C_case_study_3

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
struct User{
    char username[100];
    char password[100];
    struct User *next;
}*user;
typedef struct User User;

struct item{
    int item_no;
    char name[100];
    int price;
    int quantity;
    struct item *next;
};
typedef struct item item;


static char username[100];
static char password[100];


void read_items(const char *filename, item **items, int *num_items) {
    FILE *file = fopen("Products.txt", "r");
    if (!file) {
        perror("Failed to open file");
        exit(EXIT_FAILURE);
    }

    int item_no, price, quantity;
    char name[100];
    *num_items = 0;
    *items = NULL;

    while (fscanf(file, "%d %s %d %d", &item_no, name, &price, &quantity) == 4) {
        *items = realloc(*items, (*num_items + 1) * sizeof(item));
        if (*items == NULL) {
            perror("Failed to allocate memory");
            exit(EXIT_FAILURE);
        }
        (*items)[*num_items].item_no = item_no;
        strcpy((*items)[*num_items].name, name);
        (*items)[*num_items].price = price;
        (*items)[*num_items].quantity = quantity;
        (*num_items)++;
    }

    fclose(file);
}


void find_item(item *items, int num_items, int item_no, int quantity) {
    for (int i = 0; i < num_items; i++) {
        if (items[i].item_no == item_no && quantity <= items[i].quantity) {
            printf("Item No: %d\n", items[i].item_no);
            printf("Name: %s\n", items[i].name);
            printf("Price: %d\n", items[i].price);
            printf("Quantity: %d\n", quantity);
            return;
        }
    }
    printf("Item with number %d not found or the quantity is more than in stock\n", item_no);
}


void displayCart(item *cart, int num_items, int item_no, int quantity) {
    if (num_items == 0) {
        printf("\nCart is empty!\n");
        return;
    }

    printf("\nItems in your cart:\n");
    for (int i = 0; i < num_items; i++) {
        if(item_no==cart[i].item_no){
            printf("  Item %d:\n", cart[i].item_no);
            printf("  Name: %s\n", cart[i].name);
            printf("  Price: %d\n", cart[i].price);
            printf("  Quantity: %d\n", quantity);
    }
}
}


void printBill(struct item *cart, int numitems, int item_no, int quantity) {
    if (numitems == 0) {
        printf("\nCart is empty!\n");
        return;
    }

    int total = 0;
    printf("\nBill Summary:\n");
    for (int i = 0; i < numitems; i++) {
        if(item_no==cart[i].item_no){
            int itemTotal = cart[i].price * quantity;
            printf("Item %d:\n", cart[i].item_no);
            printf("  Name: %s\n", cart[i].name);
            printf("  Price: %d\n", cart[i].price);
            printf("  Quantity: %d\n", quantity);
            printf("  Item Total: %d\n", itemTotal);
            total += itemTotal;
        }
    }
    printf("Total Bill: %d\n", total);
}



void sign_up(struct User **users, int *numUsers) {

    printf("\nEnter username: ");
    scanf("%s", username);

    printf("Enter password: ");
    scanf("%s", password);

    *users = (struct User *)realloc(*users, (*numUsers + 1) * sizeof(struct User));

    strcpy((*users)[*numUsers].username, username);
    strcpy((*users)[*numUsers].password, password);

    (*numUsers)++;

    printf("User signed up successfully!\n");
}



int log_in(struct User *users, int numUsers) {

    printf("\nEnter username: ");
    scanf("%s", username);

    printf("Enter password: ");
    scanf("%s", password);

    for (int i = 0; i < numUsers; i++) {
        if (strcmp(users[i].username, username) == 0 && strcmp(users[i].password, password) == 0) {
            printf("Welcome %s !\n", username);
            //return;
            break;
        }
        printf("Invalid username or password Try again!\n");
        break;
    }

}



int admin_login() {

    printf("\nEnter username: ");
    scanf("%s", username);

    printf("Enter password: ");
    scanf("%s", password);

    
    if (strcmp(username, "admin") == 0 && strcmp(password, "a123") == 0) {
        printf("Welcome Admin %s !\n", username);
        return 1;
        }
    else{    
        printf("Admin Username or Password did not match!\n");
        return 0;
        }
    }




int main(){
    int choice;
    int choice2;
    int choice3;
    int choice4;
    
    struct User *users = NULL;
    struct item *cart = NULL;
    int numUsers = 0;
    int num_items = 0;
    int item_no;
    int quantity;
    int c;
    

    main_menu:
    printf("\n");
    printf("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n");
    printf("                                       WELCOME  TO  SHOP                                             \n");
    printf("=====================================================================================================\n");
    
    printf("\n\n");
    printf("1. ADMINISTRATOR\n");
    printf("2. CUSTOMER\n");
    printf("3. EXIT\n");
    printf("\n");
    printf("=====================================================================================================\n");
    printf("Enter your choice: ");
    scanf("%d", &choice);
    
    printf("\n\n");
    switch (choice)
    {
    case 1:
    c = admin_login();
    if (c == 1) {
    admin:
    printf("*****************************************************************************************************\n");
    printf("                                          ADMINISTRATOR                                              \n");
    printf("-----------------------------------------------------------------------------------------------------\n");
    printf("1. HOME\n");
    printf("2. ADMIN DETAILS\n");
    printf("3. SETTINGS\n");
    printf("4. MAIN MENU\n");
    printf("5. EXIT\n");
    printf("-----------------------------------------------------------------------------------------------------\n");
    printf("Enter your choice: ");
    scanf("%d", &choice4);
        switch(choice4)
        {
            case 1:
            printf("*****************************************************************************************************\n");
            printf("                                           HOME                                                      \n");
            printf("-----------------------------------------------------------------------------------------------------\n");
            break;

            case 2:
            printf("*****************************************************************************************************\n");
            printf("                                        ADMIN DETAILS                                                \n");
            printf("Admin Username : admin\n");
            printf("Admin Password : a123\n");
            printf("-----------------------------------------------------------------------------------------------------\n");
            goto admin;
            break;

            case 3:
            printf("*****************************************************************************************************\n");
            printf("                                           SETTINGS                                                  \n");
            printf("-----------------------------------------------------------------------------------------------------\n");
            break;

            case 4:
            goto main_menu;
            break;

            case 5:
            goto exit;
            break;

            default:
            printf("INVALID NUMBER TYPED, TRY AGAIN\n");
            goto admin;
            break;

        }
    }
    else {
            printf("-----------------------------------------------------------------------------------------------------\n");
            goto main_menu;
    }
        break;
    case 2:
    sign:
    printf("\n 1.SIGN UP \n 2.LOG IN\n 3.MAIN MENU\n 4.EXIT\n");
    printf("Enter your choice: ");
    scanf("%d", &choice2);

        switch (choice2)
        {
        case 1:
        printf("*****************************************************************************************************\n");
        printf("                                       CREATE AN ACCOUNT                                             \n");
        sign_up(&users, &numUsers);
        goto customer_options;
        printf("-----------------------------------------------------------------------------------------------------\n");
        break;
        case 2:
        printf("*****************************************************************************************************\n");
        printf("                                 LOG IN TO AN EXISTING ACCOUNT                                       \n");
        if (log_in(users, numUsers)) {
            printf("Login successful!\n");
            customer_options:
            printf("*****************************************************************************************************\n");
            printf("                                            CUSTOMER                                                 \n");
            printf("-----------------------------------------------------------------------------------------------------\n\n");
            printf("1. CUSTOMER PROFILE\n");
            printf("2. BUY ITEMS\n");
            printf("3. CUSTOMER CART\n");
            printf("4. BILL\n");
            printf("5. MAIN MENU\n");
            printf("6. EXIT\n");
            printf("-----------------------------------------------------------------------------------------------------\n");
            printf("Enter your choice: ");
            scanf("%d", &choice3);
            switch (choice3)
            {
            case 1:
                printf("*****************************************************************************************************\n");
                printf("                                     CUSTOMER PROFILE                                                \n");
                printf("Username: %s\n", username);
                printf("Password: %s\n", password);
                printf("-----------------------------------------------------------------------------------------------------\n");
                goto customer_options;
                break;
            case 2:
                
                printf("*****************************************************************************************************\n");
                printf("                                        BUY ITEMS                                                    \n");
                printf("|Item no.|     |Product|     |Price|    |Quantity|\n");
                printf("       |1|     |Frooti|      |15|       |30|\n");
                printf("       |2|     |Grapes|      |5|        |20|\n");
                printf("       |3|     |Chocolate|   |20|       |45|\n");
                printf("       |4|     |Apple|       |10|       |25|\n");
                printf("       |5|     |Guava|       |10|       |20|\n");
                // item i1 = {1,"Frooti", 15 , 30};
                // item i2 = {2,"Grapes", 5 , 20};
                // item i3 = {3,"Chocolate", 5 , 45};
                // item i4 = {4,"Apple", 10 , 25};
                // item i5 = {5,"Guava", 10 , 20};
          
                read_items("Products.txt", &cart, &num_items);
                
                printf("Enter the item number: ");
                scanf("%d", &item_no);

                printf("Enter the quantity you want: ");
                scanf("%d", &quantity);

                find_item(cart, num_items, item_no, quantity);
                
                
                printf("-----------------------------------------------------------------------------------------------------\n");
                goto customer_options;
                break;
            case 3:
                printf("*****************************************************************************************************\n");
                printf("                                        CUSTOMER CART                                                \n");
                displayCart(cart, num_items,item_no, quantity);
                goto customer_options;
                printf("-----------------------------------------------------------------------------------------------------\n");
                break;
            
            case 4:
                printf("*****************************************************************************************************\n");
                printf("                                            BILL                                                     \n");
                printBill(cart, num_items, item_no, quantity);
                printf("\n");
                printf("-----------------------------------------------------------------------------------------------------\n");
                break;
            case 5:
                goto main_menu;
                break;
            case 6:
                goto exit;
                break;
            default:
                printf("INVALID NUMBER TYPED, TRY AGAIN\n");
                goto customer_options;
                break;
            }
        } else {
            
            printf("-----------------------------------------------------------------------------------------------------\n");
            goto sign;
        }
        break;
        
        case 3:
            goto main_menu;
            break;

        case 4:
            goto exit;
            break;
        default:
            printf("INVALID NUMBER TYPED, TRY AGAIN\n");
            goto sign;
            break;
        }
    break;

    
    case 3:
    exit:
    free(users);
    printf("*****************************************************************************************************\n");
    printf("                                              EXIT                                                   \n");
    printf("-----------------------------------------------------------------------------------------------------\n");
    return 0;

    default:
    printf("INVALID NUMBER TYPED, TRY AGAIN\n");
    goto main_menu;
        break;
    }
}