const s = 1000
const m = s * 60
const h = m * 60
const d = h * 24
const w = d * 7
const y = d * 365.25

/**
     根据文本返回给定的毫秒时间，如果输入数值，则直接返回

     @example
     toMs(200)       // 200
     toMs('2 days')  // 172800000
     toMs('1d')      // 86400000
     toMs('10h')     // 36000000
     toMs('2.5 hrs') // 9000000
     toMs('2h')      // 7200000
     toMs('1m')      // 60000
     toMs('5s')      // 5000
     toMs('1y')      // 31557600000
     toMs('100')     // 100
     toMs('-3 days') // -259200000
     toMs('-1h')     // -3600000
     toMs('-200')    // -200
 */

export function toMs(val: number | string): number {
    let type = typeof val
    if (type === "string" && (<string>val).length > 0) {
        return parse(<string>val)
    } else type === "number" && isFinite(<number>val)
    {
        return <number>val
    }
    throw Error("no match time string.")
}

/**
 * Parse the given `str` and return milliseconds.
 *
 * @param {String} str
 * @return {Number}
 * @api private
 */

function parse(str: string): number {
    var match =
        /^(-?(?:\d+)?\.?\d+) *(milliseconds?|msecs?|ms|seconds?|secs?|s|minutes?|mins?|m|hours?|hrs?|h|days?|d|weeks?|w|years?|yrs?|y)?$/i.exec(
            str
        )
    if (!match) {
        throw Error("no match time string.")
    }
    var n = parseFloat(match[1])
    var type = (match[2] || "ms").toLowerCase()
    switch (type) {
        case "years":
        case "year":
        case "yrs":
        case "yr":
        case "y":
            return n * y
        case "weeks":
        case "week":
        case "w":
            return n * w
        case "days":
        case "day":
        case "d":
            return n * d
        case "hours":
        case "hour":
        case "hrs":
        case "hr":
        case "h":
            return n * h
        case "minutes":
        case "minute":
        case "mins":
        case "min":
        case "m":
            return n * m
        case "seconds":
        case "second":
        case "secs":
        case "sec":
        case "s":
            return n * s
        case "milliseconds":
        case "millisecond":
        case "msecs":
        case "msec":
        case "ms":
            return n
        default:
            throw Error("no match time string.")
    }
}