My attempt for the 2014-03-20 test

2014-03-20/src/Book.php

@@ -1,4 +1,34 @@
 <?php
 class Book
 {
+    private $_data = [];
+
+    public function __construct(array $data)
+    {
+        if (isset($data['publishDate'])) {
+            $dateTime = new DateTime();
+            $dateTime->setTimestamp($data['publishDate']);
+
+            $data['publishDate'] = $dateTime;
+        }
+
+        $this->_data = $data;
+    }
+
+    public function __call($name, array $args)
+    {
+        $name = str_replace('get', '', $name);
+
+        if (strlen($name) < 1) {
+            return null;
+        }
+
+        $field = strtolower($name[0]) . substr($name, 1);
+
+        if (!isset($this->_data[$field])) {
+            return null;
+        }
+
+        return $this->_data[$field];
+    }
 }

2014-03-20/src/BooksCollection.php

@@ -1,4 +1,124 @@
 <?php
+use DominionEnterprises\Util;
+use DominionEnterprises\Util\Arrays;
+use DominionEnterprises\Util\Http;
+
 class BooksCollection implements IBooksCollection
 {
+    /**
+     * @var array data returned by the book api
+     */
+    private $_data = [];
+
+    /**
+     * @var array url params to pass off to the book api
+     */
+    private $_param = [];
+
+    /**
+     * @var string
+     */
+    private $_sort = '';
+
+    /**
+     * @var int position of iterator on $_data array
+     */
+    private $_position = 0;
+
+    public function find()
+    {
+        $this->_param = [];
+        $this->_data = [];
+        $this->_sort = '';
+
+        return $this;
+    }
+
+    public function where(array $where)
+    {
+        $this->_param = $where;
+
+        return $this;
+    }
+
+    public function sort($field)
+    {
+        $this->_sort = $field;
+
+        $this->_data = $this->_callApi($this->_param, $this->_sort);
+
+        return $this;
+    }
+
+    public function rewind()
+    {
+        $this->_position = 0;
+    }
+
+    public function current()
+    {
+        return new Book($this->_data[$this->_position]);
+    }
+
+    public function key()
+    {
+        return $this->_position;
+    }
+
+    public function next()
+    {
+        ++$this->_position;
+    }
+
+    public function valid()
+    {
+        return array_key_exists($this->_position, $this->_data);
+    }
+
+    public function count()
+    {
+        return count($this->_data);
+    }
+
+    /**
+     * Returns array of books based on parameter and sort
+     *
+     * @see /src/Book.php
+     *
+     * @param array $param parameter to pass to book api
+     * @param string $sort sort value of title, genre, or price
+     * @return array of Book
+     */
+    private function _callApi(array $param = [], $sort = '')
+    {
+        Util::throwIfNotType(['string' => [$sort]], true);
+
+        Util::ensure(true, in_array($sort, ['title', 'genre', 'price']));
+
+        $apiParam = ['sort' => $sort];
+        Arrays::copyIfKeysExist($param, $apiParam, ['genre', 'offset', 'limit']);
+
+        $ret = [];
+        do {
+            $request = json_decode(file_get_contents('http://chadicus.herokuapp.com/books?' . Http::buildQueryString($apiParam)), true);
+
+            if (!isset($request['total'])) {
+                $request['total'] = 0;
+                continue;
+            }
+
+            foreach ($request['books'] as $book) {
+                $ret[] = $this->_getBookInfo($book['url']);
+            }
+        } while ($request['total'] != count($ret));
+
+        return $ret;
+    }
+
+    private function _getBookInfo($urlPath)
+    {
+        Util::throwIfNotType(['string' => [$urlPath]]);
+
+        return json_decode(file_get_contents("http://chadicus.herokuapp.com{$urlPath}"), true);
+    }
 }