// library.cpp
// ----------------------------------------------------------------------
// Do not modify this file.  
//
// CSE 143
// Homework 2
// http://www.cs.washington.edu/education/courses/143/00su/homework/hw2/
// 25 Jun 2000; updated on 28 Jun 2000, 02 Jul 2000


#include <fstream.h>
#include <iomanip.h>
#include <string.h>
#include <assert.h>

#include "library.h"

const int MAX_LINE_LENGTH = 120;  // when reading from a file

//////////////////////////////////////////////////////////////////////
// misc. utility functions

void waitForChar(void) 
{
  char junkchar;
  cout << endl << "Type a character and ENTER to continue... ";
  cin >> junkchar;
}


//////////////////////////////////////////////////////////////////////
// finances

int computeFine(int daysOverdue)
{
  assert(daysOverdue > 0);
  return (FIXED_FINE + PER_DAY_FINE * daysOverdue);
}


//////////////////////////////////////////////////////////////////////
// I/O

void readBookFile(char fileName[], LibraryBook bookList[], 
                  int maxBookCount, int &bookCount)
{
  assert(maxBookCount > 0);
  assert(strlen(fileName) > 0);

  // counts number of book records read so far
  bookCount = 0;                

  // Mac and UNIX users:  omit ios::nocreate argument
  ifstream inFile(fileName, ios::nocreate);

  if (!inFile) {
    cerr << endl << "unable to open file: " << fileName << endl;
    bookCount = -1;
    return;
  }

  while (inFile && (bookCount < maxBookCount)) {
    char title[MAX_TITLE_LENGTH], author[MAX_AUTHOR_LENGTH];
    int ID;

    inFile >> ID;

    // need to skip the trailing whitespace after ID,
    // i.e. trailing characters, including endline (\n)
    char line[MAX_LINE_LENGTH];
        
    inFile.getline(line, MAX_LINE_LENGTH);

    inFile.getline(title, MAX_TITLE_LENGTH);
    if (strlen(title) == 0) {
      // stop at first blank line
      break;
    }

    inFile.getline(author, MAX_AUTHOR_LENGTH);
    
    LibraryBook newBook(ID, title, author);
    bookList[bookCount] = newBook;

    bookCount++;
  }
} // end readBookFile


void processTransactionsFile(char fileName[], 
                          LibraryBook bookList[], int bookCount) 
{
  assert(bookCount > 0);
  assert(strlen(fileName) > 0);

  // Mac and UNIX users:  omit ios::nocreate argument
  ifstream inFile(fileName, ios::nocreate  );

  if (!inFile) {
    cerr << endl << "unable to open file: " << fileName << endl;
    return;
  }

  int transactionCount = 0;

  while (inFile) {
    int month, day, year, userID, bookID;
    char transactionCode; 
                
    transactionCount++;
    if (transactionCount % ENTRIES_PER_SCREEN == 0) {
      waitForChar();
    }
                
    // dec is not a local variable, but a manipulator that forces cin
    // to read values in decimal (base 10) format
    inFile >> dec >> month >> day >> year 
           >> userID >> transactionCode >> bookID;
                
    // need to skip the trailing whitespace after bookID,
    // i.e. extract trailing characters, including \n
    char line[MAX_LINE_LENGTH]; 
    inFile.getline(line, MAX_LINE_LENGTH);
                
    Date transactionDate(month, day, year);
    if (!transactionDate.isValid()) {
      cerr << "invalid transaction date" << endl;
      return;
    }
                
    if (userID <= 0 || 
        !(transactionCode == 'i' || transactionCode == 'o')) {
      cerr << "invalid transaction ID or code" << endl;
      return;
    }
                
    int i = findBookByID(bookList, bookCount, bookID);
                
    char bookTitle [MAX_TITLE_LENGTH];  
    bookList[i].getTitle (bookTitle);
    
    cout << endl << "transaction date:  ";
    transactionDate.printDate();
    cout << "\tbook ID:  " << bookID << endl;
    cout << "title:  " << bookTitle << endl;

    cout << "check ";
    if (transactionCode == 'o') {
      cout << "out";
    } else {
      cout << "in";
    }

    cout << " by user " << userID << endl;

    if (transactionCode == 'o') {  // check out book
      // verify book is not checked out 
      if (bookList[i].isCheckedOut()) {
        cerr << "transaction invalid; cannot check out a book "
             << "which is already checked out" << endl;
        return;
      }
      
      bookList[i].checkOut(transactionDate, userID, LOAN_DURATION);
    } else {  // check in (return) book
      // verify book is checked out
      if (!bookList[i].isCheckedOut()) {
        cerr << "transaction invalid; cannot check in a book "
             << "which is not checked out" << endl;
        return;
      }

      cout << "due ";
      (bookList[i].getDueDate()).printDate();
                        
      if (bookList[i].isOverdue(transactionDate)) {
        int daysPastDue = bookList[i].daysOverdue(transactionDate);
                                
        cout << ", overdue by " << daysPastDue << " days, ";
        cout << "overdue fine:  " << computeFine(daysPastDue) 
             << " cents" << endl;
      } //end overdue book

      bookList[i].checkIn();
    } // end check-in
  } // end loop over lines in file
} // end readTransactionsFile


int findBookByID(LibraryBook bookList[], int bookCount, int searchID)
{
  for (int i = 0; i < bookCount; i++) {
    if (bookList[i].getID() == searchID) {
      return i;
    }
  }

  return -1; 
} // end findBookByID


void printBookList(LibraryBook bookList[], int bookCount) 
{
  for (int i = 0; i < bookCount; i++) {
    bookList[i].printRecord();
    cout << endl;

    if ((i + 1) % ENTRIES_PER_SCREEN == 0) {
      waitForChar();
    }
  }

  cout << bookCount << " total books listed" << endl << endl;
} // end printBookList