stmbl

//
//  scanf.c
//  test
//
//  Created by crinq on 05.12.13.
//  Copyright (c) 2013 Rene Hopf. All rights reserved.
//

#include "scanf.h"

int scanf_(const char *format, ...){
	int ret = 0;
	char rx_buf[APP_TX_BUF_SIZE];
	va_list arg;
	if(UB_USB_CDC_GetStatus()==USB_CDC_CONNECTED){
		if(UB_USB_CDC_ReceiveString(rx_buf)==RX_READY){
			va_start(arg, format);
			ret = vfsscanf_(rx_buf, format, arg);
			va_end(arg);
		}else{
			ret = -1;
		}
	}
	return(ret);
}

int sscanf_(const char* buf, const char *format, ...){
	int ret = 0;

	va_list arg;
	va_start(arg, format);
	ret = vfsscanf_(buf, format, arg);
	va_end(arg);
	return(ret);
}


int isBinDigit(char c){
	return(c == '0' || c == '1');
}

int isChar(char c){
	return((c <= 'Z' && c >= 'A') || (c <= 'z' && c >= 'a') || isDecDigit(c));
}

int isNameChar(char c){
	return(isChar(c) || c == '_' || c == '-' || c == '.');
}

int isDecDigit(char c){
	return(c >= '0' && c <= '9');
}

int isHexDigit(char c){
	return((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')  || (c >= 'a' && c <= 'f'));
}

int isWhitespace(char c){
	return(c == ' ' || c == '\t');
}

int vfsscanf_(const char *buf, const char *format, va_list arg){
	int buffer_pos = 0;
	int format_pos = 0;
	int string_pos = 0;
	int ret = 0;
	int found = 0;

	int *i;
	float *f;
	char *c;
	int invert;
	float tf;

	int state = 0;  // 0 = last char = normal char
	// 1 = last char = '%'
	// 2 = last char = '\'

	while(format[format_pos]){
		found = 0;
		switch(state){
			case 0:
				switch(format[format_pos]){
					case '%':
						state = 1;
						format_pos++;
						continue;
						break;

					case '\'':
						state = 2;
						format_pos++;
						continue;
						break;

					case ' ': // parse whithespaces
						while(isWhitespace(buf[buffer_pos])){
							buffer_pos++;
              found++;
						}
            found++;
						break;

					default:
						if(format[format_pos] != buf[buffer_pos++]){
							return(ret);
						}
						found++;
				}
				break;

			case 1:
				switch(format[format_pos]){
					case '%':
						if(buf[buffer_pos++] != '%'){
							return(ret);
						}
						found++;
						break;

					case 'c':
						c = va_arg(arg, char *);
						*c = buf[buffer_pos++];
						found++;
						break;

					case 's':
						string_pos = 0;
						c = va_arg(arg, char *);
						//while(isChar(buf[buffer_pos])){
						while(!isWhitespace(buf[buffer_pos])){
							c[string_pos] = buf[buffer_pos++];
							string_pos++;
							c[string_pos] = '\0';
							found++;
						}
						break;

					case 'N':
						string_pos = 0;
						c = va_arg(arg, char *);
						//while(isChar(buf[buffer_pos])){
						while(isNameChar(buf[buffer_pos])){
							c[string_pos] = buf[buffer_pos++];
							string_pos++;
							c[string_pos] = '\0';
							found++;
						}
						break;

					case 'i':
						i = va_arg(arg, int *);
						*i = 0;
						invert = 1;
						if(buf[buffer_pos] == '-'){
							invert = -1;
							buffer_pos++;
						}
						else if(buf[buffer_pos] == '+'){
							buffer_pos++;
						}
						while(isDecDigit(buf[buffer_pos])){
							*i *= 10;
							*i += buf[buffer_pos++] - '0';
							found++;
						}
						*i *= invert;
						break;

					case 'b':
						i = va_arg(arg, int *);
						*i = 0;
						invert = 1;
						if(buf[buffer_pos] == '-'){
							invert = -1;
							buffer_pos++;
						}
						else if(buf[buffer_pos] == '+'){
							buffer_pos++;
						}
						if(!(buf[buffer_pos] == 'b' || buf[buffer_pos] == 'B')){
							return(ret);
						}
						buffer_pos++;
						while(isBinDigit(buf[buffer_pos])){
							*i *= 2;
							*i += buf[buffer_pos++] - '0';
							found++;
						}
						*i *= invert;
						break;

					case 'h':
						i = va_arg(arg, int *);
						*i = 0;
						invert = 1;
						if(buf[buffer_pos] == '-'){
							invert = -1;
							buffer_pos++;
						}
						else if(buf[buffer_pos] == '+'){
							buffer_pos++;
						}
						if(buf[buffer_pos++] != '0'){
							return(ret);
						}
						if(buf[buffer_pos++] != 'x'){
							return(ret);
						}
						while(isHexDigit(buf[buffer_pos])){
							*i *= 16;
							if(buf[buffer_pos] < 'A'){
								*i += buf[buffer_pos++] - '0';
							}
							else if(buf[buffer_pos] < 'a'){
								*i += buf[buffer_pos++] - 'A' + 10;
							}
							else{
								*i += buf[buffer_pos++] - 'a' + 10;
							}
							found++;
						}
						*i *= invert;
						break;

					case 'f':
						f = va_arg(arg, float *);
						*f = 0;
						tf = 10;
						invert = 1;
						if(buf[buffer_pos] == '-'){
							invert = -1;
							buffer_pos++;
						}
						else if(buf[buffer_pos] == '+'){
							buffer_pos++;
						}
						while(isDecDigit(buf[buffer_pos])){
							*f *= 10;
							*f += buf[buffer_pos++] - '0';
							found++;
						}
						if(buf[buffer_pos] == '.'){
							buffer_pos++;
							while(isDecDigit(buf[buffer_pos])){
								*f += (buf[buffer_pos++] - '0') / tf;
								tf *= 10;
								found++;
							}
						}
						*f *= invert;
						break;

					default:
						return(ret);
						break;
				}
				state = 0;
				break;

			case 2:
				switch(format[format_pos]){
					case '\'':
						if(buf[buffer_pos++] != '\''){
							return(ret);
						}
						found++;
						break;

					case 'n':
						if(buf[buffer_pos++] != '\n'){
							return(ret);
						}
						found++;
						break;

					default:
						return(ret);
						break;
				}
				state = 0;
				break;

			default:
				break;
		}

		format_pos++;
		if(!found){
      return(ret);
		}
    ret++;
	}
	return(ret);
}