#include "string_functions.h"

using namespace std;

unsigned long string_length(const string STR) {
  unsigned long result = -1;
  result = STR.length(); // set result to the length of the string
  return result;
}

char string_char_at(const string STR, const int IDX) {
  char result = '\0';
  result = STR.at(IDX);
  return result;
}

string string_append(const string LEFT, const string RIGHT) {
  string result = LEFT;
  result = LEFT + RIGHT;
  return result;
}

string string_insert(const string STR, const string TO_INSERT, const int IDX) {
  string result = STR;
  result.insert(IDX, TO_INSERT);
  return result;
}

size_t string_find(const string STR, const char C) {
  size_t result = 0;
  result = STR.find_first_of(C);
  return result;
}

string string_substring(const string STR, const int IDX, const int LEN) {
  string result = STR;
  result = STR.substr(IDX, LEN);
  return result;
}

string string_replace(const string STR, const string TEXT_TO_REPLACE,
                      const string REPLACE_WITH) {
  string result = STR;
  auto index = STR.find(TEXT_TO_REPLACE);
  if (index != -1ul) {
    result.replace(STR.find(TEXT_TO_REPLACE), TEXT_TO_REPLACE.length(),
                   REPLACE_WITH);
  }
  return result;
}

string string_first_word(const string STR) {
  string result = STR;
  result = STR.substr(0, STR.find_first_of(' '));
  return result;
}

string string_remove_first_word(const string STR) {
  string result = STR;
  if (STR.find_first_of(' ') != -1ul) {
    result = STR.substr(STR.find_first_of(' ') + 1, STR.length() - 1);
  } else {
    result = "";
  }
  return result;
}

string string_second_word(const string STR) {
  string result = STR;
  result = string_remove_first_word(STR);
  result = string_first_word(result);
  return result;
}

string string_third_word(const string STR) {
  string result = STR;
  result = string_remove_first_word(STR);
  result = string_remove_first_word(result);
  result = string_first_word(result);
  return result;
}

string string_nth_word(const string STR, const int N) {
  string result = STR;
  for (int i = 0; i < N - 1; i++) {
    result = string_remove_first_word(result);
  }
  result = string_first_word(result);
  return result;
}

vector<string> string_tokenize(const string STR, const char DELIMINATOR) {
  vector<string> result;
  result = {""};
  for (unsigned long i = 0; i < STR.length(); i++) {
    if (STR[i] == DELIMINATOR) {
      result.push_back("");
      continue;
    }
    result[result.size() - 1] += STR[i];
  }
  return result;
}

string string_substitute(const string STR, const char TARGET,
                         const char REPLACEMENT) {
  string result = STR;
  while (result.find(TARGET) != -1ul) {
    result[result.find(TARGET)] = REPLACEMENT;
  }
  return result;
}

string string_to_lower(const string STR) {
  string result = STR;
  for (unsigned int i = 0; i < STR.length(); i++) {
    char newChar = STR[i];
    if (newChar >= 'A' && newChar <= 'Z') {
      newChar = (char)(newChar + 32);
    }
    result[i] = newChar;
  }
  return result;
}

string string_to_upper(const string STR) {
  string result = STR;
  for (unsigned int i = 0; i < STR.length(); i++) {
    char newChar = STR[i];
    if (newChar >= 'a' && newChar <= 'z') {
      newChar = (char)(newChar - 32);
    }
    result[i] = newChar;
  }
  return result;
}

int string_compare(const string LHS, const string RHS) {
  int result = 0;
  if (LHS > RHS) {
    result = 1;
  } else {
    if (LHS < RHS) {
      result = -1;
    }
  }
  return result;
}