var express = require('express');
var mongo = require('mongodb');
var app = express();
var bodyParser = require('body-parser');
var session = require('express-session');
var path = require('path');
var link = require('url');
app.set('views',path.join(__dirname,'views'));
app.set('view engine','ejs');
app.use(express.static(path.join(__dirname,"public")));
app.use(session({
	secret : 'qtoquizandotoonline',
	resave : false,
	saveUninitialized : true
}));

var url="mongodb://localhost:27017/online_quiz";

app.use(bodyParser.urlencoded({ extended : true }));
app.listen(3000,function(err){
	if(err)
	{
		console.log("Error in listening Port");
	}
	console.log("listening to port : 3000")
});
app.get('/signin',function(req,res){
    if(!req.session.user)
     {
        res.render('signin');
     }
     else
     {
         if(req.session.type=='0')
         {
            res.redirect('/admin');
         }
         else if(req.session.type=='1')
        {
            res.redirect('/faculty');
        }
        else if(req.session.type=='2')
        {
             res.redirect('/student');
        }
     }
});
app.get('/admin',function(req,res){
    if(!req.session.user )
    {
        res.redirect('/');
    }
     else if(result[0].type=='1')
      {
         res.redirect('/faculty');
      }
  else if(result[0].type=='2')
      {
         res.redirect('/student');
      }
    else
    {
        mongo.connect(url,function(err,db) {
           if(err)
              {
                  console.log("connection problem");
              }

          var dbo=db.db("online_quiz");
          dbo.collection("registered_clg").find({},{projection : { _id : 0, college : 1}}).toArray(function(err,user)
          {
              console.log(user);
              res.render('admin',{info : user});
          });
    });
    }
});
app.get('/',function(req,res){
	if(!req.session.user)
	{
		res.redirect('/signin');
	}
	else
	{
		mongo.connect(url,function(err,db){
        		if(err)
        		{
        			throw err;
        		}
        		var dbo=db.db("online_quiz");
        		dbo.collection("credentials").aggregate([{$match : { email : req.session.user}}]).toArray(function(err,result){
        			if(err)
        			{
        			  console.log("err");
        			}
        			else
        			{
        			  var type = result[0].type;
                      var user = result[0].name;
                        if(type=='0')
                        {
                           res.redirect('/admin');
                        }
                        else if(type=='1')
                        {
                           res.redirect('/faculty');
                        }
                        else if(type=='2')
                        {
                           res.redirect('/student');
                        }
                  }
        		});
        	});

	}
});

app.post('/sign_in',function(req,res){

             mongo.connect(url,function(err,db) {
             if(err)
                {
                    console.log("connection problem");
                };

            var dbo=db.db("online_quiz");
            dbo.collection("credentials").findOne({email : req.body.email},function(err,user){
            if(err)
            {
                console.log("error");
            }
            if(!user)
            {
                res.write("User Does Not Exist..!<br><a href="/">click here to try again</a>")
                console.log("user not found");
            }
            else if(user.password!=req.body.pass)
            {
                console.log("Wrong password");
                res.redirect('/');
            }
            else
            {
                req.session.user = req.body.email;
                console.log("successful login");

                dbo.collection("credentials").aggregate([{$match : { email : req.session.user}}]).toArray(function(err,result){
                        if(err)
                        {
                          console.log("err");
                        }
                        else
                        {
                           req.session.name = result[0].name;
                           req.session.type = result[0].type;
                           if(result[0].type=='0')
                            {
                               res.redirect('/admin');
                            }
                            else if(result[0].type=='1')
                                {
                                   res.redirect('/faculty');
                                }
                            else if(result[0].type=='2')
                                {
                                   res.redirect('/student');
                                }
                        }
                    });
                }
            });
    });

});

app.post('/sign_up',function(req,res){

    var name = req.body.name;

    var email = req.body.email;

    var pass = req.body.pass;

    var repass = req.body.repass;

    var college = req.body.college;

    var stream = req.body.stream;

    var type = "2";

    var section = req.body.section;

    var batch = req.body.batch;

    var data={
        "name":name,
        "email":email,
        "password":pass,
        "type" : type,
        "section" : section,
        "stream" : stream,
        "college":college,
        "batch":batch
    }
    mongo.connect(url,function(err,db) {
          if(err) throw err;

          var dbo=db.db("online_quiz");
          dbo.collection("credentials").findOne({email : data.email},function(err,user){
            if(err)
            {
                console.log(error);
            }
            if(user)
            {
                console.log("user already exit");
                res.redirect('/');
            }
            else
            {
                dbo.collection("credentials").insertOne(data,function(err,db){
                    if(err)
                    {
                        console.log("error in signup in insertion");
                    }
                    else
                    {
                        console.log("successfully registered");
                        res.redirect('/');
                    }
                });
            }
          });

    });

});

app.get('/signup',function(req,res){
    if(!req.session.user)
    {
        mongo.connect(url,function(err,db){
            if(err)
            {
                console.log("error in connecting");
            }
            else
            {
                var dbo=db.db("online_quiz");
                dbo.collection("registered_clg").find({},{ projection: { _id: 0, college: 1} }).toArray(function(err,result){
                    if(err)
                    {
                        console.log("error in finding array of college in signup");
                    }
                    else
                    {
                        res.render('signup',{info : result});
                     }
                })
            }
        });
    }
    else
     {
        res.redirect('/');
    }
});
app.get('/logout',function(req,res){
   if(!req.session.user)
   {
    res.redirect('/');
   }
   req.session.destroy();
   console.log("You are successfully Logged Out");
   res.redirect('/');
});

app.post('/add_clg',function(req,res){
    if(!req.session.user)
    {
        res.redirect('/');
    }
    else
    {

        var college = req.body.college;

        var domain = req.body.domain;

        var date = new Date();

        var sub = req.body.subjects;

        var subjects = sub.split(",");
        var data = {
            "college" : college,
            "domain" : domain,
            "date" : date,
            "subjects" : subjects
        }
       mongo.connect(url,function(err,db){
            if(err)
            {
                res.send("error in connecting");
            }
            else
            {
                var dbo=db.db("online_quiz");
                dbo.collection("registered_clg").findOne({college : data.college},function(err,user){
                    if(err)
                    {
                        console.log("error in finding college exist or not");
                    }
                    else if(user)
                    {
                      res.send("This College Already Exist");
                    }
                    else if(!user)
                    {
                         dbo.collection("registered_clg").insertOne(data,function(err,db){
                            if(err)
                            {
                                res.send("error in registering college");
                            }
                            res.send("successfully Submitted!!");
                         });
                    }
                });

            }
       });
       //res.redirect('/admin');
    }
});
 app.post('/del_clg',function(req,res){
      mongo.connect(url,function(err,db){
            if(err)
            {
                res.send("error in connecting");
            }
            else
            {
                console.log(req.body.array);
                var array = req.body.array;
                for(var i=0;i<array.length;i++){

                    var dbo=db.db("online_quiz");

                    dbo.collection("registered_clg").deleteOne({college : array[i]},function(err,user){
                        if(err)
                        {
                            console.log("error in deleting college");
                        }

                    });
                }
               res.send("successfully Deleted");
             }
         });
       });
 app.post('/create_test',function(req,res){

      var testname = req.body.testname;
      var test_key = req.body.test_key;
      var teachername = req.body.teachername;
      var email = req.body.email;
      var college = req.body.college;
      var subject = req.body.subject;
      var section = req.body.section;
      var start_time = req.body.start_time;
      var start_date = req.body.start_date;
      var end_time = req.body.end_time;
      var end_date = req.body.end_date;

      var data = {
        "testname" : testname,
        "test_key" : test_key,
        "teachername" : teachername,
        "email" : email,
        "college" : college,
        "subject" : subject,
        "section" : section,
        "start_time" : start_time,
        "start_date" : start_date,
        "end_time" : end_time,
        "end_date" : end_date
      }

      mongo.connect(url,function(err,db) {
          if(err) throw err;

          var dbo=db.db("online_quiz");
          dbo.collection("testTable").findOne({testname : data.testname},function(err,user){
            if(err)
            {
                console.log(error);
            }
            else if(user)
            {
                res.send("0");
            }
            else
            {
                dbo.collection("testTable").insertOne(data,function(err,db){
                    if(err)
                    {
                        console.log("error in signup in insertion");
                    }
                    else
                    {
                        res.send("successfully Details Submitted");
                    }
                });
            }
        });

 });
});

app.get('/faculty',function(req,res){
    if(!req.session.user )
    {
        res.redirect('/');
    }
     else if(result[0].type=='0')
    {
      res.redirect('/admin');
    }
    else if(result[0].type=='2')
    {
       res.redirect('/student');
    }
    else
     {
      mongo.connect(url,function(err,db){
          if(err)
          {
              throw err;
          }
          else
          {
              var dbo=db.db("online_quiz");
              dbo.collection("credentials").aggregate([{$match : { email : req.session.user}}]).toArray(function(err,result){
                  if(err)
                  {
                    console.log("err");
                  }
                  else
                  {
                   var college = result[0].college;
                   dbo.collection("registered_clg").aggregate([{$match : { college : college}}]).toArray(function(err,user){
                      if(err)
                      {
                        console.log("err");
                      }
                      else
                      {

                        var subject = user[0].subjects;

                        res.render('faculty',{
                        name : req.session.name,
                        email : req.session.user,
                        college : college,
                        subject : subject
                        });
                      }
                    });
                  }
              });
          }
        });
        }
    });

app.post('/add_question',function(req,res){

    var testname = req.body.testname;
    var college = req.body.college;
    var section = req.body.section;
    var question = req.body.question;
    var option1 = req.body.option1;
    var option2 = req.body.option2;
    var option3 = req.body.option3;
    var option4 = req.body.option4;
    var answer = req.body.answer;
    var mark = req.body.mark;
    var teacherEmail = req.body.teacherEmail;
    console.log(testname);
    var data = {
        "testname" : testname,
        "teacherEmail" : teacherEmail,
        "college"  : college,
        "section"  : section,
        "question" : question,
        "option1"  : option1,
        "option2"  : option2,
        "option3"  : option3,
        "option4"  : option4,
        "answer"  : answer,
        "mark"  : mark
    }

     mongo.connect(url,function(err,db){
                if(err)
                {
                    res.send("err");
                }
                else
                {
                    var dbo=db.db("online_quiz");
                    dbo.collection("Question").insertOne(data,function(err,result){
                        if(err)
                        {
                          res.send("err");
                        }
                        else
                        {
                            res.send("Added");
                        }
                    });
                }

     });
});

app.get('/view_test',function(req,res){
  if(!req.session.user)
  {
    res.redirect('/');
  }
  else
  {
    mongo.connect(url,function(err,db){
        if(err) throw err;
        else
        {
            var dbo=db.db("online_quiz");
             dbo.collection("testTable").find({email : req.session.user},{projection : { _id : 0, testname : 1}}).toArray(function(err,user){
              if(err)
              {
                console.log("err");
              }
              else
              {
                  res.render('view_test',{ tests : user});
              }
            });
        }
    });
  }
});

app.get('/students',function(req,res){
 if(!req.session.user)
 {
   if(req.session.type != "1")
   {
    req.session.destroy();
   }
    res.redirect('/');
 }
 else
 {
     mongo.connect(url,function(err,db){
        if(err) throw err;
        else
        {
            var url = require('url');
            var adr = req.url;
            var q = url.parse(adr, true);
            var qdata = q.query; //returns an object: { year: 2017, month: 'february' }
            var testid = qdata.name //returns 'february'
            testid =testid.replace(/["']/g,"");
            console.log(testid);
            console.log(req.session.user);
            var dbo=db.db("online_quiz");
            dbo.collection("Result").find({testname : testid,teacherEmail : req.session.user}).toArray(function(err,user){
                    if(err)
                    {
                      console.log("err");
                    }
                    else
                    {
                        console.log(user);
                      res.render('students',{ studentData : user });
                    }
                });
        }
      });
 }
});
app.get('/profile',function(req,res){
   if(!req.session.user)
   {
    res.redirect('/');
   }
    if(req.session.type != "1")
    {
       req.session.destroy();
       res.redirect('/');
    }
   else
   {
      mongo.connect(url,function(err,db){
        if(err) throw err;
        else
         {
            var dbo = db.db("online_quiz");
            dbo.collection('credentials').find({email : req.session.user},{projection : { _id : 0}}).toArray(function(err,result){
               var x = result[0].type;
               var type;
               if(x == "0")
               {
                 type = "Admin";
               }
               else if(x == 1)
               {
                 type = "Teacher";
               }
               else
               {
                 type = "student";
               }
                res.render('profile',{
                    name : result[0].name,
                    email : result[0].email,
                    type : type,
                    stream : result[0].stream,
                    college : result[0].college

                });
            });
         }
      });
    }
});

app.post('/change_password',function(req,res){
    if(!req.session.user)
    {
        res.redirect('/');
    }
    else
    {
        mongo.connect(url,function(err,db){
        if(err) throw err;
        else
         {
            var password = req.body.password;
            var new_password = req.body.new_password;
            var repeat_password = req.body.repeat_password;
            console.log(password+" "+new_password+" "+repeat_password);
            var dbo = db.db("online_quiz");
            dbo.collection("credentials").find({email : req.session.user},{projection : { _id : 0}}).toArray(function(err,result){
                if(password != result[0].password)
                {
                    res.send("1");
                }
                else if(new_password != repeat_password)
                {
                    res.send("2");
                }
                else{
                    var myquery = {password : result[0].password};
                    var newvalue = { $set : {password : new_password}};
                    dbo.collection('credentials').updateOne(myquery,newvalue,function(err,result){
                        if(err)
                        {
                            res.send("Error in Changing Password");
                        }
                        else
                        {
                            res.send("0");
                        }
                    });
                }
            });
        }
        });
    }
});

app.get('/student_view_test',function(req,res){
   if(!req.session.user)
   {
    res.redirect('/');
   }
   else if(req.session.type != "2")
   {
    res.redirect('/');
   }
   else
   {
       mongo.connect(url,function(err,db){
        if(err) throw err;
        else

          {
            var dbo = db.db("online_quiz");
            dbo.collection("Result").find({email : req.session.user}).toArray(function(err,user){
                if(err)
                {
                    console.log("err");
                }
                else
                {
                    res.render('student_view_test',{ info : user});
                }
            });
         }
        });
   }
});

app.get('/student',function(req,res){
    if(!req.session.user)
    {
        res.redirect('/');
    }
     else if(result[0].type=='0')
      {
         res.redirect('/Admin');
      }
      else if(result[0].type=='2')
      {
         res.redirect('/faculty');
      }
    else
    {
        mongo.connect(url,function(err,db){
        if(err) throw err;
        else
         {
            var dbo = db.db("online_quiz");
            dbo.collection("credentials").find({email : req.session.user},{projection : {_id : 0,college : 1,section : 1}}).toArray(function(err,user){
                var college = user[0].college;
                var section = user[0].section;

                dbo.collection("testTable").find({college : college, section : section},{projection : { _id : 0, testname : 1}}).toArray(function(err,result){
                    console.log(result);
                    res.render('student',{ info : result});
                });
            });

         }
       });
    }
 });
app.get('/key_check',function(req,res){
  if(!req.session.user)
  {
    res.redirect('/');
  }
  else
  {
     mongo.connect(url,function(err,db){
        if(err) throw err;
        else
         {
                var url = require('url');
                var a = req.url;
                var h = url.parse(a, true);
                var qdata = h.query; //returns an object: { year: 2017, month: 'february' }
                var testname = qdata.testname;
                testname = testname.replace(/["']/g,"");
                var dbo = db.db("online_quiz");
                dbo.collection("credentials").find({email : req.session.user},{projection : {_id : 0,college : 1,section : 1}}).toArray(function(err,user){
                var college = user[0].college;
                res.render('key_check',{college : college,testname : testname});
              });
          }
      });
   }
});

app.post('/check_key',function(req,res){
   if(!req.session.user)
   {
     res.redirect('/');
   }
   else
   {
      mongo.connect(url,function(err,db){
        if(err) throw err;
        else
         {
            var college = req.body.college;
            var testname = req.body.testname;
            var key = req.body.key;
            var dbo = db.db("online_quiz");
            dbo.collection('testTable').find({college : college,testname : testname}).toArray(function(err,result){
                if(key == result[0].test_key)
                {
                  res.send("key matched");
                }
                else
                {
                   res.send("Invalid Key");
                }
            });
         }
      });
   }
});
app.get('/test',function(req,res){
    if(!req.session.user)
    {
        res.redirect('/');
    }
    else if(req.session.type != "2")
    {
         res.redirect('/');
    }
    else
    {

            mongo.connect(url,function(err,db){
            if(err) throw err;
            else
             {
                var url = require('url');
                var a = req.url;
                var h = url.parse(a, true);
                var qdata = h.query; //returns an object: { year: 2017, month: 'february' }
                var testname = qdata.name;
                testname = testname.replace(/["']/g,"");
                var dbo = db.db("online_quiz");
                dbo.collection("credentials").find({email : req.session.user},{projection : {_id : 0,college : 1,section : 1}}).toArray(function(err,user){
                    var college = user[0].college;
                    var section = user[0].section;
                    dbo.collection("Question").find({college : college, section : section, testname : testname}).toArray(function(err,result){
                       res.render('test',{ data : result });
                    });
                });
            }
           });
    }
});

app.get('/practice',function(req,res){
  if(!req.session.user)
  {
    res.redirect('/');
  }
  if(req.session.type == "0" || req.session.type == "1")
  {
    req.session.destroy();
    res.redirect('/');
  }
  else
  {
      mongo.connect(url,function(err,db){
           if (err) {
            console.log("error in connecting database");
           }
           else
           {
              var dbo=db.db("online_quiz");
              dbo.collection("credentials").find({email : req.session.user}).toArray(function(err,result){
                 var college = result[0].college;
                 dbo.collection("registered_clg").find({college : college}).toArray(function(err,user){
                     var subjects = user[0].subjects;
                     res.render('practice',{ info : subjects });
                 });
              });
           }
      });
  }
});

app.get('/practice_test',function(req,res){
       if(!req.session.user)
       {
        res.redirect('/');
       }
       if(req.session.type == "0" || req.session.type == "1")
        {
          req.session.destroy();
          res.redirect('/');
        }
        else
        {
            mongo.connect(url,function(err,db){
               if (err) {
                console.log("error in connecting database");
               }
               else
               {
                  var url = require('url');
                  var adr = req.url;
                  var q = url.parse(adr, true);
                  var qdata = q.query; //returns an object: { year: 2017, month: 'february' }
                  var subject = qdata.name //returns 'february'
                  subject = subject.replace(/["']/g,"");
                  var dbo = db.db("online_quiz");
                  dbo.collection('practice_questions').find({subject : subject}).toArray(function(err,result){
                      if(err)
                      {
                        console.log("error");
                      }
                      else
                      {
                        res.render('practice_test',{ data : result });
                      }
                  });
               }
            });
        }
});