/*
  Questions to ask:
  
  1) Difference between c strings and strings?
  - We know the length of string
  - String has functions built in

 */


#include "string.h"
#include <iostream>
using namespace std;

String::String()
{
  init(DEFAULT_SIZE,"");
}

String::String(int size) 
{
  init(size,"");
}

String::String(char* initString)
{
  init(DEFAULT_SIZE, initString);
}

String::String(int size, char* initString)
{
  init(size,initString);
}

void String::init(int initCapacity, char* initString)
{
  stringLength = strlen(initString);               // Get the length of the c_string
  arrayLength = max(initCapacity,stringLength);    // Array length is max
  str = new char[arrayLength];                       // dynamically create array
  strcpy(str,initString);                            // copy contents of initString
}

const char* String::c_str() const
{
  return str;
}

char& String::at ( int pos )
{
  return str[pos];
}


int String::capacity ( ) const
{
  return arrayLength;
}


int String::size ( ) const
{
  return stringLength;
}

void String::clear()
{
  at(0) = '\0';
  stringLength = 0;
}

int String::compare ( const String& str ) const
{
  return strcmp(this->str,str.c_str());
}

String& String::append(const string& str)
{
  int finalSize = strlen(str) + stringLength + 1;
  if(finalSize > arrayLength) {       // if we dont have enough room
    char* tmp = new char[finalSize];  // create new array
	this->arrayLength = finalSize;	  // We have a new array length
    strcpy(tmp, this->str);           // copy into tmp
    strcat(tmp, str);                 // concatenate into tmp
    delete this->str;                 // delete old memory
    this->str = tmp;                  // copy the ptr from tmp to class var
  }
  else {
    strcat(this->str, str);  // we have enough memory so just simple strcat
  }
  
  this->stringLength = finalSize;   // we have a new stringLength!
  return this;
}

// This is operator overloading so we can cout this class.  You can look
// forward to learning this soon!
ostream& operator << (ostream& os, const String& s)
{
  return os << s.c_str();
}


int main()
{
  String s("Hello");
  cout << s.c_str() << endl;
  s.at(1) = 'a';
  cout << s.c_str() << endl;
  
  cout << s.compare(s) << endl;
  
  String s2(" World");
  cout << s.append(s2) << endl;
  cout << s << endl;
  
}