using Memento

function setup_logging(filename::String, handlername::Symbol=:log)
    isdir(dirname(filename)) || mkdir(dirname(filename))
    logger = Memento.config!("info", fmt="{date}| {msg}")
    handler = DefaultHandler(filename, DefaultFormatter("{date}| {msg}"))
    logger.handlers[String(handlername)] = handler
    return logger
end

macro logtime(logger, ex)
    quote
        local stats = Base.gc_num()
        local elapsedtime = Base.time_ns()
        local val = $(esc(ex))
        elapsedtime = Base.time_ns() - elapsedtime
        local diff = Base.GC_Diff(Base.gc_num(), stats)
        local ts = time_string(elapsedtime,
            diff.allocd,
            diff.total_time,
            Base.gc_alloc_count(diff)
            )
        $(esc(info))($(esc(logger)), ts)
        val
    end
end

function time_string(elapsedtime, bytes, gctime, allocs)
    str = @sprintf("%10.6f seconds", elapsedtime/1e9)
    if bytes != 0 || allocs != 0
        bytes, mb = Base.prettyprint_getunits(bytes, length(Base._mem_units), Int64(1024))
        allocs, ma = Base.prettyprint_getunits(allocs, length(Base._cnt_units), Int64(1000))
        if ma == 1
            str*= @sprintf(" (%d%s allocation%s: ", allocs, Base._cnt_units[ma], allocs==1 ? "" : "s")
        else
            str*= @sprintf(" (%.2f%s allocations: ", allocs, Base._cnt_units[ma])
        end
        if mb == 1
            str*= @sprintf("%d %s%s", bytes, Base._mem_units[mb], bytes==1 ? "" : "s")
        else
            str*= @sprintf("%.3f %s", bytes, Base._mem_units[mb])
        end
        if gctime > 0
            str*= @sprintf(", %.2f%% gc time", 100*gctime/elapsedtime)
        end
        str*=")"
    elseif gctime > 0
        str*= @sprintf(", %.2f%% gc time", 100*gctime/elapsedtime)
    end
    return str
end

import Base: info, @time

Base.info(x) = info(getlogger(), x)
macro time(x)
    return :(@logtime(getlogger(Main), $(esc(x))))
end