/*
 * Bank accounts list: original implementation
 */

import tester.Tester;

/*
                                                                
             +---------+                        
             |  ILoA   |<------+
             +---------+       |
             +---------+       |
                  |            |
                  |            |
                 /_\           |
                  |            |
        +--------------+       |
        v              v       |  
   +-------+  +------------+   |    
   | MTLoA |  | ConsLoA    |   |  
   +-------+  +------------+   |  
            +-| Acct first |   |
            | | ILoA rest  |---+
            | +------------+
            v
   +---------------+
   | Acct          |
   +---------------+
   | String owner  |
   | String kind   |
   | int balance   |
   +---------------+  
*/
                          
// to represent an account in a bank
class Acct{
  String owner;
  String kind;
  int balance;
  
  Acct(String owner, String kind, int balance){
    this.owner = owner;
    this.kind = kind;
    this.balance = balance;
  }

/* TEMPLATE:
   FIELDS:
    ... this.owner ...             -- String
    ... this.kind ...              -- String
    ... this.balance ...           -- int

    METHODS FOR FIELDS:
    ... this.owner.equals(String) ... -- boolean  
    ... this.kind.equals(String) ... -- boolean  
  
    METHODS FOR THIS CLASS:
    ... this.same(Acct) ...       -- boolean
*/

  // is this account the same as the given one?
  boolean same(Acct that){
    return this.owner.equals(that.owner) &&
           this.kind.equals(that.kind) &&
           this.balance == that.balance;
  }

}                     

// to represent a list of books
interface ILoA{
  
  // compute the total size of this list
  int size();
  
  // does this list of accounts contain the given account?
  boolean contains(Acct a);
}                                

// to represent an empty list of accounts
class MtLoA implements ILoA{
  MtLoA(){}
  
  // compute the total size of this list
  public int size(){
    return 0;
  }
  
  // does this list of accounts contain the given account?
  public boolean contains(Acct a){
  	return false;
  }
}                                              

// to represent a nonempty list of accounts
class ConsLoA implements ILoA{
  Acct first;
  ILoA rest;
  
  ConsLoA(Acct first, ILoA rest){
    this.first = first;
    this.rest = rest;
  }
  

/* TEMPLATE:
   FIELDS:
    ... this.first ...              -- Acct
    ... this.rest ...               -- ILoB

    METHODS FOR FIELDS:
    ... this.first.same(Acct) ...       -- boolean
  
    ... this.rest.size() ...            -- int
    ... this.rest.contains(Acct) ...    -- boolean

*/
  
  // compute the total size of this list
  public int size(){
    return 1 + this.rest.size();
  }
  
  // does this list of accounts contain the given account?
  public boolean contains(Acct a){
  	return this.first.same(a) ||
  	       this.rest.contains(a);
  }
 
/*
  // produce a list of all accounts with balance below the given limit
  public ILoA allLow(int limit){
    if (this.first.balance < limit){
      return new ConsLoA(this.first, this.rest.allLow(limit));
    }
    else{
      return this.rest.allLow(limit);
    }
  }
*/

}                                                    

// Examples and tests for books and lists of books
class Examples{
  Examples(){}

  Acct chk1 = new Acct("JFK", "checking", 4000);
  Acct chk2 = new Acct("LBJ", "checking", 1000);
  Acct sav = new Acct("DDE", "savings", 2000);
  Acct credit = new Acct("RMN", "credit card", 3000);
  
  ILoA mtlob = new MtLoA();
  ILoA alist2 = new ConsLoA(this.chk1, new ConsLoA(this.chk2, this.mtlob));
  ILoA alist3 = new ConsLoA(this.sav, this.alist2);
  
  // test the method same in the classes that implement ILoB
  boolean testSame(Tester t){
    return
    t.checkExpect(
    		this.chk1.same(new Acct("JFK", "checking", 4000)),  
    		true) &&
    t.checkExpect(this.chk1.same(this.chk2),  false) &&
    t.checkExpect(this.chk1.same(this.sav),  false) ;}

  // test the method size in the classes that implement ILoB
  boolean testSize(Tester t){
    return
    t.checkExpect(this.mtlob.size(),  0) &&
    t.checkExpect(this.alist2.size(),  2) &&
    t.checkExpect(this.alist3.size(),  3);}
    
  // test the method contains in the classes that implement ILoB
  boolean testContains(Tester t){
    return
    t.checkExpect(this.mtlob.contains(this.chk1),  false) &&
    t.checkExpect(this.alist2.contains(this.sav),  false) &&
    t.checkExpect(this.alist3.contains(this.sav),  true);}

}