server/models/Problem.js

   1 const db = require("../utils/database");
   2
   3 /*
   4  * Structure:
   5  *   id: integer
   6  *   added: datetime
   7  *   uid: user id (int)
   8  *   vid: variant id (int)
   9  *   fen: varchar (optional)
  10  *   instruction: text
  11  *   solution: text
  12  */
  13
  14 const ProblemModel =
  15 {
  16   checkProblem: function(p)
  17   {
  18     if (!p.id.toString().match(/^[0-9]+$/))
  19       return "Wrong problem ID";
  20     if (!p.vid.toString().match(/^[0-9]+$/))
  21       return "Wrong variant ID";
  22     if (!p.fen.match(/^[a-zA-Z0-9, /-]*$/))
  23       return "Bad FEN string";
  24     return "";
  25   },
  26
  27   create: function(p, cb)
  28   {
  29     db.serialize(function() {
  30       const query =
  31         "INSERT INTO Problems " +
  32         "(added, uid, vid, fen, instruction, solution) " +
  33           "VALUES " +
  34         "(" + Date.now() + "," + p.uid + "," + p.vid + ",'" + p.fen  + "',?,?)";
  35       db.run(query, [p.instruction,p.solution], function(err) {
  36         return cb(err, {pid: this.lastID});
  37       });
  38     });
  39   },
  40
  41   getAll: function(cb)
  42   {
  43     db.serialize(function() {
  44       const query =
  45         "SELECT * " +
  46         "FROM Problems";
  47       db.all(query, (err,problems) => {
  48         return cb(err, problems);
  49       });
  50     });
  51   },
  52
  53   getOne: function(id, cb)
  54   {
  55     db.serialize(function() {
  56       const query =
  57         "SELECT * " +
  58         "FROM Problems " +
  59         "WHERE id = " + id;
  60       db.get(query, (err,problem) => {
  61         return cb(err, problem);
  62       });
  63     });
  64   },
  65
  66   update: function(prob, cb)
  67   {
  68     db.serialize(function() {
  69       let query =
  70         "UPDATE Problems " +
  71         "SET " +
  72           "vid = " + prob.vid + "," +
  73           "fen = '" + prob.fen + "'," +
  74           "instruction = ?," +
  75           "solution = ? " +
  76         "WHERE id = " + prob.id;
  77       db.run(query, [prob.instruction,prob.solution], cb);
  78     });
  79   },
  80
  81   remove: function(id)
  82   {
  83     db.serialize(function() {
  84       const query =
  85         "DELETE FROM Problems " +
  86         "WHERE id = " + id;
  87       db.run(query);
  88     });
  89   },
  90
  91   safeRemove: function(id, uid, cb)
  92   {
  93     db.serialize(function() {
  94       const query =
  95         "SELECT 1 " +
  96         "FROM Problems " +
  97         "WHERE id = " + id + " AND uid = " + uid;
  98       db.get(query, (err,prob) => {
  99         if (!prob)
 100           return cb({errmsg: "Not your problem"});
 101         ProblemModel.remove(id);
 102         cb(null);
 103       });
 104     });
 105   },
 106 }
 107
 108 module.exports = ProblemModel;