//  File: Bank.java

//  The Bank class uses an ArrayList to store a collection of BankAccount 
//  objects, and demonstrates the basics of list processing - creating a list,
//  adding objects to it, and traversing a list (i.e. "visiting" each object
//  on the list in turn and doing something with it)

import java.util.ArrayList ;
import java.io.PrintWriter ;
import java.io.IOException ;

/**
   This bank contains a collection of bank accounts.
*/
public class Bank
{   
   private ArrayList<BankAccount> accounts ;  // a list of BankAccount objects
   
   /**
      Constructs a bank with no bank accounts.
   */
   public Bank()
   {
      accounts = new ArrayList<BankAccount>() ;
   }

   /**
      Adds an account to this bank.
      @param newAccount the account to add
   */
   public void addAccount(BankAccount newAccount)
   {
      accounts.add(newAccount) ;  // calls "add" method of ArrayList class
   } 
   
   /**
      Print data for all accounts
   */
   public void printList() 
   {
      // print headings
      System.out.printf("%15s%20s%n","Account Number","Account Balance") ;
      
      System.out.printf("%15s%20s%n","==============","===============") ;
                         
      // for each account in this bank
      for ( int i = 0 ; i < accounts.size() ; i++ )
      {
         BankAccount current = accounts.get( i ) ;  // get next account
         
         // print account number and balamce to screen
         System.out.printf("%15s     $%14.2f%n",current.getAccountNumber(),
                           current.getBalance()) ;
      }
   }
   
   /**
      Gets the sum of the balances of all accounts in this bank.
      @return the sum of the balances
   */
   public double getTotalBalance()
   {
      double total = 0;
      
      // for each account in this bank
      for ( int index = 0 ; index < accounts.size() ; index++)
      {
          BankAccount current = accounts.get(index) ;   // get the account
          total = total + current.getBalance() ;  // add its balance to accum
      }
      return total ;
   }

   /**
      Counts the number of bank accounts whose balance is at
      least a given value.
      @param atLeast the balance required to count an account
      @return the number of accounts having at least the given balance
   */
   public int count(double atLeast)
   {
      int matches = 0 ;
      for ( int i = 0 ; i < accounts.size() ; i++ )
      {
         BankAccount current = accounts.get( i ) ;  // get the account
         if (current.getBalance() >= atLeast) 	    // found one...
           matches++ ;                              // ...increment counter 
      }
      return matches ;
   }

   /**
      Linear search to find a bank account with a given account number.
      @param target the account number we are searching for
      @return the account with the given number, or null if there
      is no such account
   */
   public BankAccount find(String target)
   {
      for ( int i = 0 ; i < accounts.size() ; i++ )
      {
         BankAccount current = accounts.get( i ) ;        // get the account
	 String accountNum = current.getAccountNumber()	; // get account number
	 if ( accountNum.equals(target) )  		  // found a match
           return current ;			
      } 
      return null ; // No match in the entire array list
   }

   /**
      Gets the bank account with the largest balance.
      @return the account with the largest balance, or null if the
      bank has no accounts
   */
   public BankAccount getMaximum()
   {
      if (accounts.size() == 0) 		// if no accounts, return null
        return null;
      
      // assume first account is the largest 
      BankAccount largestYet = accounts.get(0) ;
      
      // for all other accounts
      for ( int i = 1; i < accounts.size(); i++ ) 
      {
         BankAccount current = accounts.get(i) ;		// get next account
         // is current account > highest so far?
         if (current.getBalance() > largestYet.getBalance())
            largestYet = current ;
      }
      return largestYet ;
   }
}