// This is my solution to Assignment 4 -- Kent
#include <stdio.h>
#include <stream.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

struct book {
    char *title;
    int pages;
    float cost;
}; // book

const int MAXBOOKS=30;

// Function headers
int page_count( struct book ** , int);
float cost_count( struct book ** , int);
void print_books( struct book ** , int);

int 
main(int argc, char **argv)
{
    int actual_count = 0;
    char yn='y';
    struct book **books;  // pointer to array of book structures pointers
    struct book **bptr;   // used to print the array
    char buffer[1024];    // buffer for title input

    // make the space for an array of book pointers
    if( (books = new struct book * [MAXBOOKS]) == NULL) {
       // there was no space available
       cout << "Not enough memory for the book pointer array" << endl;
       exit(1);
    }


    while(actual_count < MAXBOOKS) {
       // first make space for the book
       if( (books[actual_count] = new struct book) == NULL) {
          // there was no space available
          cout << "Not enough memory for the actual book structure" << endl;
          exit(1);
       }
       // get the data from the user
       cout << "Please enter the book title: ";
       cin >> buffer;
       if( (books[actual_count]->title = new char [strlen(buffer)+1]) == NULL) {
          // there was no space available
          cout << "Not enough memory for the book title" << endl;
          exit(1);
       }
       (void) strcpy(books[actual_count]->title,buffer);

       cout << "Please enter the number of pages: ";
       cin >> books[actual_count]->pages;

       cout << "Please enter the cost: ";
       cin >> books[actual_count]->cost;
       actual_count++;

       cout << "do you want to enter another? (y/n) ";
       cin >> yn;
       if( (tolower(yn) != 'y'))  // tolower() changes its arg to lowercase
         break;
    } // while

    print_books(books,actual_count);

    cout << "--------------------------" << endl;
    cout << "Total books: " << actual_count << endl;
    cout << "Total pages: " << page_count(books,actual_count)  << endl;
    cout << "Total cost: "  << cost_count(books,actual_count)   << endl;
    delete [] books;

    return 0;
} // main

/* Using a pointer, go over the array of book structures
   printing the contents of each one
*/
void
print_books( struct book ** books, int count)
{
   int i;
   struct book **bptr;
// a for loop is used to not only control the pointer
// but to make sure we don't go pas the last book
   for(i = 0,bptr=books; i < count; i++,bptr++ ) {
      cout << "book number: " << i << endl;
      cout << "title: " << (*bptr)->title << endl;
      cout << "pages: " << (*bptr)->pages << endl;
      cout << "cost: "  << (*bptr)->cost  << endl;
      cout << endl;
   } // for
} // print_books

// Add up the total count of pages
int
page_count( struct book ** books, int count)
{
    int total_pages = 0;

    for(int i = 0; i < count; i++ )
       total_pages += books[i]->pages;
    return(total_pages);
} // page_count

// Add up the total cost of all books
float
cost_count( struct book ** books, int count)
{
    float total_cost = 0.0;

    for(int i = 0; i < count; i++ )
       total_cost += books[i]->cost;
    return(total_cost);
} // page_count