<!-- Collection of code snippets by Arne Vajhøj -->
<!-- posted to eksperten.dk, usenet and other places (2002-now) -->
<?php
namespace Server\DomainLayer {
    class User {
        public $id;
        public $name;
        public $computers;
        public function __construct($id, $name, $computers = array()) {
            $this->id = $id;
            $this->name = $name;
            $this->computers = $computers;
        }
    }
    class Computer {
        public $id;
        public $type;
        public $users;
        public function __construct($id, $type, $users = array()) {
            $this->id = $id;
            $this->type = $type;
            $this->users = $users;
        }
    }
}

namespace Server\ServiceLayer {
    abstract class Manager {
        protected $dp; // DataProvider
        protected function output($result) {
            header('Content-Type: application/json');
            echo json_encode($result);
        }
        public function __construct($dp) {
            $this->dp = $dp;
        }
        public abstract function get($pathid, $query);
    }
    class UserManager extends Manager {
        public function __construct($dp) {
            parent::__construct($dp);
        }
        public function get($pathid, $query) {
            if($pathid != null) {
                $id = intval($pathid);
                $this->output($this->dp->getOneUser($id));
            } else {
                $this->output($this->dp->getAllUsers());
            }
        }
    }
    class ComputerManager extends Manager {
        public function __construct($dp) {
            parent::__construct($dp);
        }
        public function get($pathid, $query) {
            if($pathid != null) {
                $id = intval($pathid);
                $this->output($this->dp->getOneComputer($id));
            } else {
                $this->output($this->dp->getAllComputers());
            }
        }
    }
    class Facade {
        private $usrmgr;
        private $compmgr;
        public function __construct($dp) {
            $this->usrmgr = new \Server\ServiceLayer\UserManager($dp);
            $this->compmgr = new \Server\ServiceLayer\ComputerManager($dp);
        }
        public function get() {
            if(isset($_SERVER['PATH_INFO'])) {
                $pathparts = explode('/', $_SERVER['PATH_INFO']);
                if(count($pathparts) >= 2) {
                    $mgrnam = $pathparts[1];
                    $pathid = count($pathparts) >= 3 ? $pathparts[2] : null;
                    $query = isset($_SERVER['QUERY_STRING']) ? $_SERVER['QUERY_STRING'] : null;
                    if($mgrnam == 'user') {
                        return $this->usrmgr->get($pathid, $query);
                    } else if($mgrnam == 'computer') {
                        return $this->compmgr->get($pathid, $query);
                    } else {
                        throw new \Exception('Unknown resource');
                    }
                }
            }
            throw new \Exception('Bad path');
        }
        public function process() {
            $method = $_SERVER['REQUEST_METHOD'];
            if($method == 'GET') {
                $this->get();
            } else {
                throw new \Excpetion('Method not supported');
            }
        }
    }
}

namespace Server\DataAccessLayer {
    interface DataProvider {
        public function getOneUser($id);
        public function getAllUSers();
        public function getOneComputer($id);
        public function getAllComputers();
    }
    class DummyDataProvider implements DataProvider {
        public function getOneUser($id) {
            return new \Server\DomainLayer\User(1,'Anders And', array(new \Server\DomainLayer\Computer(1, 'HP PC')));
        }
        public function getAllUSers() {
            return array(new \Server\DomainLayer\User(1,'Anders And', array(new \Server\DomainLayer\Computer(1, 'HP PC'))),
                         new \Server\DomainLayer\User(2,'Georg Gearløs', array(new \Server\DomainLayer\Computer(2, 'Dell PC'))));
        }
        public function getOneComputer($id) {
            return new \Server\DomainLayer\Computer(1, 'HP PC', array(new \Server\DomainLayer\User(1,'Anders And')));
        }
        public function getAllComputers() {
            return array(new \Server\DomainLayer\Computer(1, 'HP PC', array(new \Server\DomainLayer\User(1,'Anders And'))),
                         new \Server\DomainLayer\Computer(2, 'Dell PC', new \Server\DomainLayer\User(2,'Georg Gearløs')));
        }
    }
    class DatabaseDataProvider implements DataProvider {
        private $db; // PDO connection
        public function __construct($db) {
            $this->db = $db;
        }
        public function getOneUser($id) {
            // SELECT name FROM users JOIN uc ON users.id=uc.userid JOIN computers ON uc.computerid=computers.id WHERE users.id=?
            throw new \Excpetion('Not implemented yet');
        }
        public function getAllUSers() {
            // SELECT name FROM users JOIN uc ON users.id=uc.userid JOIN computers ON uc.computerid=computers.id
            throw new \Excpetion('Not implemented yet');
        }
        public function getOneComputer($id) {
            // SELECT type FROM computers JOIN uc ON cmputers.id=uc.computerid JOIN users ON uc.userid=users.id WHERE computers.id=?
            throw new \Excpetion('Not implemented yet');
        }
        public function getAllComputers() {
            // SELECT type FROM computers JOIN uc ON cmputers.id=uc.computerid JOIN users ON uc.userid=users.id
            throw new \Excpetion('Not implemented yet');
        }
    }
}

namespace Server {
    $fac = new \Server\ServiceLayer\Facade(new \Server\DataAccessLayer\DummyDataProvider());
    $fac->process();
}

?>