/*
 * This file is a part of Winix
 * and is distributed under the 2-Clause BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/* 
 * Copyright (c) 2008-2021, Tomasz Sowa
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 */
 
#include <algorithm>
#include "patterncacher.h"
#include "core/log.h"

namespace Winix
{

PatternCacher::PatternCacher()
{
	when_delete_patterns = 13;
	how_many_delete      = 3;
	ezc_fun              = 0;
	ezc_blocks           = 0;
	ezc_obj              = 0;
}


void PatternCacher::SetEzcFunctions(TemplatesFunctions::EzcFun * fun)
{
	ezc_fun = fun;
}


void PatternCacher::SetEzcBlocks(Ezc::Blocks * blocks)
{
	ezc_blocks = blocks;
}


void PatternCacher::SetEzcObjects(Ezc::Objects<HtmlTextStream> * obj)
{
	ezc_obj = obj;
}


void PatternCacher::SetWhenDelete(size_t when_delete, size_t how_many_del)
{
	when_delete_patterns = when_delete;
	how_many_delete      = how_many_del;
}



void PatternCacher::DeleteOldPatterns()
{
	if( pattern_tab.size() < when_delete_patterns )
		return;
		
	PatternTab::iterator i;	
	PatternErase pe;
	size_t erase_index;
	
	erase_tab.resize(pattern_tab.size());
	
	for( i=pattern_tab.begin(), erase_index=0 ; i!=pattern_tab.end() ; ++i, ++erase_index)
	{
		pe.used = i->second.used;
		pe.iter = i;
		
		erase_tab[erase_index] = pe;
	}

	// sorting through 'used'
	std::sort(erase_tab.begin(), erase_tab.end());	

	for(erase_index = 0 ; erase_index<how_many_delete && erase_index<erase_tab.size() ; ++erase_index)
	{
		log << log2 << "PC: deleting ezc pattern from the cache, id: "
			<< erase_tab[erase_index].iter->second.item_id
			<< ", item used: " << erase_tab[erase_index].used << " time(s)"
			<< logend;

		pattern_tab.erase(erase_tab[erase_index].iter);
	}
}


void PatternCacher::CreatePattern(const Item & item, Ezc::Pattern & pattern)
{
	/*
	 * we do not set pattern_parser.SetBlocks()
	 * blocks cannot be created in patterns generated from virtual FS
	 * but we can call other blocks (from normal templates)
	 *
	 */
	pattern_parser.AllowInclude(false);
	pattern_parser.DeleteWhiteTextItems(false);
	pattern_parser.SetLogger(&log);
	pattern_parser.ParseString(item.item_content.content_raw, pattern);

	RebuildCache(pattern);
}





Ezc::Pattern * PatternCacher::AddPattern(const Item & item)
{
	// don't call DeleteOldPatterns() here
	// because you can delete a pattern which is in use
	// ezc functions such as: item_run, insert_page etc
	// are using GetPattern() method which can call this method

	PatternUsed pu;
	
	CreatePattern(item, pu.pattern);
	pu.used    = 1;
	pu.item_id = item.id;

	std::pair<PatternTab::iterator, bool> res = pattern_tab.insert( std::make_pair(item.id, pu) );
	
	log << log2 << "PC: added ezc pattern, item_id: " << item.id << ", url: " << item.url << logend;

return &(res.first->second.pattern);
}




Ezc::Pattern * PatternCacher::GetPattern(const Item & item)
{
PatternTab::iterator i;
	
	i = pattern_tab.find(item.id);
		
	if( i == pattern_tab.end() )
		return AddPattern(item);	
	else
	{
		log << log2 << "PC: taking pattern from the cache, id: " << item.id << ", url: " << item.url << logend;
		++(i->second.used);
		return &(i->second.pattern);
	}
}





void PatternCacher::UpdatePattern(const Item & item)
{
PatternTab::iterator i;
	
	i = pattern_tab.find(item.id);
		
	if( i == pattern_tab.end() )
		return;
		
	++(i->second.used);
	CreatePattern(item, i->second.pattern);
	
	log << log2 << "PC: updated pattern, id: " << item.id << ", url: " << item.url << logend;
}



void PatternCacher::DeletePattern(const Item & item)
{
PatternTab::iterator i;
	
	i = pattern_tab.find(item.id);
		
	if( i == pattern_tab.end() )
		return;

	log << log2 << "PC: deleted pattern, id: " << item.id << ", url: " << item.url << logend;

	pattern_tab.erase(i);
}


size_t PatternCacher::Size()
{
	return pattern_tab.size();
}


void PatternCacher::RebuildCache(Ezc::Pattern & pattern)
{
	pattern.ClearCache();

	if( ezc_obj )
		pattern.CacheObjects(*ezc_obj);

	if( ezc_fun )
		pattern.CacheFunctions(*ezc_fun);

	if( ezc_blocks )
		pattern.CacheBlocks(*ezc_blocks);
}


void PatternCacher::RebuildCache()
{
	PatternTab::iterator i = pattern_tab.begin();

	for( ; i != pattern_tab.end() ; ++i)
		RebuildCache(i->second.pattern);
}


void PatternCacher::ClearCache()
{
	PatternTab::iterator i = pattern_tab.begin();

	for( ; i != pattern_tab.end() ; ++i)
		i->second.pattern.ClearCache();
}



} // namespace Winix