misc_random

defmodule Misc.Random do

    def seed_random do
        use_monotonic = :erlang.module_info 
            |> Keyword.get( :exports ) 
            |> Keyword.get( :monotonic_time )
        time_bif = case use_monotonic do
          1   -> &:erlang.monotonic_time/0
          nil -> &:erlang.now/0
        end
        :random.seed( time_bif.() )
    end

    def string( length ) do
        get_string( length )
    end

    def string() do
        get_string( 8 )
    end

    def get_string( length ) do
        seed_random
        alphabet
            =  "abcdefghijklmnopqrstuvwxyz"
            <> "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
            <> "0123456789"
        alphabet_length = 
        
        alphabet |> String.length

        1..length
          |> Enum.map_join( 
            fn(_) ->
              alphabet |> String.at( :random.uniform( alphabet_length ) - 1 )
            end
          )
    end

    def number() do
        get_number(8)
    end

    def number( length ) do
        get_number( length )
    end

    def get_number( length ) do
        seed_random

        { number, "" } = 
          Integer.parse 1..length 
          |> Enum.map_join( fn(_) ->  :random.uniform(10) - 1 end )
        
        number
    end

end