/*
   lab11.cpp
   7/4/2005
   CIS 150
   David G. Klick
   
   Demonstrates reading structures from a binary file
   and then sorting them.
*/

#include <iostream>
#include <iomanip>
#include <fstream>
#include <cstring>
using std::cout;
using std::ifstream;
using std::ofstream;
using std::ios;
using std::setw;
using std::setprecision;
using std::showpoint;
using std::fixed;

const int MAX_ARRAY_SIZE = 10;

struct Book {
   char title[40];
   char author[35];
   double price;
   int quantity;
};

void display(Book b);
void sortByAuthor(Book b[], int len);
void sortByPrice(Book b[], int len);
void sortByQuantity(Book b[], int len);
void sortByTitle(Book b[], int len);

int main(void) {
   ifstream ifile;  // used to handle input file
   long numrecs;
   int booksInArray;
   int i;
   
   // create array of book objects
   Book books[MAX_ARRAY_SIZE];
   
   // open random access file to read in books
   ifile.open("books.dat", ios::in | ios::binary);
   
   // display error if could not open file
   if (!ifile) {
      cout << "Error: Could not open input file!\n";
      return 1;
   }

   // find out how many records are in file
   ifile.seekg(0L, ios::end);  // go to end of file
   numrecs = ifile.tellg() / sizeof(Book);
   ifile.seekg(0L, ios::beg);  // go to start of file
   
   // display error if more books than array can hold
   if (numrecs > MAX_ARRAY_SIZE) {
      cout << "Error: Too many records in file.\n";
      return 2;
   }
   
   // read book objects from file
   for (i=0; i<numrecs; i++) {
      ifile.read((char*)&books[i], sizeof(Book));
   }
   booksInArray = numrecs;

   // close file
   ifile.close();
   
   // display book info read from file
   cout << "Book information read from file:\n";
   for (i=0; i<booksInArray; i++) {
      cout << "   ";
      display(books[i]);
      cout << '\n';
   }

   // sort by quantity and redisplay
   sortByQuantity(books, booksInArray);
   cout << "Books sorted by quantity\n";
   for (i=0; i<booksInArray; i++) {
      cout << "   ";
      display(books[i]);
      cout << '\n';
   }
   
   // sort by price and redisplay
   sortByPrice(books, booksInArray);
   cout << "Books sorted by price\n";
   for (i=0; i<booksInArray; i++) {
      cout << "   ";
      display(books[i]);
      cout << '\n';
   }
   
   // sort by title and redisplay
   sortByTitle(books, booksInArray);
   cout << "Books sorted by title\n";
   for (i=0; i<booksInArray; i++) {
      cout << "   ";
      display(books[i]);
      cout << '\n';
   }
   
   // sort by author and redisplay
   sortByAuthor(books, booksInArray);
   cout << "Books sorted by author\n";
   for (i=0; i<booksInArray; i++) {
      cout << "   ";
      display(books[i]);
      cout << '\n';
   }

   return 0;
}

void display(Book b) {
   cout << b.title << ", by " << b.author
        << "(" << b.quantity << " @ $"
        << fixed << showpoint << setprecision(2)
        << b.price << ')';
}

void sortByAuthor(Book b[], int len) {
   int i, j;
   Book temp;
   
   for (i=0; i<len-1; i++) {
      for (j=i+1; j<len; j++) {
         if (stricmp(b[i].author, b[j].author) > 0) {
            temp = b[i];
            b[i] = b[j];
            b[j] = temp;
         }
      }
   }
}

void sortByPrice(Book b[], int len) {
   int i, j;
   Book temp;
   
   for (i=0; i<len-1; i++) {
      for (j=i+1; j<len; j++) {
         if (b[i].price > b[j].price) {
            temp = b[i];
            b[i] = b[j];
            b[j] = temp;
         }
      }
   }
}

void sortByQuantity(Book b[], int len) {
   int i, j;
   Book temp;
   
   for (i=0; i<len-1; i++) {
      for (j=i+1; j<len; j++) {
         if (b[i].quantity > b[j].quantity) {
            temp = b[i];
            b[i] = b[j];
            b[j] = temp;
         }
      }
   }
}

void sortByTitle(Book b[], int len) {
   int i, j;
   Book temp;
   
   for (i=0; i<len-1; i++) {
      for (j=i+1; j<len; j++) {
         if (stricmp(b[i].title, b[j].title) > 0) {
            temp = b[i];
            b[i] = b[j];
            b[j] = temp;
         }
      }
   }
}