const UserError = require('vn-loopback/util/user-error');

module.exports = Self => {
    Self.remoteMethodCtx('absences', {
        description: 'Returns an array of absences from an specified worker',
        accepts: [{
            arg: 'workerFk',
            type: 'Number',
            required: true,
        },
        {
            arg: 'started',
            type: 'Date',
            required: true,
        },
        {
            arg: 'ended',
            type: 'Date',
            required: true,
        }],
        returns: [{
            arg: 'calendar'
        },
        {
            arg: 'absences',
            type: 'Number'
        },
        {
            arg: 'holidays',
            type: 'Number'
        }],
        http: {
            path: `/absences`,
            verb: 'GET'
        }
    });

    Self.absences = async(ctx, workerFk, yearStarted, yearEnded) => {
        const models = Self.app.models;
        const isSubordinate = await models.Worker.isSubordinate(ctx, workerFk);

        if (!isSubordinate)
            throw new UserError(`You don't have enough privileges`);

        const calendar = {totalHolidays: 0, holidaysEnjoyed: 0};
        const holidays = [];

        // Get absences of year
        let absences = await Self.find({
            include: {
                relation: 'absenceType'
            },
            where: {
                workerFk: workerFk,
                dated: {between: [yearStarted, yearEnded]}
            }
        });

        let entitlementRate = 0;
        absences.forEach(absence => {
            const absenceType = absence.absenceType();
            const isHoliday = absenceType.code === 'holiday';
            const isHalfHoliday = absenceType.code === 'halfHoliday';

            if (isHoliday)
                calendar.holidaysEnjoyed += 1;
            if (isHalfHoliday)
                calendar.holidaysEnjoyed += 0.5;

            entitlementRate += absenceType.holidayEntitlementRate;

            absence.dated = new Date(absence.dated);
            absence.dated.setHours(0, 0, 0, 0);
        });

        // Get active contracts on current year
        const year = yearStarted.getFullYear();
        const contracts = await models.WorkerLabour.find({
            include: [{
                relation: 'holidays',
                scope: {
                    where: {year}
                }
            },
            {
                relation: 'workCenter',
                scope: {
                    include: {
                        relation: 'holidays',
                        scope: {
                            include: [{
                                relation: 'detail'
                            },
                            {
                                relation: 'type'
                            }],
                            where: {
                                dated: {between: [yearStarted, yearEnded]}
                            }
                        }
                    }
                }
            }],
            where: {
                and: [
                    {workerFk: workerFk},
                    {or: [{
                        ended: {gte: [yearStarted]}
                    }, {ended: null}]}
                ],

            }
        });

        // Get number of worked days
        let workedDays = 0;
        contracts.forEach(contract => {
            const started = contract.started;
            const ended = contract.ended;
            const startedTime = started.getTime();
            const endedTime = ended && ended.getTime() || yearEnded;
            const dayTimestamp = 1000 * 60 * 60 * 24;

            workedDays += Math.floor((endedTime - startedTime) / dayTimestamp);

            if (workedDays > daysInYear())
                workedDays = daysInYear();

            // Workcenter holidays
            let holidayList = contract.workCenter().holidays();
            for (let day of holidayList) {
                day.dated = new Date(day.dated);
                day.dated.setHours(0, 0, 0, 0);

                holidays.push(day);
            }
        });
        const currentContract = contracts.find(contract => {
            return contract.started <= new Date()
                && (contract.ended >= new Date() || contract.ended == null);
        });

        if (currentContract) {
            const maxHolidays = currentContract.holidays().days;
            calendar.totalHolidays = maxHolidays;

            workedDays -= entitlementRate;

            if (workedDays < daysInYear())
                calendar.totalHolidays = Math.round(2 * maxHolidays * (workedDays) / daysInYear()) / 2;
        }

        function daysInYear() {
            const year = yearStarted.getFullYear();

            return isLeapYear(year) ? 366 : 365;
        }

        return [calendar, absences, holidays];
    };

    function isLeapYear(year) {
        return year % 400 === 0 || (year % 100 !== 0 && year % 4 === 0);
    }
};