from image.docker import ManifestException
from image.docker.schema1 import DockerSchema1Manifest, DOCKER_SCHEMA1_CONTENT_TYPES
from image.docker.schema2 import (DOCKER_SCHEMA2_MANIFEST_CONTENT_TYPE,
                                  DOCKER_SCHEMA2_MANIFESTLIST_CONTENT_TYPE)
from image.docker.schema2.manifest import DockerSchema2Manifest
from image.docker.schema2.list import DockerSchema2ManifestList


def parse_manifest_from_bytes(manifest_bytes, media_type, validate=True):
  """ Parses and returns a manifest from the given bytes, for the given media type.
      Raises a ManifestException if the parse fails for some reason.
  """
  # NOTE: Docker sometimes pushed manifests encoded as utf-8, so decode them
  # if we can. Otherwise, treat the string as already unicode encoded.
  try:
    manifest_bytes = manifest_bytes.decode('utf-8')
  except:
    pass

  if media_type == DOCKER_SCHEMA2_MANIFEST_CONTENT_TYPE:
    return DockerSchema2Manifest(manifest_bytes)

  if media_type == DOCKER_SCHEMA2_MANIFESTLIST_CONTENT_TYPE:
    return DockerSchema2ManifestList(manifest_bytes)

  if media_type in DOCKER_SCHEMA1_CONTENT_TYPES:
    return DockerSchema1Manifest(manifest_bytes, validate=validate)

  raise ManifestException('Unknown or unsupported manifest media type `%s`' % media_type)