Editing Module:Sandbox/Angr pukhlya/2

local p = {}

p.date_formatting = function( frame )
	-- Unpacking date
	local date = frame.args.date or "Invalid entry"
	local format = frame.args.format or ""
	months = {"January", "February", "March", "April", "May", "June", "July",
		"August", "September", "October", "November", "December",
		["January"] = "01", ["February"] = "02", ["March"] = "03",
		["April"] = "04", ["May"] = "05", ["June"] = "06", ["July"] = "07",
		["August"] = "08", ["September"] = "09", ["October"] = "10",
		["November"] = "11", ["December"] = "12"}
	local year, day = string.match(date, "%D*(%d*)%D*(%d*)%D*")
	local ans = ""
	if year ~= "" and day ~= "" then
		if tonumber(day) > 31 then
			if tonumber(year) <= 31 then
				day, year = year, day
			else
				ans = "Invalid entry"
			end
		end
	end
	local k = nil
	local month = ""
	for i = 1, #months do
		k = string.find(date, months[i])
		if k == nil then
			k = string.find(date, string.lower(string.sub(months[i], 1, 1)) .. string.sub(months[i], 2))
		end
		if k == nil then
			k = string.find(date, string.lower(string.sub(months[i], 1, 1)) .. string.sub(months[i], 2, 3))
		end
		if k == nil then
			k = string.find(date, string.sub(months[i], 1, 1) .. string.sub(months[i], 2, 3))
		end
		if k ~= nil then
			month = months[i]
		end
	end
	if day ~= "" and year ~= "" and month == "" and string.find(date, "[-,/]") ~= nil then
		day, month, year = string.match(date, "(%d+)[-, /](%d+)[-, /](%d+)")
		local a, b, c = day, month, year
		if tonumber(a) > 31 then
			year = a
		elseif tonumber(b) > 31 then
			year = b
		elseif tonumber(c) > 31 then
			year = c
		end
		if tonumber(a) > 12 and year ~= nil and year ~= a then
			day = a
		elseif tonumber(b) > 12 and year ~= nil and year ~= b then
			day = b
		elseif tonumber(c) > 12 and year ~= nil and year ~= c then
			day = c
		end
		if (year == a and day == b) or (year == b and day == a) then
			month = months[tonumber(c)]
		elseif (year == b and day == c) or (year == c and day == b) then
			month = months[a]
		elseif (year == a and day == c) or (year == c and day == a) then
			month = months[tonumber(b)]
		else
			day, month, year = a, months[tonumber(b)], c
		end
	end
        if month == "" and day == "" and year == "" then
		ans = "Invalid entry"
        else
	right = {}
	for i = 1, 12 do
		if i == 2 then
			if year % 400 == 0 or (year % 100 ~= 0 and year % 4 == 0) then
				right[i] = 29
			else
				right[i] = 28
			end
		elseif i <= 7 then
			right[i] = 30 + i % 2
		else
			right[i] = 31 - i % 2
		end
	end
	if right[tonumber(months[month])] ~= nil and day ~= "" then
		if right[tonumber(months[month])] < tonumber(day) then
			ans = "Invalid entry"
		end
        elseif month == "" and day ~= "" and year ~= "" and string.find(date, "%a") ~= nil then
                ans = "Invalid entry"
	end
        end
	--Formatting unpacked date
        local format_old = ""
        if day ~= "" and year ~= "" and month ~= "" then
                if string.find(date, ",") ~= nil then
                        format_old = "mdy"
                elseif string.find(date, "[-,/]") ~= nil then
                        format_old = "iso"
                else
                        format_old = "dmy"
                end
        elseif year ~= "" and month ~= "" then
                format_old = "month and year"
        else
                format_old = "year"
        end
	local u_date = ""
	local dop = ""
        if format == "" then
             format = format_old
end
	if ans ~= "Invalid entry" then
		if format == "mdy" then
			u_date = month .. " " .. day .. ", " .. year
		elseif format == "dmy" then
			u_date = day .. " " .. month .. " " .. year
		elseif format == "iso" then
			u_date = year .. "-" .. months[month] .. "-" .. day
		elseif format == "year" then
			u_date = year
		elseif format == "month and year" then
			u_date = month .. " " .. year
		else
			u_date = day .. " " .. month .. " " .. year
		end
		if string.find(date, "(uncertain)") ~= nil or string.find(date, "around") ~= nil then
			dop = "circa "
		end
	else 
		u_date = ans
	end
	return dop .. u_date
end
return p