#include <stdio.h>
#include <string.h>

int main() {
char username[30];
char discountpicked;

int quantity[4] = {0};
int itemSummary[4] = {0, 0, 0, 0};
float prices[4] = {950.00, 399.00, 250.50, 89.50};

float change = 0, cash = 0;
float subtotal = 0, total = 0;
float discount = 0, VATamount = 0;

float totalEarnings = 0;
int totalOrders = 0;
int choice = 0;
int exitChoice = 0;

printf("You are currently logged out.\n");
printf("Enter Username: ");
scanf("%29s", username);

while (strcmp(username, "Admin") != 0) {
printf("Wrong username! Try Again.\n");
printf("Enter username: ");
scanf("%29s", username);
}

printf("\n===== CS 101 CASHIER SIMULATOR =====\n\n");
do {
subtotal = 0;
discount = 0;
VATamount = 0;
total = 0;
cash = 0;
change = 0;
int currentTransItems = 0;

for (int i = 0; i < 4; i++) quantity[i] = 0;

printf("\n--- New Order ---\n");
for (int i = 0; i < 4; i++) {
printf("Item %d -> ", i + 1);

while (scanf("%d", &quantity[i]) != 1) {
printf("Invalid input! Numbers only.\n");
scanf("%*s");
printf("Item %d -> ", i + 1);
}
currentTransItems += quantity[i];
}

if (currentTransItems == 0) {
printf("No items purchased. Transaction cancelled.\n");
goto ASK_CHOICE;
}
do {
printf("Is Customer Senior/PWD? Y/N: ");
scanf(" %c", &discountpicked);

if (discountpicked != 'Y' && discountpicked != 'y' &&
discountpicked != 'N' && discountpicked != 'n') {
printf("Invalid input! Please enter Y or N.\n\n");
}
} while (discountpicked != 'Y' && discountpicked != 'y' &&
discountpicked != 'N' && discountpicked != 'n');
for (int i = 0; i < 4; i++) {
subtotal += prices[i] * quantity[i];
itemSummary[i] += quantity[i];
}

if (discountpicked == 'Y' || discountpicked == 'y') {
discount = subtotal * 0.12;
VATamount = 0;
total = subtotal - discount;
} else {
discount = 0;
VATamount = subtotal - (subtotal / 1.12);
total = subtotal;
}

printf("Total to pay: %.2f\n", total);
do {
printf("Customer gave: ");
scanf("%f", &cash);

if(cash < total) {
printf("Insufficient cash! You need at least %.2f. Try again.\n", total);
}
} while (cash < total);

change = cash - total;
totalEarnings += total;
totalOrders++;

printf("\n======== RECEIPT ========\n");
printf("EMTC1CT Business\n");
printf("Lozol Taft Avenue.\n");
printf("Cashier: %s\n\n", username);

for (int i = 0; i < 4; i++) {
if (quantity[i] > 0)
printf("Item %d x %d = %.2f\n", i + 1, quantity[i], prices[i] * quantity[i]);
}

printf("\nSubtotal: %.2f\n", subtotal);
printf("Senior/PWD disc: -%.2f\n", discount);
printf("VAT amount: %.2f\n", VATamount);
printf("-------------------------\n");
printf("Items Purchased: %d\n", currentTransItems);
printf("Total: %.2f\n", total);
printf("Cash: %.2f\n", cash);
printf("Change: %.2f\n", change);
printf("=========================\n");

ASK_CHOICE:
printf("\n1 - Another transaction\n");
printf("2 - Logout / End Shift\n");
printf("Enter choice: ");
scanf("%d", &choice);
printf("=========================\n");

} while (choice == 1);

printf("\nClosing cash register manned by %s\n", username);
printf("Total orders processed: %d\n", totalOrders);

int grandTotalItems = itemSummary[0] + itemSummary[1] + itemSummary[2] + itemSummary[3];
printf("Total items sold: %d\n", grandTotalItems);

printf("Breakdown of items sold:\n");
for (int i = 0; i < 4; i++) {
printf("Item %d: %d pcs\n", i + 1, itemSummary[i]);
}

printf("Total earnings: %.2f\n", totalEarnings);
printf("===============================\n");

printf("1 - Login Again\n");
printf("2 - Exit Program\n");
printf("Enter choice: ");
scanf("%d", &exitChoice);

if (exitChoice == 1) {
printf("\nRestart program to login again.\n");
} else {
printf("Program exiting.\n");
}

return 0;
}