module RubyLLM::Providers::Bedrock::Streaming::MessageProcessing

def extract_message_info(chunk, offset)
  total_length, headers_length = read_prelude(chunk, offset)
  return unless valid_lengths?(total_length, headers_length)
  message_end = offset + total_length
  return unless chunk.bytesize >= message_end
  headers_end, payload_end = calculate_positions(offset, total_length, headers_length)
  return unless valid_positions?(headers_end, payload_end, chunk.bytesize)
  { total_length:, headers_length:, headers_end:, payload_end: }
end

def extract_payload(chunk, headers_end, payload_end)
  chunk[headers_end...payload_end]
end

def process_chunk(chunk, &)
  offset = 0
  offset = process_message(chunk, offset, &) while offset < chunk.bytesize
rescue StandardError => e
  RubyLLM.logger.debug "Error processing chunk: #{e.message}"
  RubyLLM.logger.debug "Chunk size: #{chunk.bytesize}"
end

def process_message(chunk, offset, &)
  return chunk.bytesize unless can_read_prelude?(chunk, offset)
  message_info = extract_message_info(chunk, offset)
  return find_next_message(chunk, offset) unless message_info
  process_valid_message(chunk, offset, message_info, &)
end

def process_valid_message(chunk, offset, message_info, &)
  payload = extract_payload(chunk, message_info[:headers_end], message_info[:payload_end])
  return find_next_message(chunk, offset) unless valid_payload?(payload)
  process_payload(payload, &)
  offset + message_info[:total_length]
end

def valid_payload?(payload)
  return false if payload.nil? || payload.empty?
  json_start = payload.index('{')
  json_end = payload.rindex('}')
  return false if json_start.nil? || json_end.nil? || json_start >= json_end
  true
end