local vars = {}

local additionalChars = {".", ",", "!", ":", ";"}

local function getVars(meta)
    for k, v in pairs(meta) do
        if v.t == 'MetaInlines' then
            local var_key = "$" .. k .. "$"
            local var_value = table.unpack(v)["c"]
            vars[var_key] = var_value
            for _, char in pairs(additionalChars) do
                vars[var_key .. char] = var_value .. char
                vars[char .. var_key] = char .. var_value
            end
        end
    end
    return meta
end

return {
    {
        Meta = function (meta)
            meta = getVars(meta)
            meta['outputFile'] = os.getenv("OUTPUT_FILE")
            meta['inputDir'] = os.getenv("INPUT_DIR")
        end
    },
    {
        Str = function (el)
            if vars[el.text] then
                return pandoc.Span(vars[el.text])
            else
                return el
            end
        end
    }
}