Removing Dependency from SDK Core Project

- Copied files required for Rest API SDK
- Removed PPApiContext and directly connected APIContext with PPConfigManager
- Removed duplicate data storage of configuration and credentials.
- Code Style Fixes
- Remove build.xml file as it is not required anymore
- Updated the samples
- Updated the documentations

lib/PayPal/Core/PPConfigManager.php

@@ -0,0 +1,163 @@
+<?php
+
+namespace PayPal\Core;
+
+/**
+ * Class PPConfigManager
+ *
+ * PPConfigManager loads the SDK configuration file and
+ * hands out appropriate config params to other classes
+ *
+ * @package PayPal\Core
+ */
+class PPConfigManager
+{
+
+    /**
+     * Configuration Options
+     *
+     * @var array
+     */
+    private $configs = array(
+        "http.ConnectionTimeOut" => "30",
+        "http.Retry" => "5",
+    );
+
+    /**
+     * Singleton Object
+     *
+     * @var $this
+     */
+    private static $instance;
+
+    /**
+     * Private Constructor
+     */
+    private function __construct()
+    {
+        if (defined('PP_CONFIG_PATH')) {
+            $configFile = constant('PP_CONFIG_PATH') . '/sdk_config.ini';
+        } else {
+            $configFile = implode(DIRECTORY_SEPARATOR,
+                array(dirname(__FILE__), "..", "config", "sdk_config.ini"));
+        }
+        $this->addConfigFromIni($configFile);
+    }
+
+    /**
+     * Returns the singleton object
+     *
+     * @return $this
+     */
+    public static function getInstance()
+    {
+        if (!isset(self::$instance)) {
+            self::$instance = new self();
+        }
+        return self::$instance;
+    }
+
+    /**
+     * Add Configuration from configuration.ini files
+     *
+     * @param string $fileName
+     * @return $this
+     */
+    public function addConfigFromIni($fileName)
+    {
+        if ($configs = @parse_ini_file($fileName)) {
+            $this->addConfigs($configs);
+        }
+        return $this;
+    }
+
+    /**
+     * If a configuration exists in both arrays,
+     * then the element from the first array will be used and
+     * the matching key's element from the second array will be ignored.
+     *
+     * @param [] $config
+     * @return $this
+     */
+    public function addConfigs($configs = [])
+    {
+        $this->configs = $configs + $this->configs;
+        return $this;
+    }
+
+    /**
+     * Simple getter for configuration params
+     * If an exact match for key is not found,
+     * does a "contains" search on the key
+     *
+     * @param string $searchKey
+     * @return array
+     */
+    public function get($searchKey)
+    {
+
+        if (array_key_exists($searchKey, $this->configs)) {
+            return $this->configs[$searchKey];
+        } else {
+            $arr = array();
+            foreach ($this->configs as $k => $v) {
+                if (strstr($k, $searchKey)) {
+                    $arr[$k] = $v;
+                }
+            }
+
+            return $arr;
+        }
+
+    }
+
+    /**
+     * Utility method for handling account configuration
+     * return config key corresponding to the API userId passed in
+     *
+     * If $userId is null, returns config keys corresponding to
+     * all configured accounts
+     *
+     * @param string|null $userId
+     * @return array|string
+     */
+    public function getIniPrefix($userId = null)
+    {
+
+        if ($userId == null) {
+            $arr = array();
+            foreach ($this->configs as $key => $value) {
+                $pos = strpos($key, '.');
+                if (strstr($key, "acct")) {
+                    $arr[] = substr($key, 0, $pos);
+                }
+            }
+            return array_unique($arr);
+        } else {
+            $iniPrefix = array_search($userId, $this->configs);
+            $pos = strpos($iniPrefix, '.');
+            $acct = substr($iniPrefix, 0, $pos);
+
+            return $acct;
+        }
+    }
+
+    /**
+     * returns the config file hashmap
+     */
+    public function getConfigHashmap()
+    {
+        return $this->configs;
+    }
+
+    /**
+     * Disabling __clone call
+     */
+    public function __clone()
+    {
+        trigger_error('Clone is not allowed.', E_USER_ERROR);
+    }
+
+}
+
+