#include <cstdlib>
#include <iostream>
#include <sstream>
#include <string>
#include <stdlib.h>
#include "mixed.h"

using namespace std;


void welcome();
void readline(string &line);
void parse(string line, mixed &x, char &op, mixed &y);
void perform(mixed &x, char op, mixed &y);
string trim(string &line);
mixed& readMixed(string &line);
void getValues(string line, mixed &x, char &op, mixed &y, int where);

int main(int argc, char *argv[])
{
    mixed x, y;
    char op;
    string line;
    welcome();
    while(1)
    {
        readline(line);
        parse(line, x, op, y);
        perform(x, op, y);
    }
    system("PAUSE");
    return EXIT_SUCCESS;
}
stringstream ss (stringstream::in | stringstream::out);


void welcome()
{
    cout<<"Welcome to the PCC mixed Calculator!"<<endl
    <<endl
    <<"This calculator will do simple mixed mathematics"<<endl
    <<"that involve the operators +, -, *, /, and = and two"<<endl
    <<"operands."<<endl<<endl;
}

void readline(string &line)
{
    cout<<"Input: ";
    getline(cin, line);
    if(line == "")
        exit(0);
}

void parse(string line, mixed &x, char &op, mixed &y)
{

    stringstream ss (stringstream::in | stringstream::out);
    char *target = "+-*/=";
    int firstOp = line.find_first_of(target),
    lastOp = line.find_last_of(target),
    opCount = 0,
    found=line.find_first_of(target);
    int opPluCount = 0, opMinCount = 0, opMulCount = 0;
    string begin, end;
    while (found!=string::npos)
    {
        opCount++;
        found=line.find_first_of(target,found+1);
    }
    switch(opCount)
    {
        case 0 :
            cout<<"nothing to do!!!"<<endl;
            op = '+';
            line.append("/1 + 0/1");
            firstOp = line.find_first_of('+');
            getValues(line, x, op, y, firstOp);
            break;

        case 1 : /*One operator case with two integers
                  One way of doing it would be to break things apart

                  firstOp = line.find_first_of(target);
                  op = line[firstOp];
                  line = line.substr(0, op-1) + " 0/1 " +
                  op + " "  +
                  line.substr(op+1, string::npos) + " 0/1";

                  and then there is the "easy way"
                  */

            if (line.at(firstOp) == '/') {
                line.insert(1,"/1");
                line.append("/1");
                int j = 0;
                for (size_t i=0; i < line.length(); i++)
                {
                    if(line.at(i) == '/'){
                        j++;
                        if (j==2) {
                            firstOp = i;
                            break;
                        }
                    };
                }
                cout << line << endl;
                cout << firstOp << endl;

                getValues(line, x, op, y, firstOp);
                //break; //del before going on
            }
            else {
                getValues(line, x, op, y, firstOp);
            }


            break;

        case 2 : /*
                  Whole op -Whole
                  -Whole op Whole
                  Fac op Whole
                  Whole op Frac
                  Mixed op Whole
                  Whole op Mixed
                  */

            break;

        case 3: /*
                 -Whole op -Whole
                 -Frac op Whole
                 Whole op -Frac
                 -Mixed op Whole
                 Whole op -Mix
                 Frac op Frac
                 Mixed op Mixed
                 Frac op Mixed
                 Mixed op Frac
                 */


            break;


        case 4: /*
                 -Frac op Frac
                 Frac op -Frac
                 Mixed op -Mixed
                 -Mixed op Mixed
                 -Mixed op Frac
                 -Frac op Mixed
                 Mixed op -Frac
                 Frac op -Mixed
                 -Whole op (-Frac or -Mixed)
                 (-Mixed or -Frac) op -Whole
                 */
            break;

        case 5: /*
                 -Mixed op -Mixed
                 -Frac op -Frac
                 -Frac op -Mixed
                 -Mixed op -Frac
                 */
            /*
             one way to read these would be:

             for(int i=0; i<3; i++)
             firstOp = line.find_first_of(target);

             begin = line.substr(0, firstOp-1);
             op =line[firstOp];
             end = line.substr(firstOp+1,string::npos);
             if(begin.find(" ") != string::npos)
             begin = "0 " + begin;
             if(end.find(" ") != string::npos)
             end = "0 " + end;
             line = begin + " " + op + " " + end;
             */
            getValues(line, x, op, y, 3);
            break;
    }

}
/*
 ss<<line;
 ss>>x>>op>>y;
 */

void getValues(string line, mixed &x, char &op, mixed &y, int where)
{
    static char* target = "+-/*";

    int firstOp = where;
    //int firstOp;
    //for(int i=0; i<where; i++)
    //  firstOp = line.find_first_of(target);
    op = line[firstOp];
    string begin = line.substr(0,firstOp),
    end = line.substr(firstOp+1,string::npos);
    //string begin = line.substr(0,firstOp-1),
    //end = line.substr(0,firstOp+1);
    trim(begin);
    trim(end);
    x = readMixed(begin);
    y = readMixed(end);
    /*
     The above two lines translate to:

     begin = trim(line.substr(0,firstOp-1));
     end = trim(line.substr(0,firstOp+1));
     x = readMixed(begin);
     y = readMixed(end);
     */
}

string trim(string &line)
{
    while(line[0] == ' ')
        line.erase(0);
    return line;
}

mixed& readMixed(string &line)
{
    static mixed ans;
    char junk;
    int w = 0, n = 0, d = 1;
    stringstream ss (stringstream::in | stringstream::out);
    ss<<line;
    if(line.find(" "))
        ss>>w>>n>>junk>>d;
    else
        if(line.find("/") != string::npos)
            ss>>n>>junk>>d;
        else
            ss>>w;
    ans.set(w,n,d);
    return ans;
}


void perform(mixed &x, char op, mixed &y)
{
    mixed ans;
    cout<<x<<" "<<op<<" "<<y<<" = ";
    switch(op)
    {
        case '+' :  ans = x + y;
            break;

        case '-' :  ans = x - y;
            break;

        case '*' :  ans = x * y;
            break;

        case '/' :  ans = x / y;
            break;
        case 'e' :
            op = '0';
            break;
        case '=' :  if(x == y)
            cout<<"TRUE"<<endl;
        else
            cout<<"FALSE"<<endl;
            return;

        default  :  cout<<"Unknown operator!"<<endl;
            return;
    }
    cout<<ans<<endl;
}