/*

    int2tap - Convert an Intel segment file to a loadable Spectrum tape file

    Copyright (C) 2004  Ian Cowburn (ianc@noddybox.demon.co.uk)

    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

    -------------------------------------------------------------------------

    A Spectrum BASIC line is constructed:

    <2-byte line number HI/LO>
    <2-byte length including RET LO/HI>
    <Data>
    <RET - 0x0d>

*/
static const char id[]="$Id$";

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdarg.h>

#include "basic.h"

static const char header_id[]=I2T_BASIC_H;


/* ---------------------------------------- CONSTANTS
*/
#undef TRUE
#undef FALSE

#define TRUE	1
#define FALSE	0


/* Types for AddLine()
*/
#define TYPE_END	0
#define TYPE_TOKEN	1
#define TYPE_STRING	2

/* Constants for some tokens
*/
#define TOK_VAL		176
#define TOK_QUOTE	34
#define TOK_CODE	175
#define TOK_USR		192
#define TOK_LOAD	239
#define TOK_RAND	249
#define TOK_CLEAR	253


/* ---------------------------------------- GLOBALS
*/
extern const char	*progname;

static unsigned char	mem[0x10000];
static unsigned		endptr;
static unsigned		line_no;


/* ---------------------------------------- PRIVATE FUNCTIONS
*/
static void Poke(unsigned char b, int *len)
{
    if (len)
    {
    	(*len)++;
    }

    mem[endptr++]=b;
}


static void AddLine(int type, ...)
{
    va_list va;
    int len;
    unsigned char *len_ptr;

    Poke(line_no>>8,NULL);
    Poke(line_no&0xff,NULL);
    line_no+=10;

    len_ptr=mem+endptr;
    endptr+=2;
    len=0;

    va_start(va,type);

    while(type!=TYPE_END)
    {
	char *str;

    	switch(type)
	{
	    case TYPE_TOKEN:
		Poke(va_arg(va,int),&len);
		break;

	    case TYPE_STRING:
	    	str=va_arg(va,char *);

		Poke(TOK_QUOTE,&len);

		while(*str)
		{
		    Poke(*str++,&len);
		}

		Poke(TOK_QUOTE,&len);

		break;

	    default:
	    	break;
	}

	type=va_arg(va,int);
    }

    Poke(0x0d,&len);

    *len_ptr++=len&0xff;
    *len_ptr=len>>8;
}



/* ---------------------------------------- INTERFACES
*/
void BasicInit(void)
{
    endptr=0;
    line_no=10;
}


void BasicClearLine(unsigned val)
{
    char no[64];

    sprintf(no,"%u",val);

    AddLine(TYPE_TOKEN,TOK_CLEAR,
	    TYPE_TOKEN,TOK_VAL,
	    TYPE_STRING,no,
	    TYPE_END);
}


void BasicLoadLine(void)
{
    AddLine(TYPE_TOKEN,TOK_LOAD,
	    TYPE_TOKEN,TOK_QUOTE,
	    TYPE_TOKEN,TOK_QUOTE,
	    TYPE_TOKEN,TOK_CODE,
	    TYPE_END);
}


void BasicRandUsr(unsigned val)
{
    char no[64];

    sprintf(no,"%u",val);

    AddLine(TYPE_TOKEN,TOK_RAND,
	    TYPE_TOKEN,TOK_USR,
	    TYPE_TOKEN,TOK_VAL,
	    TYPE_STRING,no,
	    TYPE_END);
}


const unsigned char *BasicBase(void)
{
    return mem;
}


const unsigned BasicLength(void)
{
    return endptr;
}


/* END OF FILE */