#include <iostream>
using namespace std;

const int key=1.1, mouse=.67, finger=.83;
const char d=0.97, l=1.12, p=1.14, t=1.235;

int main(){
    int sharp, age;
    double PI_h, PI_c, PI_a;
    char edu, screen, loop='y';
    string inputdev;

    //loops once and ask to loop again. will loop while loop=='y'
    while(loop=='y'){

        //asking for user input to define variables
        cout << "CSOZT Brain Trainer\n";
        cout << endl;
        cout << "Education level (a, c, or h): ";
        cin >> edu;
        cout << "Mental sharpness (1-10): ";
        cin >> sharp;
        cout << "Age (in years): ";
        cin >> age;
        cout << "Input device (keyboard, mouse, finger): ";
        cin >> inputdev;
        cout << "Screen size (d, l, p, t): ";
        cin >> screen;

        //sets output to show 3 decimal places
        cout.setf(ios::fixed);
        cout.showpoint;
        cout.precision(3);

        //formulae to calculate PI for each education level
        PI_h=5.17*(393+(6.3*sharp*sharp))/(1.117213218*age);
        PI_c=3.71*(405+(5.8*sharp*sharp))/(2.2913513322*age);
        PI_a=5.72*(513+(3.9*sharp*sharp))/(1.755249215*age);

        //adjusts PIs based on input device
        if(inputdev=="keyboard"){
            key*PI_h, key*PI_c, key*PI_a;
        }
        else if(inputdev=="mouse"){
            mouse*PI_h, mouse*PI_c, mouse*PI_a;
        }
        else if(inputdev=="finger"){
            finger*PI_h, finger*PI_c, finger*PI_a;
        }
        else{
            cout << "Invalid input device";
            return 0;
        }

        //switch statement to test screen size and adjust PI
        switch(screen){
            case 'd':
                d*PI_h, d*PI_c, d*PI_a;
                break;
            case 'l':
                l*PI_h, l*PI_c, l*PI_a;
                break;
            case 'p':
                p*PI_h, p*PI_c, p*PI_a;
                break;
            case 't':
                t*PI_h, t*PI_c, t*PI_a;
                break;
            default:
                cout << "Invalid screen type";
                return 0;

                // compares edu to determine which PI calculation to output
                if(edu=='a'){
                    //overrides output of PI_edu for sharpness 3 or lower
                    if(sharp<=3){
                        cout << "PI = " << PI_h << endl;
                    }
                    else{
                        cout << "PI = " << PI_a << endl;
                    }
                }
                if(edu=='c'){
                    if(sharp<=3){
                        cout << "PI = " << PI_h << endl;
                    }
                    else{
                        cout << "PI = " << PI_c << endl;
                    }
                }
                else if(edu=='h'){
                    cout << "PI = " << PI_h << endl;
                }

                //ask to repeat program
                cout << "Repeat calculation (y/n): ";
                cin >> loop;
    }
        return 0;
}