/* string.c */

#include "program.h"
#include "string.h"
#include "tty3.h"

void string_memcpy(char *dst, char src[]) {
  int i = 0;
  while(1) {
    dst[i] = src[i];
    if(src[i] == '\0') { break; }
    else { i++; }
  }
}

void sub_string(char *dst, char str[], int a, int len) {
  int i;
  for(i = 0; i < len; i++) {
    if(i + a >= 0) {
      if(str[i + a]) { dst[i] = str[i + a]; }
      else {
        while(i < len) { dst[i++] = ' '; }
      }
    }
  }
  dst[i] = '\0';
}

int name_comp(char name_a[], char name_b[]) {
  if(str_length(name_a) != str_length(name_b)) { return 0; }
  int i;
  for(i = 0; i < MAX_STR_LEN; i++) {
    if(name_a[i] != name_b[i]) { return 0; }
    if(name_a[i] == '\0' && name_b[i] == '\0') { break; }
  }
  return 1;
}

int str_length(char *str) {
  int i = 0;
  while(*str++) { i++; }
  return i;
}

int string_to_int(char *string) {
  int sum = 0;
  int string_len = str_length(string);
  int i, prod;
  while(*string) {
    prod = 1;
    for(i = 0; i < string_len - 1; i++) { prod *= 10; }
    string_len--;
    sum += ((int)*string - ASCII_INT_START)*prod;
    *string++;
  }
  return sum;
}

void rev(char *str) {
  int end = str_length(str)-1;
  int start = 0;

  while(start<end) {
    str[start] ^= str[end];
    str[end] ^= str[start];
    str[start] ^= str[end];

    ++start;
    --end;
  }
}

void int_to_string(char *s, int n) {
  int c = 0;
  while(1) {
    if (n < 10) {
      s[c++] = (char)(n + ASCII_INT_START);
      s[c] = '\0';
      break;
    } else {
      s[c++] = (char)(n%10 + ASCII_INT_START);
      n /= 10;
    }
  }
  rev(s);
}