/*
 * Loops.cpp
 * Part of SQLMeta, a language to use sql-queries in html pages.
 *
 * Copyright (C) 2001  Daan Vreeken
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

#include "sqlmeta.h"



MetaLoop::MetaLoop(MetaParser *MyParser, Cache *MyCache)
{
	Parser=MyParser;
	Parent=MyCache;

	//Store the loop in the cache (& remember the previous loop)
	Prev=Parent->Loop;
	Parent->Loop=this;
}



MetaLoop::~MetaLoop()
{
	//Restore the previous loop in the cache
	Parent->Loop=Prev;
}



CacheCommand MetaLoop::Feed(CacheBlock *Block, long *JumpID)
{
	printf("This should not be on your screen...\n");
	return Error;
}



LoopWith::LoopWith(MetaParser *MyParser, Cache *MyCache, int *Result, char *Arg1)
 : MetaLoop::MetaLoop(MyParser,MyCache)
{
	DBConnection	*Conn = (DBConnection *)new DBConnection(Parser,Parser->DB);

	//Remember the query in the cache
	PrevQuery=Parser->Query;

	SkipUntilLoop=0;

	try
	{
		if (Conn==NULL)
			throw Parser->Error(ErrMalloc,"LoopWith::LoopWith");
		if (!Conn->TryConnect())
			throw 0;
		if (!Conn->Query(Arg1))
			throw 0;
		if (!Conn->GetResult())
			throw 0;

		if (!Conn->NextRow())
			SkipUntilLoop=1;

		//Got query results..
		//Show them to the world
		Query=Conn;
		Parser->Query=Conn;
	}

	catch (int Err)
	{
		*Result=Err;
		return;
	}

	*Result=1;
	FirstBlock=1;
}



LoopWith::~LoopWith(void)
{
	//Restore previous loop's query
	Parser->Query=PrevQuery;
}



CacheCommand LoopWith::Feed(CacheBlock *Block, long *JumpID)
{
	int		Argc;

	if (FirstBlock)
	{
		FirstBlock=0;
		LoopStartID=Block->ID;
	}

	if (Block->Type==Code)
	{
		//Check arg[0] for 'loop' command
		Argc=Parent->SplitArgs(Block->Data);
		if (Argc==-1)
			return Error;

		if (!strcmp(Parent->Arg[0],"loop"))
		{
			//Check argc
			if (Argc!=1)
			{
				Parser->Error(ErrArgNr,"loop");
				return Error;
			}

			//Found 'loop' command.. want to loop again?
			if ((Query!=NULL) && (Query->NextRow()))
			{
				*JumpID=LoopStartID;
				return Jump;
			}

			//tell cache to end the loop
			return EndLoop;
		}
	}

	//It's ok...
	//Let's execute this command (unless we have no query results!)
	if (SkipUntilLoop)
		return SkipToNextCmd;
	return Exec;
}