winix/winixd/core/system.cpp

/*
 * 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) 2010-2021, 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 "system.h"
#include "misc.h"
#include "error.h"
#include "templates/templates.h"
#include "functions/functions.h"



namespace Winix
{




void System::SetCur(Cur * pcur)
{
	cur = pcur;
}


//void System::SetConfig(Config * pconfig)
//{
//	config = pconfig;
//}


void System::SetDb(Db * pdb)
{
	db = pdb;
}


//void System::SetSynchro(Synchro * psynchro)
//{
//	synchro = psynchro;
//}


void System::SetFunctions(Functions * pfunctions)
{
	functions = pfunctions;
}

void System::SetSessionManager(SessionManager * sm)
{
	session_manager = sm;
}


void System::set_dependency(WinixModelDeprecated * winix_model)
{
	WinixModelDeprecated::set_dependency(winix_model);

	dirs.set_dependency(this);
	mounts.set_dependency(this);
	//users.set_dependency(this);
	users.set_connector(model_connector);
	groups.set_dependency(this);
	rebus.set_dependency(this);
	load_avg.set_dependency(this);
	notify.set_dependency(this);
	image.set_dependency(this);
	crypt.set_dependency(this);
	thread_manager.set_dependency(this);
	job.set_dependency(winix_model);
	time_zones.set_dependency(winix_model);
}


void System::ReadTimeZones()
{
	if( config->etc_dir.empty() )
	{
		log << log1 << "System: I cannot read time zones, set etc_dir directory in the config" << logend;
		return;
	}

	if( config->time_zones_file.empty() )
	{
		log << log1 << "System:: I cannot read time zones, set time_zones_file in the config" << logend;
		return;
	}

	name_temp = config->etc_dir;
	name_temp += '/';
	name_temp += config->time_zones_file;

	time_zones.SetTimeZoneMaxId(config->time_zone_max_id);
	time_zones.ReadTimeZones(name_temp);
}


bool System::Init()
{
	//thread_manager.SetSynchro(synchro);
	thread_manager.Init();

	dirs.SetDb(db);
	dirs.SetCur(cur); // only one method is using cur, can be passed as a parameter to the method
	dirs.SetNotify(&notify);
	dirs.ReadDirs();

	mounts.SkipStaticDirs(config->dont_use_static_dirs);
	mounts.SetDirs(&dirs);
	mounts.SetDb(db);
	mounts.SetCur(cur); // only one method is using cur, can be passed as a parameter to the method
	mounts.CreateMounts();
	mounts.ReadMounts();

//	users.SetCur(cur);
//	users.SetSessionManager(session_manager);
	users.set_connector(model_connector);
	users.ReadUsers(db);

	groups.ReadGroups(db); // !! chwilowe przekazanie argumentu, db bedzie zmienione

	rebus.SetCur(cur);
	rebus.Init();


	notify.SetCur(cur);
	//notify.SetConfig(config);
	notify.SetUsers(&users);
	notify.SetDirs(&dirs);
	notify.SetThreadManager(&thread_manager);

	if( !notify.Init() )
		return false;

	image.SetDb(db);
	image.SetConfig(config);
	image.SetSystem(this);

	if( !thread_manager.Add(&image, L"image") )
		return false;

	// SetSynchro will be called by ThreadManager itself
	// job.ReadFromFile();
	if( !thread_manager.Add(&job, L"job") )
		return false;

	ReadTimeZones();
	return true;
}


/*
 * try_to_use_ssl is to be meant: config->use_ssl, config->use_ssl_static, config->use_ssl_common
 */
bool System::IsSSLRequired(bool try_to_use_ssl)
{
	bool ssl = false;

	if( try_to_use_ssl )
	{
		if( !config->use_ssl_only_for_logged_users ||
			cur->session->puser ||
			(cur->request->function && cur->request->function->need_ssl) )
		{
			ssl = true;
		}
	}

	return ssl;
}


bool System::IsSSLRequired()
{
	return IsSSLRequired(config->use_ssl);
}



/*
 * try_to_use_ssl is to be meant: config->use_ssl, config->use_ssl_static, config->use_ssl_common
 */
void System::PutUrlProto(bool can_use_ssl, std::wstring & str, bool clear_str)
{
	if( clear_str )
		str.clear();

	if( IsSSLRequired() )
		str += config->url_ssl_proto;
	else
		str += config->url_proto;
}


/*
 * try_to_use_ssl is to be meant: config->use_ssl, config->use_ssl_static, config->use_ssl_common
 */
void System::PutUrlProto(bool can_use_ssl, pt::TextStream & str, bool clear_stream)
{
	if( clear_stream )
		str.clear();

	if( IsSSLRequired(can_use_ssl) )
	{
		str << config->url_ssl_proto;
	}
	else
	{
		str << config->url_proto;
	}
}


void System::PutUrlProto(std::wstring & str, bool clear_str)
{
	return PutUrlProto(config->use_ssl, str, clear_str);
}


void System::PutUrlProto(pt::TextStream & str, bool clear_stream)
{
	return PutUrlProto(config->use_ssl, str, clear_stream);
}


void System::CreateItemLink(long parent_id, const std::wstring & url, const std::wstring & subdomain,
							std::wstring & link, bool clear_str)
{
	PutUrlProto(link, clear_str);

	if( !subdomain.empty() )
	{
		link += subdomain;
		link += '.';
	}

	link += config->base_url;
	dirs.MakePath(parent_id, link, false); // !! IMPROVE ME may some kind of error checks here?
	link += url;
}


void System::CreateItemLink(const Item & item, std::wstring & link, bool clear_str)
{
	CreateItemLink(item.parent_id, item.url, cur->request->subdomain, link, clear_str);
}



// !! IMPROVE ME
// !! mozna zrobic jakas obsluge kiedy nie mozemy sie redirectnac, np gdy wystapil blad
// !! moze zwracac jakas wartosc?
/*
	postfix will not be UrlEncoded
*/
void System::RedirectTo(const Item & item, const wchar_t * postfix, bool use_reqtype)
{
	PutUrlProto(cur->request->redirect_to);

	if( !cur->request->subdomain.empty() )
	{
		cur->request->redirect_to += cur->request->subdomain;
		cur->request->redirect_to += '.';
	}

	cur->request->redirect_to += config->base_url;

	if( item.type == Item::dir )
	{
		// item_id is pointing to a directory
		dirs.MakePath(item.id, cur->request->redirect_to, false);
	}
	else
	{
		// item_id is pointing to a file or a symlink
		if( dirs.MakePath(item.parent_id, cur->request->redirect_to, false) )
			cur->request->redirect_to += item.url;
	}

	if( postfix )
		cur->request->redirect_to += postfix;

	if( use_reqtype && cur->request->IsParam(L"reqtype") )
	{
		cur->request->redirect_to += L"/-/reqtype:";
		cur->request->redirect_to += cur->request->ParamValue(L"reqtype");
	}
}



/*
	postfix will not be UrlEncoded
*/
void System::RedirectTo(long item_id, const wchar_t * postfix, bool use_reqtype)
{
	PutUrlProto(cur->request->redirect_to);

	if( !cur->request->subdomain.empty() )
	{
		cur->request->redirect_to += cur->request->subdomain;
		cur->request->redirect_to += '.';
	}

	cur->request->redirect_to += config->base_url;
	Item * pdir = dirs.GetDir(item_id);

	if( pdir )
	{
		// item_id is pointing to a directory
		dirs.MakePath(pdir->id, cur->request->redirect_to, false);
	}
	else
	{
		// item_id is pointing to a file
//		DbItemQuery iq;

//		iq.SetAllSel(false);
//		iq.WhereId(item_id);
//		iq.sel_parent_id = true;
//		iq.sel_url       = true;

		morm::Finder<Item> finder(model_connector);

		item_temp = finder.
				select().
				where().
				eq(L"id", item_id).
				get();

		//if( db->GetItem(item_temp, iq) == WINIX_ERR_OK )
		if( item_temp.found() )
		{
			if( dirs.MakePath(item_temp.parent_id, cur->request->redirect_to, false) )
				cur->request->redirect_to += item_temp.url;
		}
		else
		{
			log << log1 << "System: can't redirect: no such item: id: " << item_id << logend;	
		}
	}

	if( postfix )
		cur->request->redirect_to += postfix;

	if( use_reqtype && cur->request->IsParam(L"reqtype") )
	{
		cur->request->redirect_to += L"/-/reqtype:";
		cur->request->redirect_to += cur->request->ParamValue(L"reqtype");
	}
}



/*
	url will not be UrlEncoded
*/
void System::RedirectTo(const wchar_t * url, bool use_reqtype)
{
	PutUrlProto(cur->request->redirect_to);

	if( !cur->request->subdomain.empty() )
	{
		cur->request->redirect_to += cur->request->subdomain;
		cur->request->redirect_to += '.';
	}

	cur->request->redirect_to += config->base_url;

	if( url[0] == '/' )
	{
		// absolute path
		cur->request->redirect_to += url;
	}
	else
	{
		// relative path
		if( !cur->request->dir_tab.empty() )
		{
			if( dirs.MakePath(cur->request->dir_tab.back()->id, cur->request->redirect_to, false) )
				cur->request->redirect_to += url;
		}
		else
		{
			cur->request->redirect_to += '/';
			cur->request->redirect_to += url;
		}
	}

	if( use_reqtype && cur->request->IsParam(L"reqtype") )
	{
		cur->request->redirect_to += L"/-/reqtype:";
		cur->request->redirect_to += cur->request->ParamValue(L"reqtype");
	}
}


/*
	url will not be UrlEncoded
*/
void System::RedirectTo(const std::wstring & url, bool use_reqtype)
{
	RedirectTo(url.c_str(), use_reqtype);
}



/*
	params will be UrlEncoded
*/
void System::AddParams(const ParamTab & param_tab, std::wstring & str, bool clear_str)
{
	if( clear_str )
		str.clear();

	for(size_t i=0 ; i<param_tab.size() ; ++i)
	{
		str += '/';
		UrlEncode(param_tab[i].name, str, false);

		if( !param_tab[i].value.empty() )
		{
			str += ':';
			UrlEncode(param_tab[i].value, str, false);
		}
	}
}


/*
	url will not be UrlEncoded
	params will be UrlEncoded
*/
void System::RedirectWithFunctionAndParamsTo(const wchar_t * url)
{
	RedirectTo(url);

	if( !cur->request->function )
		return;

	cur->request->redirect_to += '/';
	cur->request->redirect_to += cur->request->function->fun.url; 
	AddParams(cur->request->param_tab, cur->request->redirect_to, false);
}


/*
	url will not be UrlEncoded
	params will be UrlEncoded
*/
void System::RedirectWithFunctionAndParamsTo(const std::wstring & url)
{
	RedirectWithFunctionAndParamsTo(url.c_str());
}


void System::RedirectToLastDir(const wchar_t * postfix, bool use_reqtype)
{
	if( !cur->request->dir_tab.empty() )
		RedirectTo( *cur->request->dir_tab.back(), postfix, use_reqtype);
}


void System::RedirectToLastItem(const wchar_t * postfix, bool use_reqtype)
{
	if( cur->request->last_item )
		RedirectTo( *cur->request->last_item, postfix, use_reqtype );
}


void System::RedirectToLastFunction(const wchar_t * postfix, bool use_reqtype)
{
	RedirectToLastDir(0, false);
	TrimLast(cur->request->redirect_to, '/');

	if( cur->request->is_item )
	{
		cur->request->redirect_to += '/';
		cur->request->redirect_to += cur->request->item.url;
	}

	if( cur->request->function )
	{
		cur->request->redirect_to += '/';
		cur->request->redirect_to += cur->request->function->fun.url;
	}

	if( postfix )
	{
		cur->request->redirect_to += '/';
		cur->request->redirect_to += postfix;
	}

	if( use_reqtype && cur->request->IsParam(L"reqtype") )
	{
		if( !cur->request->function && !postfix )
			cur->request->redirect_to += L"/-";

		cur->request->redirect_to += L"/reqtype:";
		cur->request->redirect_to += cur->request->ParamValue(L"reqtype");
	}

}


bool System::CanChangeUser(const Item & item, long new_user_id)
{
	if( !cur->session )
		// session must be set
		return false;
	
	if( cur->session->puser && cur->session->puser->is_super_user )
		// super user is allowed everything
		return true;
		
	if( item.item_content.user_id == -1 || new_user_id == -1 || item.item_content.user_id != new_user_id )
		// only super user can change the owner of an item
		return false;

	// item.user_id is equal new_user_id -- we return true

return true;
}


bool System::CanChangeGroup(const Item & item, long new_group_id)
{
	if( !cur->session )
		// session must be set
		return false;

	if( cur->session->puser && cur->session->puser->is_super_user )
		// super user is allowed everything
		return true;

	if( item.item_content.group_id != new_group_id )
	{
		// user is allowed to change the group only if he is an owner of the item
		// he can change only into a group in which he is a member of, or into a 'no_group'
		
		if( !cur->session->puser || cur->session->puser->id == -1 )
			return false;
			
		if( item.item_content.user_id == -1 || cur->session->puser->id != item.item_content.user_id )
			return false;
			
		if( new_group_id == -1 )
			return true;
			
		if( !cur->session->puser->IsMemberOf(new_group_id) )
			return false;
			
		// is logged, is the owner of the item, is the member of the new group
	}
	
return true;
}


bool System::CanChangePrivileges(const Item & item, int new_priv)
{
	if( !cur->session )
		// session must be set
		return false;

	if( cur->session->puser && cur->session->puser->is_super_user )
		// super user is allowed everything
		return true;

	if( item.item_content.privileges != new_priv )
	{
		// the owner of an item is allowed to change the privileges

		if( !cur->session->puser || cur->session->puser->id == -1 )
			return false;

		if( item.item_content.user_id == -1 || cur->session->puser->id != item.item_content.user_id )
			return false;
	}

return true;
}


// DEPRACATED
bool System::HasReadAccess(const Item & item)
{
	return item.item_content.has_read_access();
}


// DEPRACATED
bool System::HasWriteAccess(const Item & item)
{
	return item.item_content.has_write_access();
}


// DEPRACATED
bool System::HasReadWriteAccess(const Item & item)
{
	return item.item_content.has_read_write_access();
}


// DEPRACATED
bool System::HasReadExecAccess(const Item & item)
{
	return item.item_content.has_read_exec_access();
}





bool System::HasReadExecAccessToPath(long dir_id)
{
	while( true )
	{
		Item * pdir = dirs.GetDir(dir_id);

		if( !pdir )
			return false;	

		if( !HasReadExecAccess(*pdir) )
			return false;

		dir_id = pdir->parent_id;

		if( dir_id == -1 )
			return true;
	}
}


bool System::HasReadExecAccessToPath(const std::vector<Item*> & dir_tab)
{
	for(size_t i=0 ; i < dir_tab.size() ; ++i)
	{
		if( !HasReadExecAccess(*dir_tab[i]) )
			return false;
	}
	
return true;	
}


bool System::DirsHaveReadExecPerm()
{
	return HasReadExecAccessToPath(cur->request->dir_tab);
}


// if we don't have access we only remove the item from the table
// !! moze zamienic nazwe na CheckReadAccessToItems ?
void System::CheckAccessToItems(std::vector<Item> & item_tab)
{
size_t i = 0;

	while( i < item_tab.size() )
	{
		if( !HasReadAccess(item_tab[i]) )
		{
			item_tab.erase(item_tab.begin() + i);
		}
		else
		{
			i += 1;
		}
	}
}


void System::CheckWriteAccessToItems(std::vector<Item> & item_tab)
{
size_t i = 0;

	while( i < item_tab.size() )
	{
		if( !HasWriteAccess(item_tab[i]) )
		{
			item_tab.erase(item_tab.begin() + i);
		}
		else
		{
			i += 1;
		}
	}
}


int System::NewPrivileges(int creation_mask)
{
	if( cur && cur->session && cur->session->puser )
	{
		int umask = cur->session->puser->env.to_int(L"umask", config->umask);
		return (~umask) & creation_mask;
	}
	else
	{
		return (~config->umask) & creation_mask;
	}
}

/*
	from man sticky: 
     A directory whose `sticky bit' is set becomes an append-only directory,
     or, more accurately, a directory in which the deletion of files is
     restricted.  A file in a sticky directory may only be removed or renamed
     by a user if the user has write permission for the directory and the user
     is the owner of the file, the owner of the directory, or the super-user.
     This feature is usefully applied to directories such as /tmp which must
     be publicly writable but should deny users the license to arbitrarily
     delete or rename each others' files.
*/
bool System::CanRemoveRenameChild(const Item & dir, long child_item_user_id)
{
	if( dir.type != Item::dir )
		return false;

	if( !HasWriteAccess(dir) )
		return false;

	if( (dir.item_content.privileges & 010000) == 0 )
		// there is no a sticky bit set to this directory
		return true;

	if( cur->session->puser )
	{
		if( cur->session->puser->is_super_user )
			return true;

		if( dir.item_content.user_id != -1 && cur->session->puser->id != -1 && child_item_user_id != -1 )
		{
			if( cur->session->puser->id == child_item_user_id ||
				cur->session->puser->id == dir.item_content.user_id )
				return true;
		}
	}

return false;
}




int System::NewFilePrivileges()
{
	return NewPrivileges(06666);
}


int System::NewDirPrivileges()
{
	return NewPrivileges(07777);
}





bool System::CanUseHtml(long user_id)
{
	return IsSuperUser(user_id) || IsMemberOfGroup(user_id, L"allow_html");
}


bool System::CanUseBBCode(long user_id)
{
	// logged users can use bbcode
	return (user_id != -1);
}


// !! IMPROVE ME change to a better name
bool System::CanUseOther(long user_id)
{
	return IsSuperUser(user_id) || IsMemberOfGroup(user_id, L"allow_other");
}



bool System::IsSuperUser(long user_id)
{
	User * puser = users.GetUser(user_id);

	if( !puser )
		return false;

return puser->is_super_user;
}


bool System::IsMemberOfGroup(long user_id, const wchar_t * group_name)
{
	User * puser = users.GetUser(user_id);
	
	if( !puser )
		return false;
	
	long group = groups.GetGroupId(group_name);
	
	if( group == -1 )
		// there is no such a group
		return false;
	
return puser->IsMemberOf(group);
}





// the path depends on parent_id
bool System::CreateNewFileSimpleFs(Item & item)
{
	bool res = dirs.MakePath(item.parent_id, item.item_content.file_path);

	if( res )
	{
		if( !item.item_content.file_path.empty() && item.item_content.file_path[0] == '/' )
			item.item_content.file_path.erase(0, 1);
	}
	else
	{
		log << log1 << "System: CreateNewFileSimpleFs: can't create a path to item.id: " << item.id
		<< ", item.parent_id: " << item.parent_id << logend;
	}

return res;
}




// the path depends on id
bool System::CreateNewFileHashFs(Item & item)
{
wchar_t buffer[50];
wchar_t * hash = buffer;
size_t buffer_len = sizeof(buffer)/sizeof(wchar_t);

	// get 'id' as hexadecimal
	buffer[0] = '0';
	swprintf(buffer+1, buffer_len, L"%lx", (unsigned long)item.id);

	item.item_content.file_path.clear();
	
	// make sure that the length is even
	if( (wcslen(hash) & 1) != 0 )
		hash = buffer + 1; // the first character was zero

	for(size_t i=0 ; hash[i] != 0 ; i+=2)
	{
		item.item_content.file_path += hash[i];
		item.item_content.file_path += hash[i+1];

		if( hash[i+2] != 0 )
			item.item_content.file_path += '/';
	}

	// one character more to make sure the path is unique
	// (we can have a directory without the character)
	item.item_content.file_path += '_';

return true;
}



// creating item.file_path and item.file_fs
// you should set file_type yourself
// this method uses: item.id, item.url, item.parent_id (for selecting a mountpoint)
bool System::CreateNewFile(Item & item)
{
bool res;

	if( item.type != Item::file )
	{
		log << log1 << "System: CreateNewFile: the item should be a file" << logend;
		return false;
	}

	Mount * pmount = mounts.CalcMount(item.parent_id);

	if( !pmount || pmount->fs != mounts.MountFsHashfs() )
	{
		res = CreateNewFileSimpleFs(item);
		item.item_content.file_fs = mounts.MountFsSimplefs();
	}
	else
	{
		res = CreateNewFileHashFs(item);
		item.item_content.file_fs = mounts.MountFsHashfs();
	}

	if( res )
		item.item_content.file_path += item.url;
	else
		item.item_content.file_path.clear();

return res;
}


// making a global file path (in the unix file system)
// you should call CreateNewFile before
bool System::MakeFilePath(const Item & item, std::wstring & path, bool thumb, bool create_dir, int chmod, int group)
{
	path.clear();

	if( config->upload_dir.empty() )
	{
		log << log1 << "System: MakePath: upload_dir is not set in the config file" << logend;
		return false;
	}

	if( item.item_content.file_path.empty() || item.item_content.file_type == WINIX_ITEM_FILETYPE_NONE )
	{
		log << log1 << "System: MakePath: this item has not a static file" << logend;
		return false;
	}

	path = config->upload_dir;

	if( item.item_content.file_fs == mounts.MountFsHashfs() )
		path += L"/hashfs";
	else
		path += L"/simplefs";


	if( thumb )
		path += L"/thumb";
	else
		path += L"/normal";


	if( create_dir && !CreateDirs(path, item.item_content.file_path, chmod, group, true) )
		return false;

	path += '/';
	path += item.item_content.file_path;

return true;
}


bool System::MakeRelativeFilePath(const Item & item, const std::wstring & path_prefix, std::wstring & path, bool thumb)
{
	path.clear();

	if( item.item_content.file_path.empty() || item.item_content.file_type == WINIX_ITEM_FILETYPE_NONE )
	{
		log << log1 << "System: MakePath: this item has not a static file" << logend;
		return false;
	}

	// we allow the prefix to be empty
	if( !path_prefix.empty() )
	{
		if( path_prefix[0] != '/' )
			path += '/';

		path += path_prefix;
		TrimLast(path, '/');
	}

	if( item.item_content.file_fs == mounts.MountFsHashfs() )
		path += L"/hashfs";
	else
		path += L"/simplefs";

	if( thumb )
		path += L"/thumb";
	else
		path += L"/normal";

	path += '/';
	path += item.item_content.file_path;

return true;
}


// item can be a directory, file or a symlink
// if item is a directory then the path will be with a slash at the end
bool System::MakePath(const Item & item, std::wstring & path, bool clear_path)
{
bool res;

	if( clear_path )
		path.clear();

	if( item.type == Item::dir )
	{
		res = dirs.MakePath(item.id, path);
	}
	else
	{
		res = dirs.MakePath(item.parent_id, path);

		if( res )
			path += item.url;
	}

return res;
}




bool System::AddFile(Item & item, int notify_code, bool call_plugins)
{
	if( item.type != Item::file )
		return WINIX_ERR_FILE_EXPECTED;


	//Error status = db->AddItem(item);
	item.set_connector(model_connector);
	bool status = item.insert();
	
	if( status )
	{
		log << log2 << "System: added a new file, url: " << item.url << ", id: " << item.id
			<< ", parent_id: " << item.parent_id << logend;

		if( notify_code )
			notify.ItemChanged(notify_code, item);

		if( call_plugins )
			plugin->Call(WINIX_FILE_ADDED, &item);
	}

return status;
}




bool System::EditFile(Item & item, bool with_url, int notify_code, bool call_plugins)
{
	if( item.type != Item::file )
		return WINIX_ERR_FILE_EXPECTED;

	if( cur->session && cur->session->puser )
		cur->request->item.item_content.modification_user_id = cur->session->puser->id;
	else
		cur->request->item.item_content.modification_user_id = -1;

	item.item_content.SetDateModifyToNow();

	ItemModelData item_model_data;
	item_model_data.prepare_unique_url = with_url;

	bool status = item.update(item_model_data);
	//Error status = db->EditItemById(item, with_url);
	
	if( status )
	{
		TemplatesFunctions::pattern_cacher.UpdatePattern(item);

		log << log2 << "System: modified an item" << logend;

		if( notify_code )
			notify.ItemChanged(notify_code, item);

		if( call_plugins )
			plugin->Call(WINIX_FILE_CHANGED, &item);
	}


return status;
}



time_t System::ToLocal(time_t utc_time)
{
size_t tz_id;

	if( cur->session && cur->session->puser )
		tz_id = cur->session->puser->time_zone_id;
	else
		tz_id = config->time_zone_default_id;

	TimeZone * tz = time_zones.GetZone(tz_id);

	if( tz )
		return tz->ToLocal(utc_time);

return utc_time;
}



pt::Date System::ToLocal(const pt::Date & utc_date)
{
size_t tz_id;

	if( cur->session && cur->session->puser )
		tz_id = cur->session->puser->time_zone_id;
	else
		tz_id = config->time_zone_default_id;

	TimeZone * tz = time_zones.GetZone(tz_id);

	if( tz )
		return tz->ToLocal(utc_date);

return utc_date;
}




time_t System::ToUTC(time_t local_time)
{
size_t tz_id;

	if( cur->session && cur->session->puser )
		tz_id = cur->session->puser->time_zone_id;
	else
		tz_id = config->time_zone_default_id;

	TimeZone * tz = time_zones.GetZone(tz_id);

	if( tz )
		return tz->ToUTC(local_time);

return local_time;
}



pt::Date System::ToUTC(const pt::Date & local_date)
{
size_t tz_id;

	if( cur->session && cur->session->puser )
		tz_id = cur->session->puser->time_zone_id;
	else
		tz_id = config->time_zone_default_id;

	TimeZone * tz = time_zones.GetZone(tz_id);

	if( tz )
		return tz->ToUTC(local_date);

return local_date;
}




/*
	return codes:
	ok:
	0 - the link_to is a path to a directory (out_item skipped, out_dir_tab will not be empty)
	1 - the link_to is a path to a file or a symlink (out_item is used, out_dir_tab will not be empty)

	error:
	2 - incorrect link_to
	3 - there is not a root dir
	4 - current_dir_tab was empty

	current_dir_tab can be the same container as out_dir_tab
	link_to can be a relative path (without the first slash)
*/
int System::FollowLink(const std::vector<Item*> & current_dir_tab, const std::wstring & link_to,
					   std::vector<Item*> & out_dir_tab, Item & out_item)
{
	link_to_temp = link_to; // copy the link because it can be from out_item (and will be cleared)
	out_item.Clear();

	int res = dirs.FollowLink(current_dir_tab, link_to_temp, out_dir_tab, name_temp);

	if( res == 1 )
	{
		morm::Finder<Item> finder(model_connector);

		bool status = finder.
				select().
				where().
				eq(L"parent_id", out_dir_tab.back()->id).
				eq(L"url", name_temp).
				get(out_item);

		//if( db->GetItem(out_dir_tab.back()->id, name_temp, out_item) == WINIX_ERR_OK )
		if( status )
			return 1;			
		else
			return 2;
	}

return res;
}








bool System::FollowAllLinksDirFound(std::vector<Item*> & out_dir_tab,
									bool follow_dir_default, bool stop_on_link_redirect, bool check_access)
{
	log << log3 << "System: link to a directory: ";
	dirs.LogDir(out_dir_tab);
	log << logend;

	if( check_access && !HasReadExecAccessToPath(out_dir_tab) )
	{
		log << log1 << "System: no access to the directory structure" << logend;
		return false;
	}

	if( !out_dir_tab.back()->item_content.link_to.empty() )
	{
		if( follow_dir_default )
		{
			if( !(stop_on_link_redirect && out_dir_tab.back()->item_content.link_redirect==1) )
				link_to_temp = out_dir_tab.back()->item_content.link_to;
		}
	}

return true;
}



bool System::FollowAllLinksFileOrSymlinkFound(std::vector<Item*> & out_dir_tab, Item & out_item,
											  bool stop_on_link_redirect, bool check_access)
{
	if( out_item.type == Item::symlink )
		log << log3 << "System: link to a symlink: ";
	else
		log << log3 << "System: link to a file: ";

	dirs.LogDir(out_dir_tab);
	log << out_item.url << logend;

	if( check_access && !HasReadExecAccessToPath(out_dir_tab) )
	{
		log << log1 << "System: no access to the directory structure" << logend;
		return false;
	}

	if( check_access && !HasReadAccess(out_item) )
	{
		log << log1 << "System: no read access to the file or symlink" << logend;
		return false;
	}

	if( out_item.type == Item::symlink )
	{
		if( out_item.item_content.link_to.empty() )
		{
			log << log1 << "System: symlink empty" << logend;
			return false;
		}
		else
		{
			if( !(stop_on_link_redirect && out_item.item_content.link_redirect==1) )
				link_to_temp = out_item.item_content.link_to;
		}
	}

return true;
}






/*
	return codes:
	ok:
	0 - the link_to is a path to a directory (out_item skipped, out_dir_tab will not be empty)
	1 - the link_to is a path to a file      (out_item is used, out_dir_tab will not be empty)
	    (link_to can be a path to a symlink if stop_on_link_redirect is true)

	error:
	2 - incorrect link_to
	3 - there is not a root dir
	4 - current_dir_tab was empty
	5 - limit of symlinks exceeded
	6 - permission denied to a file/symlink or a directory (or a symlink is empty)

	current_dir_tab can be the same container as out_dir_tab
	link_to can be a relative path (without the first slash)

	if follow_dir_default is true then directories with 'default' flags are followed as well

	if stop_on_link_redirect is true then the method stops on a symbolic link (or a directory 
	with 'default' flag set) where the redirection should be done, you should check then whether
	the out_item.back()->link_to is not empty (if the result was 0 ) or
	whether out_item.type is symlink (if the result was 1) 
	to make the redirection
*/
int System::FollowAllLinks(const std::vector<Item*> & current_dir_tab, const std::wstring & link_to,
					       std::vector<Item*> & out_dir_tab, Item & out_item,
						   bool follow_dir_default, bool stop_on_link_redirect, bool check_access)
{
	int res;
	size_t level = 0;
	link_to_temp = link_to;

	if( current_dir_tab.empty() )
		return 4;

	do
	{
		if( ++level > config->symlinks_follow_max )
		{
			log << log1 << "System: the number of maximum symlinks exceeded ("
						<< config->symlinks_follow_max << ")" << logend;

			res = 5;
		}
		else
		{
			// !! CHECK ME
			// FollowLink is using link_to_temp temporary variable too
			res = FollowLink(current_dir_tab, link_to_temp, out_dir_tab, out_item);
			link_to_temp.clear();

			if( res == 0 )
			{
				out_item.Clear();
				res = FollowAllLinksDirFound(out_dir_tab, follow_dir_default, stop_on_link_redirect, check_access) ? 0 : 6;
			}
			else
			if( res == 1 )
			{
				res = FollowAllLinksFileOrSymlinkFound(out_dir_tab, out_item, stop_on_link_redirect, check_access) ? 1 : 6;
			}
			else
			{
				log << log2 << "System: incorrect link: " << link_to << logend;
			}
		}
	}
	while( !link_to_temp.empty() );

return res;
}


// the same as FollowAllLinks but starts from the root directory
// link_to must begin with a slash (or can be empty then the root directory is returned)
int System::FollowAllLinks(const std::wstring & link_to,
						   std::vector<Item*> & out_dir_tab, Item & out_item,
						   bool follow_dir_default, bool stop_on_link_redirect, bool check_access)
{
	if( !link_to.empty() && link_to[0] != '/' )
		return 2;

	if( root_follow_dir_tab.size() != 1 )
		root_follow_dir_tab.resize(1);

	Item * root_dir = dirs.GetRootDir();

	if( !root_dir )
		return 3;

	root_follow_dir_tab[0] = root_dir;

	return FollowAllLinks(root_follow_dir_tab, link_to,
						  out_dir_tab, out_item, follow_dir_default, stop_on_link_redirect, check_access);
}



// the same as FollowAllLinks but operates on cur->request->dir_tab and cur->request->item
// and returns bool
// the method is making a redirection if needed
bool System::FollowAllLinks(const std::wstring & link_to,
							bool follow_dir_default, bool stop_on_link_redirect, bool check_access)
{
	int res = FollowAllLinks(cur->request->dir_tab, link_to, temp_follow_dir_tab, temp_follow_item,
							 follow_dir_default, stop_on_link_redirect, check_access);

	bool ok = (res == 0 || res == 1);

	if( ok )
	{
		cur->request->dir_tab = temp_follow_dir_tab;
		
		if( res == 0 )
		{
			cur->request->is_item = false;
			cur->request->item.Clear();
			cur->request->last_item = cur->request->dir_tab.back();
			
			if( !cur->request->dir_tab.back()->item_content.link_to.empty() )
				RedirectTo(cur->request->dir_tab.back()->item_content.link_to);

			log << log3 << "System: current directory changed" <<  logend;
		}
		else
		{
			cur->request->is_item   = true;
			cur->request->item      = temp_follow_item;
			cur->request->last_item = &cur->request->item;

			if( cur->request->item.type == Item::symlink )
				RedirectTo(cur->request->item.item_content.link_to); // cur->request->item.item_content.link_to is not empty

			log << log3 << "System: current directory changed and the new file loaded" <<  logend;
		}

		mounts.CalcCurMount();
	}
	else
	{
		if( res == 5 || res == 6 )
			cur->request->status = WINIX_ERR_PERMISSION_DENIED;
		else
			cur->request->status = WINIX_ERR_NO_ITEM;
	}

return ok;
}




/*
	adding a new file to winix
	file_path - a name of a static file (from common directory)
	url       - url of a file which will be inserted (in /var directory)

	current limitation:
	warning: the url is not prepared by PrepareUrl() (PrepareUrl is from functions)
*/
bool System::AddCommonFileToVar(const wchar_t * file_path, const wchar_t * url, const wchar_t * mime_type, bool overwrite_existing)
{
	if( config->common_dir.empty() )
	{
		log << log1 << "System: can't open a file from common directory, common_dir not set in the config" << logend;
		return false;
	}

	file_name = config->common_dir;
	file_name += '/';
	file_name += file_path;

	if( !GetUTF8File(file_name, file_content) )
	{
		log << log1 << "System: can't open a file: " << file_name << logend;
		return false;
	}

	Item * var = dirs.CreateVarDir();

	if( !var )
	{
		log << log1 << "System: can't create /var directory" << logend;
		return false;
	}

	morm::Finder<Item> finder(model_connector);

	file_content_item = finder.select().where().eq(L"parent_id", var->id).eq(L"url", url).get();

	if( file_content_item.found() )
	{
		if( !overwrite_existing )
			return true;

		file_content_item.remove();
	}

	file_content_item.Clear();
	file_content_item.parent_id     = var->id;
	file_content_item.item_content.user_id       = var->item_content.user_id;
	file_content_item.item_content.group_id      = var->item_content.group_id;
	file_content_item.item_content.privileges    = 07555;	// !! IMPROVE ME: may it should be added as a parameter to this function?
	file_content_item.subject       = url;
	file_content_item.url           = url;
	file_content_item.type          = Item::file;
	file_content_item.html_template = config->templates_index_raw;
	file_content_item.item_content.content_raw       = file_content;
	file_content_item.item_content.content_raw_type  = ItemContent::ct_other;

	if( mime_type )
		file_content_item.item_content.file_mime_type = mime_type;

	return AddFile(file_content_item, false);
}



} // namespace Winix