lib.php

<?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/>.

/**
 * This file contains the relationship API functions used to interact with the data
 * and other Moodle hooks
 *
 * @package local_relationship
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

defined('MOODLE_INTERNAL') || die();

function local_relationship_extend_settings_navigation(navigation_node $navigation) {
    global $PAGE;

    if (is_a($PAGE->context, 'context_coursecat') && has_capability('local/relationship:manage', $PAGE->context)) {
        $category_node = $navigation->get('categorysettings');
        if ($category_node) {
            $category_node->add(
                    get_string('pluginname', 'local_relationship'),
                    new moodle_url('/local/relationship/index.php', array('contextid' => $PAGE->context->id)),
                    navigation_node::TYPE_SETTING,
                    null,
                    null,
                    new pix_icon('relationship', '', 'local_relationship')
            );
        }
    }
}

function local_relationship_cron() {
    relationship_uniformly_distribute_members();

    return true;
}


//
// TODO: Refactory to "relationship class"
//

function relationship_uniformly_distribute_members($relationshipid = null) {
    global $DB;

    $params = array();
    $cond = '';
    if (!empty($relationshipid)) {
        $params['id'] = $relationshipid;
        $cond = 'WHERE rl.id = :id';
    }

    $sql = "SELECT DISTINCT rc.*
              FROM {relationship} rl
              JOIN {relationship_cohorts} rc
                ON (rc.relationshipid = rl.id AND rc.uniformdistribution = 1)
              JOIN {relationship_groups} rg
                ON (rg.relationshipid = rl.id AND rc.uniformdistribution = 1)
              {$cond}";
    $rcs = $DB->get_records_sql($sql, $params);
    foreach ($rcs AS $rc) {
        $params = array('relationshipid' => $rc->relationshipid, 'relationshipcohortid' => $rc->id);
        $sql = " SELECT cm.userid
                   FROM {relationship_cohorts} rc
                   JOIN {cohort} ch
                     ON (ch.id = rc.cohortid)
                   JOIN {cohort_members} cm
                     ON (cm.cohortid = ch.id)
              LEFT JOIN {relationship_members} rm
                     ON (rm.relationshipcohortid = rc.id AND rm.userid = cm.userid)
                  WHERE rc.id = :relationshipcohortid
                    AND ISNULL(rm.userid)";
        $users = $DB->get_records_sql($sql, $params);

        relationship_uniformly_distribute_users($rc, array_keys($users));
    }
}

function relationship_uniformly_distribute_users($relationshipcohort, $userids) {
    global $DB;

    if (empty($userids)) {
        return;
    }
    $sql = "SELECT rg.id, rg.userlimit, count(DISTINCT rm.userid) as count
              FROM {relationship_cohorts} rc
              JOIN {relationship_groups} rg
                ON (rg.relationshipid = rc.relationshipid AND rg.uniformdistribution = 1)
         LEFT JOIN {relationship_members} rm
                ON (rm.relationshipgroupid = rg.id AND rm.relationshipcohortid = rc.id)
             WHERE rc.id = :relationshipcohortid
          GROUP BY rg.id";
    $groups = $DB->get_records_sql($sql, array('relationshipcohortid' => $relationshipcohort->id));
    if (!empty($groups)) {
        foreach ($userids AS $userid) {
            $min = 99999999;
            $gmin = 0;
            foreach ($groups AS $grpid => $grp) {
                if ($grp->count < $min && ($grp->userlimit == 0 || $grp->count < $grp->userlimit)) {
                    $min = $grp->count;
                    $gmin = $grpid;
                }
            }
            if ($gmin == 0) {
                break; // there is no group to add member
            } else {
                relationship_add_member($gmin, $relationshipcohort->id, $userid);
                $groups[$gmin]->count++;
            }
        }
    }
}

/**
 * Add relationship member
 *
 * @param $relationshipgroupid
 * @param $relationshipcohortid
 * @param $userid
 * @return int|bool relationship_members id of added member or false if any error occours
 * @throws coding_exception
 */
function relationship_add_member($relationshipgroupid, $relationshipcohortid, $userid) {
    global $DB;

    $params = array('relationshipgroupid' => $relationshipgroupid, 'userid' => $userid, 'relationshipcohortid' => $relationshipcohortid);
    if ($DB->record_exists('relationship_members', $params)) {
        // No duplicates!
        return false;
    }

    $relationshipgroup = $DB->get_record('relationship_groups', array('id' => $relationshipgroupid), '*', MUST_EXIST);
    $relationshipcohort = $DB->get_record('relationship_cohorts', array('id' => $relationshipcohortid), '*', MUST_EXIST);
    $relationship = $DB->get_record('relationship', array('id' => $relationshipgroup->relationshipid), '*', MUST_EXIST);

    $record = new stdClass();
    $record->relationshipgroupid = $relationshipgroupid;
    $record->relationshipcohortid = $relationshipcohortid;
    $record->userid = $userid;
    $record->timeadded = time();

    $result = $DB->insert_record('relationship_members', $record);

    if ($result) {
        $record->id = $result;

        $event = \local_relationship\event\relationshipgroup_member_added::create(array(
                'context' => context::instance_by_id($relationship->contextid),
                'objectid' => $relationshipgroupid,
                'relateduserid' => $userid,
                'other' => $relationshipcohort->roleid,
        ));
        $event->add_record_snapshot('relationship_groups', $relationshipgroup);
        $event->add_record_snapshot('relationship', $relationship);
        $event->trigger();

        return $record->id;
    }

    return false;
}

/**
 * Remove member from a relationship
 *
 * @param int $relationshipgroupid
 * @param int $relationshipcohortid
 * @param int $userid
 * @return bool
 * @throws coding_exception
 */
function relationship_remove_member($relationshipgroupid, $relationshipcohortid, $userid) {
    global $DB;

    $params = array('relationshipgroupid' => $relationshipgroupid, 'userid' => $userid, 'relationshipcohortid' => $relationshipcohortid);
    $result = $DB->delete_records('relationship_members', $params);

    if ($result) {
        $relationshipgroup = $DB->get_record('relationship_groups', array('id' => $relationshipgroupid), '*', MUST_EXIST);
        $relationshipcohort = $DB->get_record('relationship_cohorts', array('id' => $relationshipcohortid), '*', MUST_EXIST);
        $relationship = $DB->get_record('relationship', array('id' => $relationshipgroup->relationshipid), '*', MUST_EXIST);

        $event = \local_relationship\event\relationshipgroup_member_removed::create(array(
                'context' => context::instance_by_id($relationship->contextid),
                'objectid' => $relationshipgroupid,
                'relateduserid' => $userid,
                'other' => $relationshipcohort->roleid,
        ));
        $event->add_record_snapshot('relationship_groups', $relationshipgroup);
        $event->add_record_snapshot('relationship', $relationship);
        $event->trigger();

        return true;
    }

    return false;
}

/**
 * @param $relationshipid
 * @return stdClass $relationship
 */
function relationship_get_relationship($relationshipid) {
    global $DB;

    $relationship = $DB->get_record('relationship', array('id' => $relationshipid), '*', MUST_EXIST);
    $relationship->tags = core_tag_tag::get_item_tags_array('local_relationship', 'relationship', $relationshipid);

    return $relationship;
}

/**
 * Add new relationship.
 *
 * @param stdClass $relationship
 * @return int|bool new relationship id or false if any error occours
 * @throws coding_exception
 */
function relationship_add_relationship($relationship) {
    global $DB;

    if (!isset($relationship->name)) {
        throw new coding_exception('Missing relationship name in relationship_add_relationship().');
    }
    $relationship->name = trim($relationship->name);

    if (!isset($relationship->idnumber)) {
        $relationship->idnumber = null;
    }

    if (!isset($relationship->description)) {
        $relationship->description = '';
    }

    if (!isset($relationship->descriptionformat)) {
        $relationship->descriptionformat = FORMAT_HTML;
    }

    if (empty($relationship->component)) {
        $relationship->component = '';
    }

    if (!isset($relationship->timecreated)) {
        $relationship->timecreated = time();
    }

    if (!isset($relationship->timemodified)) {
        $relationship->timemodified = $relationship->timecreated;
    }

    $result = $DB->insert_record('relationship', $relationship);

    if ($result) {
        $relationship->id = $result;
        core_tag_tag::set_item_tags('local_relationship',
            'relationship',
            $relationship->id,
            context::instance_by_id($relationship->contextid),
            $relationship->tags) ;

        $event = \local_relationship\event\relationship_created::create(array(
                'context' => context::instance_by_id($relationship->contextid),
                'objectid' => $relationship->id,
        ));
        $event->add_record_snapshot('relationship', $relationship);
        $event->trigger();

        return $relationship->id;
    }

    return false;
}

/**
 * Update existing relationship
 *
 * @param sstdClass $relationship
 * @return void
 */
function relationship_update_relationship($relationship) {
    global $DB;

    $relationship->timemodified = time();
    $result = $DB->update_record('relationship', $relationship);

    if ($result) {
        core_tag_tag::set_item_tags('local_relationship',
            'relationship',
            $relationship->id,
            context::instance_by_id($relationship->contextid),
            $relationship->tags) ;

        $event = \local_relationship\event\relationship_updated::create(array(
                'context' => context::instance_by_id($relationship->contextid),
                'objectid' => $relationship->id,
        ));
        $event->add_record_snapshot('relationship', $relationship);
        $event->trigger();

        return true;
    }

    return false;
}

/**
 * Delete relationship
 * @param stdClass $relationship
 * @return bool
 * @throws coding_exception
 * @throws dml_transaction_exception
 */
function relationship_delete_relationship($relationship) {
    global $DB;

    $cohorts = $DB->get_records('relationship_cohorts', array('relationshipid' => $relationship->id));

    if(count($cohorts) == 0) {

        $relationshipgroups = $DB->get_records('relationship_groups', array('relationshipid' => $relationship->id));
        foreach ($relationshipgroups AS $g) {
            relationship_delete_group($g);
        }

        try {
            $transaction = $DB->start_delegated_transaction();



            $DB->delete_records('relationship_cohorts', array('relationshipid' => $relationship->id));

            $DB->delete_records('relationship', array('id' => $relationship->id));

            $transaction->allow_commit();
        } catch (Exception $e) {
            $transaction->rollback($e);

            return false;
        }

        $event = \local_relationship\event\relationship_deleted::create(array(
            'context' => context::instance_by_id($relationship->contextid),
            'objectid' => $relationship->id,
        ));
        $event->add_record_snapshot('relationship', $relationship);
        $event->trigger();

        return true;
    } else {
        return -1;
    }
}

//
// Relationship Cohorts
//

/**
 * Cohorts related to a relationship
 *
 * @param $relationshipid
 * @param bool $full load full cohort and roles data
 * @return array
 * @throws coding_exception
 */
function relationship_get_cohorts($relationshipid, $full = true) {
    global $DB;

    $cohorts = $DB->get_records('relationship_cohorts', array('relationshipid' => $relationshipid));
    if ($full) {
        foreach ($cohorts AS $ch) {
            $ch->cohort = $DB->get_record('cohort', array('id' => $ch->cohortid));
            if ($role = $DB->get_record('role', array('id' => $ch->roleid))) {
                $ch->role_name = role_get_name($role);
            } else {
                $ch->role_name = false;
            }
        }
    }

    return $cohorts;
}

/**
 * Get a specific relationshipcohort by ID
 *
 * @param $relationshipcohortid
 * @param bool $full load full cohort and roles data
 * @return mixed
 * @throws coding_exception
 */
function relationship_get_cohort($relationshipcohortid, $full = true) {
    global $DB;

    $cohort = $DB->get_record('relationship_cohorts', array('id' => $relationshipcohortid), '*', MUST_EXIST);
    if ($full) {
        $cohort->cohort = $DB->get_record('cohort', array('id' => $cohort->cohortid));
        if ($role = $DB->get_record('role', array('id' => $cohort->roleid))) {
            $cohort->role_name = role_get_name($role);
        } else {
            $cohort->role_name = false;
        }
    }

    return $cohort;
}

/**
 * Add a relationshipcohort
 *
 * @param $relationshipcohort
 * @return bool|int
 */
function relationship_add_cohort($relationshipcohort) {
    global $DB;

    if (!isset($relationshipcohort->timecreated)) {
        $relationshipcohort->timecreated = time();
    }
    if (!isset($relationshipcohort->timemodified)) {
        $relationshipcohort->timemodified = $relationshipcohort->timecreated;
    }

    $relationshipcohort->id = $DB->insert_record('relationship_cohorts', $relationshipcohort);

    return $relationshipcohort->id;
}

/**
 * Update a specific relationshipcohort
 *
 * @param $relationshipcohort
 * @return bool
 */
function relationship_update_cohort($relationshipcohort) {
    global $DB;

    $relationshipcohort->timemodified = time();

    return $DB->update_record('relationship_cohorts', $relationshipcohort);
}

/**
 * Delete a specific relationshipcohort
 *
 * @param $relationshipcohort
 * @return bool
 */
function relationship_delete_cohort($relationshipcohort) {
    global $DB;
    $members = $DB->get_records('relationship_members', array('relationshipcohortid' => $relationshipcohort->id));
    foreach ($members as $m) {
        relationship_remove_member($m->relationshipgroupid, $m->relationshipcohortid, $m->userid);
    }

    return $DB->delete_records('relationship_cohorts', array('id' => $relationshipcohort->id));
}

//
// Relationship Groups
//

/**
 * Get groups from a relationship
 * @param $relationshipid
 * @return array
 */
function relationship_get_groups($relationshipid) {
    global $DB;

    $sql = "SELECT rg.*, (SELECT count(*)
                            FROM {relationship_members}
                           WHERE relationshipgroupid = rg.id) as size
              FROM {relationship_groups} rg
             WHERE rg.relationshipid = :relationshipid
          GROUP BY rg.id
          ORDER BY name";

    return $DB->get_records_sql($sql, array('relationshipid' => $relationshipid));
}

/**
 * Add a relationshipgroup
 *
 * @param $relationshipgroup
 * @return bool|int
 * @throws coding_exception
 */
function relationship_add_group($relationshipgroup) {
    global $DB;

    $relationshipgroup->name = trim($relationshipgroup->name);
    if (!isset($relationshipgroup->timecreated)) {
        $relationshipgroup->timecreated = time();
    }
    if (!isset($relationshipgroup->timemodified)) {
        $relationshipgroup->timemodified = $relationshipgroup->timecreated;
    }

    $relationship = $DB->get_record('relationship', array('id' => $relationshipgroup->relationshipid), '*', MUST_EXIST);
    $result = $DB->insert_record('relationship_groups', $relationshipgroup);

    if ($result) {
        $relationshipgroup->id = $result;

        $event = \local_relationship\event\relationshipgroup_created::create(array(
                'context' => context::instance_by_id($relationship->contextid),
                'objectid' => $relationshipgroup->id,
        ));
        $event->add_record_snapshot('relationship_groups', $relationshipgroup);
        $event->add_record_snapshot('relationship', $relationship);
        $event->trigger();
    }

    return $result;
}

/**
 * Update a relationshipgroup
 *
 * @param $relationshipgroup
 * @return bool
 * @throws coding_exception
 */
function relationship_update_group($relationshipgroup) {
    global $DB;

    $relationshipgroup->timemodified = time();
    if (isset($relationshipgroup->name)) {
        $relationshipgroup->name = trim($relationshipgroup->name);
    }
    $result = $DB->update_record('relationship_groups', $relationshipgroup);

    if ($result) {
        $relationship = $DB->get_record('relationship', array('id' => $relationshipgroup->relationshipid), '*', MUST_EXIST);

        $event = \local_relationship\event\relationshipgroup_updated::create(array(
                'context' => context::instance_by_id($relationship->contextid),
                'objectid' => $relationshipgroup->id,
        ));
        $event->add_record_snapshot('relationship_groups', $relationshipgroup);
        $event->add_record_snapshot('relationship', $relationship);
        $event->trigger();
    }

    return $result;
}

/**
 * @param $relationshipgroup
 * @return bool
 * @throws coding_exception
 * @throws dml_transaction_exception
 */
function relationship_delete_group($relationshipgroup) {
    global $DB;

    try {
        $transaction = $DB->start_delegated_transaction();

        $relationship = $DB->get_record('relationship', array('id' => $relationshipgroup->relationshipid), '*', MUST_EXIST);
        $DB->delete_records('relationship_members', array('relationshipgroupid' => $relationshipgroup->id));
        $DB->delete_records('relationship_groups', array('id' => $relationshipgroup->id));

        $transaction->allow_commit();
    } catch (Exception $e) {
        $transaction->rollback($e);

        return false;
    }

    $event = \local_relationship\event\relationshipgroup_deleted::create(array(
            'context' => context::instance_by_id($relationship->contextid),
            'objectid' => $relationshipgroup->id,
    ));
    $event->add_record_snapshot('relationship_groups', $relationshipgroup);
    $event->add_record_snapshot('relationship', $relationship);
    $event->trigger();

    return true;
}