import ngModule from '../../module';
import Component from '../../lib/component';
import './style.scss';

/**
 * Calendar.
 *
 */
export default class Calendar extends Component {
    constructor($element, $scope) {
        super($element, $scope);
        this.events = [];
        this.defaultDate = new Date();
        this.displayControls = true;
        this.skip = 1;
    }

    get defaultDate() {
        return this._defaultDate;
    }

    set defaultDate(value) {
        this._defaultDate = value;

        this.repaint();
    }

    get currentMonth() {
        return this.defaultDate;
    }

    get events() {
        return this._events;
    }

    set events(value) {
        if (!value) return;

        value.map(event => {
            event.date = new Date(event.date);
        });

        this._events = value;

        if (value.length && this.defaultDate)
            this.repaint();
    }

    get nextMonth() {
        const newDate = new Date(this.currentMonth);
        newDate.setMonth(this.currentMonth.getMonth() + 1);

        return newDate;
    }

    get previousMonth() {
        const newDate = new Date(this.currentMonth);
        newDate.setMonth(this.currentMonth.getMonth() - 1);

        return newDate;
    }

    /**
     * Returns first day of month from a given date
     *
     * @param {Date} date - Origin date
     * @return {Integer}
     */
    firstDay(date) {
        const newDate = new Date(
            date.getFullYear(),
            date.getMonth(), 1);

        return newDate;
    }

    /**
     * Returns last day of month from a given date
     *
     * @param {Date} date - Origin date
     * @return {Integer}
     */
    lastDay(date) {
        const newDate = new Date(
            date.getFullYear(),
            date.getMonth() + 1, 0);

        return newDate;
    }

    repaint() {
        const firstWeekday = this.firstDay(this.currentMonth).getDay();
        const previousLastDay = this.lastDay(this.previousMonth).getDate();
        const currentLastDay = this.lastDay(this.currentMonth).getDate();
        const maxFields = 42; // Max field limit

        let weekdayOffset = firstWeekday > 0 ? firstWeekday : 7;
        let dayPrevious = previousLastDay - (weekdayOffset - 2);
        let dayCurrent = 1;
        let dayNext = 1;

        this.days = [];

        for (let fieldIndex = 1; fieldIndex <= maxFields; fieldIndex++) {
            if (fieldIndex < weekdayOffset) {
                this.addDay(this.previousMonth, dayPrevious, 'gray');
                dayPrevious++;
            } else if (fieldIndex >= weekdayOffset && dayCurrent <= currentLastDay) {
                this.addDay(this.currentMonth, dayCurrent);
                dayCurrent++;
            } else if (fieldIndex >= weekdayOffset && dayCurrent > currentLastDay) {
                this.addDay(this.nextMonth, dayNext, 'gray');
                dayNext++;
            }
        }
    }

    addDay(date, day, className = '', style) {
        const newDate = new Date(
            date.getFullYear(),
            date.getMonth(), day);

        let event = this.events.find(event => {
            return event.date >= newDate && event.date <= newDate;
        });

        if (newDate.getMonth() === this.currentMonth.getMonth() && newDate.getDay() == 0)
            className = 'red';

        if (event) {
            className = event.className;
            style = event.style;
        }


        this.days.push({date: newDate, className, style, event});
    }

    /**
     * Adds a new calendar event
     *
     * @param {Date} date - Day to add event
     * @param {String} className - [green, blue, orange, red]
     * @param {String} title - Tooltip description
     * @param {Boolean} isRemovable - True if is removable by users
     */
    addEvent(date, className, title = '', isRemovable = true) {
        const event = this.events.findIndex(event => {
            return event.date >= date && event.date <= date;
        });

        if (event == -1)
            this.events.push({date, className, title, isRemovable});

        this.repaint();
    }

    removeEvent(date) {
        const event = this.events.findIndex(event => {
            return event.date >= date && event.date <= date;
        });

        if (event > -1)
            this.events.splice(event, 1);

        this.repaint();
    }

    /**
     * Moves to next month
     *
     * @param {Integer} skip - Months to skip at once
     */
    moveNext(skip = 1) {
        let next = this.defaultDate.getMonth() + skip;
        this.defaultDate.setMonth(next);
        this.repaint();

        this.emit('moveNext');
    }

    /**
     * Moves to previous month
     *
     * @param {Integer} skip - Months to skip at once
     */
    movePrevious(skip = 1) {
        let previous = this.defaultDate.getMonth() - skip;
        this.defaultDate.setMonth(previous);
        this.repaint();

        this.emit('movePrevious');
    }

    /**
     * Day selection event
     *
     * @param {Integer} index - Index from days array
     */
    select(index) {
        let day = this.days[index];
        day.index = index;

        this.emit('selection', {values: [day]});
    }

    selectAll(weekday) {
        let selected = [];
        for (let i in this.days) {
            const day = this.days[i];
            const date = day.date;
            day.index = i;
            if (date.getDay() === weekday && date.getMonth() == this.defaultDate.getMonth())
                selected.push(day);
        }
        this.emit('selection', {values: selected});
    }
}

Calendar.$inject = ['$element', '$scope', '$attrs'];

ngModule.component('vnCalendar', {
    template: require('./index.html'),
    controller: Calendar,
    bindings: {
        model: '<',
        events: '<?',
        defaultDate: '<?',
        onSelection: '&?',
        onMoveNext: '&?',
        onMovePrevious: '&?',
        displayControls: '<?',
        skip: '<?'
    }
});