/* This is a program to test rot13 speed */

#include <iostream>
#include <string>
#include <map>
#include <ctime>

using namespace std;


/* define function with standard mapping */
class Rot13 {

    map<char, char> myrotdict;

public:
    Rot13();
    void convert_inplace(string& mystr);
    string convert(const string& mystr);
};

Rot13::Rot13(){

    // initialize the mapping
    string characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    for(int i = 0; i < 26*2; ++i){

        int b = (i + 13)%26;
        int idx = (i<26)? b : b + 26;

        myrotdict[characters[i]] = characters[idx];
    }
}

void Rot13::convert_inplace(string& mystr){

    for(unsigned int i = 0; i < mystr.length(); ++i){
        char c = mystr[i];
        if(myrotdict.find(c) != myrotdict.end()){
            char newc = myrotdict[c];
            mystr[i] = newc;
        }
    }
}


string Rot13::convert(const string& mystr){
    string newstr = mystr;

    for(unsigned int i = 0; i < mystr.length(); ++i){
        char c = mystr[i];
        if(myrotdict.find(c) != myrotdict.end()){
            char newc = myrotdict[c];
            newstr[i] = newc;
        }
    }

    return newstr;
}


void bitrot_inplace(string mystr){
    for (unsigned int i = 0; i < mystr.length(); ++i){
        mystr[i] = ((mystr[i] > 0x40 && mystr[i] < 0x4E) || (mystr[i] > 0x60 && mystr[i] < 0x6E)) ? 13 : -13;
    }
}

string bitrot(const string&  mystr){
    string newstr = mystr;
    for (unsigned int i = 0; i < mystr.length(); ++i){
        cout << "----" << endl;
        char c = mystr[i];
        cout << c << endl;
        newstr[i] = ((c > 0x40 && c < 0x4E) || (c > 0x60 && c < 0x6E)) ? 13 : -13;
        cout << newstr[i] << endl;
    }

    return newstr;
}




void bitshiftrot_inplace(string& mystr){
    string characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
    for (unsigned int i = 0; i < mystr.length(); ++i){
        char c = mystr[i];
        if(characters.find(c) != string::npos){
            c = (((c & 0b11111) + 12) % 26 + 1)+(c & 0b1100000);
            mystr[i] = c;
        }
    }

}


string bitshiftrot(string mystr){
    string newstr;
    for (unsigned int i = 0; i < mystr.length(); ++i){
        char c = mystr[i];
        c = (((c & 0b11111) + 12) % 26 + 1)+(c & 0b1100000);
        newstr[i] = c;
    }

    return newstr;
}


int main()
{
    string teststr = "Hello my dear friends!";

    Rot13 myrot = Rot13();

    int trials = 10000000;

    clock_t begin, end;
    double elapsed;

    cout << " Program begins" << endl;

    cout << "Test string:" << endl;

    cout << teststr << endl;

    cout << "In place rotation" << endl;

    begin = clock();

    for(int i = 0; i < trials; ++i){
        myrot.convert_inplace(teststr);
    }

    end = clock();

    elapsed = double(end - begin) / CLOCKS_PER_SEC;

    cout << "time elapsed: " << elapsed << endl;

    cout << teststr << endl;

    cout << "Return value" << endl;

    begin = clock();

    for(int i = 0; i < trials; ++i){
        string newstr = myrot.convert(teststr);
    }

    end = clock();

    elapsed = double(end - begin) / CLOCKS_PER_SEC;

    cout << "time elapsed: " << elapsed << endl;

    cout << "Bit rot in place" << endl;

    begin = clock();

    for(int i = 0; i < trials; ++i){
         bitrot_inplace(teststr);
    }

    end = clock();

    elapsed = double(end - begin) / CLOCKS_PER_SEC;

    cout << "time elapsed: " << elapsed << endl;

/*
    cout << "Bit rot" << endl;

    cout << bitrot(teststr) << endl;

*/
    cout << "Bit shift rot in place" << endl;

    begin = clock();

    for(int i = 0; i < trials; ++i){
        bitshiftrot_inplace(teststr);
    }

    end = clock();

    elapsed = double(end - begin) / CLOCKS_PER_SEC;

    cout << "time elapsed: " << elapsed << endl;


/*
    cout << "Bit shift rot" << endl;

    cout << bitshiftrot(teststr) << endl;
*/

    return 0;
}