// FILE: newlink.cxx
// An interactive test program for the four new functions of the
// expanded linked list toolkit.
#include <cctype>     // Provides toupper
#include <iostream>   // Provides cout and cin
#include <cstdlib>    // Provides EXIT_SUCCESS and size_t
#include "newnode.h"   // With node::valuetype defined as double
using namespace std;
using namespace main_savitch_5;

// PROTOTYPES for functions used by this test program:
void print_menu( );
// Postcondition: A menu of choices for this program has been written to cout.

char get_user_command( );
// Postcondition: The user has been prompted to enter a one character command.
// The next character has been read (skipping blanks and newline characters), 
// and this character has been returned.

void show_list(node* display);
// Postcondition: The items on display have been printed to cout (one per line).

double get_number(const char* message);
// Postcondition: The user has been prompted to enter a real number. The
// number has been read, and returned by the function.

size_t get_position(const char* message);
// Postcondition: The user has been prompted to enter a position in the list. The
// number has been read, and returned by the function.


int main( )
{
    node* test;      // A list that we'll perform tests on
    char choice;     // A command character entered by the user
    double value;    // A value that is stored on the linked list
    size_t n;        // Argument to list_copy_front
    node* segment;   // Result of call to list_copy_segment
    
    test = NULL;
    cout << "I have initialized an empty linked list of real numbers." << endl;

    do
    {
        print_menu( );
        choice = toupper(get_user_command( ));
        switch (choice)
        {
	    case 'C':
                value = get_number("Type the number to count occurrences of: ");
		cout << "There are " << list_occurrences(test, value);
		cout << " occurrences of " << value << "." << endl;
		break;
	    case 'A':
		value = get_number("Type the number to insert: ");
		list_tail_attach(test, value);
		cout << value << " has been inserted." << endl;
		break;
	    case 'R':
		list_tail_remove(test);
		cout << " The tail has been removed. " << endl;
		break;
	    case 'S':
		n = get_position("Type the amount to copy: ");
		cout << "Here is the result of the copy of that segment: " << endl;
		segment = list_copy_front(test, n);
		show_list(segment);
		list_clear(segment);
		break;
	    case 'P':
		cout << "The list has these items: " << endl;
		show_list(test);
		break;
	    case 'Q': cout << "Ridicule is the best test of truth." << endl;
		break;
	    default:  cout << choice << " is invalid. Sorry." << endl;
        }
    }
    while (cin && (choice != 'Q'));

    if (!cin)
	cerr << "Bad input character." << endl;
    
    return EXIT_SUCCESS;
}

void print_menu( )
// Library facilities used: iostream.h
{
    cout << endl; // Print blank line before the menu
    cout << "The following choices are available: " << endl;
    cout << " C   Count the number of occurrences of some number" << endl;
    cout << " A   Attach a new number at the tail" << endl;
    cout << " R   Remove a number from the tail" << endl;
    cout << " S   Copy the front of the list, and print this segment" << endl;
    cout << endl;
    cout << " P   Print the current list" << endl;
    cout << " Q   Quit this test program" << endl;
}

char get_user_command( )
// Library facilities used: iostream.h
{
    char command;

    cout << "Enter choice: ";
    cin >> command; // Input of characters skips blanks and newline character

    return command;
}

void show_list(node* display)
// Library facilities used: iostream.h
{
    while (display != NULL)
    {
	cout << display->data( ) << endl;
	display = display->link( );
    }
}

double get_number(const char* message)
// Library facilities used: iostream.h
{
    double result;
    
    cout << message;
    cin  >> result;
    return result;
}

size_t get_position(const char* message)
// Library facilities used: iostream.h, stdlib.h
{
    size_t result;
    
    cout << message;
    cin  >> result;
    return result;
}