Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle 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 General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Extends the IMS Tool provider library data connector for moodle.

 *

 * @package    enrol_lti

 * @copyright  2016 John Okely <john@moodle.com>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace enrol_lti;

defined('MOODLE_INTERNAL') || die;

use IMSGlobal\LTI\ToolProvider;

use IMSGlobal\LTI\ToolProvider\ConsumerNonce;

use IMSGlobal\LTI\ToolProvider\Context;

use IMSGlobal\LTI\ToolProvider\DataConnector\DataConnector;

use IMSGlobal\LTI\ToolProvider\ResourceLink;

use IMSGlobal\LTI\ToolProvider\ResourceLinkShare;

use IMSGlobal\LTI\ToolProvider\ResourceLinkShareKey;

use IMSGlobal\LTI\ToolProvider\ToolConsumer;

use IMSGlobal\LTI\ToolProvider\ToolProxy;

use IMSGlobal\LTI\ToolProvider\User;

use stdClass;

/**

 * Extends the IMS Tool provider library data connector for moodle.

 *

 * @package    enrol_lti

 * @copyright  2016 John Okely <john@moodle.com>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class data_connector extends DataConnector {

    /** @var string Tool consumer table name. */

    protected $consumertable;

    /** @var string Context table name. */

    protected $contexttable;

    /** @var string Consumer nonce table name. */

    protected $noncetable;

    /** @var string Resource link table name. */

    protected $resourcelinktable;

    /** @var string Resource link share key table name. */

    protected $sharekeytable;

    /** @var string Tool proxy table name. */

    protected $toolproxytable;

    /** @var string User result table name. */

    protected $userresulttable;

    /**

     * data_connector constructor.

     */

    public function __construct() {

        parent::__construct(null, 'enrol_lti_');

        // Set up table names.

        $this->consumertable = $this->dbTableNamePrefix . DataConnector::CONSUMER_TABLE_NAME;

        $this->contexttable = $this->dbTableNamePrefix . DataConnector::CONTEXT_TABLE_NAME;

        $this->noncetable = $this->dbTableNamePrefix . DataConnector::NONCE_TABLE_NAME;

        $this->resourcelinktable = $this->dbTableNamePrefix . DataConnector::RESOURCE_LINK_TABLE_NAME;

        $this->sharekeytable = $this->dbTableNamePrefix . DataConnector::RESOURCE_LINK_SHARE_KEY_TABLE_NAME;

        $this->toolproxytable = $this->dbTableNamePrefix . DataConnector::TOOL_PROXY_TABLE_NAME;

        $this->userresulttable = $this->dbTableNamePrefix . DataConnector::USER_RESULT_TABLE_NAME;

    }

    /**

     * Load tool consumer object.

     *

     * @param ToolConsumer $consumer ToolConsumer object

     * @return boolean True if the tool consumer object was successfully loaded

     */

    public function loadToolConsumer($consumer) {

        global $DB;

        $id = $consumer->getRecordId();

        $key = $consumer->getKey();

        $result = false;

        if (!empty($id)) {

            $result = $DB->get_record($this->consumertable, ['id' => $id]);

        } else if (!empty($key)) {

            $key256 = DataConnector::getConsumerKey($key);

            $result = $DB->get_record($this->consumertable, ['consumerkey256' => $key256]);

        }

        if ($result) {

            if (empty($key256) || empty($result->consumerkey) || ($key === $result->consumerkey)) {

                $this->build_tool_consumer_object($result, $consumer);

                return true;

            }

        }

        return false;

    }

    /**

     * Save tool consumer object.

     *

     * @param ToolConsumer $consumer Consumer object

     * @return boolean True if the tool consumer object was successfully saved

     */

    public function saveToolConsumer($consumer) {

        global $DB;

        $key = $consumer->getKey();

        $key256 = DataConnector::getConsumerKey($key);

        if ($key === $key256) {

            $key = null;

        }

        $protected = ($consumer->protected) ? 1 : 0;

        $enabled = ($consumer->enabled) ? 1 : 0;

        $profile = (!empty($consumer->profile)) ? json_encode($consumer->profile) : null;

        $settingsvalue = serialize($consumer->getSettings());

        $now = time();

        $consumer->updated = $now;

        $data = [

            'consumerkey256' => $key256,

            'consumerkey' => $key,

            'name' => $consumer->name,

            'secret' => $consumer->secret,

            'ltiversion' => $consumer->ltiVersion,

            'consumername' => $consumer->consumerName,

            'consumerversion' => $consumer->consumerVersion,

            'consumerguid' => $consumer->consumerGuid,

            'profile' => $profile,

            'toolproxy' => $consumer->toolProxy,

            'settings' => $settingsvalue,

            'protected' => $protected,

            'enabled' => $enabled,

            'enablefrom' => $consumer->enableFrom,

            'enableuntil' => $consumer->enableUntil,

            'lastaccess' => $consumer->lastAccess,

            'updated' => $consumer->updated,

        ];

        $id = $consumer->getRecordId();

        if (empty($id)) {

            $consumer->created = $now;

            $data['created'] = $consumer->created;

            $id = $DB->insert_record($this->consumertable, (object) $data);

            if ($id) {

                $consumer->setRecordId($id);

                return true;

            }

        } else {

            $data['id'] = $id;

            return $DB->update_record($this->consumertable, (object) $data);

        }

        return false;

    }

    /**

     * Delete tool consumer object and related records.

     *

     * @param ToolConsumer $consumer Consumer object

     * @return boolean True if the tool consumer object was successfully deleted

     */

    public function deleteToolConsumer($consumer) {

        global $DB;

        $consumerpk = $consumer->getRecordId();

        $deletecondition = ['consumerid' => $consumerpk];

        // Delete any nonce values for this consumer.

        $DB->delete_records($this->noncetable, $deletecondition);

        // Delete any outstanding share keys for resource links for this consumer.

        $where = "resourcelinkid IN (

                      SELECT rl.id

                        FROM {{$this->resourcelinktable}} rl

                       WHERE rl.consumerid = :consumerid

                  )";

        $DB->delete_records_select($this->sharekeytable, $where, $deletecondition);

        // Delete any outstanding share keys for resource links for contexts in this consumer.

        $where = "resourcelinkid IN (

                      SELECT rl.id

                        FROM {{$this->resourcelinktable}} rl

                  INNER JOIN {{$this->contexttable}} c

                          ON rl.contextid = c.id

                       WHERE c.consumerid = :consumerid

                )";

        $DB->delete_records_select($this->sharekeytable, $where, $deletecondition);

        // Delete any users in resource links for this consumer.

        $where = "resourcelinkid IN (

                    SELECT rl.id

                      FROM {{$this->resourcelinktable}} rl

                     WHERE rl.consumerid = :consumerid

                )";

        $DB->delete_records_select($this->userresulttable, $where, $deletecondition);

        // Delete any users in resource links for contexts in this consumer.

        $where = "resourcelinkid IN (

                         SELECT rl.id

                           FROM {{$this->resourcelinktable}} rl

                     INNER JOIN {{$this->contexttable}} c

                             ON rl.contextid = c.id

                          WHERE c.consumerid = :consumerid

                )";

        $DB->delete_records_select($this->userresulttable, $where, $deletecondition);

        // Update any resource links for which this consumer is acting as a primary resource link.

        $where = "primaryresourcelinkid IN (

                    SELECT rl.id

                      FROM {{$this->resourcelinktable}} rl

                     WHERE rl.consumerid = :consumerid

                )";

        $updaterecords = $DB->get_records_select($this->resourcelinktable, $where, $deletecondition);

        foreach ($updaterecords as $record) {

            $record->primaryresourcelinkid = null;

            $record->shareapproved = null;

            $DB->update_record($this->resourcelinktable, $record);

        }

        // Update any resource links for contexts in which this consumer is acting as a primary resource link.

        $where = "primaryresourcelinkid IN (

                        SELECT rl.id

                          FROM {{$this->resourcelinktable}} rl

                    INNER JOIN {{$this->contexttable}} c

                            ON rl.contextid = c.id

                         WHERE c.consumerid = :consumerid

                )";

        $updaterecords = $DB->get_records_select($this->resourcelinktable, $where, $deletecondition);

        foreach ($updaterecords as $record) {

            $record->primaryresourcelinkid = null;

            $record->shareapproved = null;

            $DB->update_record($this->resourcelinktable, $record);

        }

        // Delete any resource links for contexts in this consumer.

        $where = "contextid IN (

                      SELECT c.id

                        FROM {{$this->contexttable}} c

                       WHERE c.consumerid = :consumerid

                )";

        $DB->delete_records_select($this->resourcelinktable, $where, $deletecondition);

        // Delete any resource links for this consumer.

        $DB->delete_records($this->resourcelinktable, $deletecondition);

        // Delete any contexts for this consumer.

        $DB->delete_records($this->contexttable, $deletecondition);

        // Delete consumer.

        $DB->delete_records($this->consumertable, ['id' => $consumerpk]);

        $consumer->initialize();

        return true;

    }

    /**

     * Load all tool consumers from the database.

     * @return array

     */

    public function getToolConsumers() {

        global $DB;

        $consumers = [];

        $rsconsumers = $DB->get_recordset($this->consumertable, null, 'name');

        foreach ($rsconsumers as $row) {

            $consumer = new ToolProvider\ToolConsumer($row->consumerkey, $this);

            $this->build_tool_consumer_object($row, $consumer);

            $consumers[] = $consumer;

        }

        $rsconsumers->close();

        return $consumers;

    }

    /*

     * ToolProxy methods.

     */

    /**

     * Load the tool proxy from the database.

     *

     * @param ToolProxy $toolproxy

     * @return bool

     */

    public function loadToolProxy($toolproxy) {

        return false;

    }

    /**

     * Save the tool proxy to the database.

     *

     * @param ToolProxy $toolproxy

     * @return bool

     */

    public function saveToolProxy($toolproxy) {

        return false;

    }

    /**

     * Delete the tool proxy from the database.

     *

     * @param ToolProxy $toolproxy

     * @return bool

     */

    public function deleteToolProxy($toolproxy) {

        return false;

    }

    /*

     * Context methods.

     */

    /**

     * Load context object.

     *

     * @param Context $context Context object

     * @return boolean True if the context object was successfully loaded

     */

    public function loadContext($context) {

        global $DB;

        if (!empty($context->getRecordId())) {

            $params = ['id' => $context->getRecordId()];

        } else {

            $params = [

                'consumerid' => $context->getConsumer()->getRecordId(),

                'lticontextkey' => $context->ltiContextId

            ];

        }

        if ($row = $DB->get_record($this->contexttable, $params)) {

            $context->setRecordId($row->id);

            $context->setConsumerId($row->consumerid);

            $context->ltiContextId = $row->lticontextkey;

            $context->type = $row->type;

            $settings = unserialize($row->settings);

            if (!is_array($settings)) {

                $settings = array();

            }

            $context->setSettings($settings);

            $context->created = $row->created;

            $context->updated = $row->updated;

            return true;

        }

        return false;

    }

    /**

     * Save context object.

     *

     * @param Context $context Context object

     * @return boolean True if the context object was successfully saved

     */

    public function saveContext($context) {

        global $DB;

        $now = time();

        $context->updated = $now;

        $settingsvalue = serialize($context->getSettings());

        $id = $context->getRecordId();

        $consumerpk = $context->getConsumer()->getRecordId();

        $isinsert = empty($id);

        if ($isinsert) {

            $context->created = $now;

            $params = [

                'consumerid' => $consumerpk,

                'lticontextkey' => $context->ltiContextId,

                'type' => $context->type,

                'settings' => $settingsvalue,

                'created' => $context->created,

                'updated' => $context->updated,

            ];

            $id = $DB->insert_record($this->contexttable, (object) $params);

            if ($id) {

                $context->setRecordId($id);

                return true;

            }

        } else {

            $data = (object) [

                'id' => $id,

                'contextid' => $consumerpk,

                'lticontextkey' => $context->ltiContextId,

                'type' => $context->type,

                'settings' => $settingsvalue,

                'updated' => $context->updated,

            ];

            return $DB->update_record($this->contexttable, $data);

        }

        return false;

    }

    /**

     * Delete context object.

     *

     * @param Context $context Context object

     * @return boolean True if the Context object was successfully deleted

     */

    public function deleteContext($context) {

        global $DB;

        $contextid = $context->getRecordId();

        $params = ['id' => $contextid];

        // Delete any outstanding share keys for resource links for this context.

        $where = "resourcelinkid IN (

                    SELECT rl.id

                      FROM {{$this->resourcelinktable}} rl

                     WHERE rl.contextid = :id

               )";

        $DB->delete_records_select($this->sharekeytable, $where, $params);

        // Delete any users in resource links for this context.

        $DB->delete_records_select($this->userresulttable, $where, $params);

        // Update any resource links for which this consumer is acting as a primary resource link.

        $where = "primaryresourcelinkid IN (

                    SELECT rl.id

                      FROM {{$this->resourcelinktable}} rl

                     WHERE rl.contextid = :id

               )";

        $updaterecords = $DB->get_records_select($this->resourcelinktable, $where, $params);

        foreach ($updaterecords as $record) {

            $record->primaryresourcelinkid = null;

            $record->shareapproved = null;

            $DB->update_record($this->resourcelinktable, $record);

        }

        // Delete any resource links for this context.

        $DB->delete_records($this->resourcelinktable, ['contextid' => $contextid]);

        // Delete context.

        $DB->delete_records($this->contexttable, $params);

        $context->initialize();

        return true;

    }

    /*

     * ResourceLink methods

     */

    /**

     * Load resource link object.

     *

     * @param ResourceLink $resourcelink ResourceLink object

     * @return boolean True if the resource link object was successfully loaded

     */

    public function loadResourceLink($resourcelink) {

        global $DB;

        $resourceid = $resourcelink->getRecordId();

        if (!empty($resourceid)) {

            $params = ['id' => $resourceid];

            $row = $DB->get_record($this->resourcelinktable, $params);

        } else if (!empty($resourcelink->getContext())) {

            $params = [

                'contextid' => $resourcelink->getContext()->getRecordId(),

                'ltiresourcelinkkey' => $resourcelink->getId()

            ];

            $row = $DB->get_record($this->resourcelinktable, $params);

        } else {

            $sql = "SELECT r.*

                      FROM {{$this->resourcelinktable}} r

           LEFT OUTER JOIN {{$this->contexttable}} c

                        ON r.contextid = c.id

                     WHERE (r.consumerid = ? OR c.consumerid = ?)

                           AND ltiresourcelinkkey = ?";

            $params = [

                $resourcelink->getConsumer()->getRecordId(),

                $resourcelink->getConsumer()->getRecordId(),

                $resourcelink->getId()

            ];

            $row = $DB->get_record_sql($sql, $params);

        }

        if ($row) {

            $resourcelink->setRecordId($row->id);

            if (!is_null($row->contextid)) {

                $resourcelink->setContextId($row->contextid);

            } else {

                $resourcelink->setContextId(null);

            }

            if (!is_null($row->consumerid)) {

                $resourcelink->setConsumerId($row->consumerid);

            } else {

                $resourcelink->setConsumerId(null);

            }

            $resourcelink->ltiResourceLinkId = $row->ltiresourcelinkkey;

            $settings = unserialize($row->settings);

            if (!is_array($settings)) {

                $settings = array();

            }

            $resourcelink->setSettings($settings);

            if (!is_null($row->primaryresourcelinkid)) {

                $resourcelink->primaryResourceLinkId = $row->primaryresourcelinkid;

            } else {

                $resourcelink->primaryResourceLinkId = null;

            }

            $resourcelink->shareApproved = (is_null($row->shareapproved)) ? null : ($row->shareapproved == 1);

            $resourcelink->created = $row->created;

            $resourcelink->updated = $row->updated;

            return true;

        }

        return false;

    }

    /**

     * Save resource link object.

     *

     * @param ResourceLink $resourcelink Resource_Link object

     * @return boolean True if the resource link object was successfully saved

     */

    public function saveResourceLink($resourcelink) {

        global $DB;

        if (is_null($resourcelink->shareApproved)) {

            $approved = null;

        } else if ($resourcelink->shareApproved) {

            $approved = 1;

        } else {

            $approved = 0;

        }

        if (empty($resourcelink->primaryResourceLinkId)) {

            $primaryresourcelinkid = null;

        } else {

            $primaryresourcelinkid = $resourcelink->primaryResourceLinkId;

        }

        $now = time();

        $resourcelink->updated = $now;

        $settingsvalue = serialize($resourcelink->getSettings());

        if (!empty($resourcelink->getContext())) {

            $consumerid = null;

            $contextid = $resourcelink->getContext()->getRecordId();

        } else if (!empty($resourcelink->getContextId())) {

            $consumerid = null;

            $contextid = $resourcelink->getContextId();

        } else {

            $consumerid = $resourcelink->getConsumer()->getRecordId();

            $contextid = null;

        }

        $id = $resourcelink->getRecordId();

        $data = [

            'consumerid' => $consumerid,

            'contextid' => $contextid,

            'ltiresourcelinkkey' => $resourcelink->getId(),

            'settings' => $settingsvalue,

            'primaryresourcelinkid' => $primaryresourcelinkid,

            'shareapproved' => $approved,

            'updated' => $resourcelink->updated,

        ];

        $returnid = null;

        if (empty($id)) {

            $resourcelink->created = $now;

            $data['created'] = $resourcelink->created;

            $id = $DB->insert_record($this->resourcelinktable, (object) $data);

            if ($id) {

                $resourcelink->setRecordId($id);

                return true;

            }

        } else {

            $data['id'] = $id;

            return $DB->update_record($this->resourcelinktable, (object) $data);

        }

        return false;

    }

    /**

     * Delete resource link object.

     *

     * @param ResourceLink $resourcelink ResourceLink object

     * @return boolean True if the resource link object and its related records were successfully deleted.

     *                 Otherwise, a DML exception is thrown.

     */

    public function deleteResourceLink($resourcelink) {

        global $DB;

        $resourcelinkid = $resourcelink->getRecordId();

        // Delete any outstanding share keys for resource links for this consumer.

        $DB->delete_records($this->sharekeytable, ['resourcelinkid' => $resourcelinkid]);

        // Delete users.

        $DB->delete_records($this->userresulttable, ['resourcelinkid' => $resourcelinkid]);

        // Update any resource links for which this is the primary resource link.

        $records = $DB->get_records($this->resourcelinktable, ['primaryresourcelinkid' => $resourcelinkid]);

        foreach ($records as $record) {

            $record->primaryresourcelinkid = null;

            $DB->update_record($this->resourcelinktable, $record);

        }

        // Delete resource link.

        $DB->delete_records($this->resourcelinktable, ['id' => $resourcelinkid]);

        $resourcelink->initialize();

        return true;

    }

    /**

     * Get array of user objects.

     *

     * Obtain an array of User objects for users with a result sourcedId.  The array may include users from other

     * resource links which are sharing this resource link.  It may also be optionally indexed by the user ID of a specified scope.

     *

     * @param ResourceLink $resourcelink Resource link object

     * @param boolean $localonly True if only users within the resource link are to be returned

     *                           (excluding users sharing this resource link)

     * @param int $idscope Scope value to use for user IDs

     * @return array Array of User objects

     */

    public function getUserResultSourcedIDsResourceLink($resourcelink, $localonly, $idscope) {

        global $DB;

        $users = [];

        $params = ['resourcelinkid' => $resourcelink->getRecordId()];

        // Where clause for the subquery.

        $subwhere = "(id = :resourcelinkid AND primaryresourcelinkid IS NULL)";

        if (!$localonly) {

            $subwhere .= " OR (primaryresourcelinkid = :resourcelinkid2 AND shareapproved = 1)";

            $params['resourcelinkid2'] = $resourcelink->getRecordId();

        }

        // The subquery.

        $subsql = "SELECT id

                     FROM {{$this->resourcelinktable}}

                    WHERE {$subwhere}";

        // Our main where clause.

        $where = "resourcelinkid IN ($subsql)";

        // Fields to be queried.

        $fields = 'id, ltiresultsourcedid, ltiuserkey, created, updated';

        // Fetch records.

        $rs = $DB->get_recordset_select($this->userresulttable, $where, $params, '', $fields);

        foreach ($rs as $row) {

            $user = User::fromResourceLink($resourcelink, $row->ltiuserkey);

            $user->setRecordId($row->id);

            $user->ltiResultSourcedId = $row->ltiresultsourcedid;

            $user->created = $row->created;

            $user->updated = $row->updated;

            if (is_null($idscope)) {

                $users[] = $user;

            } else {

                $users[$user->getId($idscope)] = $user;

            }

        }

        $rs->close();

        return $users;

    }

    /**

     * Get array of shares defined for this resource link.

     *

     * @param ResourceLink $resourcelink ResourceLink object

     * @return array Array of ResourceLinkShare objects

     */

    public function getSharesResourceLink($resourcelink) {

        global $DB;

        $shares = [];

        $params = ['primaryresourcelinkid' => $resourcelink->getRecordId()];

        $fields = 'id, shareapproved, consumerid';

        $records = $DB->get_records($this->resourcelinktable, $params, 'consumerid', $fields);

        foreach ($records as $record) {

            $share = new ResourceLinkShare();

            $share->resourceLinkId = $record->id;

            $share->approved = $record->shareapproved == 1;

            $shares[] = $share;

        }

        return $shares;

    }

    /*

     * ConsumerNonce methods

     */

    /**

     * Load nonce object.

     *

     * @param ConsumerNonce $nonce Nonce object

     * @return boolean True if the nonce object was successfully loaded

     */

    public function loadConsumerNonce($nonce) {

        global $DB;

        // Delete any expired nonce values.

        $now = time();

        $DB->delete_records_select($this->noncetable, "expires <= ?", [$now]);

        // Load the nonce.

        $params = [

            'consumerid' => $nonce->getConsumer()->getRecordId(),

            'value' => $nonce->getValue()

        ];

        $result = $DB->get_field($this->noncetable, 'value', $params);

        return !empty($result);

    }

    /**

     * Save nonce object.

     *

     * @param ConsumerNonce $nonce Nonce object

     * @return boolean True if the nonce object was successfully saved

     */

    public function saveConsumerNonce($nonce) {

        global $DB;

        $data = [

            'consumerid' => $nonce->getConsumer()->getRecordId(),

            'value' => $nonce->getValue(),

            'expires' => $nonce->expires

        ];

        return $DB->insert_record($this->noncetable, (object) $data, false);

    }

    /*

     * ResourceLinkShareKey methods.

     */

    /**

     * Load resource link share key object.

     *

     * @param ResourceLinkShareKey $sharekey ResourceLink share key object

     * @return boolean True if the resource link share key object was successfully loaded

     */

    public function loadResourceLinkShareKey($sharekey) {

        global $DB;

        // Clear expired share keys.

        $now = time();

        $where = "expires <= :expires";

        $DB->delete_records_select($this->sharekeytable, $where, ['expires' => $now]);

        // Load share key.

        $fields = 'resourcelinkid, autoapprove, expires';

        if ($sharekeyrecord = $DB->get_record($this->sharekeytable, ['sharekey' => $sharekey->getId()], $fields)) {

            if ($sharekeyrecord->resourcelinkid == $sharekey->resourceLinkId) {

                $sharekey->autoApprove = $sharekeyrecord->autoapprove == 1;

                $sharekey->expires = $sharekeyrecord->expires;

                return true;

            }

        }

        return false;

    }

    /**

     * Save resource link share key object.

     *

     * @param ResourceLinkShareKey $sharekey Resource link share key object

     * @return boolean True if the resource link share key object was successfully saved

     */

    public function saveResourceLinkShareKey($sharekey) {

        global $DB;

        if ($sharekey->autoApprove) {

            $approve = 1;

        } else {

            $approve = 0;

        }

        $expires = $sharekey->expires;

        $params = [

            'sharekey' => $sharekey->getId(),

            'resourcelinkid' => $sharekey->resourceLinkId,

            'autoapprove' => $approve,

            'expires' => $expires

        ];

        return $DB->insert_record($this->sharekeytable, (object) $params, false);

    }

    /**

     * Delete resource link share key object.

     *

     * @param ResourceLinkShareKey $sharekey Resource link share key object

     * @return boolean True if the resource link share key object was successfully deleted

     */

    public function deleteResourceLinkShareKey($sharekey) {

        global $DB;

        $DB->delete_records($this->sharekeytable, ['sharekey' => $sharekey->getId()]);

        $sharekey->initialize();

        return true;

    }

    /*

     * User methods

     */

    /**

     * Load user object.

     *

     * @param User $user User object

     * @return boolean True if the user object was successfully loaded

     */

    public function loadUser($user) {

        global $DB;

        $userid = $user->getRecordId();

        $fields = 'id, resourcelinkid, ltiuserkey, ltiresultsourcedid, created, updated';

        if (!empty($userid)) {

            $row = $DB->get_record($this->userresulttable, ['id' => $userid], $fields);

        } else {

            $resourcelinkid = $user->getResourceLink()->getRecordId();

            $userid = $user->getId(ToolProvider\ToolProvider::ID_SCOPE_ID_ONLY);

            $row = $DB->get_record_select(

                $this->userresulttable,

                "resourcelinkid = ? AND ltiuserkey = ?",

                [$resourcelinkid, $userid],

                $fields

            );

        }

        if ($row) {

            $user->setRecordId($row->id);

            $user->setResourceLinkId($row->resourcelinkid);

            $user->ltiUserId = $row->ltiuserkey;

            $user->ltiResultSourcedId = $row->ltiresultsourcedid;

            $user->created = $row->created;

            $user->updated = $row->updated;

            return true;

        }

        return false;

    }

    /**

     * Save user object.

     *

     * @param User $user User object

     * @return boolean True if the user object was successfully saved

     */

    public function saveUser($user) {

        global $DB;

        $now = time();

        $isinsert = is_null($user->created);

        $user->updated = $now;

        $params = [

            'ltiresultsourcedid' => $user->ltiResultSourcedId,

            'updated' => $user->updated

        ];

        if ($isinsert) {

            $params['resourcelinkid'] = $user->getResourceLink()->getRecordId();

            $params['ltiuserkey'] = $user->getId(ToolProvider\ToolProvider::ID_SCOPE_ID_ONLY);

            $user->created = $now;

            $params['created'] = $user->created;

            $id = $DB->insert_record($this->userresulttable, (object) $params);

            if ($id) {

                $user->setRecordId($id);

                return true;

            }

        } else {

            $params['id'] = $user->getRecordId();

            return $DB->update_record($this->userresulttable, (object) $params);

        }

        return false;

    }

    /**

     * Delete user object.

     *

     * @param User $user User object

     * @return boolean True if the user object was successfully deleted

     */

    public function deleteUser($user) {

        global $DB;

        $DB->delete_records($this->userresulttable, ['id' => $user->getRecordId()]);

        $user->initialize();

        return true;

    }

    /**

     * Fetches the list of Context objects that are linked to a ToolConsumer.

     *

     * @param ToolConsumer $consumer

     * @return Context[]

     */

    public function get_contexts_from_consumer(ToolConsumer $consumer) {

        global $DB;

        $contexts = [];

        $contextrecords = $DB->get_records($this->contexttable, ['consumerid' => $consumer->getRecordId()], '', 'lticontextkey');

        foreach ($contextrecords as $record) {

            $context = Context::fromConsumer($consumer, $record->lticontextkey);

            $contexts[] = $context;

        }

        return $contexts;

    }

    /**

     * Fetches a resource link record that is associated with a ToolConsumer.

     *

     * @param ToolConsumer $consumer

     * @return ResourceLink

     */

    public function get_resourcelink_from_consumer(ToolConsumer $consumer) {

        global $DB;

        $resourcelink = null;

        if ($resourcelinkrecord = $DB->get_record($this->resourcelinktable, ['consumerid' => $consumer->getRecordId()],

            'ltiresourcelinkkey')) {

            $resourcelink = ResourceLink::fromConsumer($consumer, $resourcelinkrecord->ltiresourcelinkkey);

        }

        return $resourcelink;

    }

    /**

     * Fetches a resource link record that is associated with a Context object.

     *

     * @param Context $context

     * @return ResourceLink

     */

    public function get_resourcelink_from_context(Context $context) {

        global $DB;

        $resourcelink = null;

        if ($resourcelinkrecord = $DB->get_record($this->resourcelinktable, ['contextid' => $context->getRecordId()],

            'ltiresourcelinkkey')) {

            $resourcelink = ResourceLink::fromContext($context, $resourcelinkrecord->ltiresourcelinkkey);

        }

        return $resourcelink;

    }

    /**

     * Fetches the list of ToolConsumer objects that are linked to a tool.

     *

     * @param int $toolid

     * @return ToolConsumer[]

     */

    public function get_consumers_mapped_to_tool($toolid) {

        global $DB;

        $consumers = [];

        $consumerrecords = $DB->get_records('enrol_lti_tool_consumer_map', ['toolid' => $toolid], '', 'consumerid');

        foreach ($consumerrecords as $record) {

            $consumers[] = ToolConsumer::fromRecordId($record->consumerid, $this);

        }

        return $consumers;

    }

    /**

     * Builds a ToolConsumer object from a record object from the DB.

     *

     * @param stdClass $record The DB record object.

     * @param ToolConsumer $consumer

     */

    protected function build_tool_consumer_object($record, ToolConsumer $consumer) {

        $consumer->setRecordId($record->id);

        $consumer->name = $record->name;

        $key = empty($record->consumerkey) ? $record->consumerkey256 : $record->consumerkey;

        $consumer->setKey($key);

        $consumer->secret = $record->secret;

        $consumer->ltiVersion = $record->ltiversion;

        $consumer->consumerName = $record->consumername;

        $consumer->consumerVersion = $record->consumerversion;

        $consumer->consumerGuid = $record->consumerguid;

        $consumer->profile = json_decode($record->profile ?? '');

        $consumer->toolProxy = $record->toolproxy;

        $settings = unserialize($record->settings);