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/>.
/**
 * lib.php - Contains Plagiarism plugin specific functions called by Modules.
 *
 * @since 2.0
 * @package    plagiarism_crot
 * @subpackage plagiarism
 * @author     Dan Marsden, Sergey Butakov, Svetlana Kim
 * @copyright  2010 Dan Marsden, Sergey Butakov, Svetlana Kim
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

if (!defined('MOODLE_INTERNAL')) {
    die('Direct access to this script is forbidden.');    ///  It must be included from a Moodle page
}

//get global class
global $CFG, $DB;
require_once($CFG->dirroot.'/plagiarism/lib.php');

///// Crot Class ////////////////////////////////////////////////////
class plagiarism_plugin_crot extends plagiarism_plugin {
     /**
     * hook to allow plagiarism specific information to be displayed beside a submission 
     * @param array  $linkarray contains all relevant information for the plugin to generate a link
     * @return string
     * 
     */
    public function get_links($linkarray) {
        //$userid, $file, $cmid, $course, $module
        global $DB, $CFG;
        $cmid = $linkarray['cmid'];
        $userid = $linkarray['userid'];
        $file = $linkarray['file'];
        $course = $linkarray['course'];
//sw 08/27
        $cid = $course->id;
        if (empty($cid)) { $cid = $course;}
// end sw 08/27
//        if (!empty($plagiarismsettings['crot_use'])) { //sw 4-21
 //           if (isset($data->crot_use)) { //sw 4-21

        //add link/information about this file to $output
        if (!empty($file)){ //sw
            if (!$plagiarism_crot_files_rec = $DB->get_record("plagiarism_crot_files", array("file_id"=>$file->get_id()))) {
                $output .= '';// if there is no record in plagiarism_crot_files about this file then nothing to show
            }
            else {
                if (!$crot_doc_rec = $DB->get_record("plagiarism_crot_documents", array("crot_submission_id"=>$plagiarism_crot_files_rec->id))) {
                    $output .= '';// if there is no record in plagiarism_crot_documents about this file then nothing to show
                }
                else {
                    $sql_query = "SELECT max(number_of_same_hashes) as max FROM {$CFG->prefix}plagiarism_crot_spair WHERE submission_a_id ='$crot_doc_rec->id' OR  submission_b_id = '$crot_doc_rec->id'";
                    if (!$similarity = $DB->get_record_sql($sql_query)) {// get maximum number of same hashes for the current document
                        $output .= '<br><b>'.get_string('no_similarities','plagiarism_crot').'</b>';
                    }
                    else {
                        $sql_query = "SELECT count(*) as cnt from {$CFG->prefix}plagiarism_crot_fingerprint where crot_doc_id = '$crot_doc_rec->id'";
                        $numbertotal = $DB->get_record_sql($sql_query);// get total number of hashes for the current document
                        $perc =  round(($similarity->max / $numbertotal->cnt) * 100, 2);
                        $output .= "<br><b> <a href=\"../../plagiarism/crot/index.php?id_a=$crot_doc_rec->id&user_id=$userid&cid=$cid\">".$perc."%</a></b>";
                    }
                }
            }
          }else{
              // For online text/type-ins
              $path =  $linkarray['content'];
              $path = strip_tags($path);
              $path = sha1($path);
              $sql_query = "SELECT * FROM {$CFG->prefix}plagiarism_crot_files WHERE path ='$path' AND courseid = $course AND cm = $cmid ORDER BY file_id DESC LIMIT 1";
              $file = $DB->get_record_sql($sql_query);
              $fileid = $file->file_id;
              
              if (!$plagiarism_crot_files_rec = $DB->get_record("plagiarism_crot_files", array("file_id"=>$fileid))) {
                  $output .= '<small><i>Pending</i></small> ';// if there is no record in plagiarism_crot_files about this file then nothing to show
              }
              else {
                  if (!$crot_doc_rec = $DB->get_record("plagiarism_crot_documents", array("crot_submission_id"=>$plagiarism_crot_files_rec->id))) {
                      $output .= '';// if there is no record in plagiarism_crot_documents about this file then nothing to show
                  }
                  else {
                      $sql_query = "SELECT max(number_of_same_hashes) as max FROM {$CFG->prefix}plagiarism_crot_spair WHERE submission_a_id ='$crot_doc_rec->id' OR  submission_b_id = '$crot_doc_rec->id'";
                      if (!$similarity = $DB->get_record_sql($sql_query)) {// get maximum number of same hashes for the current document
                          $output .= '<br><b>'.get_string('no_similarities','plagiarism_crot').'</b>';
                      }
                      else {
                          $sql_query = "SELECT count(*) as cnt from {$CFG->prefix}plagiarism_crot_fingerprint where crot_doc_id = '$crot_doc_rec->id'";
                          $numbertotal = $DB->get_record_sql($sql_query);// get total number of hashes for the current document
                          $perc =  round(($similarity->max / $numbertotal->cnt) * 100, 2);
                          $output .= "<br><b> <a href=\"../../plagiarism/crot/index.php?id_a=$crot_doc_rec->id&user_id=$userid&cid=$cid\">".$perc."%</a></b> ";
                      }
                  }
              }
          }//sw
//} //sw 4-21
//} // sw 4-41
        return $output;
    }

    /* hook to save plagiarism specific settings on a module settings page
     * @param object $data - data from an mform submission.
    */
    public function save_form_elements($data) {
        global $DB;
        $plagiarismsettings = (array)get_config('plagiarism');
        if (!empty($plagiarismsettings['crot_use'])) {
            if (isset($data->crot_use)) {
                //array of posible plagiarism config options.
                $plagiarismelements = $this->config_options();
                //first get existing values
                $existingelements = $DB->get_records_menu('plagiarism_crot_config', array('cm'=>$data->coursemodule),'','name,id');
                foreach($plagiarismelements as $element) {
                    $newelement = new object();
                    $newelement->cm = $data->coursemodule;
                    $newelement->name = $element;
                    $newelement->value = (isset($data->$element) ? $data->$element : 0);
                    if (isset($existingelements[$element])) { //update
                        $newelement->id = $existingelements[$element];
                        $DB->update_record('plagiarism_crot_config', $newelement);
                    } else { //insert
                        $DB->insert_record('plagiarism_crot_config', $newelement);
                    }
                }

            }
        }
    }

    /**
     * hook to add plagiarism specific settings to a module settings page
     * @param object $mform  - Moodle form
     * @param object $context - current context
     */
    public function get_form_elements_module($mform, $context) {
        global $DB;
        $plagiarismsettings = (array)get_config('plagiarism');
        if (!empty($plagiarismsettings['crot_use'])) {
            $cmid = optional_param('update', 0, PARAM_INT); //there doesn't seem to be a way to obtain the current cm a better way - $this->_cm is not available here.
            if (!empty($cmid)) {
                $plagiarismvalues = $DB->get_records_menu('plagiarism_crot_config', array('cm'=>$cmid),'','name,value');
            }
            $plagiarismelements = $this->config_options();

            $ynoptions = array( 0 => get_string('no'), 1 => get_string('yes'));
            $mform->addElement('header', 'crotdesc', get_string('crot', 'plagiarism_crot'));
            $mform->addHelpButton('crotdesc', 'crot', 'plagiarism_crot');
            $mform->addElement('select', 'crot_use', get_string("usecrot", "plagiarism_crot"), $ynoptions);
            $mform->addElement('select', 'crot_local', get_string("comparestudents", "plagiarism_crot"), $ynoptions);
            $mform->disabledIf('crot_local', 'crot_use', 'eq', 0);
            $mform->setDefault('crot_local', '1');
            $mform->addElement('select', 'crot_global', get_string("compareinternet", "plagiarism_crot"), $ynoptions);
            $mform->disabledIf('crot_global', 'crot_use', 'eq', 0);
            
            foreach ($plagiarismelements as $element) {
                if (isset($plagiarismvalues[$element])) {
                    $mform->setDefault($element, $plagiarismvalues[$element]);
                }
            }
        }
        //Add elements to form using standard mform like:
        //$mform->addElement('hidden', $element);
        //$mform->disabledIf('plagiarism_draft_submit', 'var4', 'eq', 0);
    }

    /**
     * hook to allow a disclosure to be printed notifying users what will happen with their submission
     * @param int $cmid - course module id
     * @return string
     */
    public function print_disclosure($cmid) {
         global $DB, $OUTPUT;
         // check if this cmid has plagiarism enabled
         $select = 'cm = ? AND '.$DB->sql_compare_text('name').' = "crot_use"';
         if (! $crot_use = $DB->get_record_select('plagiarism_crot_config', $select, array($cmid))) {
            return;
         } else if ($crot_use->value == 0) {
            return;
         }
        $plagiarismsettings = (array)get_config('plagiarism');
        echo $OUTPUT->box_start('generalbox boxaligncenter', 'intro');
        $formatoptions = new stdClass;
        $formatoptions->noclean = true;
        echo format_text($plagiarismsettings['crot_student_disclosure'], FORMAT_MOODLE, $formatoptions);
        echo $OUTPUT->box_end();
    }

    /**
     * hook to allow status of submitted files to be updated - called on grading/report pages.
     *
     * @param object $course - full Course object
     * @param object $cm - full cm object
     */
    public function update_status($course, $cm) {
        //called at top of submissions/grading pages - allows printing of admin style links or updating status
    }

    /**
     * called by admin/cron.php 
     *
     */
    public function cron() {
        //do any scheduled task stuff
        global $CFG;
        require_once($CFG->dirroot.'/plagiarism/crot/crot_cron.php');
        
    }
    public function config_options() {
        return array('crot_use','crot_local', 'crot_global');
    }
}

function crot_event_files_done($eventdata) {
    global $DB;
    $result = true;
        //a file has been uploaded - submit this to the plagiarism prevention service.
        
    return $result;
}
function crot_event_file_uploaded($eventdata) {
     global $DB, $CFG;
    $result = true;
        //mainly used by assignment finalize - used if you want to handle "submit for marking" events
        //a file has been uploaded/finalised - submit this to the plagiarism prevention service.
    
//    $plagiarismvalues = $DB->get_records_menu('plagiarism_crot_config', array('cm'=>$eventdata->cmid),'','name,value');

    $cmid = (!empty($eventdata->cm->id)) ? $eventdata->cm->id : $eventdata->cmid;
    $plagiarismvalues = $DB->get_records_menu('plagiarism_crot_config', array('cm'=>$cmid), '', 'name,value');
    if (empty($plagiarismvalues['crot_use'])) {
        return $result;
    }
    else {
    //sw 21/02
        $cm = $DB->get_record('course_modules', array('id' => $eventdata->cmid));
        if (empty($cm)) {
        	$cm = $DB->get_record('course_modules', array('id' => $cmid));
	}
    //sw    
        if (empty($cm)) {
        return $result;
    	}
        $modulename = $DB->get_field('modules', 'name', array('id' => $cm->module));
        //sw uncommented
        require_once("$CFG->dirroot/mod/$modulename/lib.php");
        //sw
	$status_value = array('queue','in_processing','end_processing');
        $modulecontext = get_context_instance(CONTEXT_MODULE, $eventdata->cmid);
        // put files that were submitted for marking into queue for check up
//sw
	if ($eventdata->modulename == 'assignment') {
	    require_once("$CFG->dirroot/mod/assignment/lib.php");
	    $assignmentbase = new assignment_base($cmid);
	    $submission = $assignmentbase->get_submission($eventdata->userid);
	    $fs = get_file_storage();
	    if ($files = $fs->get_area_files($modulecontext->id, 'mod_assignment', 'submission', $submission->id, "timemodified", false)) {
	        foreach ($files as $file) {
        	    if ($file->get_filename() ==='.') {
            		// This 'file' is actually a directory - nothing to submit.
            		continue;
        	    }
            	    $newelement = new stdclass();
            	    $newelement->file_id = $file->get_id();
            	    $newelement->path = $file->get_contenthash();
            	    $newelement->status = $status_value[0]; 
            	    $newelement->time = time(); 
            	    $newelement->cm = $eventdata->cmid;    
            	    $newelement->courseid = $eventdata->courseid; 
            	    $result=$DB->insert_record('plagiarism_crot_files', $newelement);
            	    echo "\nfile ".$file->get_filename()." was queued up for plagiarism detection service\n";
		}
	    }
	}
	else { 
	    if ($eventdata->modulename == 'assign') {
//sw
            foreach ($eventdata->pathnamehashes as $hash) {
        	$fs = get_file_storage();
        	$file = $fs->get_file_by_hash($hash);
        	if (empty($file)||($file->get_filename() ==='.')) {
                // This 'file' is actually a directory - nothing to submit.
            	    continue;
        	}
                $newelement = new stdclass();
                $newelement->file_id = $file->get_id();
                $newelement->path = $file->get_contenthash();
                $newelement->status = $status_value[0]; 
                $newelement->time = time(); 
                $newelement->cm = $eventdata->cmid;    
                $newelement->courseid = $eventdata->courseid; 
                $result=$DB->insert_record('plagiarism_crot_files', $newelement);
                echo "\nfile ".$file->get_filename()." was queued up for plagiarism detection service\n";
            }          
//ws
	    } //end assign
	}

///ws            
            
        return $result;
    }
}

// Event handler for type-in/online text submissions
// @author Hamman Samuel
function crot_event_content_uploaded($eventdata) {
    global $DB;
    
    if ($eventdata->modulename == "assign") {
      $context = get_context_instance(CONTEXT_COURSE, $eventdata->courseid);
      $filename = "crot_" . $eventdata->courseid . "_" . $eventdata->cmid. "_" . $eventdata->userid . "_" .time().".txt";
      $filepath = "/"; // has to start and end with /, rule of the Moodle file storage api
      print_r($eventdata);
      $filerecord = new stdclass();
      $filerecord->contextid = $context->id;
      $filerecord->userid = $eventdata->userid;
      $filerecord->component = "assignsubmission_onlinetext";
      $filerecord->filearea = "onlinetext";
      //sw
      $filerecord->itemid = $eventdata->itemid;
      $uid321 = $filerecord->userid;
      
      $urecm = $DB->get_record('user', array('id' => $uid321));
      
      $filerecord->author = $urecm->firstname." ".$urecm->lastname;
      // sw end
      $filerecord->filepath = $filepath;
      $filerecord->filename = $filename;
      
      $fs = get_file_storage(); // using file storage system ensures that the file can be located by other api calls
                                // this creates a hash-version of the file in the Moodle data folder and also creates entries in the 'files' table
      $content = strip_tags($eventdata->content);
      $file = $fs->create_file_from_string($filerecord, $content); // convert online text to a text file
      
      $content = strip_tags($eventdata->content);
      $plagiarism_file = new object(); // create an entry in the crot table
      $plagiarism_file->file_id = $file->get_id();
      $plagiarism_file->path = $file->get_contenthash();
      $plagiarism_file->status = 'queue';
      $plagiarism_file->time = time();
      $plagiarism_file->cm = $eventdata->cmid;
      $plagiarism_file->courseid = $eventdata->courseid;
      //$plagiarism_file->userid = $eventdata->userid;
      
      $result = $DB->insert_record('plagiarism_crot_files', $plagiarism_file);
      echo "\nType-in assignment was queued up for plagiarism detection service\n";
  }
  
  return $result;
}

function crot_event_mod_created($eventdata) {
    $result = true;
        //a new module has been created - this is a generic event that is called for all module types
        //make sure you check the type of module before handling if needed.

    return $result;
}

function crot_event_mod_updated($eventdata) {
    $result = true;
        //a module has been updated - this is a generic event that is called for all module types
        //make sure you check the type of module before handling if needed.

    return $result;
}

function crot_event_mod_deleted($eventdata) {
    $result = true;
        //a module has been deleted - this is a generic event that is called for all module types
        //make sure you check the type of module before handling if needed.

    return $result;
}