#!/usr/bin/python

"""A program to convert printf statements to efficient serial commands."""

code = {}
code["print_hex_char"] = """void print_hex_char(char p) {
  char d = p >> 4;
  if(d >= 10)
    d += ('a' - 10);
  else
    d += ('0' - 0);
  putc(d);
  d = p & 0xf;
  if(d >= 10)
    d += ('a' - 10);
  else
    d += ('0' - 0);
  putc(d);
}

"""

code["print_decimal_char"] = """void print_decimal_uchar(unsigned char p) {
  char d = '0';
  while(p >= 100) {
    p -= 100;
    d++;
  }
  putc(d);
  d = '0';
  while(p >= 10) {
    p -= 10;
    d++;
  }
  putc(d);
  d = '0' + p;
  putc(d);
}

void print_decimal_char(char p) {
  char d = '0';
  if(p < 0) {
    p = -p;
    putc('-');
  }
  print_decimal_uchar((unsigned char)p);
}

"""

code["print_newline"] = """void print_newline() {
  putc('\n');
  putc('\r');
}

"""

def output_char(c):
    return "putc(%d);" % ord(c)

def generate_printf(s, p):
    o = ""
    needed = {}
    params = p
    while(s):
        c = s[0]
        if(c != '%'):
            o = o + output_char(c) + '\n'
            s = s[1:]
        else:
            if(s[1] == 'd'):
                o = o + "print_decimal_char(%s)\n" % params[0]
                params = params[1:]
                needed["print_decimal_char"] = 1
                s = s[2:]
            elif(s[1] == 'x'):
                o = o + "print_hex_char(%s)\n" % params[0]
                params = params[1:]
                s = s[2:]
                needed["print_hex_char"] = 1
    for i in needed.keys():
        print code[i]
    print o

import re
def recognise_printf(s):
    m = re.match('printf\s*\("([^"]*)"\s*,\s*(.*)\)\s*;', s)
    n = re.split("\s*,\s*", m.group(2))
    generate_printf(m.group(1), n);

recognise_printf('printf("hello world! %d %x\n", alpha, beta);');