--[[
                                                  
     Licensed under GNU General Public License v2 
      * (c) 2013,      Luke Bonham                
      * (c) 2010-2012, Peter Hofmann              
                                                  
--]]

local helpers      = require("lain.helpers")
local naughty      = require("naughty")
local wibox        = require("wibox")

local string       = { format = string.format,
                       gsub   = string.gsub,
                       match  = string.match }

local setmetatable = setmetatable

-- Network infos
-- lain.widgets.net

local function worker(args)
    local net = { last_t = 0, last_r = 0 }

    function net.get_device()
        local ws = helpers.read_pipe("ip link show | cut -d' ' -f2,9")
        ws = ws:match("%w+: UP") or ws:match("ppp%w+: UNKNOWN")
        if ws  then return ws:match("(%w+):")
        else return "network off" end
    end

    local args     = args or {}
    local timeout  = args.timeout or 2
    local units    = args.units or 1024 --kb
    local notify   = args.notify or "on"
    local screen   = args.screen or 1
    local settings = args.settings or function() end
    local iface    = args.iface or net.get_device()

    net.widget = wibox.widget.textbox('')

    helpers.set_map(iface, true)

    function update()
        net_now = {}

        if iface == "" or string.match(iface, "network off")
        then
            iface = net.get_device()
        end

        net_now.carrier  = helpers.first_line(string.format('/sys/class/net/%s/carrier', iface)) or '0'
        net_now.state    = helpers.first_line(string.format('/sys/class/net/%s/operstate', iface)) or 'down'

        local now_t      = helpers.first_line(string.format('/sys/class/net/%s/statistics/tx_bytes', iface)) or 0
        local now_r      = helpers.first_line(string.format('/sys/class/net/%s/statistics/rx_bytes', iface)) or 0

        if now_t ~= net.last_t or now_r ~= net.last_r then  
            net_now.sent     = (now_t - net.last_t) / timeout / units
            net_now.sent     = string.gsub(string.format('%.1f', net_now.sent), ',', '.')
            net_now.received = (now_r - net.last_r) / timeout / units
            net_now.received = string.gsub(string.format('%.1f', net_now.received), ',', '.')

            widget = net.widget
            settings()

            net.last_t = now_t
            net.last_r = now_r
        end

        if not string.match(net_now.carrier, "1") and notify == "on"
        then
            if helpers.get_map(iface)
            then
                naughty.notify({
                    title    = iface,
                    text     = "no carrier",
                    icon     = helpers.icons_dir .. "no_net.png",
                    screen   = screen
                })
                helpers.set_map(iface, false)
            end
        else
            helpers.set_map(iface, true)
        end
    end

    helpers.newtimer(iface, timeout, update)

    return setmetatable(net, { __index = net.widget })
end

return setmetatable({}, { __call = function(_, ...) return worker(...) end })