// This file is a part of Framsticks GDK library.
// Copyright (C) 2002-2006  Szymon Ulatowski.  See LICENSE.txt for details.
// Refer to http://www.frams.alife.pl/ for further information.

#ifndef _MULTIPARAMLOAD_H_
#define _MULTIPARAMLOAD_H_

#include <stdio.h>
#include "param.h"
#include "virtfile.h"

/** "param" file parser for loading multiple objects.
    The loader can be configured to recognize multiple object types from object headers
    and automatically call ParamInterface::load for matching class.
    By using MultiParamLoader::go() function you can receive status events, they can be
    used to handle multiple object instances or parse complex files (see loadtest.cpp sample code).
    A simple MultiParamLoader::run() can be used if you need any events.
 */
class MultiParamLoader
{
VirtFILE *file;
SListTempl<VirtFILE*> filestack;
char ownfile;
SList params;
int status;
SString lasterror, lastcomment, lastunknown;
ParamInterface *lastclass;
int breakcond;
Param emptyparam;

void init();
void load();

int maybeBreak(int cond)
{ status=cond; return breakcond & cond; }

VirtFILE* popstack();
void clearstack();

  public:
MultiParamLoader() {init();}
MultiParamLoader(VirtFILE *f) {init(); load(f);}
MultiParamLoader(const char* filename) {init(); load(filename);}

~MultiParamLoader() {abort();}

void reset();

void load(VirtFILE *f);
void load(const char* filename);

/** register the object class. classes' names will be matched with object headers ("xxx:" in the file) */
void addClass(ParamInterface *pi) {params+=pi;}
void removeClass(ParamInterface *pi) {params-=pi;}
void clearClasses() {params.clear();}

/** to be used in the main loop: while(event=loader.go()) { ... }
    loader.go() will return on specified events (@see breakOn(), noBreakOn())
    then you can handle the event and resume loading
 */
virtual int go();
/** same value as 'go()' */
int getStatus() {return status;}
int finished() {return (status==Finished);}

VirtFILE *getFile() {return file;}

/** abort immediately and close the file if needed */
void abort();
/** @param conditions can be combined bitwise, eg. MultiParamLoader::BeforeObject |  MultiParamLoader::OnComment
    @see BreakConfitions
*/
void breakOn(int conditions) {breakcond|=conditions;}
void noBreakOn(int conditions) {breakcond&=~conditions;}
/**
   - BeforeObject: found an object with recognized classname
   - AfterObject: the object was loaded into the registered class interface
   - BeforeUnknown: unknown (not registered) object header detected.
@see getClass(), GetClassName()
 */
enum BreakConditions { Finished=0, BeforeObject=1, AfterObject=2, 
		       BeforeUnknown=4, OnComment=8, OnError=16, Loading=32 };

/** can be used BeforeObject and AfterObject */
ParamInterface *getClass() {return lastclass;}
/** can be used BeforeUnknown, BeforeObject, AfterObject */
const SString& getClassName() {return lastunknown;}
/** unknown object will be loaded if you set its class BeforeUnknown */
void setClass(ParamInterface *pi) {lastclass=pi;}
/** can be used OnComment */
const SString& getComment() {return lastcomment;}
/** can be used OnError */
const SString& getError() {return lasterror;}
/** can be used BeforeObject and BeforeUnknown */
int loadObjectNow(ParamInterface *pi);
/** can be used BeforeObject */
int loadObjectNow() {return loadObjectNow(getClass());}
/** can be used BeforeObject and BeforeUnknown.
    object data will not be loaded. */
int skipObject() {return loadObjectNow(&emptyparam);}
/** @return 1 if no errors */
int run();

void include(SString& filename);
bool returnFromIncluded();
bool alreadyIncluded(const char* filename);

};

#endif