const fs = require('fs')
const SamlStrategy = require('passport-saml').Strategy
const dbconn = require('./dbconn')
const methods = require('./methods')
// pwd encryption
const bcrypt = require('bcryptjs')
const saltRounds = 10
// forgot pwd
const async = require('async')
const crypto = require('crypto')
const nodemailer = require('nodemailer')

module.exports = function (app, config, passport) {

  // =========== PASSPORT =======
  passport.serializeUser(function (user, done) {
    done(null, user);
  });

  passport.deserializeUser(function (user, done) {
    done(null, user);
  });

  var samlStrategy = new SamlStrategy({
      // URL that goes from the Identity Provider -> Service Provider
      callbackUrl: config.passport.saml.path,
      // Base address to call logout requests
      logoutUrl: config.passport.saml.logoutUrl,
      
      entryPoint: config.passport.saml.entryPoint,
      issuer: config.passport.saml.issuer,
      identifierFormat: null,
      
      // Service Provider private key
      decryptionPvk: fs.readFileSync(__dirname + '/cert/key.pem', 'utf8'),
      // Service Provider Certificate
      privateCert: fs.readFileSync(__dirname + '/cert/key.pem', 'utf8'),
      // Identity Provider's public key
      cert: fs.readFileSync(__dirname + '/cert/cert_idp.pem', 'utf8'),
      
      validateInResponseTo: false,
      disableRequestedAuthnContext: true
  },
  function (profile, done) {
    return done(null, {
      id: profile.nameID,
      idFormat: profile.nameIDFormat,
      email: profile.email,
      firstName: profile.givenName,
      lastName: profile.sn
    });
  });
  
  passport.use(samlStrategy);

  // ============= SAML ==============
  app.post(config.passport.saml.path,
    passport.authenticate(config.passport.strategy,
      {
        failureRedirect: '/',
        failureFlash: true
      }),
    function (req, res) {
      res.redirect('/');
    }
  );

  // to generate Service Provider's XML metadata
  app.get('/saml/metadata', 
    function(req, res) {
      res.type('application/xml');
      var spMetadata = samlStrategy.generateServiceProviderMetadata(fs.readFileSync(__dirname + '/cert/cert.pem', 'utf8'));
      res.status(200).send(spMetadata);
    }
  );

  // ======== NODEMAILER ====================
  var smtpTransport = nodemailer.createTransport({
    host: config.mailer.host,
    secureConnection: config.mailer.secureConnection,
    port: config.mailer.port,
    auth: {
      user: config.mailer.authUser,
      pass: config.mailer.authPass
    },
    tls: {
        ciphers: config.mailer.tlsCiphers
    } 
  });
  
  var mailOptions = {
    to: "",
    from: config.mailer.from,
    subject: "",
    text: ""
  };
  
  // ======== APP ROUTES ====================
  app.get('/', function (req, res) {
    res.redirect('/profile')
  });

  app.get('/login',
    passport.authenticate(config.passport.strategy,
      {
        successRedirect: '/',
        failureRedirect: '/login'
      })
  );

  app.get('/logout', function (req, res) {
    if (req.user == null) {
      return res.redirect('/');
    }
    
    req.user.nameID = req.user.id;
    req.user.nameIDFormat = req.user.idFormat;
    return samlStrategy.logout(req, function(err, uri) {
      req.logout();
      
      if ( req.session ) {
        req.session.destroy((err) => {
          if(err) {
              return console.log(err);
          }
        });
      }
     
      return res.redirect(uri);
    });
  });

  app.get('/profile', function (req, res) {
    if (req.isAuthenticated()) {
      methods.getUserByEmail(req.user.email, function(data, err){
        if (!err) {
          res.render('profile', {
            user: data,
            email: req.user.email
          });
        }
      })
    } else {
      res.redirect('/login');
    }
  });

  app.get('/services', function (req, res) {
    if (req.isAuthenticated()) {
      async.waterfall([
        // get userId by email from userdb
        function(done) {
          methods.getUserIdByEmail(req.user.email, function(userId, err) {
            if (!err) {
              done(err, userId)
            }
          })
        },
        // get user-project-role from userdb
        function(userId, done) {
          methods.getUserProjectRole(userId, function(userProjects, err) {
            if (!err) {
              done(err, userProjects)
            }
          })
        },
        // get all projects from projectdb
        function(userProjects, done) {
          methods.getAllProjects(function(projectsOverview, err) {
            if (!err) {
              done(err, userProjects, projectsOverview)
            }
          })
        },
        // create JSON object of projects and user status for front-end
        function(userProjects, projectsOverview, done) {
          var allProjects = []  // JSON object
          
          var userProjectId = []  // array of user's project_id
          for (var i = 0; i < userProjects.length; i++) {
            userProjectId.push(userProjects[i].project_id)
          }

          for (var i = 0; i < projectsOverview.length; i++) {
            // check if projectId is exist in userProjectId[]
            var status = "You cannot access this service"
            if (userProjectId.indexOf(projectsOverview[i].id) > -1) {
              status = "You can access this service"
            }
            // add data to JSON object
            allProjects.push({
              id: projectsOverview[i].id,
              title: projectsOverview[i].title,
              summary: projectsOverview[i].onelinesummary,
              cp: projectsOverview[i].contact_email,
              userStatus: status
            });
          }

          // render the page
          res.render('services', {
            user: req.user,
            project: allProjects
          });
        }
      ])
    } else {
      res.redirect('/login');
    }
  });

  app.get('/security', function (req, res) {
    if (req.isAuthenticated()) {
      console.log(req.user)
      res.render('security', {
        user: req.user // useful for view engine, useless for HTML
      });
    } else {
      res.redirect('/login');
    }
  });

  app.post('/updateProfile', function (req, res) {
    var userData = {
      title: req.body.inputTitle,
      firstname: req.body.inputFirstname,
      lastname: req.body.inputLastname,
      email: req.body.inputEmail,
      organisation: req.body.inputOrganisation,
      industry: req.body.inputIndustry,
      speciality: req.body.inputSpeciality,
    }
    
    if (req.isAuthenticated()) {
      if (userData.email) {
        dbconn.user.query('UPDATE user SET ? WHERE email = "' +userData.email+'"', userData, function (err, rows, fields) {
            //if (err) throw err;
            if (err) {
              req.flash('error', "Failed");
            }
            else {
              req.flash('success', 'Profile updated!');
            }
            res.redirect('/profile');
        })
      }
    } else {
      res.redirect('/login');
    }
  });
  
  app.post('/changePwd', function (req, res) {
    if (req.isAuthenticated()) {
      var currPwd = req.body.inputCurrPwd
      var newPwd = req.body.inputNewPwd
      var retypePwd = req.body.inputConfirm

      methods.getUserIdByEmail(req.user.email, function(userId, err) {
        if (!err) {
          // Load hashed passwd from DB
          dbconn.user.query('SELECT password FROM credential WHERE user_id='+userId, function (err, rows, fields) {
            if (err) {
              res.redirect('/500')
              throw err
            }
            var userPwd = rows[0].password

            // check if the password is correct
            bcrypt.compare(currPwd, userPwd, function(err, isMatch) {
              if (err) {
                res.redirect('/500')
                throw err
              }
              else if (!isMatch) {
                req.flash('error', "Sorry, your password was incorrect. Please double-check your password.")
                res.redirect('/security')
              }
              else {
                if ( newPwd != retypePwd ) {
                  req.flash('error', "Passwords do no match. Please make sure you re-type your new password correctly.")
                  res.redirect('/security')
                }
                else {
                  // update password
                  bcrypt.genSalt(saltRounds, function(err, salt) {
                    bcrypt.hash(newPwd, salt, function(err, hash) {
                      var credentialData = {
                        password: hash,
                        user_id: userId
                      }
                      methods.updateCredential(credentialData, function(err){
                        if (err) {
                          req.flash('error', "Database error: Password cannot be modified.")
                          throw err
                        }
                        else {
                          req.flash('success', "Pasword updated!")
                          console.log('pasword updated!')
                        }
                        res.redirect('/security')
                      })
                    });
                  });
                }
              }
          }) 
        })
        }
      })  
    }
    else {
      res.redirect('/login');
    }
  });

  app.get('/forgotPwd', function (req, res) {
    res.render('forgotPwd', {
      user: req.user
    });
  });

  app.post('/forgotPwd', function(req, res, next) {
    //methods.currentDate();

    var emailAddress = req.body.inputEmail;
    var emailContent = "Hi there,\n\n"+
      "we've received a request to reset your password. However, this email address is not on our database of registered users.\n\n"+
      "Thanks,\nM4_LAB Team";
    var emailSubject = "Account Access Attempted";
    
    async.waterfall([
      function(done) {
        crypto.randomBytes(20, function(err, buf) {
          var token = buf.toString('hex');
          done(err, token);
        });
      },
      function(token, done) {
        methods.checkUserEmail(emailAddress, function(err, user){
          if (user) {
            console.log("email: user found");
            emailSubject = "M4_LAB Password Reset";
            emailContent = "Hi User,\n\n"+
              "we've received a request to reset your password. If you didn't make the request, just ignore this email.\n\n"+
              "Otherwise, you can reset your password using this link: http://" + req.headers.host + "/reset/" + token + "\n" +
              "This password reset is only valid for 1 hour.\n\n"+
              "Thanks,\nM4_LAB Team"
            
            var credentialData = {
              user_id: user.id,
              resetPasswordToken: token,
              resetPasswordExpires: Date.now() + 3600000 // 1 hour
            }
            methods.updateCredential(credentialData, function(err) {
              done(err, token, user);
            });
          }
          else {
            done(err, null, null);
          }
        });
      },
      function(token, user, done) {
        mailOptions.to = emailAddress;
        mailOptions.subject = emailSubject;
        mailOptions.text = emailContent;
        smtpTransport.sendMail(mailOptions, function(err) {
          done(err, 'done');
        });
      }
    ], function(err) {
      if (err) {
        req.flash('error', 'An error occured. Please try again.');
      }
      else {
        req.flash('success', 'An e-mail has been sent to ' + emailAddress + ' with further instructions.');
      }
      res.redirect('/forgotPwd');
    });
  });

  app.get('/reset/:token', function(req, res) {
    methods.checkUserToken(req.params.token, function(err, user){
      //console.log(user);
      if (!user) {
        req.flash('error', 'Password reset token is invalid or has expired.');
        res.redirect('/forgotPwd');
      }
      else {
        res.render('reset');
      }
    });
  });

  app.post('/reset/:token', function(req, res) {
    methods.checkUserToken(req.params.token, function(err, user){
      if (user) {
        // encrypt password
        bcrypt.genSalt(saltRounds, function(err, salt) {
          bcrypt.hash(req.body.inputNewPwd, salt, function(err, hash) {
            var credentialData = {
              password: hash,
              user_id: user.user_id
            }
            // update password
            methods.updateCredential(credentialData, function(err){
              if (err) {
                req.flash('error', "Database error: Password cannot be modified.")
                throw err
              }
              else {
                req.flash('success', "Your pasword has been updated.")
                console.log('pasword updated!')
                res.redirect('/login')
                // todo: send confirmation email
              }
            })
          });
        });
      }
      else {
        req.flash('error', "User not found.")
        res.redirect('/login')
      }
    });
   
    //res.redirect('/login')
  });

  // todo: user registration with captcha
  app.get('/registration', function(req, res) {
    res.render('registration')
  })

  app.post('/registration', function(req, res) {
    // TODO:
    // create gitlab account?
    // send email to activate profile?

    // user data
    var curDate = new Date()
    var userData = {
      title: req.body.inputTitle,
      firstname: req.body.inputFirstname,
      lastname: req.body.inputLastname,
      email: req.body.inputEmail,
      organisation: req.body.inputOrganisation,
      industry: req.body.inputIndustry,
      speciality: req.body.inputSpeciality,
      createdDate: curDate.toISOString().slice(0,10)
    }
    // encrypt password
    bcrypt.genSalt(saltRounds, function(err, salt) {
      bcrypt.hash(req.body.inputPassword, salt, function(err, hash) {
        // create account
        var newAccount = {
          profile: userData,
          password: hash
        }
        methods.registerNewUser(newAccount, function(err){
          if (err) {
            req.flash('error', "Failed");
          }
          else {
            req.flash('success', 'Your account has been created. Please log in.');
          }
          res.redirect('/registration');
        })
      });
    });
  })

  app.get('/email/:email', function(req, res) {
    methods.checkUserEmail(req.params.email, function(err, user){
      if (!err) {
        if (user) {
          res.send(false)
        }
        else {
          res.send(true)
        }  
      }
    })
  })

};