// CS 1A Lab 4
// Student: Adam Creeger
// Student ID: 20160381
#include <iostream>
#include <string>
#include <sstream>
using namespace std;
// main client --------------------------------------------------------
int main()
{
    int stamps = 0;
    int userInYogurt = 0;
    string userInReward;
    string userInStr;
    string bufferString;
    //Main Loop
    while (true) {
        //Menu Loop
        while (cout << "In order to make a purchase: Press 'P'.  To shut down: Press 'S'." << endl &&
            getline(cin, bufferString)) {
            istringstream iss{ bufferString };
            if ((iss >> userInStr)) {
                if ((userInStr.substr(0, 1) == "P") || (userInStr.substr(0, 1) == "p")) {
                    break;
                }
                else if ((userInStr.substr(0, 1) == "S") || (userInStr.substr(0, 1) == "s")) {
                    cout << "Program terminated by user." << endl;
                    return 0;
                }
            }
        }
        //Reward purchase
        if (stamps >= 10) {
            cout << "You have " << stamps << " reward stamps!" << endl;
            cout << "You can redeem a yogurt for 10 stamps. Would you like to accept? Y/N?" << endl;
            getline(cin, userInReward);
            cout << "You received " << stamps / 10 << " yogurts!" << endl;

            if ((userInReward.substr(0, 1) == "Y") ^ (userInReward.substr(0, 1) == "y")) {
                cout << "Enjoy your free yogurt!" << endl;
                stamps -= 10;
            }
            else
                while ((cout << "How many yogurts would you like to purchase?" << endl)
                    && getline(cin, bufferString))
                {
                    istringstream iss{ bufferString };
                    if (iss >> userInYogurt) {
                        if (userInYogurt > 0 && userInYogurt < 1000) {
                            //Adjust stamp counter
                            stamps += userInYogurt;
                            cout << "You purchased " << userInYogurt << " yogurts!" << endl;
                            cout << "You have " << stamps << " yogurt stamps!" << endl;
                            break;
                        }
                        cout << "ERROR: Character input not valid." << endl;
                    }
                }
        }
        //Normal purchase
        else if (stamps < 10) {
            while ((cout << "How many yogurts would you like to purchase?" << endl)
                && getline(cin, bufferString))
            {
                istringstream iss{ bufferString };
                if (iss >> userInYogurt) {
                    if (userInYogurt > 0 && userInYogurt < 1000) {
                        //Adjust stamp counter
                        stamps += userInYogurt;
                        cout << "You purchased " << userInYogurt << " yogurts!" << endl;
                        cout << "You have " << stamps << " yogurt stamps!" << endl;
                        break;
                    }
                    cout << "ERROR: Character input not valid." << endl;
                }
            }
        }
    }
}