#include <ctype.h>
#include <string.h>

#include "audio_error.h"
#include "audio_mem.h"
#include "esp_log.h"

static char *TAG = "AUDIO_URL";

static unsigned char char_to_hex(unsigned char x) {
  return x > 9 ? x + 0x37 : x + 0x30;
}

char *audio_url_encode(const char *str) {
  int out_len = (strlen(str) + 1) * 3;
  char *final = audio_malloc(out_len);
  AUDIO_MEM_CHECK(TAG, final, return NULL);
  char *tmp = final;
  for (size_t i = 0; i < strlen(str); i++) {
    if (isalnum((unsigned char)str[i]) || (str[i] == '-') || (str[i] == '_') ||
        (str[i] == '.') || (str[i] == '!') || (str[i] == '@') ||
        (str[i] == '#') || (str[i] == '$') || (str[i] == '&') ||
        (str[i] == '*') || (str[i] == '(') || (str[i] == ')') ||
        (str[i] == '=') || (str[i] == ':') || (str[i] == '/') ||
        (str[i] == ',') || (str[i] == ';') || (str[i] == '?') ||
        (str[i] == '+') || (str[i] == '\'') || (str[i] == '~')) {
      *final++ = str[i];
    } else {
      *final++ = '%';
      *final++ = char_to_hex((unsigned char)str[i] >> 4);
      *final++ = char_to_hex((unsigned char)str[i] % 16);
    }
  }
  *final = 0;
  return tmp;
}

char *audio_url_decode(const char *str) {
  char *final = audio_malloc(strlen(str) + 1);
  AUDIO_MEM_CHECK(TAG, final, return NULL);
  char *tmp = final;
  while (*str) {
    if (*str == '%') {
      char buffer[3] = {str[1], str[2], 0};
      *final++ = strtol(buffer, NULL, 16);
      str += 3;
    } else {
      *final++ = *str++;
    }
  }
  *final = 0;
  return tmp;
}