<?php
/**
 * module.calendar.php, Kopano calender to ics im/exporter
 *
 * Author: Christoph Haas <christoph.h@sprinternet.at>
 * Copyright (C) 2012-2016 Christoph Haas
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

include_once('vendor/autoload.php');

use Sabre\VObject;

class CalendarModule extends Module
{

    private $DEBUG = false;    // enable error_log debugging

    private $busystates = null;

    private $labels = null;

    private $attendeetype = null;

    /**
     * @constructor
     * @param $id
     * @param $data
     */
    public function __construct($id, $data)
    {
        parent::__construct($id, $data);

        // init default timezone
        date_default_timezone_set(PLUGIN_CALENDARIMPORTER_DEFAULT_TIMEZONE);

        // init mappings
        $this->busystates = array(
            "FREE",
            "TENTATIVE",
            "BUSY",
            "OOF"
        );

        $this->labels = array(
            "NONE",
            "IMPORTANT",
            "WORK",
            "PERSONAL",
            "HOLIDAY",
            "REQUIRED",
            "TRAVEL REQUIRED",
            "PREPARATION REQUIERED",
            "BIRTHDAY",
            "SPECIAL DATE",
            "PHONE INTERVIEW"
        );

        $this->attendeetype = array(
            "NON-PARTICIPANT", // needed as zarafa starts counting at 1
            "REQ-PARTICIPANT",
            "OPT-PARTICIPANT",
            "NON-PARTICIPANT"
        );
    }

    /**
     * Executes all the actions in the $data variable.
     * Exception part is used for authentication errors also
     * @return boolean true on success or false on failure.
     */
    public function execute()
    {
        $result = false;

        if (!$this->DEBUG) {
            /* disable error printing - otherwise json communication might break... */
            ini_set('display_errors', '0');
        }

        foreach ($this->data as $actionType => $actionData) {
            if (isset($actionType)) {
                try {
                    if ($this->DEBUG) {
                        error_log("exec: " . $actionType);
                    }
                    switch ($actionType) {
                        case "load":
                            $result = $this->loadCalendar($actionType, $actionData);
                            break;
                        case "export":
                            $result = $this->exportCalendar($actionType, $actionData);
                            break;
                        case "import":
                            $result = $this->importCalendar($actionType, $actionData);
                            break;
                        case "importattachment":
                            $result = $this->getAttachmentPath($actionType, $actionData);
                            break;
                        default:
                            $this->handleUnknownActionType($actionType);
                    }

                } catch (MAPIException $e) {
                    if ($this->DEBUG) {
                        error_log("mapi exception: " . $e->getMessage());
                    }
                } catch (Exception $e) {
                    if ($this->DEBUG) {
                        error_log("exception: " . $e->getMessage());
                    }
                }
            }
        }

        return $result;
    }

    /**
     * Generates a random string with variable length.
     * @param $length the lenght of the generated string
     * @return string a random string
     */
    private function randomstring($length = 6)
    {
        // $chars - all allowed charakters
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";

        srand((double)microtime() * 1000000);
        $i = 0;
        $pass = "";
        while ($i < $length) {
            $num = rand() % strlen($chars);
            $tmp = substr($chars, $num, 1);
            $pass = $pass . $tmp;
            $i++;
        }
        return $pass;
    }

    /**
     * Get a property from the array.
     * @param $props
     * @param $propname
     * @return string
     */
    private function getProp($props, $propname)
    {
        if (isset($props["props"][$propname])) {
            return $props["props"][$propname];
        }
        return "";
    }

    private function getDurationStringFromMintues($minutes, $pos = false)
    {
        $pos = $pos === true ? "+" : "-";
        $str = $pos . "P";


        // variables for holding values
        $mins = intval($minutes);
        $hours = 0;
        $days = 0;
        $weeks = 0;

        // calculations
        if ($mins >= 60) {
            $hours = (int)($mins / 60);
            $mins = $mins % 60;
        }
        if ($hours >= 24) {
            $days = (int)($hours / 24);
            $hours = $hours % 60;
        }
        if ($days >= 7) {
            $weeks = (int)($days / 7);
            $days = $days % 7;
        }

        // format result
        if ($weeks) {
            $str .= "{$weeks}W";
        }
        if ($days) {
            $str .= "{$days}D";
        }
        if ($hours) {
            $str .= "{$hours}H";
        }
        if ($mins) {
            $str .= "{$mins}M";
        }

        return $str;
    }

    /**
     * The main export function, creates the ics file for download
     * @param $actionType
     * @param $actionData
     */
    private function exportCalendar($actionType, $actionData)
    {
        // Get store id
        $storeid = false;
        if (isset($actionData["storeid"])) {
            $storeid = $actionData["storeid"];
        }

        // Get records
        $records = array();
        if (isset($actionData["records"])) {
            $records = $actionData["records"];
        }

        // Get folders
        $folder = false;
        if (isset($actionData["folder"])) {
            $folder = $actionData["folder"];
        }

        $response = array();
        $error = false;
        $error_msg = "";

        // write csv
        $token = $this->randomstring(16);
        $file = PLUGIN_CALENDARIMPORTER_TMP_UPLOAD . "ics_" . $token . ".ics";
        file_put_contents($file, "");

        $store = $GLOBALS["mapisession"]->openMessageStore(hex2bin($storeid));
        if ($store) {
            // load folder first
            if ($folder !== false) {
                $mapifolder = mapi_msgstore_openentry($store, hex2bin($folder));

                $table = mapi_folder_getcontentstable($mapifolder);
                $list = mapi_table_queryallrows($table, array(PR_ENTRYID));

                foreach ($list as $item) {
                    $records[] = bin2hex($item[PR_ENTRYID]);
                }
            }

            $vcalendar = new VObject\Component\VCalendar();

            // Add static stuff to vcalendar
            $vcalendar->add('METHOD', 'PUBLISH');
            $vcalendar->add('X-WR-CALDESC', 'Exported Zarafa Calendar');
            $vcalendar->add('X-WR-TIMEZONE', date_default_timezone_get());

            // TODO: add VTIMEZONE object to ical.

            for ($index = 0, $count = count($records); $index < $count; $index++) {
                $message = mapi_msgstore_openentry($store, hex2bin($records[$index]));

                // get message properties.
                $properties = $GLOBALS['properties']->getAppointmentProperties();
                $plaintext = true;
                $messageProps = $GLOBALS['operations']->getMessageProps($store, $message, $properties, $plaintext);

                $vevent = $vcalendar->add('VEVENT', [
                    'SUMMARY' => $this->getProp($messageProps, "subject"),
                    'DTSTART' => date_timestamp_set(new DateTime(), $this->getProp($messageProps, "startdate")),
                    'DTEND' => date_timestamp_set(new DateTime(), $this->getProp($messageProps, "duedate")),
                    'CREATED' => date_timestamp_set(new DateTime(), $this->getProp($messageProps, "creation_time")),
                    'LAST-MODIFIED' => date_timestamp_set(new DateTime(), $this->getProp($messageProps, "last_modification_time")),
                    'PRIORITY' => $this->getProp($messageProps, "importance"),
                    'X-MICROSOFT-CDO-INTENDEDSTATUS' => $this->busystates[intval($this->getProp($messageProps, "busystatus"))], // both seem to be valid...
                    'X-MICROSOFT-CDO-BUSYSTATUS' => $this->busystates[intval($this->getProp($messageProps, "busystatus"))], // both seem to be valid...
                    'X-ZARAFA-LABEL' => $this->labels[intval($this->getProp($messageProps, "label"))],
                    'CLASS' => $this->getProp($messageProps, "private") ? "PRIVATE" : "PUBLIC",
                    'COMMENT' => "eid:" . $records[$index]
                ]);

                // Add organizer
                $vevent->add('ORGANIZER', 'mailto:' . $this->getProp($messageProps, "sender_email_address"));
                $vevent->ORGANIZER['CN'] = $this->getProp($messageProps, "sender_name");

                // Add Attendees
                if (isset($messageProps["recipients"]) && count($messageProps["recipients"]["item"]) > 0) {
                    foreach ($messageProps["recipients"]["item"] as $attendee) {
                        $att = $vevent->add('ATTENDEE', "mailto:" . $this->getProp($attendee, "email_address"));
                        $att["CN"] = $this->getProp($attendee, "display_name");
                        $att["ROLE"] = $this->attendeetype[intval($this->getProp($attendee, "recipient_type"))];
                    }
                }

                // Add alarms
                if (!empty($this->getProp($messageProps, "reminder")) && $this->getProp($messageProps, "reminder") == 1) {
                    $valarm = $vevent->add('VALARM', [
                        'ACTION' => 'DISPLAY',
                        'DESCRIPTION' => $this->getProp($messageProps, "subject") // reuse the event summary
                    ]);

                    // Add trigger
                    $durationValue = $this->getDurationStringFromMintues($this->getProp($messageProps, "reminder_minutes"), false);
                    $valarm->add('TRIGGER', $durationValue); // default trigger type is duration (see 4.8.6.3)

                    /*
                    $valarm->add('TRIGGER', date_timestamp_set(new DateTime(), $this->getProp($messageProps, "reminder_time"))); // trigger type "DATE-TIME"
                    $valarm->TRIGGER['VALUE'] = 'DATE-TIME';
                    */
                }

                // Add location
                if (!empty($this->getProp($messageProps, "location"))) {
                    $vevent->add('LOCATION', $this->getProp($messageProps, "location"));
                }

                // Add description
                $body = $this->getProp($messageProps, "isHTML") ? $this->getProp($messageProps, "html_body") : $this->getProp($messageProps, "body");
                if (!empty($body)) {
                    $vevent->add('DESCRIPTION', $body);
                }
            }

            // write combined ics file
            file_put_contents($file, file_get_contents($file) . $vcalendar->serialize());
        }

        if (count($records) > 0) {
            $response['status'] = true;
            $response['download_token'] = $token;
            // TRANSLATORS: Filename suffix for exported files
            $response['filename'] = count($records) . dgettext("plugin_calendarimporter", "_events.ics");
        } else {
            $response['status'] = false;
            $response['message'] = dgettext("plugin_calendarimporter", "No events found. Export skipped!");
        }

        $this->addActionData($actionType, $response);
        $GLOBALS["bus"]->addData($this->getResponseData());
    }

    /**
     * The main import function, parses the uploaded ics file
     * @param $actionType
     * @param $actionData
     */
    private function importCalendar($actionType, $actionData)
    {
        // Get uploaded vcf path
        $icsfile = false;
        if (isset($actionData["ics_filepath"])) {
            $icsfile = $actionData["ics_filepath"];
        }

        // Get store id
        $storeid = false;
        if (isset($actionData["storeid"])) {
            $storeid = $actionData["storeid"];
        }

        // Get folder entryid
        $folderid = false;
        if (isset($actionData["folderid"])) {
            $folderid = $actionData["folderid"];
        }

        // Get uids
        $uids = array();
        if (isset($actionData["uids"])) {
            $uids = $actionData["uids"];
        }

        $response = array();
        $error = false;
        $error_msg = "";

        // parse the ics file a last time...
        $parser = null;
        try {
            $parser = VObject\Reader::read(
                fopen($icsfile, 'r')
            );
        } catch (Exception $e) {
            $error = true;
            $error_msg = $e->getMessage();
        }

        $events = array();
        if (count($parser->VEVENT) > 0) {
            $events = $this->parseCalendarToArray($parser);
            $store = $GLOBALS["mapisession"]->openMessageStore(hex2bin($storeid));
            $folder = mapi_msgstore_openentry($store, hex2bin($folderid));

            $importall = false;
            if (count($uids) == count($events)) {
                $importall = true;
            }

            $propValuesMAPI = array();
            $properties = $GLOBALS['properties']->getAppointmentProperties();
            // extend properties...
            $properties["body"] = PR_BODY;

            $count = 0;

            // iterate through all events and import them :)
            foreach ($events as $event) {
                if (isset($event["startdate"]) && ($importall || in_array($event["internal_fields"]["event_uid"], $uids))) {

                    $message = mapi_folder_createmessage($folder);

                    // parse the arraykeys
                    foreach ($event as $key => $value) {
                        if ($key !== "internal_fields") {
                            if (isset($properties[$key])) {
                                $propValuesMAPI[$properties[$key]] = $value;
                            }
                        }
                    }

                    $propValuesMAPI[$properties["commonstart"]] = $propValuesMAPI[$properties["startdate"]];
                    $propValuesMAPI[$properties["commonend"]] = $propValuesMAPI[$properties["duedate"]];
                    $propValuesMAPI[$properties["duration"]] = ($propValuesMAPI[$properties["duedate"]] - $propValuesMAPI[$properties["startdate"]]) / 60; // Minutes needed
                    $propValuesMAPI[$properties["reminder"]] = false; // needed, overwritten if there is a timer

                    $propValuesMAPI[$properties["message_class"]] = "IPM.Appointment";
                    $propValuesMAPI[$properties["icon_index"]] = "1024";

                    // TODO: set attendees and alarms

                    mapi_setprops($message, $propValuesMAPI);
                    mapi_savechanges($message);
                    if ($this->DEBUG) {
                        error_log("New event added: \"" . $event["subject"] . "\".\n");
                    }
                    $count++;
                }
            }

            $response['status'] = true;
            $response['count'] = $count;
            $response['message'] = "";

        } else {
            $response['status'] = false;
            $response['count'] = 0;
            $response['message'] = $error ? $error_msg : dgettext("plugin_calendarimporter", "ICS file empty!");
        }

        $this->addActionData($actionType, $response);
        $GLOBALS["bus"]->addData($this->getResponseData());
    }

    /**
     * Store the file to a temporary directory, prepare it for oc upload
     * @param $actionType
     * @param $actionData
     * @private
     */
    private function getAttachmentPath($actionType, $actionData)
    {
        // Get store id
        $storeid = false;
        if (isset($actionData["store"])) {
            $storeid = $actionData["store"];
        }

        // Get message entryid
        $entryid = false;
        if (isset($actionData["entryid"])) {
            $entryid = $actionData["entryid"];
        }

        // Check which type isset
        $openType = "attachment";

        // Get number of attachment which should be opened.
        $attachNum = false;
        if (isset($actionData["attachNum"])) {
            $attachNum = $actionData["attachNum"];
        }

        // Check if storeid and entryid isset
        if ($storeid && $entryid) {
            // Open the store
            $store = $GLOBALS["mapisession"]->openMessageStore(hex2bin($storeid));

            if ($store) {
                // Open the message
                $message = mapi_msgstore_openentry($store, hex2bin($entryid));

                if ($message) {
                    $attachment = false;

                    // Check if attachNum isset
                    if ($attachNum) {
                        // Loop through the attachNums, message in message in message ...
                        for ($i = 0; $i < (count($attachNum) - 1); $i++) {
                            // Open the attachment
                            $tempattach = mapi_message_openattach($message, (int)$attachNum[$i]);
                            if ($tempattach) {
                                // Open the object in the attachment
                                $message = mapi_attach_openobj($tempattach);
                            }
                        }

                        // Open the attachment
                        $attachment = mapi_message_openattach($message, (int)$attachNum[(count($attachNum) - 1)]);
                    }

                    // Check if the attachment is opened
                    if ($attachment) {

                        // Get the props of the attachment
                        $props = mapi_attach_getprops($attachment, array(PR_ATTACH_LONG_FILENAME, PR_ATTACH_MIME_TAG, PR_DISPLAY_NAME, PR_ATTACH_METHOD));
                        // Content Type
                        $contentType = "application/octet-stream";
                        // Filename
                        $filename = "ERROR";

                        // Set filename
                        if (isset($props[PR_ATTACH_LONG_FILENAME])) {
                            $filename = $props[PR_ATTACH_LONG_FILENAME];
                        } else {
                            if (isset($props[PR_ATTACH_FILENAME])) {
                                $filename = $props[PR_ATTACH_FILENAME];
                            } else {
                                if (isset($props[PR_DISPLAY_NAME])) {
                                    $filename = $props[PR_DISPLAY_NAME];
                                }
                            }
                        }

                        // Set content type
                        if (isset($props[PR_ATTACH_MIME_TAG])) {
                            $contentType = $props[PR_ATTACH_MIME_TAG];
                        } else {
                            // Parse the extension of the filename to get the content type
                            if (strrpos($filename, ".") !== false) {
                                $extension = strtolower(substr($filename, strrpos($filename, ".")));
                                $contentType = "application/octet-stream";
                                if (is_readable("mimetypes.dat")) {
                                    $fh = fopen("mimetypes.dat", "r");
                                    $ext_found = false;
                                    while (!feof($fh) && !$ext_found) {
                                        $line = fgets($fh);
                                        preg_match("/(\.[a-z0-9]+)[ \t]+([^ \t\n\r]*)/i", $line, $result);
                                        if ($extension == $result[1]) {
                                            $ext_found = true;
                                            $contentType = $result[2];
                                        }
                                    }
                                    fclose($fh);
                                }
                            }
                        }


                        $tmpname = tempnam(TMP_PATH, stripslashes($filename));

                        // Open a stream to get the attachment data
                        $stream = mapi_openpropertytostream($attachment, PR_ATTACH_DATA_BIN);
                        $stat = mapi_stream_stat($stream);
                        // File length =  $stat["cb"]

                        $fhandle = fopen($tmpname, 'w');
                        $buffer = null;
                        for ($i = 0; $i < $stat["cb"]; $i += BLOCK_SIZE) {
                            // Write stream
                            $buffer = mapi_stream_read($stream, BLOCK_SIZE);
                            fwrite($fhandle, $buffer, strlen($buffer));
                        }
                        fclose($fhandle);

                        $response = array();
                        $response['tmpname'] = $tmpname;
                        $response['filename'] = $filename;
                        $response['status'] = true;
                        $this->addActionData($actionType, $response);
                        $GLOBALS["bus"]->addData($this->getResponseData());
                    }
                }
            } else {
                $response['status'] = false;
                $response['message'] = dgettext("plugin_calendarimporter", "Store could not be opened!");
                $this->addActionData($actionType, $response);
                $GLOBALS["bus"]->addData($this->getResponseData());
            }
        } else {
            $response['status'] = false;
            $response['message'] = dgettext("plugin_calendarimporter", "Wrong call, store and entryid have to be set!");
            $this->addActionData($actionType, $response);
            $GLOBALS["bus"]->addData($this->getResponseData());
        }
    }

    /**
     * Function that parses the uploaded ics file and posts it via json
     * @param $actionType
     * @param $actionData
     */
    private function loadCalendar($actionType, $actionData)
    {
        $error = false;
        $error_msg = "";

        if (is_readable($actionData["ics_filepath"])) {
            $parser = null;

            try {
                $parser = VObject\Reader::read(
                    fopen($actionData["ics_filepath"], 'r')
                );
                //error_log(print_r($parser->VTIMEZONE, true));
            } catch (Exception $e) {
                $error = true;
                $error_msg = $e->getMessage();
            }
            if ($error) {
                $response['status'] = false;
                $response['message'] = $error_msg;
            } else {
                if (count($parser->VEVENT) == 0) {
                    $response['status'] = false;
                    $response['message'] = dgettext("plugin_calendarimporter", "No event in ics file");
                } else {
                    $response['status'] = true;
                    $response['parsed_file'] = $actionData["ics_filepath"];
                    $response['parsed'] = array(
                        'events' => $this->parseCalendarToArray($parser),
                        'timezone' => isset($parser->VTIMEZONE->TZID) ? (string)$parser->VTIMEZONE->TZID : (string)$parser->{'X-WR-TIMEZONE'},
                        'calendar' => (string)$parser->PRODID
                    );
                }
            }
        } else {
            $response['status'] = false;
            $response['message'] = dgettext("plugin_calendarimporter", "File could not be read by server");
        }

        $this->addActionData($actionType, $response);
        $GLOBALS["bus"]->addData($this->getResponseData());

        if ($this->DEBUG) {
            error_log("parsing done, bus data written!");
        }
    }

    /**
     * Create a array with contacts
     *
     * @param {VObject} $calendar ics parser object
     * @return array parsed events
     * @private
     */
    private function parseCalendarToArray($calendar)
    {
        $events = array();
        foreach ($calendar->VEVENT as $Index => $vEvent) {
            // Sabre\VObject\Parser\XML\Element\VEvent
            $properties = array();

            //uid - used for front/backend communication
            $properties["internal_fields"] = array();
            $properties["internal_fields"]["event_uid"] = base64_encode($Index . $vEvent->UID);

            $properties["startdate"] = (string)$vEvent->DTSTART->getDateTime()->getTimestamp();
            $properties["duedate"] = (string)$vEvent->DTEND->getDateTime()->getTimestamp();
            $properties["location"] = (string)$vEvent->LOCATION;
            $properties["subject"] = (string)$vEvent->SUMMARY;
            $properties["body"] = (string)$vEvent->DESCRIPTION;
            $properties["comment"] = (string)$vEvent->COMMENT;
            $properties["timezone"] = (string)$vEvent->DTSTART["TZID"];
            $properties["organizer"] = (string)$vEvent->ORGANIZER;
            $properties["busystatus"] = array_search((string)$vEvent->{'X-MICROSOFT-CDO-INTENDEDSTATUS'}, $this->busystates); // X-MICROSOFT-CDO-BUSYSTATUS
            $properties["transp"] = (string)$vEvent->TRANSP;
            //$properties["trigger"] = (string)$vEvent->COMMENT;
            $properties["priority"] = (string)$vEvent->PRIORITY;
            $properties["private"] = ((string)$vEvent->CLASS) == "PRIVATE" ? true : false;
            if (!empty((string)$vEvent->{'X-ZARAFA-LABEL'})) {
                $properties["label"] = array_search((string)$vEvent->{'X-ZARAFA-LABEL'}, $this->labels);
            }
            $properties["last_modification_time"] = (string)$vEvent->{'LAST-MODIFIED'}->getDateTime()->getTimestamp();
            $properties["creation_time"] = (string)$vEvent->CREATED->getDateTime()->getTimestamp();
            $properties["rrule"] = (string)$vEvent->RRULE;

            // Attendees
            $properties["attendees"] = array();
            if (isset($vEvent->ATTENDEE) && count($vEvent->ATTENDEE) > 0) {
                foreach ($vEvent->ATTENDEE as $attendee) {
                    $properties["attendees"][] = array(
                        "name" => (string)$attendee["CN"],
                        "mail" => (string)$attendee,
                        "status" => (string)$attendee["PARTSTAT"],
                        "role" => (string)$attendee["ROLE"]
                    );
                }
            }

            // Alarms
            $properties["alarms"] = array();
            if (isset($vEvent->VALARM) && count($vEvent->VALARM) > 0) {
                foreach ($vEvent->VALARM as $alarm) {
                    $properties["alarms"][] = array(
                        "description" => (string)$alarm->DESCRIPTION,
                        "trigger" => (string)$alarm->TRIGGER,
                        "type" => (string)$alarm->TRIGGER["VALUE"]
                    );
                }
            }

            array_push($events, $properties);
        }

        return $events;
    }
}