Edytujesz Moduł:WiekLataDni

local p = {}

local function trim(v)
	if v == nil then
		return nil
	end
	v = tostring(v):match("^%s*(.-)%s*$")
	if v == "" then
		return nil
	end
	return v
end

local function isLeap(y)
	return (y % 4 == 0 and y % 100 ~= 0) or (y % 400 == 0)
end

local function daysInMonth(y, m)
	local t = {31,28,31,30,31,30,31,31,30,31,30,31}
	if m == 2 and isLeap(y) then
		return 29
	end
	return t[m]
end

local function isValidDate(y, m, d)
	if not y or not m or not d then
		return false
	end
	if m < 1 or m > 12 then
		return false
	end
	if d < 1 or d > daysInMonth(y, m) then
		return false
	end
	return true
end

local function daysBeforeYear(y)
	y = y - 1
	return 365 * y + math.floor(y / 4) - math.floor(y / 100) + math.floor(y / 400)
end

local function serialDay(y, m, d)
	local n = d
	for i = 1, m - 1 do
		n = n + daysInMonth(y, i)
	end
	return daysBeforeYear(y) + n
end

local function pluralYears(n)
	local mod10 = n % 10
	local mod100 = n % 100

	if mod10 == 1 and mod100 ~= 11 then
		return "rok"
	elseif mod10 >= 2 and mod10 <= 4 and not (mod100 >= 12 and mod100 <= 14) then
		return "lata"
	else
		return "lat"
	end
end

local function pluralDays(n)
	if n == 1 then
		return "dzień"
	end
	return "dni"
end

local function getCurrentDate(frame)
	local y = tonumber(frame:preprocess("{{CURRENTYEAR}}"))
	local m = tonumber(frame:preprocess("{{CURRENTMONTH}}"))
	local d = tonumber(frame:preprocess("{{CURRENTDAY2}}"))
	return y, m, d
end

local function getArgs(frame)
	local parent = frame:getParent()
	local src = frame.args

	if parent and next(parent.args) then
		src = parent.args
	end

	local args = {}
	for k, v in pairs(src) do
		args[k] = trim(v)
	end
	return args
end

function p.policz(frame)
	local args = getArgs(frame)

	local y1 = tonumber(args[1] or args.rok1 or args.rok)
	local m1 = tonumber(args[2] or args.miesiac1 or args.miesiąc1 or args.miesiac or args.miesiąc)
	local d1 = tonumber(args[3] or args.dzien1 or args.dzień1 or args.dzien or args.dzień)

	local y2 = tonumber(args[4] or args.rok2)
	local m2 = tonumber(args[5] or args.miesiac2 or args.miesiąc2)
	local d2 = tonumber(args[6] or args.dzien2 or args.dzień2)

	if not isValidDate(y1, m1, d1) then
		return '<span class="error">Błąd: nieprawidłowa data początkowa.</span>'
	end

	if y2 or m2 or d2 then
		if not isValidDate(y2, m2, d2) then
			return '<span class="error">Błąd: nieprawidłowa data końcowa.</span>'
		end
	else
		y2, m2, d2 = getCurrentDate(frame)
	end

	local startSerial = serialDay(y1, m1, d1)
	local endSerial = serialDay(y2, m2, d2)

	if endSerial < startSerial then
		return '<span class="error">Błąd: data końcowa jest wcześniejsza niż początkowa.</span>'
	end

	local years = y2 - y1
	local annivDayInEndYear = math.min(d1, daysInMonth(y2, m1))

	if (m2 < m1) or (m2 == m1 and d2 < annivDayInEndYear) then
		years = years - 1
	end

	local annivYear = y1 + years
	local annivDay = math.min(d1, daysInMonth(annivYear, m1))
	local anniversarySerial = serialDay(annivYear, m1, annivDay)

	local days = endSerial - anniversarySerial

	return years .. " " .. pluralYears(years) .. " i " .. days .. " " .. pluralDays(days)
end

return p