<?php

/**
 * Simple class to use for user notifications
 *
 * @internal
 */
class ResourceSpaceUserNotification
{
    /**
     * @var array $message_parts
     * Array of message text components and optional find/replace arrays for language strings
     */
    private $message_parts = [];

    /**
     * @var array $subject
     * Array of subject parts
     */
    private $subject = [];

    /**
     * @var string $url
     */
    public $url = "";

    /**
     * @var array $template
     */
    public $template;

    /**
     * @var array $templatevars
     */
    public $templatevars;

     /**
     * @var array $user_preference  Optional array of (boolean only) user preferences, with required and default values to check for when sending notification e.g.
     * ["user_pref_resource_access_notifications"=>["requiredvalue"=>true,"default"=>$admin_resource_access_notifications],"actions_resource_requests" =>["requiredvalue"=>false,"default"=>true]]
     * or
     * ["user_pref_system_management_notifications" => true]
     *
     * All preferences must be set to the required values for the notification to be sent
     *
     */
    public $user_preference;

    /**
     * @var array $eventdata  Optional array for linking the system message to a specific activity e.g. resource or account request so that it can be deleted once the request has been processed.
     *                  ["type"] e.g. MANAGED_REQUEST
     *                  ["ref"]
     */
    public $eventdata = [];

    /**
     * Set the notification message
     *
     * @param  string   $text       Text or $lang string using the 'lang_' prefix
     * @param  array    $find       Array of find strings to use for str_replace() in $lang strings
     * @param  array    $replace    Array of replace strings to use for str_replace()
     *
     * @return void
     */
    public function set_text($text, $find = [], $replace = [])
    {
        $this->message_parts = [[$text, $find, $replace]];
    }

    /**
     * Append text to the notification message
     *
      * @param  string   $text       Text or $lang string using the 'lang_' prefix
      * @param  array    $find       Array of find strings to use for str_replace() in $lang strings
      * @param  array    $replace    Array of replace strings to use for str_replace()
      * @return void
     */
    public function append_text($text, $find = [], $replace = [])
    {
        $this->message_parts[] = [$text, $find, $replace];
    }

    /**
     * Append multiple text elements to the notification message
     *
      * @param  array   $messages    Array of text components as per append_text()
      * @return void
     */
    public function append_text_multi($textarr)
    {
        $this->message_parts = array_merge($this->message_parts, $textarr);
    }

    /**
     * Prepend text component to the notification message
     *
      * @param  string   $text       Text or $lang string using the 'lang_' prefix
      * @param  array    $find       Array of find strings to use for str_replace() in $lang strings
      * @param  array    $replace    Array of replace strings to use for str_replace()
      * @return void
     */
    public function prepend_text($text, $find = [], $replace = [])
    {
        array_unshift($this->message_parts, [$text, $find, $replace]);
    }

    /**
     * Prepend multiple text elements to the notification message
     *
      * @param  array   $messages    Array of text components as per append_text()
      * @return void
     */
    public function prepend_text_multi($textarr)
    {
        // Loop in reverse order so that the parts get ordered correctly at start
        for ($n = count($textarr); $n--; $n >= 0) {
            array_unshift($this->message_parts, $textarr[$n]);
        }
    }

    /**
     * Set the notification subject
     *
     * @param  string   $text       Text or $lang string using the 'lang_' prefix
     * @param  array    $find       Array of find strings to use for str_replace() in $lang strings
     * @param  array    $replace    Array of replace strings to use for str_replace()
     *
     * @return void
     */
    public function set_subject($text, $find = [], $replace = [])
    {
        $this->subject = [[$text, $find, $replace]];
    }

    /**
     * Append text to the notification subject
     *
      * @param  string   $text       Text or $lang string using the 'lang_' prefix
      * @param  array    $find       Array of find strings to use for str_replace() in $lang strings
      * @param  array    $replace    Array of replace strings to use for str_replace()
      * @return void
     */
    public function append_subject($text, $find = [], $replace = [])
    {
        $this->subject[] = [$text, $find, $replace];
    }

    /**
     * Get the message text, by default this is resolved into single string with text translated and with the find/replace completed
     * Note that if not returning raw data the correct $lang must be set by  before this is called
      * @param  bool    $unresolved       Return the raw message parts to use in another message object. False by default
     *
     * @return string|array
     */
    public function get_text($unresolved = false)
    {
        global $lang;
        if ($unresolved) {
            return $this->message_parts;
        }
        $messagetext = "";
        foreach ($this->message_parts as $message_part) {
            $text = $message_part[0];
            if (substr($text, 0, 5) == "lang_") {
                $langkey = substr($text, 5);
                $text = str_replace('[applicationname]', $GLOBALS['applicationname'], $lang[$langkey]);
            }
            if (substr($text, 0, 5) == "i18n_") {
                $i18n_string = substr($text, 5);
                $text = i18n_get_translated($i18n_string);
            }
            if (isset($message_part[1]) && isset($message_part[2]) && count($message_part[1])  == count($message_part[2])) {
                $text = str_replace($message_part[1], $message_part[2], $text);
            }
            $messagetext .= $text;
        }
        return $messagetext;
    }

    public function get_subject()
    {
        global $lang;
        $fullsubject = "";
        foreach ($this->subject as $subjectpart) {
            $text = $subjectpart[0];
            if (substr($text, 0, 5) == "lang_") {
                $langkey = substr($text, 5);
                $text = $lang[$langkey];
            }

            if (isset($subjectpart[1]) && isset($subjectpart[2])) {
                $text = str_replace($subjectpart[1], $subjectpart[2], $text);
            }
            $fullsubject .= $text;
        }
        return $fullsubject;
    }
}

/**
 * Gets messages for a given user (returns true if there are messages, false if not)
 * Note that messages are passed by reference.
 *
 * @param  array $messages  Array that will be populated by messages. Passed by reference
 * @param  int $user        User ID
 * @param  bool $get_all    Retrieve all messages? Setting to TRUE will include all seen and expired messages
 * @param  bool $sort       Sort by message ID in ascending or descending order
 * @param  string $order_by Order of messages returned
 * @return bool             Flag to indicate if any messages exist
 */
function message_get(&$messages, $user, $get_all = false, $sort = "ASC", $order_by = "ref")
{
    switch ($order_by) {
        case "ref":
            $sql_order_by = "user_message.ref";
            break;
        case "created":
            $sql_order_by = "message.created";
            break;
        case "from":
            $sql_order_by = "owner";
            break;
        case "fullname":
            $sql_order_by = "user.fullname";
            break;
        case "message":
            $sql_order_by = "message.message";
            break;
        case "expires":
            $sql_order_by = "message.expires";
            break;
        case "seen":
            $sql_order_by = "user_message.seen";
            break;
    }

    if (!validate_sort_value($sort)) {
        $sort = "ASC";
    }

    $messages = ps_query("SELECT user_message.ref, message.ref AS 'message_id', user.username AS owner, user_message.seen, message.created, message.expires, message.message, message.url, message.owner as ownerid, message.type " .
        "FROM `user_message`
		INNER JOIN `message` ON user_message.message=message.ref " .
        "LEFT OUTER JOIN `user` ON message.owner=user.ref " .
        "WHERE user_message.user = ?" .
        ($get_all ? " " : " AND message.expires > NOW()") .
        ($get_all ? " " : " AND user_message.seen='0'") .
        " ORDER BY " . $sql_order_by . " " . $sort, array("i",$user));
    return count($messages) > 0;
}

/**
 * Add a new resourcespace system message
 *
 * @param  mixed $users             User ID, or array of user IDs
 * @param  string $text             Message text
 * @param  string $url              URL to include as link in message
 * @param  int $owner               ID of message creator/owner
 * @param  int $notification_type   Message type e.g. MESSAGE_ENUM_NOTIFICATION_TYPE_SCREEN, MESSAGE_ENUM_NOTIFICATION_TYPE_EMAIL. See definitions.php
 * @param  int $ttl_seconds         Lifetime of message in seconds before expiry
 * @param  int $related_activity    ID of related activity type - see SYSTEM NOTIFICATION TYPES section in definitions.php
 * @param  int $related_ref         Related activity ID - used with type above to delete redundant messages e.g. once a user or resource request has been approved
 * @return void
 */
function message_add($users, $text, $url = "", $owner = null, $notification_type = MESSAGE_ENUM_NOTIFICATION_TYPE_SCREEN, $ttl_seconds = MESSAGE_DEFAULT_TTL_SECONDS, $related_activity = 0, $related_ref = 0)
{
    global $userref,$applicationname,$lang, $baseurl, $baseurl_short,$header_colour_style_override;

    if (!is_int_loose($notification_type)) {
        $notification_type = intval($notification_type); // make sure this in an integer
    }

    $orig_text = $text;

    if (!is_array($users)) {
        $users = array($users);
    }

    if (checkperm('E')) {
        $validusers = get_users(0, "", "u.username", true);
        $validuserrefs = array_column($validusers, "ref");
        $users = array_filter($users, function ($user) use ($validuserrefs) {
            return in_array($user, $validuserrefs);
        });
    }

    if (is_null($owner) || (isset($userref) && $userref != $owner)) {
        // Can't send messages from another user
        $owner = $userref;
    }

    ps_query("INSERT INTO `message` (`owner`, `created`, `expires`, `message`, `url`, `related_activity`, `related_ref`, `type`) VALUES (? , NOW(), DATE_ADD(NOW(), INTERVAL ? SECOND), ?, ?, ?, ?, ?)", array("i",$owner,"i",$ttl_seconds,"s",$text,"s",str_replace($baseurl . '/', $baseurl_short, $url),"i",$related_activity,"i",$related_ref,"i",$notification_type));
    $message_ref = sql_insert_id();

    foreach ($users as $user) {
        ps_query("INSERT INTO `user_message` (`user`, `message`) VALUES (?, ?)", array("i",(int)$user,"i",$message_ref));

        $user_info = get_user($user);
        // send an email if the user has notifications and emails setting and the message hasn't already been sent via email
        if (~$notification_type & MESSAGE_ENUM_NOTIFICATION_TYPE_EMAIL) {
            get_config_option(['user' => $user_info['ref'], 'usergroup' => $user_info['usergroup']], 'email_and_user_notifications', $notifications_always_email, $GLOBALS['system_wide_config_options']['email_and_user_notifications']);
            if ($notifications_always_email) {
                if ($user_info['email'] !== '') {
                    if (substr($url, 0, 1) == "/") {
                        // If a relative link is provided make sure we add the full URL when emailing
                        $parsed_url = parse_url($baseurl);
                        $url = $baseurl . (isset($parsed_url["path"]) ? str_replace($parsed_url["path"], "", $url) : $url);
                    }

                    $message_text = nl2br($orig_text);

                    // Add system header image to email
                    $headerimghtml = "";
                    $img_url = get_header_image(true);
                    $img_div_style = "max-height:50px;padding: 5px;";
                    $img_div_style .= "background: " . ((isset($header_colour_style_override) && $header_colour_style_override != '') ? $header_colour_style_override : "rgba(0, 0, 0, 0.6)") . ";";
                    $headerimghtml = '<div style="' . $img_div_style . '"><img src="' . $img_url . '" style="max-height:50px;"  /></div><br /><br />';

                    if ($url !== '' && strpos($message_text, $url) === false) {
                        // Add the URL to the message if not already present
                        $message_text = $message_text . "<br /><br /><a href='" . $url . "'>" . $url . "</a>";
                    }
                    send_mail($user_info['email'], $applicationname . ": " . $lang['notification_email_subject'], $headerimghtml . $message_text);
                }
            }
        }
    }
}

/**
 * Remove a message from message table and associated user_messages
 *
 * @param  int $message Message ID
 * @return void
 */
function message_remove($message)
{
    ps_query("DELETE FROM user_message WHERE message = ?", array("i",$message));
    ps_query("DELETE FROM message WHERE ref = ?", array("i",$message));
}

/**
 * Mark a message as seen
 *
 * @param  int $message Message ID
 * @param  int $seen_type    - see definitons.php
 * @return void
 */
function message_seen($message, $seen_type = MESSAGE_ENUM_NOTIFICATION_TYPE_SCREEN)
{
    ps_query("UPDATE `user_message` SET seen = seen | ? WHERE `ref` = ?", array("i",$seen_type,"i",$message));
}

/**
 * Mark a message as unseen
 *
 * @param  int $message Message ID
 * @return void
 */
function message_unseen($message)
{
    ps_query("UPDATE `user_message` SET seen = '0' WHERE `ref` = ?", array("i",$message));
}

/**
 * Flags all non-read messages as read for given user and seen type
 *
 * @param  int $user    User ID
 * @param  int $seen_type    - see definitons.php
 * @return void
 */
function message_seen_all($user, $seen_type = MESSAGE_ENUM_NOTIFICATION_TYPE_SCREEN)
{
    $messages = array();
    if (message_get($messages, $user, true)) {
        foreach ($messages as $message) {
            message_seen($message['ref']);
        }
    }
}

/**
 * Remove all messages from message and user_message tables that have expired (regardless of read).
 * This will be called from a cron job.
 *
 * @return void
 */
function message_purge()
{
    ps_query("DELETE FROM user_message WHERE message IN (SELECT ref FROM message where expires < NOW())", array());
    ps_query("DELETE FROM message where expires < NOW()", array());
}

/**
 * Delete all selected messages
 *
 * @param $messages List of message refs in JSON list format
 * @return void
 */
function message_deleteselusrmsg($messages)
{
    global $userref;

    $parameters = array("i",(int)$userref);
    $messages = json_decode($messages, true);
    if (count($messages) > 0) {
        $parameters = array_merge($parameters, ps_param_fill($messages, "i"));

        ps_query("DELETE FROM user_message WHERE user = ? AND ref IN (" . ps_param_insert(count($messages)) . ")", $parameters);
    }
}

/**
 * Mark all selected messages as seen
 *
 * @param $messages List of message refs in JSON list format
 * @return void
 */
function message_selectedseen($messages)
{
    global $userref;

    $parameters = array("i",(int)$userref);
    $messages = json_decode($messages, true);
    $parameters = array_merge($parameters, ps_param_fill($messages, "i"));

    if (is_array($messages) && count($messages) > 0) {
        ps_query("UPDATE user_message SET seen = '1' WHERE user = ? AND ref IN (" . ps_param_insert(count($messages)) . ")", $parameters);
    }
}

/**
 * Mark all selected messages as unseen
 *
 * @param $messages List of message refs in JSON list format
 * @return void
 */
function message_selectedunseen($messages)
{
    global $userref;

    $parameters = array("i",(int)$userref);
    $messages = json_decode($messages, true);
    $parameters = array_merge($parameters, ps_param_fill($messages, "i"));

    if (is_array($messages) && count($messages) > 0) {
        ps_query("UPDATE user_message SET seen = '0' WHERE user = ? AND ref IN (" . ps_param_insert(count($messages)) . ")", $parameters);
    }
}

/**
 * Send a summary of all unread notifications as an email
 * from the standard cron_copy_hitcount
 *
 * @return boolean  Returns false if not due to run
 */
function message_send_unread_emails()
{
    global $lang, $applicationname, $baseurl, $list_search_results_title_trim, $user_pref_daily_digest, $applicationname, $actions_on, $inactive_message_auto_digest_period, $user_pref_inactive_digest;

    $lastrun = get_sysvar('daily_digest', '1970-01-01');

    # Don't run if already run in last 24 hours.
    if (time() - strtotime($lastrun) < 24 * 60 * 60) {
        echo " - Skipping message_send_unread_emails (daily_digest) - last run: " . $lastrun . "<br />\n";
        return false;
    }

    $sendall = array();

    // Get all the users who have chosen to receive the digest email (or the ones that have opted out if set globally)
    if ($user_pref_daily_digest) {
        $allusers = get_users("", "", "u.username", "", -1, 1);
        $nodigestusers = get_config_option_users('user_pref_daily_digest', 0);
        $digestusers = array_diff(array_column($allusers, "ref"), $nodigestusers);
    } else {
        $digestusers = get_config_option_users('user_pref_daily_digest', 1);
    }

    if ($inactive_message_auto_digest_period > 0 && is_numeric($inactive_message_auto_digest_period)) {
        // Add any users who have not logged on to the array
        $allusers = get_users(0, "", "u.ref", false, -1, 1, false, "u.ref, u.username, u.last_active");
        foreach ($allusers as $user) {
            if (!in_array($user["ref"], $digestusers) && strtotime((string)$user["last_active"]) < date(time() - $inactive_message_auto_digest_period *  60 * 60 * 24)) {
                debug("message_send_unread_emails: Processing unread messages for inactive user: " . $user["username"]);
                $digestusers[] = $user["ref"];
                $sendall[] = $user["ref"];
            }
        }
    }

    if (!empty($digestusers)) {
        $digestuserschunks = array_chunk($digestusers, SYSTEM_DATABASE_IDS_CHUNK_SIZE);
        $unreadmessages = [];
        foreach ($digestuserschunks as $chunk) {
            # Get all unread notifications created since last run, or all messages sent to inactive users.
            # Build array of sql query parameters

            $parameters = array();

            $parameters = array_merge($parameters, ps_param_fill($chunk, "i"));
            $parameters = array_merge($parameters, array("s",$lastrun));
            $digestusers_sql = " AND u.ref IN (" . ps_param_insert(count($chunk)) . ")";

            $sendall_chunk = array_intersect($sendall, $chunk);
            if (count($sendall_chunk) > 0) {
                $parameters  = array_merge($parameters, ps_param_fill($sendall_chunk, "i"));
                $sendall_sql = " OR u.ref IN (" . ps_param_insert(count($sendall_chunk)) . ")";
            } else {
                $sendall_sql = "";
            }

            $unreadmessages = array_merge(
                $unreadmessages,
                ps_query(
                    "SELECT u.ref AS userref, u.email, m.ref AS messageref, m.message, m.created, m.url
                    FROM user_message um
                        JOIN user u ON u.ref = um.user
                        JOIN message m ON m.ref = um.message
                        WHERE um.seen = 0
                        $digestusers_sql
                        AND u.email <> ''
                        AND (m.created > ?
                            $sendall_sql)
                        ORDER BY m.created DESC",
                    $parameters
                )
            );
        }
    } else {
        $parameters = array("s",$lastrun);
        $unreadmessages = ps_query(
            "SELECT u.ref AS userref, u.email, m.ref AS messageref, m.message, m.created, m.url
                FROM user_message um
                    JOIN user u ON u.ref = um.user
                    JOIN message m ON m.ref = um.message
                    WHERE um.seen = 0
                    AND u.email <> ''
                    AND (m.created > ?)
                    ORDER BY m.created DESC",
            $parameters
        );

        if (!empty($sendall)) {
            $sendall_chunks = array_chunk($sendall, SYSTEM_DATABASE_IDS_CHUNK_SIZE);

            foreach ($sendall_chunks as $sendall_chunk) {
                if (count($sendall_chunk) > 0) {
                    $parameters_chunk  = array_merge($parameters, ps_param_fill($sendall_chunk, "i"));
                    $sendall_sql = " OR u.ref IN (" . ps_param_insert(count($sendall_chunk)) . ")";
                }

                $unreadmessages = array_merge(
                    $unreadmessages,
                    ps_query(
                        "SELECT u.ref AS userref, u.email, m.ref AS messageref, m.message, m.created, m.url
                        FROM user_message um
                            JOIN user u ON u.ref = um.user
                            JOIN message m ON m.ref = um.message
                            WHERE um.seen = 0
                            AND u.email <> ''
                            AND (m.created > ?
                                $sendall_sql)
                            ORDER BY m.created DESC",
                        $parameters_chunk
                    )
                );
            }
        }
    }

    // Keep record of the current value for these config options. setup_user() may override them with the user group specific ones.
    $current_inactive_message_auto_digest_period = $inactive_message_auto_digest_period;
    $current_user_pref_inactive_digest = $user_pref_inactive_digest;
    $current_user_pref_daily_digest = $user_pref_daily_digest;

    foreach ($digestusers as $digestuser) {
        // Reset config variables before setting up the user to not have logic influenced by the previous iteration.
        $inactive_message_auto_digest_period = $current_inactive_message_auto_digest_period;
        $user_pref_inactive_digest = $current_user_pref_inactive_digest;
        $user_pref_daily_digest = $current_user_pref_daily_digest;

        $messageuser = get_user($digestuser);
        if (!$messageuser) {
            // Invalid user
            continue;
        }

        setup_user($messageuser);

        $pref_msg_user_for_inactive_digest = $pref_msg_user_pref_daily_digest = null;
        get_config_option(['user' => $messageuser['ref'], 'usergroup' => $messageuser['usergroup']], 'user_pref_inactive_digest', $pref_msg_user_for_inactive_digest);
        get_config_option(['user' => $messageuser['ref'], 'usergroup' => $messageuser['usergroup']], 'user_pref_daily_digest', $pref_msg_user_pref_daily_digest);

        if ($inactive_message_auto_digest_period == 0 || (!$pref_msg_user_for_inactive_digest && !$pref_msg_user_pref_daily_digest)) {
            debug("Skipping email digest for user ref " . $digestuser . " as user or group preference disabled");
            continue;
        }

        $usermail = $messageuser["email"];
        if (!filter_var($usermail, FILTER_VALIDATE_EMAIL)) {
            debug("Skipping email digest for user ref " . $digestuser . " due to invalid email:  " . $usermail);
            continue;
        }

        $messageflag = false;
        $actionflag = false;
        // Set up an array of message to delete for this user if they have chosen to purge the messages
        $messagerefs = array();

        // Start the new email
        if (in_array($digestuser, $sendall)) {
            $message = $lang['email_auto_digest_inactive'] . "<br /><br />";
        } else {
            $message = $lang['email_daily_digest_text'] . "<br /><br />";
        }
        $message .= "<style>.InfoTable td {padding:5px; margin: 0px;border: 1px solid #000;}</style><table class='InfoTable'>";
        $message .= "<tr><th>" . $lang["columnheader-date_and_time"] . "</th><th>" . $lang["message"] . "</th><th></th></tr>";

        foreach ($unreadmessages as $unreadmessage) {
            if ($unreadmessage["userref"] == $digestuser) {
                // Message applies to this user
                $messageflag = true;
                $usermail = $unreadmessage["email"];
                $msgurl = $unreadmessage["url"];
                if (substr($msgurl, 0, 1) == "/") {
                    // If a relative link is provided make sure we add the full URL when emailing
                    $msgurl = $baseurl . $msgurl;
                }
                $message .= "<tr><td>" . nicedate($unreadmessage["created"], true, true, true) . "</td><td>" . $unreadmessage["message"] . "</td><td><a href='" . $msgurl . "'>" . $lang["link"] . "</a></td></tr>";
                $messagerefs[] = $unreadmessage["messageref"];
            }
        }

        if (count($messagerefs) == 0) {
            $message .= "<tr><td colspan='3'>" . $lang["nomessages"] . "</td></tr>";
        }

        if ($actions_on) {
            if (!$actions_on) {
                break;
            }

            $user_actions = get_user_actions(false, '', 'date', 'DESC');
            $action_count = count($user_actions);
            $actions_truncated = false;
            if ($action_count > 1000) {
                $user_actions = array_slice($user_actions, 0, 1000);
                $actions_truncated = true;
            }

            if ($action_count > 0) {
                $actionflag = true;
                debug("Adding actions to message for user " . $usermail);
                if ($messageflag) {
                    $message .= "</table><br /><br />";
                }
                $message .= $lang['email_daily_digest_actions'] . "<br /><br />" . $lang["actions_introtext"] . "<br />";

                if ($actions_truncated) {
                    $message .= escape(str_replace(array('[total]', '[application_name]'), array($action_count, $applicationname), $lang['email_actions_truncated'])) . "<br />";
                }

                $message .= "<style>.InfoTable td {padding:5px; margin: 0px;border: 1px solid #000;}</style><table class='InfoTable'>";
                $message .= "<tr><th>" . $lang["date"] . "</th>";
                $message .= "<th>" . $lang["property-reference"] . "</th>";
                $message .= "<th>" . $lang["description"] . "</th>";
                $message .= "<th>" . $lang["type"] . "</th></tr>";


                foreach ($user_actions as $user_action) {
                    $actionlinks = hook("actioneditlink", '', array($user_action));
                    if ($actionlinks) {
                        $actioneditlink = $actionlinks["editlink"];
                        $actionviewlink = $actionlinks["viewlink"];
                    } else {
                        $actioneditlink = '';
                        $actionviewlink = '';
                    }

                    if ($user_action["type"] == "resourcereview") {
                        $actioneditlink = $baseurl . "/pages/edit.php";
                        $actionviewlink = $baseurl . "/pages/view.php";
                    } elseif ($user_action["type"] == "resourcerequest") {
                        $actioneditlink = $baseurl . "/pages/team/team_request_edit.php";
                    } elseif ($user_action["type"] == "userrequest") {
                        $actioneditlink = $baseurl . "/pages/team/team_user_edit.php";
                    }

                    $linkparams["ref"] = $user_action["ref"];
                    $editlink = ($actioneditlink == '') ? '' : generateURL($actioneditlink, $linkparams);
                    $viewlink = ($actionviewlink == '') ? '' : generateURL($actionviewlink, $linkparams);
                    $message .= "<tr>";
                    $message .= "<td>" . nicedate($user_action["date"], true, true, true) . "</td>";
                    $message .= "<td><a href=\"" . $editlink . "\" >" . $user_action["ref"] . "</a></td>";
                    $message .= "<td>" . tidy_trim(TidyList($user_action["description"]), $list_search_results_title_trim) . "</td>";
                    $message .= "<td>" . $lang["actions_type_" . $user_action["type"]] . "</td>";
                    $message .= "<td><div class=\"ListTools\">";
                    if ($editlink != "") {
                        $message .= "&nbsp;&nbsp;<a href=\"" . $editlink . "\" >" . $lang["action-edit"] . "</a>";
                    }
                    if ($viewlink != "") {
                        $message .= "&nbsp;&nbsp;<a href=\"" . $viewlink . "\" >" . $lang["view"] . "</a>";
                    }
                    $message .= "</div>";
                    $message .= "</td></tr>";
                } // End of each $user_actions loop
            }
        }

        // Send the email
        debug("Sending summary to user ref " . $digestuser . ", email " . $usermail);
        $message .= "</table>";

        $userprefurl = $baseurl . "/pages/user/user_preferences.php#UserPreferenceEmailSection";
        $message .= "<br /><br />" . $lang["email_digest_disable"] . "<br /><a href='" . $userprefurl  . "'>" . $userprefurl . "</a>";

        if ($messageflag || $actionflag) {
            // Send mail
            send_mail($usermail, $applicationname . ": " . $lang["email_daily_digest_subject"], $message);
        }

        get_config_option(['user' => $messageuser['ref'], 'usergroup' => $messageuser['usergroup']], 'user_pref_daily_digest_mark_read', $mark_read);
        if ($mark_read && count($messagerefs) > 0) {
            $parameters = array("i",MESSAGE_ENUM_NOTIFICATION_TYPE_EMAIL);
            $parameters = array_merge($parameters, ps_param_fill($messagerefs, "i"));
            $parameters = array_merge($parameters, array("i",$digestuser));
            ps_query("UPDATE user_message SET seen = ? WHERE message IN (" . ps_param_insert(count($messagerefs)) . ") and user = ?", $parameters);
        }
    }

    set_sysvar("daily_digest", date("Y-m-d H:i:s"));
    return true;
}

/**
 * Remove all messages related to a certain activity (e.g. resource request or resource submission)
 * matching the given ref(s)

 * @param  int $remote_activity     ID of related activity type - see SYSTEM NOTIFICATION TYPES section in definitions.php
 * @param  mixed $remote_refs       Related activity ID or array of IDs
 * @return void
 */
function message_remove_related($remote_activity = 0, $remote_refs = array())
{
    if ($remote_activity == 0 || $remote_refs == 0 || (is_array($remote_refs) && count($remote_refs) == 0)) {
        return false;
    }
    if (!is_array($remote_refs)) {
        $remote_refs = array($remote_refs);
    }
    $parameters = array("i", $remote_activity);
    $parameters = array_merge($parameters, ps_param_fill($remote_refs, "i"));

    $relatedmessages = ps_array("select ref value from message where related_activity = ? and related_ref in (" . ps_param_insert(count($remote_refs)) . ");", $parameters, "");
    if (count($relatedmessages) > 0) {
        $parameters = ps_param_fill($relatedmessages, "i");
        ps_query("DELETE FROM message WHERE ref in (" . ps_param_insert(count($relatedmessages)) . ");", $parameters);
        ps_query("DELETE FROM user_message WHERE message in (" . ps_param_insert(count($relatedmessages)) . ");", $parameters);
    }
}

/**
* Send a system notification or email to the system administrators according to preference
*
* @param string  $message      Message text
* @param string  $url          Optional URL
*
* @return void
*/
function system_notification($message, $url = "")
{
    global $lang, $applicationname;
    $admin_notify_emails = array();
    $admin_notify_users = array();
    $notify_users = get_notification_users("SYSTEM_ADMIN");
    $subject = str_replace("[application_name]", $applicationname, $lang["system_notification"]);
    foreach ($notify_users as $notify_user) {
        get_config_option(['user' => $notify_user['ref'], 'usergroup' => $notify_user['usergroup']], 'user_pref_system_management_notifications', $send_message);
        if (!$send_message) {
            continue;
        }
        get_config_option(['user' => $notify_user['ref'], 'usergroup' => $notify_user['usergroup']], 'email_user_notifications', $send_email);
        if ($send_email && $notify_user["email"] != "") {
            $admin_notify_emails[] = $notify_user['email'];
        } else {
            $admin_notify_users[] = $notify_user["ref"];
        }
    }
    foreach ($admin_notify_emails as $admin_notify_email) {
        $template = "system_notification_email";
        $templatevars = array("message" => $message,"url" => $url);
        $messageplain = $message . "\n\n" . $url;
        send_mail($admin_notify_email, $subject, $messageplain, '', '', $template, $templatevars);
    }

    if (count($admin_notify_users) > 0) {
        message_add($admin_notify_users, $message, $url, 0);
    }
}

/**
* Get all message refs for a given user
*
* @param string  $user      User ID
*
* @return void
*/
function message_getrefs($user)
{
    $user_messages = ps_query("SELECT ref FROM user_message WHERE user = ?", array("i",$user));

    $js_array = array_values($user_messages);

    echo json_encode($js_array);
}

/**
 * Get all messages between the given user IDs
 *
 * @param  int        $users    User ID
 * @param  array      $msgusers Array of other user IDs
 *
 * @param  array    $filteropts Array of extra options to filter and sort messages returned
 *                              "msgfind"    - (string) Text to find
 *                              "sort_desc"  - (bool) Sort by message ID in descending order? False = Ascending
 *                              "limit"      - (int) Maximum number of messages to return
 *
 * @return array   Array of messages
 */
function message_get_conversation(int $user, $msgusers = array(), $filteropts = array()): array
{
    array_map("is_int_loose", $msgusers);
    if (count($msgusers) == 0 || !is_int_loose($user)) {
        return array();
    }

    $msgfind = $filteropts['msgfind'] ?? '';
    $sort_desc = $filteropts['sort_desc'] ?? false;
    $limit = $filteropts['limit'] ?? 0;

    # Build array of sql query parameters
    $parameters = ps_param_fill($msgusers, "i");
    $parameters = array_merge($parameters, array("i",$user), array("i",$user));
    $parameters = array_merge($parameters, ps_param_fill($msgusers, "i"));
    if ($msgfind != "") {
        $parameters = array_merge($parameters, array("s", $msgfind));
    }
    if ($limit > 0) {
        $parameters = array_merge($parameters, array("i", (int)$limit));
    }
    $msgquery = "SELECT message.created,
                        message.owner,
                        message.message,
                        message.url,
                        message.expires,
                        message.type,
                        user_message.user,
                        user_message.ref,
                        user_message.seen
                   FROM message
              LEFT JOIN user_message ON user_message.message=message.ref
                  WHERE ((owner IN(" . ps_param_insert(count($msgusers)) . ") AND user_message.user = ?)
                     OR (owner = ? AND user_message.user IN(" . ps_param_insert(count($msgusers)) . ")))"
           .  ($msgfind != "" ? (" AND message.message LIKE ?") : " " )
           . " AND type & '" . MESSAGE_ENUM_NOTIFICATION_TYPE_USER_MESSAGE . "'"
           . " ORDER BY user_message.ref " . ($sort_desc ? "DESC" : "ASC")
           . ($limit > 0 ? " LIMIT ?" : "");

    return ps_query($msgquery, $parameters);
}

/**
 * Send a user to user(s) message
 *
 * @param  array $users     Array of user IDs or usernames/groupnames from user select
 * @param  string $text     Message text
 * @return bool|string      True if sent ok or error message
 */
function send_user_message($users, $text)
{
    global $userref, $lang;
    $users = remove_groups_smart_from_userlist($users);
    $users = explode(",", resolve_userlist_groups($users));
    
    for ($n = 0; $n < count($users); $n++) {
        if (!is_int_loose($users[$n])) {
            $uref = get_user_by_username(trim($users[$n]));
            if (!$uref) {
                return $lang["error_invalid_user"];
            }
            $users[$n] = $uref;
        }
    }
    message_add($users, $text, "", $userref, MESSAGE_ENUM_NOTIFICATION_TYPE_USER_MESSAGE + MESSAGE_ENUM_NOTIFICATION_TYPE_SCREEN, 30 * 24 * 60 * 60);
    return true;
}

/**
 * Send system notifications to specified users, checking the user preferences first if specified
 *
 * @param  array  $users            Array of user IDs or array of user details from get_users()
 * @param  ResourceSpaceUserNotification $notifymessage    An instance of a ResourceSpaceUserNotification object holding message properties
 * @param  bool   $forcemail        Force system to send email instead of notification?
 *
 * @return array  Array containing resulting messages - can be used for testing when emails are not being sent
 *                This will contain two arrays:-
 *                          "emails"       array of emails sent, with the following elements:-
 *                              "email"     => Email address
 *                              "subject"   => Email subject
 *                              "body"      => Body text
 *
 *                          "messages"      Array of system messages sent with the following elements :-
 *                              "user"      => User ID
 *                              "message"   => message text
 *                              "url"       => url
 */
function send_user_notification(array $users, $notifymessage, $forcemail = false)
{
    global $userref, $lang, $plugins, $header_colour_style_override;

    // Need to global $applicationname as it is used inside the lang files
    global $applicationname;
    $userlanguages = []; // This stores the users in their relevant language key element

    // Set up $results array
    $results = [];
    $results["messages"] = [];
    $results["emails"] = [];
    foreach ($users as $notify_user) {
        $userdetails = $notify_user;
        if (!is_array($userdetails)) {
            $userdetails = get_user((int)$userdetails);
        } elseif (!isset($userdetails["lang"])) {
            // Need full user info
            $userdetails = get_user($userdetails["ref"]);
        }
        if (!$userdetails) {
            continue;
        }

        $send_message = true;
        // Check if preferences should prevent the notification from being sent
        if (isset($notifymessage->user_preference) && is_array($notifymessage->user_preference)) {
            foreach ($notifymessage->user_preference as $preference => $vals) {
                if ($preference != "") {
                    $requiredvalue  = (bool)$vals["requiredvalue"];
                    $default        = (bool)$vals["default"];
                    get_config_option(['user' => $userdetails['ref'], 'usergroup' => $userdetails['usergroup']], $preference, $check_pref, $default);
                    debug(" - Required preference: " . $preference . " = " . ($requiredvalue ? "TRUE" : "FALSE"));
                    debug(" - User preference value: " . $preference . " = " . ($check_pref ? "TRUE" : "FALSE"));
                    if ($check_pref != $requiredvalue) {
                        debug("Skipping notification to user #" . $userdetails['ref']);
                        $send_message = false;
                    }
                }
            }
        }
        if (!$send_message) {
            continue;
        }
        debug("Sending notification to user #" . $userdetails["ref"]);
        get_config_option(['user' => $userdetails['ref'], 'usergroup' => $userdetails['usergroup']], 'email_user_notifications', $send_email);
        if (!isset($userlanguages[$userdetails['lang']])) {
            $userlanguages[$userdetails['lang']] = [];
            $userlanguages[$userdetails['lang']]["emails"] = [];
            $userlanguages[$userdetails['lang']]["message_users"] = [];
        }
        if (($send_email && filter_var($userdetails["email"], FILTER_VALIDATE_EMAIL)) || $forcemail) {
            debug("Sending email to user #" . $userdetails["ref"]);
            $userlanguages[$userdetails['lang']]["emails"][] = $userdetails["email"];
        } else {
            debug("Sending system message to user #" . $userdetails["ref"]);
            $userlanguages[$userdetails['lang']]["message_users"][] = $userdetails["ref"];
        }
    }
    $url = $notifymessage->url ?? null;
    $headerimghtml = "";
    if (!isset($notifymessage->template)) {
        // Add header image to email if not using template
        $img_url = get_header_image(true);
        $img_div_style = 'float: left;width: 100%;max-height:50px;padding: 5px;';
        $img_div_style .= "background: " . ((isset($header_colour_style_override) && $header_colour_style_override != '') ? $header_colour_style_override : "#fff") . ";";

        $headerimghtml .= '<div style="' . $img_div_style . '">';
        $headerimghtml .= '<div style="float: left;">';
        $headerimghtml .= '<div>';

        $headerimghtml .= '<img src="' . $img_url . '" style="max-height:50px;"  />';
        $headerimghtml .= '</div></div></div><br /><br />';
    }

    foreach ($userlanguages as $userlanguage => $notifications) {
        debug("Processing notifications for language: '" . $userlanguage . "'");
        // Save the current lang array
        $saved_lang = $lang;
        if ($userlanguage != "en") {
            if (substr($userlanguage, 2, 1) == '-' && substr($userlanguage, 0, 2) != 'en') {
                $langpath = __DIR__ . "/../languages/" . safe_file_name(substr($userlanguage, 0, 2)) . ".php";
                if (file_exists($langpath)) {
                    include $langpath;
                }
            }
            $langpath = __DIR__ . "/../languages/" . safe_file_name($userlanguage) . ".php";
            if (file_exists($langpath)) {
                include $langpath;
            }
        }

        # Register plugin languages in reverse order
        for ($n = count($plugins) - 1; $n >= 0; $n--) {
            if (!isset($plugins[$n])) {
                continue;
            }
            register_plugin_language($plugins[$n]);
        }

        // Load in the correct language strings
        lang_load_site_text($lang, "", $userlanguage);

        $subject = $notifymessage->get_subject();
        $messagetext = $notifymessage->get_text();
        if (count($notifications["message_users"]) > 0) {
            $activitytype = $notifymessage->eventdata["type"] ?? null;
            $relatedactivity = $notifymessage->eventdata["ref"] ?? null;
            foreach ($notifications["message_users"] as $notifyuser) {
                $results["messages"][] = ["user" => $notifyuser,"message" => $messagetext,"url" => $url];
            }
            message_add($notifications["message_users"], $messagetext, (string) $url, $userref, MESSAGE_ENUM_NOTIFICATION_TYPE_SCREEN, MESSAGE_DEFAULT_TTL_SECONDS, $activitytype, $relatedactivity);
        }
        if (count($notifications["emails"]) > 0) {
            if (!empty($url) && !is_null($url) && strpos($messagetext, $url) === false) {
                // Add the URL to the message if not already present
                $messagetext = $messagetext . "<br /><br /><a href='" . $url . "'>" . $url . "</a>";
            }

            foreach ($notifications["emails"] as $emailrecipient) {
                send_mail($emailrecipient, $subject, $headerimghtml . $messagetext, "", "", $notifymessage->template, $notifymessage->templatevars);
                $results["emails"][] = ["email" => $emailrecipient,"subject" => $subject,"body" => $headerimghtml . $messagetext];
            }

            foreach ($notifications["message_users"] as $notifyuser) {
                $results[$notifyuser] = ["type" => "messsage","body" => $messagetext];
            }
        }
        // Restore the saved $lang array
        $lang = $saved_lang;
    }
    return $results;
}

/**
 * Gets the user message for the given ref
 *
 * @param  int  $ref            Message ID
 * @param  bool $checkaccess    Check if user can see the given message?
 *
 * @return array|bool  Array with two elements: 'message' => message text,'url'=> message URL and 'owner' => message owner
 *                     False if user has no access or the requested message doesn't exist,
 */
function get_user_message(int $ref, bool $checkaccess = true)
{
    global $userref;
    if ($checkaccess) {
        $validmessages = ps_array("SELECT `message` value FROM user_message WHERE user = ?", ["i",$userref]);
        if (!in_array($ref, $validmessages)) {
            return false;
        }
    }
    $message = ps_query("SELECT message, url, owner FROM message WHERE ref = ?", ["i",$ref]);

    return $message ? ["message" => $message[0]["message"],"url" => $message[0]["url"],"owner" => $message[0]["owner"]] : false;
}

/**
 * Send notifications about file integrity failures
 *
 * @param array $failures   Array of resources that have failed integrity check
 *
 */
function send_integrity_failure_notices(array $failures): void
{
    $last_integrity_check_notify = get_sysvar('last_integrity_check_notify', '1970-01-01');
    if (time() - strtotime($last_integrity_check_notify) < 24 * 60 * 60) {
        if ('cli' == PHP_SAPI) {
            echo " - Skipping sending of integrity failure notifications - last sent: " . $last_integrity_check_notify . PHP_EOL;
        }
    } else {
        if ('cli' == PHP_SAPI) {
            echo " - Sending summary messages to administrators" . PHP_EOL;
        }

    # Send notification
        $message = new ResourceSpaceUserNotification();
        $message->set_subject("lang_file_integrity_summary");
        $message->set_text("lang_file_integrity_summary_failed");
        $message->append_text("<br><br>");
        if (count($failures) < 1000) {
            // Show links to the resources that have failed this time.
            // If too many have failed it will still include a link to the general search for all failed resources.
            $message->append_text("<table class='ListviewStyle'");
            $n = 1;
            foreach (array_chunk($failures, 200) as $arr_failed) {
                $message->append_text("<tr><td class='SingleLine'><a href='");
                $message->append_text($GLOBALS["baseurl"] . "/pages/search.php?search=!list" . implode(":", $arr_failed));
                $message->append_text("'>");
                $message->append_text("lang_file_integrity_fail_search");
                $message->append_text(" ({$n})");
                $message->append_text("</a></td></tr>");
                $n++;
            }
            $message->append_text("</table>");
        }

        $message->url = $GLOBALS["baseurl"] . "/pages/search.php?search=!integrityfail";

        $notify_users = get_notification_users("SYSTEM_ADMIN");
        send_user_notification($notify_users, $message);
        set_sysvar("last_integrity_check_notify", date("Y-m-d H:i:s"));
    }
}

/**
 * Limit the length of !list special search url by adding a maximum of 650 characters of resource references per link including separators.
 * Mail servers may break very long text strings into multiple lines and this will cause the special search to fail.
 * Loading URLs of great length may also cause a Request-URI Too Long error in the browser.
 * Multiple urls will be returned, formatted to include in action dates notifications.
 *
 * @param  array   $resource_refs   Array containing resource references to include in url.
 *
 * @return array   Array containing 'single' value of url (650 characters of resources or less) and 'multiple' value of url (more than 650 characters of resources).
 */
function build_specialsearch_list_urls(array $resource_refs)
{
    global $baseurl, $lang;

    $return_urls['single'] = ''; // Two values returned to determine where the url is placed in message_add() - multiple urls must be passed in message, not url parameter.
    $return_urls['multiple'] = '';

    if (count($resource_refs) === 0) {
        return $return_urls;
    }

    $total_string_length = 0;
    $link = 1;
    $resource_links = array();
    foreach ($resource_refs as $cur_ref) {
        $cur_ref_length = strlen($cur_ref) + 1; // +1 represents separator ':'
        $total_string_length = $total_string_length + $cur_ref_length;
        if ($total_string_length > 650) {
            $total_string_length = $cur_ref_length;
            $link = ++$link;
        }
        $resource_links[$link][] = $cur_ref;
    }

    if (count($resource_links) === 1) {
        $return_urls['single'] = "$baseurl/pages/search.php?search=!list" . implode(":", $resource_refs);
    } else {
        $urls = array('<br /><div><ul>');

        foreach ($resource_links as $link_no => $refs_chunk) {
            $url = $baseurl . "/pages/search.php?search=!list";
            $url .= implode(":", $refs_chunk);
            $url = '<li><a href="' . $url . '">' . escape($lang["show_affected_resources"]) . ' [' . escape($lang["group_no"]) . ' ' . $link_no . ']</a></li>';
            $urls[] = $url;
        }

        $urls[] = '</ul></div>';
        $return_urls['multiple'] = implode("", $urls);
    }

    return $return_urls;
}