#!/usr/bin/env python
#
# Protocol Buffers - Google's data interchange format
# Copyright 2008 Google Inc.  All rights reserved.
# https://developers.google.com/protocol-buffers/
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#
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# notice, this list of conditions and the following disclaimer.
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"""A conformance test implementation for the Python protobuf library.

See conformance.proto for more information.
"""

import struct
import sys
import os
from google.protobuf import message
from google.protobuf import json_format
import conformance_pb2

sys.stdout = os.fdopen(sys.stdout.fileno(), 'wb', 0)
sys.stdin = os.fdopen(sys.stdin.fileno(), 'rb', 0)

test_count = 0
verbose = False

class ProtocolError(Exception):
  pass

def do_test(request):
  test_message = conformance_pb2.TestAllTypes()
  response = conformance_pb2.ConformanceResponse()
  test_message = conformance_pb2.TestAllTypes()

  try:
    if request.WhichOneof('payload') == 'protobuf_payload':
      try:
        test_message.ParseFromString(request.protobuf_payload)
      except message.DecodeError as e:
        response.parse_error = str(e)
        return response

    elif request.WhichOneof('payload') == 'json_payload':
      try:
        json_format.Parse(request.json_payload, test_message)
      except json_format.ParseError as e:
        response.parse_error = str(e)
        return response

    else:
      raise ProtocolError("Request didn't have payload.")

    if request.requested_output_format == conformance_pb2.UNSPECIFIED:
      raise ProtocolError("Unspecified output format")

    elif request.requested_output_format == conformance_pb2.PROTOBUF:
      response.protobuf_payload = test_message.SerializeToString()

    elif request.requested_output_format == conformance_pb2.JSON:
      response.json_payload = json_format.MessageToJson(test_message)

  except Exception as e:
    response.runtime_error = str(e)

  return response

def do_test_io():
  length_bytes = sys.stdin.read(4)
  if len(length_bytes) == 0:
    return False   # EOF
  elif len(length_bytes) != 4:
    raise IOError("I/O error")

  # "I" is "unsigned int", so this depends on running on a platform with
  # 32-bit "unsigned int" type.  The Python struct module unfortunately
  # has no format specifier for uint32_t.
  length = struct.unpack("<I", length_bytes)[0]
  serialized_request = sys.stdin.read(length)
  if len(serialized_request) != length:
    raise IOError("I/O error")

  request = conformance_pb2.ConformanceRequest()
  request.ParseFromString(serialized_request)

  response = do_test(request)

  serialized_response = response.SerializeToString()
  sys.stdout.write(struct.pack("<I", len(serialized_response)))
  sys.stdout.write(serialized_response)
  sys.stdout.flush()

  if verbose:
    sys.stderr.write("conformance_python: request=%s, response=%s\n" % (
                       request.ShortDebugString().c_str(),
                       response.ShortDebugString().c_str()))

  global test_count
  test_count += 1

  return True

while True:
  if not do_test_io():
    sys.stderr.write("conformance_python: received EOF from test runner " +
                     "after %s tests, exiting\n" % (test_count))
    sys.exit(0)