// (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
//
// You can contact Ascensio System SIA at Lubanas st. 125a-25, Riga, Latvia, EU, LV-1021.
//
// 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.
//
// 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.Blocks;

public class ImageBlockModifier : BlockModifier
{
    public override string ModifyLine(string line)
    {
        line = Regex.Replace(line,
                                @"\!" +                   // opening !
                                @"(?<algn>\<|\=|\>)?" +   // optional alignment atts
                                Globals.BlockModifiersPattern + // optional style, public class atts
                                @"(?:\. )?" +             // optional dot-space
                                @"(?<url>[^\s(!]+)" +     // presume this is the src
                                @"\s?" +                  // optional space
                                @"(?:\((?<title>([^\)]+))\))?" +// optional title
                                @"\!" +                   // closing
                                @"(?::(?<href>(\S+)))?" +     // optional href
                                @"(?=\s|\.|,|;|\)|\||$)",               // lookahead: space or simple punctuation or end of string
                            new MatchEvaluator(ImageFormatMatchEvaluator)
                            );
        return line;
    }

    string ImageFormatMatchEvaluator(Match m)
    {
        var atts = BlockAttributesParser.ParseBlockAttributes(m.Groups["atts"].Value, "img");
        if (m.Groups["algn"].Length > 0)
        {
            atts += " align=\"" + Globals.ImageAlign[m.Groups["algn"].Value] + "\"";
        }

        if (m.Groups["title"].Length > 0)
        {
            atts += " title=\"" + m.Groups["title"].Value + "\"";
            atts += " alt=\"" + m.Groups["title"].Value + "\"";
        }
        else
        {
            atts += " alt=\"\"";
        }
        // Get Image Size?

        var res = "<img src=\"" + m.Groups["url"].Value + "\"" + atts + " />";

        if (m.Groups["href"].Length > 0)
        {
            var href = m.Groups["href"].Value;
            var end = string.Empty;
            var endMatch = Regex.Match(href, @"(.*)(?<end>\.|,|;|\))$");
            if (m.Success && !string.IsNullOrEmpty(endMatch.Groups["end"].Value))
            {
                href = href[0..^1];
                end = endMatch.Groups["end"].Value;
            }
            res = "<a href=\"" + Globals.EncodeHTMLLink(href) + "\">" + res + "</a>" + end;
        }

        return res;
    }
}