models/assessment.js

   1 const AssessmentEntity = require("../entities/assessment");
   2 const CourseEntity = require("../entities/course");
   3 const ObjectId = require("bson-objectid");
   4 const UserEntity = require("../entities/user");
   5 const TokenGen = require("../utils/tokenGenerator");
   6
   7 const AssessmentModel =
   8 {
   9     getByRefs: function(initials, code, name, cb)
  10     {
  11         UserEntity.getByInitials(initials, (err,user) => {
  12             if (!!err || !user)
  13                 return cb(err || {errmsg: "User not found"});
  14             CourseEntity.getByPath(user._id, code, (err2,course) => {
  15                 if (!!err2 || !course)
  16                     return cb(err2 || {errmsg: "Course not found"});
  17                 AssessmentEntity.getByPath(course._id, name, (err3,assessment) => {
  18                     if (!!err3 || !assessment)
  19                         return cb(err3 || {errmsg: "Assessment not found"});
  20                     cb(null,assessment);
  21                 });
  22             });
  23         });
  24     },
  25
  26     checkPassword: function(aid, number, password, cb)
  27     {
  28         AssessmentEntity.getById(aid, (err,assessment) => {
  29             if (!!err || !assessment)
  30                 return cb(err, assessment);
  31             const paperIdx = assessment.papers.findIndex( item => { return item.number == number; });
  32             if (paperIdx === -1)
  33                 return cb({errmsg: "Paper not found"}, false);
  34             cb(null, assessment.papers[paperIdx].password == password);
  35         });
  36     },
  37
  38     add: function(uid, cid, name, cb)
  39     {
  40         // 1) Check that course is owned by user of ID uid
  41         CourseEntity.getById(cid, (err,course) => {
  42             if (!!err || !course)
  43                 return cb({errmsg: "Course retrieval failure"});
  44             if (!course.uid.equals(uid))
  45                 return cb({errmsg:"Not your course"},undefined);
  46             // 2) Insert new blank assessment
  47             AssessmentEntity.insert(cid, name, cb);
  48         });
  49     },
  50
  51     update: function(uid, assessment, cb)
  52     {
  53         const aid = ObjectId(assessment._id);
  54         // 1) Check that assessment is owned by user of ID uid
  55         AssessmentEntity.getById(aid, (err,assessmentOld) => {
  56             if (!!err || !assessmentOld)
  57                 return cb({errmsg: "Assessment retrieval failure"});
  58             CourseEntity.getById(ObjectId(assessmentOld.cid), (err2,course) => {
  59                 if (!!err2 || !course)
  60                     return cb({errmsg: "Course retrieval failure"});
  61                 if (!course.uid.equals(uid))
  62                     return cb({errmsg:"Not your course"},undefined);
  63                 // 2) Replace assessment
  64                 delete assessment["_id"];
  65                 assessment.cid = ObjectId(assessment.cid);
  66                 AssessmentEntity.replace(aid, assessment, cb);
  67             });
  68         });
  69     },
  70
  71     // Set password in responses collection
  72     startSession: function(aid, number, password, cb)
  73     {
  74         AssessmentEntity.getPaperByNumber(aid, number, (err,paper) => {
  75             if (!!err)
  76                 return cb(err,null);
  77             if (!paper && !!password)
  78                 return cb({errmsg: "Cannot start a new exam before finishing current"},null);
  79             if (!!paper)
  80             {
  81                 if (!password)
  82                     return cb({errmsg: "Missing password"});
  83                 if (paper.password != password)
  84                     return cb({errmsg: "Wrong password"});
  85             }
  86             AssessmentEntity.getQuestions(aid, (err,questions) => {
  87                 if (!!err)
  88                     return cb(err,null);
  89                 if (!!paper)
  90                     return cb(null,{paper:paper,questions:questions});
  91                 const pwd = TokenGen.generate(12); //arbitrary number, 12 seems enough...
  92                 AssessmentEntity.startSession(aid, number, pwd, (err2,ret) => {
  93                     cb(err2, {
  94                         questions: questions,
  95                         password: pwd,
  96                     });
  97                 });
  98             });
  99         });
 100     },
 101
 102     newAnswer: function(aid, number, password, input, cb)
 103     {
 104         // Check that student hasn't already answered
 105         AssessmentEntity.hasInput(aid, number, password, input.index, (err,ret) => {
 106             if (!!err)
 107                 return cb(err,null);
 108             if (!!ret)
 109                 return cb({errmsg:"Question already answered"},null);
 110             AssessmentEntity.setInput(aid, number, password, input, (err2,ret2) => {
 111                 if (!!err2 || !ret2)
 112                     return cb(err2,ret2);
 113                 return cb(null,ret2);
 114             });
 115         });
 116     },
 117
 118     // NOTE: no callbacks for 2 next functions, failures are not so important
 119     // (because monitored: teachers can see what's going on)
 120
 121     newConnection: function(aid, number)
 122     {
 123         //increment discoCount, reset discoTime to NULL, update totalDisco
 124         AssessmentEntity.getDiscoTime(aid, number, (err,discoTime) => {
 125             if (!!discoTime)
 126                 AssessmentEntity.addDisco(aid, number, discoTime - Date.now());
 127         });
 128     },
 129
 130     endSession: function(aid, number, password, cb)
 131     {
 132         AssessmentEntity.endAssessment(aid, number, password, (err,ret) => {
 133             if (!!err || !ret)
 134                 return cb(err,ret);
 135             AssessmentEntity.getConclusion(aid, (err2,conclusion) => {
 136                 cb(err2, {conclusion:conclusion});
 137             });
 138         });
 139     },
 140 };
 141
 142 module.exports = AssessmentModel;