export class Highlighter {
    constructor(layout, clockElement, mode) {
        this._layout = layout;
        this._clockElement = clockElement;
        this._mode = mode === 'seconds' ? 'seconds' : 'time';
        this._time = null;
    }

    display(time) {
        if (this._mode === 'seconds') {
            const second = this._getSecond(time);
            if (this._getCurrentSecond() !== second) {
                this._clearAll();
                this._highlight(`second${second}`);
            }
        } else {
            const minute = this._getMinute(time);
            if (this._getCurrentMinute() !== minute) {
                const dotMinute = this._getDotMinute(time);
                const hour = this._getHour(time);
                this._clearAll();
                this._highlight('on');
                for (let i = 1; i <= dotMinute; i++) {
                    this._highlight(`dot${i}`);
                }
                this._highlight(`minute${minute}`);
                this._highlight(`hour${hour}`);
            }
        }
        this._time = time;
    }

    _getSecond(time) {
        if (typeof this._layout.getSeconds === 'function') {
            return this._layout.getSeconds(time);
        }
        return time.getSeconds();
    }

    _getDotMinute(time) {
        if (typeof this._layout.getDotMinute === 'function') {
            return this._layout.getDotMinute(time);
        }
        return time.getMinutes() % 5;
    }

    _getMinute(time) {
        if (typeof this._layout.getMinutes === 'function') {
            return this._layout.getMinutes(time);
        }
        return time.getMinutes();
    }

    _getHour(time) {
        if (typeof this._layout.getHours === 'function') {
            return this._layout.getHours(time);
        }
        const hour = time.getHours();
        if (time.getMinutes() >= 25) {
            return (hour + 1) % 24;
        }
        return hour;
    }

    _clearAll() {
        const items = this._clockElement.getElementsByClassName('item');
        for (let i = 0; i < items.length; i++) {
            items.item(i).classList.remove('active');
        }
    }

    _highlight(itemClass) {
        const items = this._clockElement.getElementsByClassName(`item ${itemClass}`);
        for (let i = 0; i < items.length; i++) {
            items.item(i).classList.add('active');
        }
    }

    _getCurrentSecond() {
        return !!this._time && this._time.getSeconds() || -1;
    }

    _getCurrentMinute() {
        return !!this._time && this._time.getMinutes() || -1;
    }
}