/*
   Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
// scriplib.c

#include "cmdlib.h"
#include "inout.h"
#include "scriplib.h"

/*
   =============================================================================

                        PARSING STUFF

   =============================================================================
 */

typedef struct
{
	char filename[1024];
	char    *buffer,*script_p,*end_p;
	int line;
} script_t;

#define MAX_INCLUDES    8
script_t scriptstack[MAX_INCLUDES];
script_t    *script;
int scriptline;

char token[MAXTOKEN];
qboolean endofscript;
qboolean tokenready;                     // only true if UnGetToken was just called

/*
   ==============
   AddScriptToStack
   ==============
 */
void AddScriptToStack( char *filename ){
	int size;

	script++;
	if ( script == &scriptstack[MAX_INCLUDES] ) {
		Error( "script file exceeded MAX_INCLUDES" );
	}
	strcpy( script->filename, ExpandPath( filename ) );

	size = LoadFile( script->filename, (void **)&script->buffer );

	printf( "entering %s\n", script->filename );

	script->line = 1;

	script->script_p = script->buffer;
	script->end_p = script->buffer + size;
}


/*
   ==============
   LoadScriptFile
   ==============
 */
void LoadScriptFile( char *filename ){
	script = scriptstack;
	AddScriptToStack( filename );

	endofscript = false;
	tokenready = false;
}


/*
   ==============
   ParseFromMemory
   ==============
 */
void ParseFromMemory( char *buffer, int size ){
	script = scriptstack;
	script++;
	if ( script == &scriptstack[MAX_INCLUDES] ) {
		Error( "script file exceeded MAX_INCLUDES" );
	}
	strcpy( script->filename, "memory buffer" );

	script->buffer = buffer;
	script->line = 1;
	script->script_p = script->buffer;
	script->end_p = script->buffer + size;

	endofscript = false;
	tokenready = false;
}


/*
   ==============
   UnGetToken

   Signals that the current token was not used, and should be reported
   for the next GetToken.  Note that

   GetToken (true);
   UnGetToken ();
   GetToken (false);

   could cross a line boundary.
   ==============
 */
void UnGetToken( void ){
	tokenready = true;
}


qboolean EndOfScript( qboolean crossline ){
	if ( !crossline ) {
		Error( "Line %i is incomplete\n",scriptline );
	}

	if ( !strcmp( script->filename, "memory buffer" ) ) {
		endofscript = true;
		return false;
	}

	free( script->buffer );
	if ( script == scriptstack + 1 ) {
		endofscript = true;
		return false;
	}
	script--;
	scriptline = script->line;
	printf( "returning to %s\n", script->filename );
	return GetToken( crossline );
}

/*
   ==============
   GetToken
   ==============
 */
qboolean GetToken( qboolean crossline ){
	char    *token_p;

	if ( tokenready ) {                       // is a token allready waiting?
		tokenready = false;
		return true;
	}

	if ( script->script_p >= script->end_p ) {
		return EndOfScript( crossline );
	}

//
// skip space
//
skipspace:
	while ( *script->script_p <= 32 )
	{
		if ( script->script_p >= script->end_p ) {
			return EndOfScript( crossline );
		}
		if ( *script->script_p++ == '\n' ) {
			if ( !crossline ) {
				Error( "Line %i is incomplete\n",scriptline );
			}
			scriptline = script->line++;
		}
	}

	if ( script->script_p >= script->end_p ) {
		return EndOfScript( crossline );
	}

	// ; # // comments
	if ( *script->script_p == ';' || *script->script_p == '#'
		 || ( script->script_p[0] == '/' && script->script_p[1] == '/' ) ) {
		if ( !crossline ) {
			Error( "Line %i is incomplete\n",scriptline );
		}
		while ( *script->script_p++ != '\n' )
			if ( script->script_p >= script->end_p ) {
				return EndOfScript( crossline );
			}
		goto skipspace;
	}

	// /* */ comments
	if ( script->script_p[0] == '/' && script->script_p[1] == '*' ) {
		if ( !crossline ) {
			Error( "Line %i is incomplete\n",scriptline );
		}
		script->script_p += 2;
		while ( script->script_p[0] != '*' && script->script_p[1] != '/' )
		{
			script->script_p++;
			if ( script->script_p >= script->end_p ) {
				return EndOfScript( crossline );
			}
		}
		script->script_p += 2;
		goto skipspace;
	}

//
// copy token
//
	token_p = token;

	if ( *script->script_p == '"' ) {
		// quoted token
		script->script_p++;
		while ( *script->script_p != '"' )
		{
			*token_p++ = *script->script_p++;
			if ( script->script_p == script->end_p ) {
				break;
			}
			if ( token_p == &token[MAXTOKEN] ) {
				Error( "Token too large on line %i\n",scriptline );
			}
		}
		script->script_p++;
	}
	else{   // regular token
		while ( *script->script_p > 32 && *script->script_p != ';' )
		{
			*token_p++ = *script->script_p++;
			if ( script->script_p == script->end_p ) {
				break;
			}
			if ( token_p == &token[MAXTOKEN] ) {
				Error( "Token too large on line %i\n",scriptline );
			}
		}
	}

	*token_p = 0;

	if ( !strcmp( token, "$include" ) ) {
		GetToken( false );
		AddScriptToStack( token );
		return GetToken( crossline );
	}

	return true;
}


/*
   ==============
   TokenAvailable

   Returns true if there is another token on the line
   ==============
 */
qboolean TokenAvailable( void ){
	char    *search_p;

	search_p = script->script_p;

	if ( search_p >= script->end_p ) {
		return false;
	}

	while ( *search_p <= 32 )
	{
		if ( *search_p == '\n' ) {
			return false;
		}
		search_p++;
		if ( search_p == script->end_p ) {
			return false;
		}

	}

	if ( *search_p == ';' ) {
		return false;
	}

	return true;
}