"""
Provide a surrogate or placeholder for another object to control access
to it or add other responsibilities.
"""

import abc


class Subject(metaclass=abc.ABCMeta):
    """
    Define the common interface for RealSubject and Proxy so that a
    Proxy can be used anywhere a RealSubject is expected.
    """

    @abc.abstractmethod
    def request(self):
        pass


class Proxy(Subject):
    """
    Maintain a reference that lets the proxy access the real subject.
    Provide an interface identical to Subject's.
    """

    def __init__(self, real_subject):
        self._real_subject = real_subject

    def request(self):
        # ...
        self._real_subject.request()
        # ...


class RealSubject(Subject):
    """
    Define the real object that the proxy represents.
    """

    def request(self):
        pass


def main():
    real_subject = RealSubject()
    proxy = Proxy(real_subject)
    proxy.request()


if __name__ == "__main__":
    main()    	
    	

    	
    		
class ProxyBookList {
    private $bookList = NULL; 
    //bookList is not instantiated at construct time
    function __construct() {
    }
    function getBookCount() {
        if (NULL == $this->bookList) {
            $this->makeBookList(); 
        }
        return $this->bookList->getBookCount();
    }
    function addBook($book) {
        if (NULL == $this->bookList) {
            $this->makeBookList(); 
        }
        return $this->bookList->addBook($book);
    }  
    function getBook($bookNum) {
        if (NULL == $this->bookList) {
            $this->makeBookList();
        } 
        return $this->bookList->getBook($bookNum);
    }
    function removeBook($book) {
        if (NULL == $this->bookList) {
            $this->makeBookList();
        } 
        return $this->bookList->removeBook($book);
    }
    //Create 
    function makeBookList() {
        $this->bookList = new bookList();
    }
}

class BookList {
    private $books = array();
    private $bookCount = 0;
    public function __construct() {
    }
    public function getBookCount() {
        return $this->bookCount;
    }
    private function setBookCount($newCount) {
        $this->bookCount = $newCount;
    }
    public function getBook($bookNumberToGet) {
        if ( (is_numeric($bookNumberToGet)) && ($bookNumberToGet <= $this->getBookCount())) {
            return $this->books[$bookNumberToGet];
        } else {
           return NULL;
        }
    }
    public function addBook(Book $book_in) {
        $this->setBookCount($this->getBookCount() + 1);
        $this->books[$this->getBookCount()] = $book_in;
        return $this->getBookCount();
    }
    public function removeBook(Book $book_in) {
        $counter = 0;
        while (++$counter <= $this->getBookCount()) {
          if ($book_in->getAuthorAndTitle() == $this->books[$counter]->getAuthorAndTitle()) {
            for ($x = $counter; $x < $this->getBookCount(); $x++) {
              $this->books[$x] = $this->books[$x + 1];
          }
          $this->setBookCount($this->getBookCount() - 1);
        }
      }
      return $this->getBookCount();
    }
}

class Book {
    private $author;
    private $title;
    function __construct($title_in, $author_in) {
      $this->author = $author_in;
      $this->title  = $title_in;
    }
    function getAuthor() {
        return $this->author;
    }
    function getTitle() {
        return $this->title;
    }
    function getAuthorAndTitle() {
      return $this->getTitle().' by '.$this->getAuthor();
    }
}

  writeln( 'BEGIN TESTING PROXY PATTERN';
  writeln('');
 
  $proxyBookList = new ProxyBookList();
  $inBook = new Book('PHP for Cats','Larry Truett');
  $proxyBookList->addBook($inBook);
 
  writeln('test 1 - show the book count after a book is added');
  writeln($proxyBookList->getBookCount());
  writeln('');
 
  writeln('test 2 - show the book');
  $outBook = $proxyBookList->getBook(1);
  writeln($outBook->getAuthorAndTitle()); 
  writeln('');
 
  $proxyBookList->removeBook($outBook);
 
  writeln('test 3 - show the book count after a book is removed');
  writeln($proxyBookList->getBookCount());
  writeln('');

  writeln('END TESTING PROXY PATTERN');

  function writeln($line_in) {
    echo $line_in."
";
  }
    	
    	

    	
    		
// 5. To support plug-compatibility between
// the wrapper and the target, create an interface
interface SocketInterface {
    String readLine();
    void  writeLine(String str);
    void  dispose();
}

class SocketProxy implements SocketInterface {
    // 1. Create a "wrapper" for a remote,
    // or expensive, or sensitive target
    private Socket socket;
    private BufferedReader in;
    private PrintWriter out;

    public SocketProxy(String host, int port, boolean wait) {
        try {
            if (wait) {
                // 2. Encapsulate the complexity/overhead of the target in the wrapper
                ServerSocket server = new ServerSocket(port);
                socket = server.accept();
            } else {
                socket = new Socket(host, port);
            }
            in  = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            out = new PrintWriter(socket.getOutputStream(), true);
        } catch(IOException e) {
            e.printStackTrace();
        }
    }

    public String readLine() {
        String str = null;
        try {
            str = in.readLine();
        } catch( IOException e ) {
            e.printStackTrace();
        }
        return str;
    }

    public void writeLine(String str) {
        // 4. The wrapper delegates to the target
        out.println(str);
    }

    public void dispose() {
        try {
            socket.close();
        } catch(IOException e) {
            e.printStackTrace();
        }
    }
}

public class ProxyDemo {
    public static void main( String[] args ) {
        // 3. The client deals with the wrapper
        SocketInterface socket = new SocketProxy( "127.0.0.1", 8080, args[0].equals("first") ? true : false );
        String  str;
        boolean skip = true;
        while (true) {
            if (args[0].equals("second") && skip) {
                skip = !skip;
            } else {
                str = socket.readLine();
                System.out.println("Receive - " + str);
                if (str.equals(null)) {
                    break;
                }
            }
            System.out.print( "Send ---- " );
            str = new Scanner(System.in).nextLine();
            socket.writeLine( str );
            if (str.equals("quit")) {
                break;
            }
        }
        socket.dispose();
    }
}