# Test Shanda cipher - encrypt then decrypt should give original

Code.require_file("lib/odinsea/util/bit_tools.ex", ".")
Code.require_file("lib/odinsea/net/cipher/shanda_cipher.ex", ".")

alias Odinsea.Net.Cipher.ShandaCipher
alias Odinsea.Util.BitTools

import Bitwise

# Test with simple data
data = <<0x01, 0x00, 0x07, 0x70, 0x00, 0x04, 0x00>>
IO.puts("Original data: #{Base.encode16(data)}")

# Encrypt
encrypted = ShandaCipher.encrypt(data)
IO.puts("Encrypted: #{Base.encode16(encrypted)}")

# Decrypt
decrypted = ShandaCipher.decrypt(encrypted)
IO.puts("Decrypted: #{Base.encode16(decrypted)}")

IO.puts("Match: #{data == decrypted}")
IO.puts("")

# If they don't match, let's debug step by step
if data != decrypted do
  IO.puts("MISMATCH! Let's debug...")
  IO.puts("")
  
  # Manual encrypt - first pass only
  bytes = :binary.bin_to_list(data)
  data_len = length(bytes)
  data_length = data_len &&& 0xFF
  
  IO.puts("Data length: #{data_len}")
  IO.puts("Initial bytes: #{inspect(bytes)}")
  IO.puts("")
  
  # First pass (j=0, forward)
  IO.puts("=== Pass 0 (forward) ===")
  {result0, remember0} = Enum.reduce(Enum.with_index(bytes), {[], 0}, fn {cur, i}, {acc, remember} ->
    cur = BitTools.roll_left(cur, 3)
    cur = (cur + data_length) &&& 0xFF
    cur = bxor(cur, remember)
    new_remember = cur
    cur = BitTools.roll_right(cur, data_length &&& 0xFF)
    cur = bxor(cur, 0xFF)
    cur = (cur + 0x48) &&& 0xFF
    {[cur | acc], new_remember}
  end)
  result0 = Enum.reverse(result0)
  IO.puts("After pass 0: #{inspect(result0)}, remember: #{remember0}")
end