/* string.cpp
 * A String ADT
 * Anthony Larrain
 * spring 2006 csc309
 *
 * Note: print statements have been included in the constructors, the destructor
 * and assignment. 
 */
 
#include <iostream>
#include <cstring>
#include <cctype>
#include <ctime>
#include <cstdlib>
using namespace std;


class String
{
    public:
        // Constructors                   
        String(const char *cstring = ""); // convert constructor       
        String(char character);           // convert constructor
        String(const String & str);       // copy constructor
                
        //Destructor
        ~String(); 
               
        //Assignment Operator
        const String & operator= (const String &rhs);
        
        // Transformers
        String & toLower();
        String & toUpper(); 
        
        // Other
        int size() const;
        // output string to the strean and newline
        void println(ostream &out) const; 
        // output string - No newline
        void print(ostream &out) const;  
        
        bool equals(const String & other) const;   
    
    private:
        char *buffer;
        int len;
};

String random()
{
    srand(time(NULL));
    static char vowel [] = {'a','e','i','o','u'};
    static char novow  [] = {'b','d','p','c','t'};
    static char word [4];
    word[0] = novow[rand() % 5];
    word[1] = vowel[rand() % 5];
    word[2] = novow[rand() % 5];
    word[3] = '\0';
    String str(word);
    return str;
}
    

int main()
{
    String s1,            // no arg constructor
           s2("Sunday"),  // c-style string convert constructor
           s3(s2),        // copy constructor
           s4('M');       // character convert constructor  
   
    s1.println(cout);   
    s2.println(cout);   
    s3.println(cout);   
    s4.println(cout);    
    s2.toUpper();     
    s3.println(cout);    
    s1 = s4;              // calling assignment 
    s1.println(cout);  
    s1 = random();        // calling assignment and destructor
    s1.println(cout);
    
    char word[81];
    cout << "Enter a word" << endl;
    cin >> word;
    String s5(word);
    cout << "You entered ";
    s5.println(cout);
    
    s5.toLower();
    s5.println(cout);
    cout << "The number of characters is " << s5.size() << endl;
    
    cout << "Enter a sentence " << endl;   
    
    // need to get rid of newline character.
    cin.ignore(2,'\n');
    cin.getline(word, 81);    
    s5 = word;         // calling c-style convert and assignment  
    
    String s6 = "SUNDAY";
    s2.println(cout);
    s6.println(cout);   
    if(s2.equals(s6)){
        cout << "They are equal" << endl;
    }else{
        cout << "Not equal" << endl;
    }
        
    system("pause");
    return 0;
}

String::~String()
{
    cout << "Calling Destructor" << endl;  
	delete [] buffer;
}

String::String(const String & str)
{
    cout << "Calling Copy" << endl;  
    len = str.len;
    // one more for '\0'
    buffer = new char[len + 1];    
    strcpy(buffer, str.buffer);       
}
String::String(const char *cstring)
{
    cout << "Calling c-style string convert" << endl;
    if(cstring == NULL){
        cstring = "";        
    }
	len = strlen(cstring);	
	buffer = new char[len + 1];
    strcpy(buffer, cstring);
}

String::String (char character)
{
	len = 1;
	buffer = new char[len + 1];
	buffer[0] = character;
	buffer[1] = '\0';
}

const String & String::operator= (const String& rhs)
{
    cout << "Calling Assignment " <<endl;   
    // check for self asignment ..  str = str; 
	if(this != &rhs){
		if (len != rhs.len){
			delete [] buffer;
			buffer = new char [rhs.len + 1];
		}
		len = rhs.len;
		strcpy( buffer, rhs.buffer);
	}
	return *this;
}

String & String::toLower()
{
	for(int  i = 0; i < len; i++) {
        buffer[i] = tolower(buffer[i]);
    }
	return *this;
}
String & String::toUpper()
{
	for(int  i = 0; i < len; i++) {
        buffer[i] = toupper(buffer[i]);
    }
	return *this;
}
void String::println(ostream &out) const
{
    out << buffer << endl;
}
void String::print(ostream &out) const
{
    out << buffer;
}
int String::size() const 
{
    return len;
}
bool String::equals(const String & other) const
{    
    if(size() != other.size()){       
        return false;
    }
    for(int i = 0; i < size(); i++){
        if(buffer[i] != other.buffer[i]){
            return false;
        }
    }
    return true;
}