declare('fuzzy', {})
local time_map = {
    months  = {value = 2419200},
    weeks   = {value =  604800, noun = ' week'},
    days    = {value =   86400, noun = ' day'},
    hours   = {value =    3600, noun = ' hour'},
    minutes = {value =      60, noun = ' minute'},
    seconds = {value =       0, noun = ' second'}
}

local difftime = os.difftime
local floor = math.floor

function fuzzy.diff(b, a, fuzziness)
    --fuzziness should be called with the key name you wish for the diff to stop being fuzzy.
    --if you want to see ## days ago, then set fuzziness to 'weeks'
    fuzziness = fuzziness or 'weeks'
    local diff = difftime(b, a)
    if diff < 0 then return nil end

    local str, ftime = ''
    if (diff >= time_map.months.value or fuzziness == 'none') then
        return a

    elseif (diff >= time_map.weeks.value and diff < time_map[fuzziness].value) then
        ftime = floor(diff / time_map.weeks.value)
        str = ftime..time_map.weeks.noun

    elseif (diff >= time_map.days.value and diff < time_map[fuzziness].value) then
        ftime = floor(diff / time_map.days.value)
        str = ftime..time_map.days.noun

    elseif (diff >= time_map.hours.value and diff < time_map[fuzziness].value) then
        ftime = floor(diff / time_map.hours.value)
        str = ftime..time_map.hours.noun

    elseif (diff >= time_map.minutes.value and diff < time_map[fuzziness].value) then
        ftime = floor(diff / time_map.minutes.value)
        str = ftime..time_map.minutes.noun

    elseif (diff < time_map[fuzziness].value) then
        ftime = diff
        str = ftime..time_map.seconds.noun

    else
        return a
    end

    if (ftime > 1) then str = str..'s' end
    str = str..' ago'

    return str
end