Rent_A_Car

import java.util.*; //Import Scanner Class
class Rent_A_Car{
    public static void main(){
        clr(); //Clearing the screen
        boolean flag = false, flag2 = true, car_flag = false;
        String enteredModelName, customerName, dateRented;
        int daysRented, renter = 0;
        String renterName[] = new String[15]; //Array for storing names of customers who have rented cars
        String rentedCars[] = new String[15]; //Array for storing Model names of the cars that have been rented
        String rentedDate[] = new String[15]; //Array for storing the Date of when the cars were rented
        int rentedDays[] = new int[15]; // Array for storing the number of days the cars have been rented
        Scanner sc = new Scanner(System.in); //Initializing Scanner class
        Scanner sc_str = new Scanner(System.in); //Initializing Scanner class for Strings
        char again = 'n', mainmenu = 'n'; //Two variables to ask user if they want to retry or go back to the main menu
        String carModels[] = {"Toyota Corolla", "Toyota Yaris", "Toyota Fortuner", "Toyota Land Cruiser", "Nissan Tiida", "Nissan Patrol", "Ford Explorer", "Ford Focus", "Mitsubishi Lancer", "Mitsubishi Pajero", "GMC Yukon XL"}; //Names of cars
        int costPerDay[] = {50, 45, 100, 200, 50, 200, 100, 75, 50, 100, 250}; //Rental cost per day
        String usernames[] = {"Rayaan", "Swarna", "1"}; //Array for storing usernames
        String passwords[] = {"chicken", "computers", "1"}; //Array for storing passwords
        welcome(); //Welcoming user
        prt("\nUsername: ");
        String username = sc.next(); //Entered username by user
        prt("Password: ");
        String password = sc.next(); //Entered password by user
        for(int i = 0; i < 3; i++){ //For loop for index number of arrays because we have 3 usernames
            if (username.equalsIgnoreCase(usernames[i]) && password.equals(passwords[i])){ //Verifying username and password match
                do{
                    printMenu(usernames[i]); //Printing menu
                    int choice = sc.nextInt(); //Variable for storing user's choice
                    switch(choice){
                        case 1:
                        clr();
                        for(int x = 0; x < costPerDay.length-1; x++){ //Sort the arrays in descending order of cost per day using bubble sort
                            for(int j = x + 1; j < costPerDay.length; j++){
                                if(costPerDay[x] < costPerDay[j]){
                                    int t = costPerDay[x]; //temporary variable
                                    String s = carModels[x]; //temporary variable
                                    costPerDay[x] = costPerDay[j];
                                    costPerDay[j] = t;
                                    carModels[x] = carModels[j];
                                    carModels[j] = s;
                                }
                            }
                        }
                        for(int x = 0; x < carModels.length; x++){ //Printing the Cars in descending order of cost per day
                            prtln(carModels[x] + " - " + costPerDay[x] );
                        }
                        prtln("\nReturn to Main Menu? (y/n)"); //Asking user if they want to return to main menu
                        mainmenu = sc.next().charAt(0); //Variable for storing choice
                        break;
                        //End of case 1//
                        case 2:
                        do{
                            clr();
                            prtln("Enter the name of the car");
                            enteredModelName = sc_str.nextLine();
                            for(int x = 0; x < carModels.length; x++){ //Validating model name and printing its details
                                if (carModels[x].equalsIgnoreCase(enteredModelName)){
                                    car_flag = true;
                                    clr();
                                    prtln("Car name: " + carModels[x]);
                                    prtln("Cost per day: " + costPerDay[x]);
                                    break;
                                }
                            }
                            if(!car_flag){ //Error message if car wasn't found
                                prtln("Not Found!");
                            }
                            prtln("\nAgain? (y/n)"); //Asking user if they want to try again
                            again = sc.next().charAt(0);
                        }while(again == 'y' );
                        prtln("\nReturn to Main Menu? (y/n)");
                        mainmenu = sc.next().charAt(0);
                        break;
                        //End of case 2//
                        case 3:
                        do{
                            clr();
                            prtln("Rent A Car");
                            sc = new Scanner(System.in); //Reinitializing scanner to prevent fall through
                            sc_str = new Scanner(System.in);
                            car_flag = false;
                            do{
                                prt("Model Name: ");
                                enteredModelName = sc_str.nextLine();
                                for(int x = 0; x < carModels.length; x++){
                                    if (carModels[x].equalsIgnoreCase(enteredModelName)){ //Validating car model
                                        car_flag = true;
                                        rentedCars[renter] = carModels[x]; //Storing car model in the array
                                        break;
                                    }
                                }
                                if(!car_flag){
                                    prtln("Not Found!");
                                }
                            }while(!car_flag);
                            do{
                                prt("Customer Name: ");
                                customerName = sc_str.nextLine();
                                renterName[renter] = customerName; //Storing name in the array
                            }while(!verifyName(customerName)); //Function for validating name
                            do{
                                prt("Number of Days Rented: ");
                                daysRented = sc.nextInt();
                                rentedDays[renter] = daysRented; //Storing number of days rented in the array
                            }while(!verifyNumber(daysRented)); //Function for validating number entered
                            do{
                                prt("Date (dd/mm/yyyy): ");
                                dateRented = sc_str.next();
                                rentedDate[renter] = dateRented; //Storing date in the array
                            }while(!verifyDate(dateRented)); //Function for validating date

                            //Printing Receipt
                            clr();
                            prtln("------------------------------------------------------------------------------------------------------------------------------------------------------------------");
                            prtln("Rayaan Rent A Car");
                            prtln("------------------------------------------------------------------------------------------------------------------------------------------------------------------");
                            prtln("Customer name: " + renterName[renter]);
                            prtln("Date: " + rentedDate[renter]);
                            prtln("Car Model: " + rentedCars[renter]);
                            prtln("Rent Per Day: " + costPerDay[renter]);
                            prtln("Number of Days Rented: " + rentedDays[renter]);
                            prtln("Total Cost: " + costPerDay[renter]*rentedDays[renter]);
                            prtln("------------------------------------------------------------------------------------------------------------------------------------------------------------------");
                            renter++;
                            prtln("\nAgain? (y/n)");
                            again = sc.next().charAt(0);
                        }while(again == 'y');
                        prtln("\nReturn to Main Menu? (y/n)");
                        mainmenu = sc.next().charAt(0);
                        break;
                        //End of case 3//
                        case 4:
                        clr();
                        for(int x = 0; x < rentedDays.length-1; x++){ //Sort the arrays in descending order of number of days rented using bubble sort
                            for(int j = x + 1; j < rentedDays.length; j++){
                                if(rentedDays[x] < rentedDays[j]){
                                    //Temporary variables
                                    int newDays = rentedDays[x];
                                    int newCost = costPerDay[x];
                                    String newRentedCars = rentedCars[x];
                                    String newDate = rentedDate[x];
                                    String newName = renterName[x];
                                    //Sorting
                                    costPerDay[x] = costPerDay[j];
                                    costPerDay[j] = newCost;
                                    rentedCars[x] = rentedCars[j];
                                    rentedCars[j] = newRentedCars;
                                    renterName[x] = renterName[j];
                                    renterName[j] = newName;
                                    rentedDate[x] = rentedDate[j];
                                    rentedDate[j] = newDate;
                                }
                            }
                        }
                        //Printing the rented cars
                        for(int x = 0; x < renter; x++){
                            prtln(rentedCars[x] + "\t" + renterName[x] + "\t" + rentedDays[x] + "\t" + rentedDate[x]);
                        }
                        prtln("\nReturn to Main Menu? (y/n)");
                        mainmenu = sc.next().charAt(0);
                        break;
                        //End of case 4//
                        case 5:
                        exit();//Cool Exit
                        default: //if user enters NOTA
                        prtln("Wrong input");
                        prtln("\nReturn to Main Menu? (y/n)");
                        mainmenu = sc.next().charAt(0);
                    }//End of switch//
                    flag = true; flag2 = false; //For knowing if username and/or password is vaild
                    if(mainmenu == 'n')
                        exit(); // I added an extra if construct so that if the user enters n it exits instead of doing nothing
                }while(mainmenu == 'y');
            }else if(username.equalsIgnoreCase(usernames[i]) && !password.equals(passwords[i])){
                prtln("Invalid Password!");
                flag2 = false;
                break;
            }else if(!username.equalsIgnoreCase(usernames[i]) && password.equals(passwords[i])){
                prtln("Invalid Username!");
                flag2 = false;
                break;
            }
        }
        if(flag2){
            prtln("Invalid Username and Password!");
        }
        if(!flag){
            prtln("\nDo you want to try again? (y/n)");
            char restart = sc.next().charAt(0);
            if (restart == 'y'){
                main(); //Start all over again
            }else{
                exit();//Cool Exit
            }
        }
    }

    //Function for System.out.println
    public static void prtln(String s){
        System.out.println(s);
    }

    //Function for System.out.print
    public static void prt(String s){
        System.out.print(s);
    }

    //Function for clearing screen
    public static void clr(){
        prt("\f");
    }

    //Function for welcoming
    public static void welcome(){
        prtln("Hello");
        try{ //Cool Welcome
            Thread.sleep(700);
        }catch (InterruptedException e){
            e.printStackTrace();
        }
        clr(); //Clearing the screen
        prtln("------------------------------------------------------------------------------------------------------------------------------------------------------------------"); //Cool effect
        prtln("Welcome to Rayaan Rent A Car"); //:)
        prtln("------------------------------------------------------------------------------------------------------------------------------------------------------------------"); //Cool effect
    }

    //Function for printing menu
    public static void printMenu(String s){
        prtln("\f"+"Welcome, " + s +"\n"); //Welcoming users, \f for clearing the screen
        prtln("Select an option:");
        prtln("1. Display the details of the car arranged in the descending order of rent");
        prtln("2. Search for a specific model and display the details");
        prtln("3. Rent a Car");
        prtln("4. Display the details of the cars that have been rented, arranged in the descending order of number of days for rent");
        prtln("5. Exit");
    }

    //Function for verifying name
    public static boolean verifyName(String s){
        boolean name_flag = false;
        s = s.toUpperCase();
        for(int i = 0; i < s.length(); i++){
            char x = s.charAt(i);
            if(x >= 'A' && x <= 'Z' || x == ' '){
                name_flag = true;
            }else{
                prtln("Name can only contain letters! Try Again");
                name_flag = false;
            }
        }
        return name_flag;
    }

    //Function for verifying number
    public static boolean verifyNumber(int n){
        if(n > 0){
            return true;
        }else{
            prtln("Has to be more than zero! Try Again");
            return false;
        }
    }

    //Function for verifying date(very complex)
    public static boolean verifyDate(String date){
        Scanner sc = new Scanner(System.in);
        int d, m, y;
        String dd, mm, yy;
        boolean flag = false;
        int maxDays[]={0,31,28,31,30,31,30,31,31,30,31,30,31};//Array for storing the maximum days of every month
        if(date.length() == 10){ //Performing the task only when number of digits is 10
            dd = date.substring(0,2); //Extracting the day
            mm = date.substring(3,5); //Extracting the month
            yy = date.substring(6); //Extracting the year
            d = Integer.parseInt(dd); //Day in Integer format
            m = Integer.parseInt(mm); //Month in Integer format
            y = Integer.parseInt(yy); //Year in Integer format

            if((y%400==0) || ((y%100!=0)&&(y%4==0))){ // condition for leap year
                maxDays[2]=29;
            }

            /* checking whether the day, month and year are within acceptable range
            i.e. there cannot be an input like 35/01/2013 because it is unacceptable*/

            if(m<0 || m>12 || d<0 || d>maxDays[m] || y<0 || y>9999){ // Performing Date Validation
                prtln("The day, month or year are outside acceptable limit");
                flag = false;
            }
            else{
                flag = true;
            }
        }
        else{
            prtln("Wrong Input");
            flag = false;
        }
        return flag;
    }

    public static void exit(){//Coolest Exit function
        try{//Cool Exit
            clr();
            prt("Exiting");
            Thread.sleep(100);
            prt(".");
            Thread.sleep(600);
            prt(".");
            Thread.sleep(600);
            prt(".");
            Thread.sleep(100);
        }catch (InterruptedException e){
            e.printStackTrace();
        }
        System.exit(0);
    }
}

/*
 ****************************************************************************************************************************************************************************************************
 ******************************************* Variable Description ***********************************************************************************************************************************
 ****************************************************************************************************************************************************************************************************
 Variable           Type        Location        Purpose
 ========           ====        ========        =======
 flag               boolean     main()          for validating username and password
 flag2              boolean     main()          for validating username and password
 enteredModelName   String      main()          for accepting and storing model name entered by the user
 customerName       String      main()          for accepting and storing Customer's name
 dateRented         String      main()          for accepting and storing date entered by the user
 daysRented         int         main()          for accepting and storing number of days for rent entered by user
 renter             int         main()          for renting cars and storing them in arrays. This is for the array index
 renterName[]       String[]    main()          for storing the name of the customer who is renting the car
 rentedCars[]       String[]    main()          for storing the model names of the cars that have been rented
 rentedDate[]       String[]    main()          for storing the date the car has been rented
 rentedDays[]       int[]       main()          for storing the number of days the car has been rented for
 again              char        main()          for storing the user's choice whether they want to repeat a function
 mainmenu           char        main()          for storing the user's choice whether they want to go to the main menu or exit
 carModels[]        String[]    main()          for storing the names of the car models that are available for rent
 costPerDay[]       int[]       main()          for storing the cost per day of a car
 usernames[]        String[]    main()          for storing the usernames
 passwords[]        String[]    main()          for storing the passwords
 choice             int         main()          for storing user's choice
 ------             ---         ------          -------------------------
 dd, mm, yy         String      verifyDate()    for storing the values entered by the user after Substring-ing them eliminating the '/'
 d, m, y            int         verifyDate()    for storing the values by parsing them in Integer form from the date entered by the user
 maxDays[]          int[]       verifyDate()    for storing the maximum number of days of each month
 =========          =====       ============    ========================================================================================
 ****************************************************************************************************************************************************************************************************
 */
//:)
//Hope you liked the "neatness" (of the output)