import AnsiUp from 'ansi_up';
import { ObjectID } from 'mongodb';
import md5 from './md5';

const AU = new AnsiUp();

export function ansiToHtml(str: string) {
    return AU.ansi_to_html(str);
}

export function gravatar(email: string, s = 32) {
    return `//gravatar.loli.net/avatar/${md5((email || '').toString().trim().toLowerCase())}?d=mm&s=${s}`;
}

export function datetimeSpan(dt: Date | ObjectID, relative = true, format = '%Y-%m-%d %H:%M:%S') {
    if (!dt) return 'DATETIME_SPAN_ERROR';
    if (dt instanceof ObjectID) dt = new Date(dt.generationTime * 1000);
    else if (typeof dt === 'number' || typeof dt === 'string') dt = new Date(dt);
    return '<span class="time{0}" data-timestamp="{1}">{2}</span>'.format(
        relative ? ' relative' : '',
        dt.getTime() / 1000,
        dt.format(format),
    );
}

export function* paginate(page: number, numPages: number) {
    const radius = 2;
    let first: number;
    let last: number;
    if (page > 1) {
        if (page > 2) yield ['first', 1];
        yield ['previous', page - 1];
    }
    if (page <= radius) [first, last] = [1, Math.min(1 + radius * 2, numPages)];
    else if (page >= numPages - radius) {
        [first, last] = [Math.max(1, numPages - radius * 2), numPages];
    } else {
        [first, last] = [page - radius, page + radius];
    }
    if (first > 1) yield ['ellipsis', 0];
    for (let page0 = first; page0 < last + 1; page0++) {
        if (page0 !== page) yield ['page', page0];
        else yield ['current', page];
    }
    if (last < numPages) yield ['ellipsis', 0];
    if (page < numPages) {
        yield ['next', page + 1];
        if (page < numPages - 1) yield ['last', numPages];
    }
}

export function size(s: number, base = 1) {
    s *= base;
    const unit = 1024;
    const unitNames = ['Bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB'];
    for (const unitName of unitNames) {
        if (s < unit) return '{0} {1}'.format(Math.round(s * 10) / 10, unitName);
        s /= unit;
    }
    return `${Math.round(s * unit)} ${unitNames[unitNames.length - 1]}`;
}

function _digit2(number: number) {
    return number < 10 ? `0${number}` : number.toString();
}

export function formatSeconds(_seconds = '0') {
    const seconds = parseInt(_seconds, 10);
    return '{0}:{1}:{2}'.format(
        _digit2(Math.floor(seconds / 3600)),
        _digit2(Math.floor((seconds % 3600) / 60)),
        _digit2(seconds % 60),
    );
}

global.Hydro.lib.misc = {
    gravatar, datetimeSpan, paginate, size, formatSeconds, ansiToHtml,
};