#!/usr/bin/env elixir

Mix.install([])

defmodule QuickHexTest do
  def hex_to_binary(hex_string) when is_binary(hex_string) do
    try do
      # First validate that the string contains only valid hex characters
      if String.match?(hex_string, ~r/^[0-9A-Fa-f]+$/) do
        # Ensure even length (pad with leading zero if needed)
        padded_hex = if rem(String.length(hex_string), 2) == 1 do
          "0" <> hex_string
        else
          hex_string
        end
        
        case Base.decode16(padded_hex, case: :mixed) do
          {:ok, binary} -> {:ok, binary}
          :error -> {:error, :invalid_hex}
        end
      else
        {:error, :invalid_hex}
      end
    rescue
      _ -> {:error, :invalid_hex}
    end
  end
  
  def test do
    IO.puts("Testing hex validation:")
    
    # Valid hex
    result1 = hex_to_binary("6000782000")
    IO.puts("Valid hex '6000782000': #{inspect(result1)}")
    
    # Invalid hex
    result2 = hex_to_binary("invalid_hex")
    IO.puts("Invalid hex 'invalid_hex': #{inspect(result2)}")
    
    # Mixed valid/invalid
    result3 = hex_to_binary("60G0782000")
    IO.puts("Invalid hex '60G0782000': #{inspect(result3)}")
    
    # Empty string
    result4 = hex_to_binary("")
    IO.puts("Empty string '': #{inspect(result4)}")
  end
end

QuickHexTest.test()