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

/**
 * Flat 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;
    }

    /**
     * Returns the initial date
     *
     * @return {Date} - Default date
     */
    get defaultDate() {
        return this._defaultDate;
    }

    /**
     * Sets a new initial date
     *
     * @param {Date} value - New default date
     */
    set defaultDate(value) {
        this._defaultDate = value;

        this.repaint();
    }

    /**
     * Sets initial events
     *
     * @param {Array} value - Array of events
     */
    set data(value) {
        if (!value) return;

        this.events = [];

        value.forEach(event => {
            this.addEvent(event);
        });

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

    /**
     * Gets current month date
     */

    get currentMonth() {
        return this.defaultDate;
    }

    /**
     * Gets next month date
     *
     * @return {Date}
     */
    get nextMonth() {
        const newDate = new Date(this.currentMonth);
        newDate.setMonth(this.currentMonth.getMonth() + 1);

        return newDate;
    }

    /**
     * Gets previous month date
     *
     * @return {Date}
     */
    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++) {
            // Insert previous month days
            if (fieldIndex < weekdayOffset) {
                const dated = new Date(
                    this.previousMonth.getFullYear(),
                    this.previousMonth.getMonth(), dayPrevious);

                this.insertDay(dated, 'gray');
                dayPrevious++;
            }

            // Insert current month days
            if (fieldIndex >= weekdayOffset && dayCurrent <= currentLastDay) {
                const dated = new Date(
                    this.currentMonth.getFullYear(),
                    this.currentMonth.getMonth(), dayCurrent);

                this.insertDay(dated);
                dayCurrent++;
            }

            // Insert next month days
            if (fieldIndex >= weekdayOffset && dayCurrent > currentLastDay) {
                const dated = new Date(
                    this.nextMonth.getFullYear(),
                    this.nextMonth.getMonth(), dayNext);

                this.insertDay(dated, 'gray');
                dayNext++;
            }
        }
    }

    /**
     * Inserts a date on an array of month days
     *
     * @param {Date} dated - Date of month
     * @param {String} className - Default class style
     */
    insertDay(dated, className = '') {
        let event = this.events.find(event => {
            return event.dated >= dated && event.dated <= dated;
        });

        // Weeekends
        if (dated.getMonth() === this.currentMonth.getMonth() && dated.getDay() == 0)
            className = 'red';

        this.days.push({dated, className, event});
    }

    /**
     * Adds a new calendar event
     *
     * @param {Object} options - Event params
     * @param {Date} options.dated - Day to add event
     * @param {String} options.title - Tooltip description
     * @param {String} options.className - ClassName style
     * @param {Object} options.style - Style properties
     * @param {Boolean} options.isRemovable - True if is removable by users
     */
    addEvent(options) {
        if (!Object.hasOwnProperty.call(options, 'isRemovable'))
            options.isRemovable = true;

        options.dated = new Date(options.dated);
        options.dated.setHours(0, 0, 0, 0);

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

        if (event < 0)
            this.events.push(options);
    }

    /**
     * Removes an event from an array of events
     * @param {Object} dated - Dated event
     */
    removeEvent(dated) {
        dated = new Date(dated);
        dated.setHours(0, 0, 0, 0);

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

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

    /**
     * Moves to next month(s)
     *
     * @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(s)
     *
     * @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]});
    }

    /**
     * WeekDay selection event
     *
     * @param {Integer} weekday - weekday index
     */
    selectAll(weekday) {
        let selected = [];
        for (let i in this.days) {
            const day = this.days[i];
            const date = day.dated;
            day.index = i;
            if (date.getDay() === weekday && date.getMonth() == this.defaultDate.getMonth())
                selected.push(day);
        }
        this.emit('selection', {values: selected});
    }
}

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

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