#!/usr/bin/env texlua

local ldl_texts = languages.data.labels.texts
local u         = utf

local function localize_it (str, lang)
    local current_language = lang or languages.current(tex.language)
    return ldl_texts[u.lower(str)].labels[current_language]
end

local function modification_date (filename, format)
    local attr = lfs.attributes(filename)
    if type(attr) == "table" and attr.mode ~= "directory" then
        if format == "nice" then
            return os.date("%Y-%m-%dT%X",attr.modification) ..  os.timezone(true)
        elseif format == "long" then
            local tmp  = string.explode(os.date("%d %B %Y %H:%M",attr.modification), " ")
            local day, month, year, time = table.unpack(tmp)
            return day .. ". " .. localize_it(month) .. " " .. year .. " " .. time
        else
            local tmp  = string.explode(os.date("%d %B %Y",attr.modification), " ")
            local day, month, year = table.unpack(tmp)
            return day .. ". " .. localize_it(month) .. " " .. year
        end
    end
    return "<unset>"
end

documentdata.modification_date = modification_date