darkrc/bin/tasknotif

#!/usr/bin/env lua

local json = require "cjson"
local arrr = require "arrr"
local shapeshift = require "shapeshift"
local lumber = require("lumber")

local log = lumber.new {
	level = lumber.levels.WARN;
	format = require "lumber.format.term";
	filter = function(message)
		if type(message) == "string" then
			return message
		else
			return require("inspect")(message)
		end
	end
}

local default_config = {
	{ notify = "zenity", minutes = 60 };
	{ notify = "notify", minutes = 180 };
}

local function zulu_offset()
	local current = os.date("*t")
	current.isdst = false
	local zulu = os.date("!*t")
	--- @cast zulu -string
	--- @cast current -string
	return os.difftime(os.time(current), os.time(zulu))
end

local config_file do
	local xdg_home = os.getenv("XDG_CONFIG_HOME")
	local home = os.getenv("HOME")
	if xdg_home then
		config_file = xdg_home .. "/task/tasknotif.lua"
	elseif home then
		config_file = home .. "/.config/task/tasknotif.lua"
	else
		config_file = "tasknotif.lua"
	end
end

local params do
	local parse = arrr {
		{ "Configuration to use (default: "..config_file..")", "--config", "-c" };
		{ "Sets the log level", "--log", nil, true };
		{ "Ignore anything that's already due soon at program start", "--pre-check" };
	}

	local validate = shapeshift.table {
		__extra = "keep";
		precheck = shapeshift.default(false, shapeshift.is.boolean);
	}

	params = select(2, validate(parse(arg)))
end

if params.log then
	log.level = lumber.levels[string.upper(params.log)]
end

log:debug("Params", params)

log:info "Starting taskwarrior notifier"

--- @type table
local config if params.config then
	config = assert(loadfile(params.config))()
else
	local chunk = loadfile(config_file)
	config = chunk and chunk() or default_config
end

local done = {}
for severity in ipairs(config) do
	done[severity] = {}
end

--- @param run boolean Whether there should be any notification at all
local function check(run)
	-- Save handled tasks in the current loop so the same task doesn't get several notififations at once
	local handled = {}
	if run == nil then run = true end
	for severity, condition in ipairs(config) do
		log:debug(condition)
		local data = json.decode(io.popen("task export"):read("*a"))
		for _, task in ipairs(data) do
			if task.status == "pending" and task.due then
				do
					local d = {}
					d.year, d.month, d.day, d.hour, d.min, d.sec
					= task.due:match("(%d%d%d%d)(%d%d)(%d%d)T(%d%d)(%d%d)(%d%d)Z")
					d.sec = d.sec + zulu_offset()
					task.due = os.time(d)
				end

				-- If anything gets postponed outside of the warning time,
				-- remove it from the done list
				if done[severity][task.uuid] then
					if os.difftime(task.due, os.time()) > 60 * condition.minutes then
						done[severity][task.uuid] = nil
					end
				end

				if os.difftime(task.due, os.time()) < 60 * condition.minutes then
					if handled[task.uuid] then
						log:info("Skipping task "..task.uuid..": already handled in this loop")
					end
					if not done[severity][task.uuid] then
						done[severity][task.uuid] = task
						if run and not handled[task.uuid] then
							log:info("Notifying:", task.uuid, task.description)
							if condition.notify == "zenity" then
								os.execute(string.format("zenity --warning --title '%s' --text '%s'", "Task due soon", task.description))
							elseif condition.notify == "notify" then
								os.execute("notify-send 'Task due soon' '"..task.description:gsub([[']], [['"'"']]).."'")
							else
								error("Unknown notification type: " .. tostring(condition.notify))
							end
							handled[task.uuid] = task
						end
					end
				end
			end
		end
	end
end

if params.precheck then
	log:info "Doing initial pre-scan"
	check(false)
end

log:info "Starting scan loop"
while true do
	check(true)
	if not os.execute("sleep 30") then
		log:info "Exiting taskwarrior notifier"
		os.exit()
	end
end