s*<code");
    }

    public override Type FallbackFormattingState
    {
        get { return null; }
    }
}