function datePickerValue()

in webui/js/ponymail.js [1384:1431]
43 lines of code
15 McCabe index (conditional complexity)

function datePickerValue(seedPeriod) {
    // This is for recalcing the set options if spawned from a
    // select/input box with an existing value derived from an
    // earlier call to datePicker
    let rv = seedPeriod
    if (seedPeriod && seedPeriod.search && seedPeriod.search(/=|-/) != -1) {

        // Less than N units ago?
        if (seedPeriod.match(/lte/)) {
            let m = seedPeriod.match(/lte=(\d+)([dMyw])/)
            let unitt = DATE_UNITS[m[2]]
            if (parseInt(m[1]) != 1) {
                unitt += "s"
            }
            rv = "Less than " + m[1] + " " + unitt + " ago"
        }

        // More than N units ago?
        if (seedPeriod.match(/gte/)) {
            let m = seedPeriod.match(/gte=(\d+)([dMyw])/)
            let unitt = DATE_UNITS[m[2]]
            if (parseInt(m[1]) != 1) {
                unitt += "s"
            }
            rv = "More than " + m[1] + " " + unitt + " ago"
        }

        // Date range?
        if (seedPeriod.match(/dfr/)) {
            let mf = seedPeriod.match(/dfr=(\d+-\d+-\d+)/)
            let mt = seedPeriod.match(/dto=(\d+-\d+-\d+)/)
            if (mf && mt) {
                rv = "From " + mf[1] + " to " + mt[1]
            }
        }

        // Month??
        if (seedPeriod.match(/^(\d+)-(\d+)$/)) {
            let mr = seedPeriod.match(/(\d+)-(\d+)/)
            if (mr) {
                let dfrom = new Date(parseInt(mr[1]), parseInt(mr[2]) - 1, 1, 0, 0, 0)
                rv = MONTHS[dfrom.getMonth()] + ', ' + mr[1]
            }
        }

    }
    return rv
}