import textio.TextIO;

/**
 * This program is a demonstration of the StringList class.
 * The user can choose to perform any of three list operations:
 * find, insert, and delete.  After each operation, the contents
 * of the list are displayed.   Note that any list item input by
 * the user is converted to lower case.
 */
public class ListDemo {


    public static void main(String[] args) {

        StringList list;    // The list of strings.

        String usersItem;   // An item typed in by the user.

        String[] elements;  // The elements in the list, obtained by
                            //    calling list.getElements().  This
                            //    is used to display the list contents
                            //    to the user.

        boolean done;       // This will be set to true then the user
                            //   wants to exit from the program.

        done = false;

        list = new StringList();  // Start with an empty list.

        while (done == false) {

            // Get and display the elements that are currently in the list.

            elements = list.getElements();
            if (elements.length == 0)
                System.out.println("\n\nThere are no elements in the list.");
            else {
                System.out.println("\n\nElements of the list:");
                for (int i = 0; i < elements.length; i++)
                    System.out.println("   " + elements[i]);
            }

            // Display a menu of available operations, and get the
            // user's choice.

            System.out.println("\n\nChoose an operation on the list:");
            System.out.println("    1.  Add an item.");
            System.out.println("    2.  Delete an item.");
            System.out.println("    3.  Find an item.");
            System.out.println("    4.  Exit from this program.");
            System.out.print("Enter the number of your choice:  ");
            int menuChoice = TextIO.getlnInt();

            // Carry out the operation selected by the user.  For
            // items 1 to 3, get a string from the user and call
            // the appropriate method from the list.

            switch (menuChoice) {
            case 1:  // Insert an item.
                System.out.print("\nEnter the item to be added:  ");
                usersItem = TextIO.getln().trim().toLowerCase();
                list.insert(usersItem);
                System.out.println("OK");
                break;
            case 2:  // Delete an item.
                System.out.print("\nEnter the item to be deleted:  ");
                usersItem = TextIO.getln().trim().toLowerCase();
                if ( list.delete(usersItem) )
                    System.out.println("OK");
                else
                    System.out.println("That item was not found in the list.");
                break;
            case 3:  // Check whether an item occurs in the list.
                System.out.print("\nEnter an item to find:  ");
                usersItem = TextIO.getln().trim().toLowerCase();
                if ( list.find(usersItem) )
                    System.out.println("Yes, that item is in the list.");
                else
                    System.out.println("No, that item is not in the list.");
                break;
            case 4:  // Exit from this program.
                done = true;
                break;
            default:
                System.out.println("Illegal choice.");
                break;
            } // end switch


        } // end while

        System.out.println("\n\nExiting program.");

    } // end main()


}  // end class ListDemo