/***********************************************************************
 *
 * Copyright (C) 2020 wereturtle
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 ***********************************************************************/

#include "cmark-gfm-core-extensions.h"
#include "cmark-gfm-extension_api.h"

#include "CmarkGfmAPI.h"

CmarkGfmAPI* CmarkGfmAPI::instance = NULL;

CmarkGfmAPI* CmarkGfmAPI::getInstance() 
{
	if (NULL == instance)
	{
		instance = new CmarkGfmAPI();
	}

	return instance;
}

CmarkGfmAPI::~CmarkGfmAPI()
{
	cmark_arena_reset();
}

MarkdownAST* CmarkGfmAPI::parse(const QString& text, const bool smartTypographyEnabled)
{
	int opts = CMARK_OPT_DEFAULT | CMARK_OPT_FOOTNOTES;

    if (smartTypographyEnabled)
    {
        opts |= CMARK_OPT_SMART;
    }

    apiMutex.lock();

	cmark_mem* mem = cmark_get_arena_mem_allocator();
	cmark_parser* parser = cmark_parser_new_with_mem(opts, mem);
    
    cmark_parser_attach_syntax_extension(parser, tableExt);
    cmark_parser_attach_syntax_extension(parser, strikethroughExt);
    cmark_parser_attach_syntax_extension(parser, autolinkExt);
    cmark_parser_attach_syntax_extension(parser, tagfilterExt);
    cmark_parser_attach_syntax_extension(parser, tasklistExt);
	
    cmark_parser_feed(parser, text.toLatin1().data(), text.length());

    cmark_node* root = cmark_parser_finish(parser);
	MarkdownAST* ast = new MarkdownAST(root);
    cmark_parser_free(parser);
    cmark_node_free(root);
	cmark_arena_reset();

    apiMutex.unlock();

	return ast;
}

QString CmarkGfmAPI::renderToHtml(const QString& text, const bool smartTypographyEnabled)
{
	int opts = CMARK_OPT_DEFAULT | CMARK_OPT_FOOTNOTES;

    if (smartTypographyEnabled)
    {
        opts |= CMARK_OPT_SMART;
    }

	apiMutex.lock();
    
	cmark_mem* mem = cmark_get_arena_mem_allocator();
	cmark_parser* parser = cmark_parser_new_with_mem(opts, mem);
    
    cmark_parser_attach_syntax_extension(parser, tableExt);
    cmark_parser_attach_syntax_extension(parser, strikethroughExt);
    cmark_parser_attach_syntax_extension(parser, autolinkExt);
    cmark_parser_attach_syntax_extension(parser, tagfilterExt);
    cmark_parser_attach_syntax_extension(parser, tasklistExt);

	cmark_parser_feed(parser, text.toLatin1().data(), text.length());
	
	cmark_node* root = cmark_parser_finish(parser);
	char* output = cmark_render_html(root, opts, cmark_parser_get_syntax_extensions(parser));
	QString html = QString::fromUtf8(output);
    
	cmark_parser_free(parser);
	cmark_arena_reset();

	apiMutex.unlock();

	return html;
}

CmarkGfmAPI::CmarkGfmAPI() 
{	
	cmark_gfm_core_extensions_ensure_registered();
	tableExt = cmark_find_syntax_extension("table");
	strikethroughExt = cmark_find_syntax_extension("strikethrough");
	autolinkExt = cmark_find_syntax_extension("autolink");
	tagfilterExt = cmark_find_syntax_extension("tagfilter");
	tasklistExt = cmark_find_syntax_extension("tasklist");
}