--[[

     Licensed under GNU General Public License v2
      * (c) 2018, Luca CPZ
      * (c) 2013, Conor Heine

--]]

local helpers = require('lain.helpers')
local focused = require('awful.screen').focused
local naughty = require('naughty')
local wibox = require('wibox')
local string = string
local type = type

-- ThinkPad battery infos and widget creator
-- http://www.thinkwiki.org/wiki/Tp_smapi
-- lain.widget.contrib.tp_smapi

local function factory(apipath)
	local tp_smapi = {
		path = apipath or '/sys/devices/platform/smapi',
	}

	function tp_smapi.get(batid, feature)
		return helpers.first_line(string.format('%s/%s/%s', tp_smapi.path, batid or 'BAT0', feature or ''))
	end

	function tp_smapi.installed(batid)
		return tp_smapi.get(batid, 'installed') == '1'
	end

	function tp_smapi.status(batid)
		return tp_smapi.get(batid, 'state')
	end

	function tp_smapi.percentage(batid)
		return tp_smapi.get(batid, 'remaining_percent')
	end

	-- either running or charging time
	function tp_smapi.time(batid)
		local status = tp_smapi.status(batid)
		local mins_left = tp_smapi.get(
			batid,
			string.match(string.lower(status), 'discharging') and 'remaining_running_time' or 'remaining_charging_time'
		)
		if not string.find(mins_left, '^%d+') then
			return 'N/A'
		end
		return string.format('%02d:%02d', math.floor(mins_left / 60), mins_left % 60) -- HH:mm
	end

	function tp_smapi.hide()
		if not tp_smapi.notification then
			return
		end
		naughty.destroy(tp_smapi.notification)
		tp_smapi.notification = nil
	end

	function tp_smapi.show(batid, seconds, scr)
		if not tp_smapi.installed(batid) then
			return
		end

		local mfgr = tp_smapi.get(batid, 'manufacturer') or 'no_mfgr'
		local model = tp_smapi.get(batid, 'model') or 'no_model'
		local chem = tp_smapi.get(batid, 'chemistry') or 'no_chem'
		local status = tp_smapi.get(batid, 'state')
		local time = tp_smapi.time(batid)
		local msg

		if status and status ~= 'idle' then
			msg = string.format(
				'[%s] %s %s',
				status,
				time ~= 'N/A' and time or 'unknown remaining time',
				string.lower(status):gsub(' ', ''):gsub('\n', '') == 'charging' and ' until charged' or ' remaining'
			)
		else
			msg = 'On AC power'
		end

		tp_smapi.hide()
		tp_smapi.notification = naughty.notify({
			title = string.format('%s: %s %s (%s)', batid, mfgr, model, chem),
			text = msg,
			timeout = type(seconds) == 'number' and seconds or 0,
			screen = scr or focused(),
		})
	end

	function tp_smapi.create_widget(args)
		args = args or {}

		local pspath = args.pspath or '/sys/class/power_supply/'
		local batteries = args.batteries or (args.battery and { args.battery }) or {}
		local timeout = args.timeout or 30
		local settings = args.settings or function() end

		if #batteries == 0 then
			helpers.line_callback('ls -1 ' .. pspath, function(line)
				local bstr = string.match(line, 'BAT%w+')
				if bstr then
					batteries[#batteries + 1] = bstr
				end
			end)
		end

		local all_batteries_installed = true

		for _, battery in ipairs(batteries) do
			if not tp_smapi.installed(battery) then
				naughty.notify({
					preset = naughty.config.critical,
					title = 'tp_smapi: error while creating widget',
					text = string.format('battery %s is not installed', battery),
				})
				all_batteries_installed = false
				break
			end
		end

		if not all_batteries_installed then
			return
		end

		tpbat = {
			batteries = batteries,
			widget = args.widget or wibox.widget.textbox(),
		}

		function tpbat.update()
			tpbat_now = {
				n_status = {},
				n_perc = {},
				n_time = {},
				status = 'N/A',
			}

			for i = 1, #batteries do
				tpbat_now.n_status[i] = tp_smapi.status(batteries[i]) or 'N/A'
				tpbat_now.n_perc[i] = tp_smapi.percentage(batteries[i])
				tpbat_now.n_time[i] = tp_smapi.time(batteries[i]) or 'N/A'

				if not tpbat_now.n_status[i]:lower():match('full') then
					tpbat_now.status = tpbat_now.n_status[i]
				end
			end

			widget = tpbat.widget -- backwards compatibility
			settings()
		end

		helpers.newtimer('thinkpad-batteries', timeout, tpbat.update)

		return tpbat
	end

	return tp_smapi
end

return factory