'use strict';

const moment = require('moment-timezone');
const db = require('../../models/index');
const Op = require('sequelize').Op;

const {
    UI_TIMEZONE,
    BOOKING_CHANGE_PERCENTAGE_CHARGE,
    CHARGE_BOOKING_CHANGE_UNDER_TIME,
    ALLOWED_BOOKING_CANCELLATION_TIME,
    incidentType
} = require('../../constants/constants');

const bulkWriteBookingChangeIncidents = (incidents) => {
    return new Promise((resolve, reject) => {
        const asyncJobs = [];
        incidents.forEach((incident) => {
            asyncJobs.push(db.bookingChangeIncident.findOrCreate({where: incident, defaults: incident}));
        });

        Promise.all(asyncJobs)
            .then(() => {
                resolve();
            })
            .catch((error) => reject(error));
    });
};

const chargeBookingChanges = (changes) => {
    return new Promise((resolve, reject) => {
        if (Array.isArray(changes)){
            const incidents = [];
            changes.forEach((change) => {
                const { oldReservation, newReservation } = change;
                if (oldReservation && newReservation){
                    const oldResourceId = oldReservation.resourceId;
                    const oldStart = oldReservation.start ? moment.utc(oldReservation.start) : null;
                    const oldEnd = oldReservation.end ? moment.utc(oldReservation.end) : null;

                    const newStart = newReservation.start ? moment.utc(newReservation.start) : null;
                    const newEnd = newReservation.end ? moment.utc(newReservation.end) : null;
                    const reservationCreationTimestamp = newReservation.createdAt ? moment.utc(newReservation.createdAt) : null;

                    const reservationTimezone = newReservation.timezone ? newReservation.timezone : UI_TIMEZONE;
                    const reservationHourlyRate = oldReservation.hourlyRate ? oldReservation.hourlyRate : newReservation.hourlyRate;
                    const canceled = newReservation.canceled;

                    if (oldStart && oldEnd && newStart && newEnd && reservationHourlyRate){
                        const oldReservationLength = oldEnd.diff(oldStart, 'hours', true);
                        const newReservationLength = newEnd.diff(newStart, 'hours', true);

                        const differenceFromNow = oldStart.diff(moment.utc(), 'minutes');

                        if (differenceFromNow < CHARGE_BOOKING_CHANGE_UNDER_TIME){
                            const { reservationId, memberId, resourceId } = newReservation;

                            if (!canceled) {
                                // Check if new reservation is on same day
                                const sameDay = oldStart.tz(reservationTimezone).isSame(newStart.tz(reservationTimezone), 'day');

                                if (sameDay) {
                                    // Reservation moved in same day
                                    // Check if member shortened the reservation

                                    if (newReservationLength < oldReservationLength) {
                                        const differenceInLength = oldReservationLength - newReservationLength;
                                        const chargeFee = differenceInLength * reservationHourlyRate * BOOKING_CHANGE_PERCENTAGE_CHARGE / 100;

                                        const incident = {
                                            reservationId,
                                            memberId,
                                            oldResourceId: oldResourceId || resourceId,
                                            newResourceId: resourceId,
                                            oldBookingStart: oldReservation.start,
                                            oldBookingEnd: oldReservation.end,
                                            newBookingStart: newReservation.start,
                                            newBookingEnd: newReservation.end,
                                            incidentType: incidentType.BOOKING_SHORTENED,
                                            chargeFee,
                                        };

                                        incidents.push(incident);
                                    }
                                } else {
                                    // Reservation moved to another day
                                    // Add cancellation charge
                                    const chargeFee = oldReservationLength * reservationHourlyRate * BOOKING_CHANGE_PERCENTAGE_CHARGE / 100;

                                    const incident = {
                                        reservationId,
                                        memberId,
                                        oldResourceId: oldResourceId || resourceId,
                                        newResourceId: resourceId,
                                        oldBookingStart: oldReservation.start,
                                        oldBookingEnd: oldReservation.end,
                                        newBookingStart: newReservation.start,
                                        newBookingEnd: newReservation.end,
                                        incidentType: incidentType.BOOKING_MOVED_TO_ANOTHER_DAY,
                                        chargeFee,
                                    };

                                    incidents.push(incident);
                                }
                            }else{
                                const differenceFromCreation = moment.utc().diff(reservationCreationTimestamp, 'minutes');

                                if (differenceFromCreation > ALLOWED_BOOKING_CANCELLATION_TIME){
                                    const chargeFee = reservationHourlyRate * oldReservationLength * BOOKING_CHANGE_PERCENTAGE_CHARGE / 100;
                                    const incident = {
                                        reservationId,
                                        memberId,
                                        oldResourceId: oldResourceId || resourceId,
                                        newResourceId: null,
                                        oldBookingStart: oldReservation.start,
                                        oldBookingEnd: oldReservation.end,
                                        newBookingStart: null,
                                        newBookingEnd: null,
                                        incidentType: incidentType.BOOKING_CANCELED_LATE,
                                        chargeFee,
                                    };

                                    incidents.push(incident);
                                }
                            }
                        }
                    }
                }
            });
            resolve(bulkWriteBookingChangeIncidents(incidents));
        }else{
            reject('Input argument is not an array !');
        }
    });
};

const getChargedCanceledReservations = (reservationIds) => {
    const filters = {
        reservationId: {
            [Op.in]: reservationIds,
        },
        incidentType: incidentType.BOOKING_CANCELED_LATE,
    };

    const attributes = ['memberId', 'oldBookingStart', 'oldBookingEnd'];

    return db.bookingChangeIncident.findAll({attributes, where: filters});
};

module.exports = {
    chargeBookingChanges,
    getChargedCanceledReservations,
};