--[[

     Licensed under GNU General Public License v2
      * (c) 2018, Uli Schlacter
      * (c) 2018, Otto Modinos
      * (c) 2013, Luca CPZ

--]]

local helpers = require('lain.helpers')
local Gio = require('lgi').Gio
local focused = require('awful.screen').focused
local wibox = require('wibox')
local naughty = require('naughty')
local gears = require('gears')
local math = math
local string = string
local tconcat = table.concat
local type = type
local query_size = Gio.FILE_ATTRIBUTE_FILESYSTEM_SIZE
local query_free = Gio.FILE_ATTRIBUTE_FILESYSTEM_FREE
local query_used = Gio.FILE_ATTRIBUTE_FILESYSTEM_USED
local query = query_size .. ',' .. query_free .. ',' .. query_used

-- File systems info
-- lain.widget.fs

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

	local fs = {
		widget = args.widget or wibox.widget.textbox(),
		units = {
			[1] = 'Kb',
			[2] = 'Mb',
			[3] = 'Gb',
			[4] = 'Tb',
			[5] = 'Pb',
			[6] = 'Eb',
			[7] = 'Zb',
			[8] = 'Yb',
		},
	}

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

	function fs.show(seconds, scr)
		fs.hide()
		fs.update(function()
			fs.notification_preset.screen = fs.followtag and focused() or scr or 1
			fs.notification = naughty.notify({
				preset = fs.notification_preset,
				timeout = type(seconds) == 'number' and seconds or 5,
			})
		end)
	end

	local timeout = args.timeout or 600
	local partition = args.partition
	local threshold = args.threshold or 99
	local showpopup = args.showpopup or 'on'
	local settings = args.settings or function() end

	fs.followtag = args.followtag or false
	fs.notification_preset = args.notification_preset

	if not fs.notification_preset then
		fs.notification_preset = {
			font = 'Monospace 10',
			fg = '#FFFFFF',
			bg = '#000000',
		}
	end

	local function update_synced()
		local pathlen = 10
		fs_now = {}

		local notifypaths = {}
		for _, mount in ipairs(Gio.unix_mounts_get()) do
			local path = Gio.unix_mount_get_mount_path(mount)
			local root = Gio.File.new_for_path(path)
			local info = root:query_filesystem_info(query)

			if info then
				local size = info:get_attribute_uint64(query_size)
				local used = info:get_attribute_uint64(query_used)
				local free = info:get_attribute_uint64(query_free)

				if size > 0 then
					local units = math.floor(math.log(size) / math.log(1024))

					fs_now[path] = {
						units = fs.units[units],
						percentage = math.floor(100 * used / size), -- used percentage
						size = size / math.pow(1024, units),
						used = used / math.pow(1024, units),
						free = free / math.pow(1024, units),
					}

					if fs_now[path].percentage > 0 then -- don't notify unused file systems
						notifypaths[#notifypaths + 1] = path

						if #path > pathlen then
							pathlen = #path
						end
					end
				end
			end
		end

		widget = fs.widget
		settings()

		if partition and fs_now[partition] and fs_now[partition].percentage >= threshold then
			if not helpers.get_map(partition) then
				naughty.notify({
					preset = naughty.config.presets.critical,
					title = 'Warning',
					text = string.format('%s is above %d%% (%d%%)', partition, threshold, fs_now[partition].percentage),
				})
				helpers.set_map(partition, true)
			else
				helpers.set_map(partition, false)
			end
		end

		local fmt = '%-' .. tostring(pathlen) .. 's %4s\t%6s\t%6s\n'
		local notifytable = { [1] = string.format(fmt, 'path', 'used', 'free', 'size') }
		fmt = '\n%-' .. tostring(pathlen) .. 's %3s%%\t%6.2f\t%6.2f %s'
		for _, path in ipairs(notifypaths) do
			notifytable[#notifytable + 1] = string.format(
				fmt,
				path,
				fs_now[path].percentage,
				fs_now[path].free,
				fs_now[path].size,
				fs_now[path].units
			)
		end

		fs.notification_preset.text = tconcat(notifytable)
	end

	function fs.update(callback)
		Gio.Async.start(gears.protected_call.call)(function()
			update_synced()
			if type(callback) == 'function' and callback then
				callback()
			end
		end)
	end

	if showpopup == 'on' then
		fs.widget:connect_signal('mouse::enter', function()
			fs.show(0)
		end)
		fs.widget:connect_signal('mouse::leave', function()
			fs.hide()
		end)
	end

	helpers.newtimer(partition or 'fs', timeout, fs.update)

	return fs
end

return factory