--[[

     Licensed under GNU General Public License v2
      * (c) 2013,      Luca CPZ
      * (c) 2010-2012, Peter Hofmann

--]]

local helpers = require('lain.helpers')
local naughty = require('naughty')
local wibox = require('wibox')
local string = string

-- Network infos
-- lain.widget.net

local function factory(args)
	args = args or {}

	local net = { widget = args.widget or wibox.widget.textbox(), devices = {} }
	local timeout = args.timeout or 2
	local units = args.units or 1024 -- KB
	local notify = args.notify or 'on'
	local wifi_state = args.wifi_state or 'off'
	local eth_state = args.eth_state or 'off'
	local screen = args.screen or 1
	local format = args.format or '%.1f'
	local settings = args.settings or function() end

	-- Compatibility with old API where iface was a string corresponding to 1 interface
	net.iface = (
		args.iface and (type(args.iface) == 'string' and { args.iface })
		or (type(args.iface) == 'table' and args.iface)
	) or {}

	function net.get_devices()
		net.iface = {} -- reset at every call
		helpers.line_callback('ip link', function(line)
			net.iface[#net.iface + 1] = not string.match(line, 'LOOPBACK') and string.match(line, '(%w+): <') or nil
		end)
	end

	if #net.iface == 0 then
		net.get_devices()
	end

	function net.update()
		-- These are the totals over all specified interfaces
		net_now = {
			devices = {},
			-- Bytes since last iteration
			sent = 0,
			received = 0,
		}

		for _, dev in ipairs(net.iface) do
			local dev_now = {}
			local dev_before = net.devices[dev] or { last_t = 0, last_r = 0 }
			local now_t = tonumber(helpers.first_line(string.format('/sys/class/net/%s/statistics/tx_bytes', dev)) or 0)
			local now_r = tonumber(helpers.first_line(string.format('/sys/class/net/%s/statistics/rx_bytes', dev)) or 0)

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

			dev_now.sent = (now_t - dev_before.last_t) / timeout / units
			dev_now.received = (now_r - dev_before.last_r) / timeout / units

			net_now.sent = net_now.sent + dev_now.sent
			net_now.received = net_now.received + dev_now.received

			dev_now.sent = string.format(format, dev_now.sent)
			dev_now.received = string.format(format, dev_now.received)

			dev_now.last_t = now_t
			dev_now.last_r = now_r

			if
				wifi_state == 'on'
				and helpers.first_line(string.format('/sys/class/net/%s/uevent', dev)) == 'DEVTYPE=wlan'
			then
				dev_now.wifi = true
				if string.match(dev_now.carrier, '1') then
					dev_now.signal = tonumber(string.match(helpers.lines_from('/proc/net/wireless')[3], '(%-%d+%.)'))
						or nil
				end
			else
				dev_now.wifi = false
			end

			if
				eth_state == 'on'
				and helpers.first_line(string.format('/sys/class/net/%s/uevent', dev)) ~= 'DEVTYPE=wlan'
			then
				dev_now.ethernet = true
			else
				dev_now.ethernet = false
			end

			net.devices[dev] = dev_now

			-- Notify only once when connection is lost
			if string.match(dev_now.carrier, '0') and notify == 'on' and helpers.get_map(dev) then
				naughty.notify({
					title = dev,
					text = 'No carrier',
					icon = helpers.icons_dir .. 'no_net.png',
					screen = screen,
				})
				helpers.set_map(dev, false)
			elseif string.match(dev_now.carrier, '1') then
				helpers.set_map(dev, true)
			end

			net_now.carrier = dev_now.carrier
			net_now.state = dev_now.state
			net_now.devices[dev] = dev_now
			-- net_now.sent and net_now.received will be
			-- the totals across all specified devices
		end

		net_now.sent = string.format(format, net_now.sent)
		net_now.received = string.format(format, net_now.received)

		widget = net.widget
		settings()
	end

	helpers.newtimer('network', timeout, net.update)

	return net
end

return factory