[locationinfo] Add backend for Microsoft Exchange Server

We use the php-ews library which can be easily integrated via composer

1 files changed, 203 insertions, 0 deletions

diff --git a/modules-available/locationinfo/inc/coursebackend/coursebackend_exchange.inc.php b/modules-available/locationinfo/inc/coursebackend/coursebackend_exchange.inc.php
new file mode 100755
index 00000000..538f7382
--- /dev/null
+++ b/modules-available/locationinfo/inc/coursebackend/coursebackend_exchange.inc.php
@@ -0,0 +1,203 @@
+<?php
+
+require_once __DIR__ . '/../../vendor/autoload.php';
+
+use jamesiarmes\PhpEws\Client;
+use jamesiarmes\PhpEws\Enumeration\DefaultShapeNamesType;
+use jamesiarmes\PhpEws\Enumeration\DistinguishedFolderIdNameType;
+use jamesiarmes\PhpEws\Enumeration\ItemQueryTraversalType;
+use jamesiarmes\PhpEws\Enumeration\ResponseClassType;
+use jamesiarmes\PhpEws\Request\FindItemType;
+use jamesiarmes\PhpEws\Request\ResolveNamesType;
+use jamesiarmes\PhpEws\Type\CalendarViewType;
+use jamesiarmes\PhpEws\Type\DistinguishedFolderIdType;
+use jamesiarmes\PhpEws\Type\EmailAddressType;
+use jamesiarmes\PhpEws\Type\ItemResponseShapeType;
+
+class CourseBackend_Exchange extends CourseBackend {
+
+    private $username = '';
+    private $password = '';
+    private $baseUrl;
+    private $client_version;
+    private $timezone = 'W. Europe Standard Time';  // TODO: make this configurable some time
+    private $verifyHostname = true;
+    private $verifyCert = true;
+
+    /**
+     * @return string return display name of backend
+     */
+    public function getDisplayName() {
+        return "Microsoft Exchange";
+    }
+
+    /**
+     * @returns \BackendProperty[] list of properties that need to be set
+     */
+    public function getCredentialDefinitions() {
+        $options = [Client::VERSION_2007, Client::VERSION_2007_SP1, Client::VERSION_2009, Client::VERSION_2010,
+            Client::VERSION_2010_SP1, Client::VERSION_2010_SP2, Client::VERSION_2013, Client::VERSION_2013_SP1, Client::VERSION_2016];
+        return [
+            new BackendProperty('baseUrl', 'string'),
+            new BackendProperty('username', 'string'),
+            new BackendProperty('password', 'password'),
+            new BackendProperty('client_version', $options),
+            new BackendProperty('verifyCert', 'bool', true),
+            new BackendProperty('verifyHostname', 'bool', true)
+        ];
+    }
+
+    /**
+     * @return boolean true if the connection works, false otherwise
+     */
+    public function checkConnection() {
+        $client = $this->getClient();
+        $request = new ResolveNamesType();
+        $request->UnresolvedEntry = $this->username;
+        $request->ReturnFullContactData = false;
+
+        try {
+            $response = $client->ResolveNames($request);
+        } catch (Exception $e) {
+            error_log("There was an error");
+            error_log($e->getMessage());
+            return false;
+        }
+
+        if ($response->ResponseMessages->ResolveNamesResponseMessage[0]->ResponseCode == "NoError") {
+            $mailadress = $response->ResponseMessages->ResolveNamesResponseMessage[0]->ResolutionSet->Resolution[0]->Mailbox->EmailAddress;
+            return !empty($mailadress);
+        }
+        return false;
+    }
+
+    /**
+     * uses json to setCredentials, the json must follow the form given in
+     * getCredentials
+     *
+     * @param array $data assoc array with data required by backend
+     * @returns bool if the credentials were in the correct format
+     */
+    public function setCredentialsInternal($data) {
+        foreach (['username', 'password'] as $field) {
+            if (empty($data[$field])) {
+                $this->error = 'setCredentials: Missing field ' . $field;
+                return false;
+            }
+        }
+
+        if (empty($data['baseUrl'])) {
+            $this->error = "No url is given";
+            return false;
+        }
+
+        $this->username = $data['username'];
+        $this->password = $data['password'];
+
+        $this->baseUrl = $data['baseUrl'];
+        $this->client_version = $data['client_version'];
+
+        $this->verifyHostname = $data['verifyHostname'];
+        $this->verifyCert = $data['verifyCert'];
+
+        return true;
+    }
+
+    /**
+     * @return int desired caching time of results, in seconds. 0 = no caching
+     */
+    public function getCacheTime() {
+        return 0;
+    }
+
+    /**
+     * @return int age after which timetables are no longer refreshed should be
+     * greater then CacheTime
+     */
+    public function getRefreshTime() {
+        return 0;
+    }
+
+    /**
+     * Internal version of fetch, to be overridden by subclasses.
+     *
+     * @param $roomIds array with local ID as key and serverId as value
+     * @return array a recursive array that uses the roomID as key
+     * and has the schedule array as value. A shedule array contains an array in this format:
+     * ["start"=>'JJJJ-MM-DD HH:MM:SS',"end"=>'JJJJ-MM-DD HH:MM:SS',"title"=>string]
+     */
+    protected function fetchSchedulesInternal($requestedRoomIds) {
+        $startDate = new DateTime('today 0:00');
+        $endDate = new DateTime('+7 days 0:00');
+        $client = $this->getClient();
+
+        $schedules = [];
+        foreach ($requestedRoomIds as $roomId) {
+            $items = $this->findEventsForRoom($client, $startDate, $endDate, $roomId);
+
+            // Iterate over the events that were found, printing some data for each.
+            foreach ($items as $item) {
+                $start = new DateTime($item->Start);
+                $end = new DateTime($item->End);
+
+                $schedules[$roomId][] = array(
+                    'title' => $item->Subject,
+                    'start' => $start->format('Y-m-d') . "T" . $start->format('G:i:s'),
+                    'end' => $end->format('Y-m-d') . "T" . $end->format('G:i:s')
+                );
+            }
+        }
+        return $schedules;
+    }
+
+    public function findEventsForRoom($client, $start_date, $end_date, $email_room) {
+        $request = new FindItemType();
+        $request->Traversal = ItemQueryTraversalType::SHALLOW;
+        $request->ItemShape = new ItemResponseShapeType();
+        $request->ItemShape->BaseShape = DefaultShapeNamesType::ALL_PROPERTIES;
+
+        $request->CalendarView = new CalendarViewType();
+        $request->CalendarView->StartDate = $start_date->format('c');
+        $request->CalendarView->EndDate = $end_date->format('c');
+        $folder_id = new DistinguishedFolderIdType();
+        $folder_id->Id = DistinguishedFolderIdNameType::CALENDAR;
+        $folder_id->Mailbox = new EmailAddressType();
+        $folder_id->Mailbox->EmailAddress = $email_room;
+        $request->ParentFolderIds->DistinguishedFolderId[] = $folder_id;
+        $response = $client->FindItem($request);
+        $response_messages = $response->ResponseMessages->FindItemResponseMessage;
+
+        $items = [];
+        foreach ($response_messages as $response_message) {
+            // Make sure the request succeeded.
+            if ($response_message->ResponseClass != ResponseClassType::SUCCESS) {
+                $code = $response_message->ResponseCode;
+                $message = $response_message->MessageText;
+                error_log("Failed to search for events with \"$code: $message\"\n");
+                continue;
+            }
+            $items = $response_message->RootFolder->Items->CalendarItem;
+        }
+        return $items;
+    }
+
+    public function getClient() {
+        $client = new Client($this->baseUrl, $this->username, $this->password, $this->client_version);
+        $client->setTimezone($this->timezone);
+        $client->setCurlOptions(array(
+            CURLOPT_SSL_VERIFYPEER => $this->verifyHostname,
+            CURLOPT_SSL_VERIFYHOST => $this->verifyCert
+        ));
+
+        return $client;
+    }
+
+    function var_error_log($object = null) {
+        ob_start(); // start buffer capture
+        var_dump($object); // dump the values
+        $contents = ob_get_contents(); // put the buffer into a variable
+        ob_end_clean(); // end capture
+        error_log($contents); // log contents of the result of var_dump( $object )
+    }
+}
+?>