using System;
using System.Collections.Generic;
using System.Text;

namespace AnonymeMethoden
{
    class Program
    {
        static void Main(string[] args)
        {
            Bank sparkasse = new Bank();

            sparkasse.Add(new BankAccount("Donald Duck", -1000));
            sparkasse.Add(new BankAccount("Daisy Duck", 3000));
            sparkasse.Add(new BankAccount("Dagobert Duck", 2500000));

            SearchHelper search = new SearchHelper(sparkasse);

            Console.WriteLine("\nPleitegeier");
            search.FindUeberzogeneAccounts();

            Console.WriteLine("\nMillionäre");
            search.FindMillionaires();

            Console.WriteLine("\nMehr als 5000 Taler");
            search.FindLargerThan(5000);

            Console.WriteLine("\nMehr als 100 Taler");
            search.FindLargerThan(100);

            Console.ReadKey();

        }
    }
    
    public class BankAccount
    {
        private string _ownerName;
        private int _balance;

        public BankAccount(string ownerName, int balance)
        {
            _ownerName = ownerName;
            _balance = balance;
        }
    
        public string OwnerName
        {
            get
            {
                return _ownerName;
            }
        }

        public int Balance
        {
            get
            {
                return _balance;
            }
        }
    }

    public class Bank
    {
        public delegate bool FilterDelegate(BankAccount ba);

        List<BankAccount> accounts = new List<BankAccount>();

        public void Add(BankAccount account)
        {
            accounts.Add(account);
        }

        public IEnumerable<BankAccount> FindAccounts(FilterDelegate filter)
        {
            List<BankAccount> filteredaccounts = new List<BankAccount>();
            foreach (BankAccount b in accounts)
            {
                if (filter(b)) yield return b;
            }
        }        
    }
    
    public class SearchHelper
    {
        Bank bnk;

        public SearchHelper(Bank b)
        {
            bnk = b;
        }

        public void FindUeberzogeneAccounts()
        {
            foreach (BankAccount ba 
                in bnk.FindAccounts(delegate(BankAccount acc) { return acc.Balance < 0; }))
            {
                Console.WriteLine("Owner: {0}, Balance: {1}", ba.OwnerName, ba.Balance);
            }
        }

        public void FindMillionaires()
        {
            foreach (BankAccount ba
                in bnk.FindAccounts(delegate(BankAccount acc) { return acc.Balance > 500000; }))
            {
                Console.WriteLine("Owner: {0}, Balance: {1}", ba.OwnerName, ba.Balance);
            }
        }

        public void FindLargerThan(int amount)
        {
            foreach (BankAccount ba
                            in bnk.FindAccounts(delegate(BankAccount acc) { return acc.Balance > amount; }))
            {
                Console.WriteLine("Owner: {0}, Balance: {1}", ba.OwnerName, ba.Balance);
            }
        }
    }


}