'use strict';

// SQL car reservation before-hook
module.exports = function(Mcarreservation) {
  Mcarreservation.beforeRemote('create',
    function(ctx, model, next) {

      Promise.try(doReservation(Mcarreservation, ctx, model, next)).catch(
          (e) => {
            e.statusCode = e.status = 404;
            next(e);
            return;
          }
        );
    });
};

function doReservation(Mcarreservation, ctx, model, next) {
  // models
  var sqlCarReservation = Mcarreservation.app.models.CarReservation;
  var sCar = Mcarreservation.app.models.sCar;
  // data source
  var postgres = sCar.app.dataSources.postgres;
  // begin transaction
  sqlCarReservation.beginTransaction({
    isolationLevel: sqlCarReservation.Transaction.READ_COMMITTED,
  }, function(err, tx) {
    if (err) throw err;
    // lock car for update
    postgres.connector.execute(
      'SELECT * FROM sCar WHERE mongoId = $1 FOR UPDATE;'
      , [ctx.req.body.carId], function(err, data) {
        sCar.findOne({where: {mongoId: ctx.req.body.carId}}).then((car)=>{
          sqlCarReservation.find(
            {
              where: {sCarId: car.id},
            }).then((data)=> {
              data.forEach((element) => {
                var start1 = element.startDate.getTime();
                var end1 = element.endDate.getTime();
                var start2 =  ctx.req.body.startDate;
                var end2 = ctx.req.body.endDate;
                if ((start1 >=  start2 && start1 <= end2) ||
                  (start2 >= start1 && start2 <= end1)) {
                  tx.rollback(function(err) {
                    if (err) throw err;

                    var error = new Error('Car is already reserved');

                    throw error;
                  });
                }
              });

              if (err) {
                tx.rollback(function(err) {
                  if (err) throw err;
                });
                throw err;
              }
              // fetch car from sql
              sCar.findOne({where: {mongoId: ctx.req.body.carId}})
                .then((car)=>{
                  // create reservation
                  sqlCarReservation.create(
                    {
                      timeStamp: ctx.req.body.timeStamp,
                      sCar: car,
                      startDate: ctx.req.body.startDate,
                      endDate: ctx.req.body.endDate,
                    },
                    {transaction: tx},
                    function(err, cr) {
                      if (err) {
                        tx.rollback(function(err) {
                          if (err)  throw err;
                        });
                        throw err;
                      }
                      // commit and end before-hook
                      tx.commit(function(err) {
                        if (err)  throw err;
                        next();
                      });
                    });
                });
            });
        });
      });
  });
}