from abc import ABCMeta, abstractmethod
from collections import namedtuple

from six import add_metaclass

from app import app, storage as store
from data import model
from data.model import db_transaction
from util.morecollections import AttrDict


class Repository(namedtuple('Repository', ['id', 'name', 'namespace_name', 'description',
                                           'is_public'])):
  """
  Repository represents a namespaced collection of tags.
  """


@add_metaclass(ABCMeta)
class DockerRegistryV1DataInterface(object):
  """
  Interface that represents all data store interactions required by a Docker Registry v1.
  """

  @abstractmethod
  def placement_locations_and_path_docker_v1(self, namespace_name, repo_name, image_id):
    """
    Returns all the placements for the image with the given V1 Docker ID, found under the given
    repository or None if no image was found.
    """
    pass

  @abstractmethod
  def docker_v1_metadata(self, namespace_name, repo_name, image_id):
    """
    Returns various pieces of metadata associated with an image with the given V1 Docker ID,
    including the checksum and its V1 JSON metadata.
    """
    pass

  @abstractmethod
  def update_docker_v1_metadata(self, namespace_name, repo_name, image_id, created_date_str,
                                comment, command, compat_json, parent_image_id=None):
    """
    Updates various pieces of V1 metadata associated with a particular image.
    """
    pass

  @abstractmethod
  def storage_exists(self, namespace_name, repo_name, image_id):
    """
    Returns whether storage already exists for the image with the V1 Docker ID under the given
    repository.
    """
    pass

  @abstractmethod
  def store_docker_v1_checksums(self, namespace_name, repo_name, image_id, checksum,
                                content_checksum):
    """
    Stores the various V1 checksums for the image with the V1 Docker ID.
    """
    pass

  @abstractmethod
  def is_image_uploading(self, namespace_name, repo_name, image_id):
    """
    Returns whether the image with the V1 Docker ID is currently marked as uploading.
    """
    pass

  @abstractmethod
  def update_image_uploading(self, namespace_name, repo_name, image_id, is_uploading):
    """
    Marks the image with the V1 Docker ID with the given uploading status.
    """
    pass

  @abstractmethod
  def update_image_sizes(self, namespace_name, repo_name, image_id, size, uncompressed_size):
    """
    Updates the sizing information for the image with the given V1 Docker ID.
    """
    pass

  @abstractmethod
  def get_image_size(self, namespace_name, repo_name, image_id):
    """
    Returns the wire size of the image with the given Docker V1 ID.
    """
    pass

  @abstractmethod
  def create_bittorrent_pieces(self, namespace_name, repo_name, image_id, pieces_bytes):
    """
    Saves the BitTorrent piece hashes for the image with the given Docker V1 ID.
    """
    pass

  @abstractmethod
  def image_ancestry(self, namespace_name, repo_name, image_id):
    """
    Returns a list containing the full ancestry of Docker V1 IDs, in order, for the image with the
    given Docker V1 ID.
    """
    pass

  @abstractmethod
  def repository_exists(self, namespace_name, repo_name):
    """
    Returns whether the repository with the given name and namespace exists.
    """
    pass

  @abstractmethod
  def create_or_link_image(self, username, namespace_name, repo_name, image_id, storage_location):
    """
    Adds the given image to the given repository, by either linking to an existing image visible to
    the user with the given username, or creating a new one if no existing image matches.
    """
    pass

  @abstractmethod
  def create_temp_hidden_tag(self, namespace_name, repo_name, image_id, expiration):
    """
    Creates a hidden tag under the matching namespace pointing to the image with the given V1 Docker
    ID.
    """
    pass

  @abstractmethod
  def list_tags(self, namespace_name, repo_name):
    """
    Returns all the tags defined in the repository with the given namespace and name.
    """
    pass

  @abstractmethod
  def create_or_update_tag(self, namespace_name, repo_name, image_id, tag_name):
    """
    Creates or updates a tag under the matching repository to point to the image with the given
    Docker V1 ID.
    """
    pass

  @abstractmethod
  def find_image_id_by_tag(self, namespace_name, repo_name, tag_name):
    """
    Returns the Docker V1 image ID for the HEAD image for the tag with the given name under the
    matching repository, or None if none.
    """
    pass

  @abstractmethod
  def delete_tag(self, namespace_name, repo_name, tag_name):
    """
    Deletes the given tag from the given repository.
    """
    pass

  @abstractmethod
  def load_token(self, token):
    """
    Loads the data associated with the given (deprecated) access token, and, if
    found returns True.
    """
    pass

  @abstractmethod
  def verify_robot(self, username, token):
    """
    Returns True if the given robot username and token match an existing robot
    account.
    """
    pass

  @abstractmethod
  def change_user_password(self, user, new_password):
    """
    Changes the password associated with the given user.
    """
    pass

  @abstractmethod
  def get_repository(self, namespace_name, repo_name):
    """
    Returns the repository with the given name under the given namespace or None
    if none.
    """
    pass

  @abstractmethod
  def create_repository(self, namespace_name, repo_name, user=None):
    """
    Creates a new repository under the given namespace with the given name, for
    the given user.
    """
    pass

  @abstractmethod
  def repository_is_public(self, namespace_name, repo_name):
    """
    Returns whether the repository with the given name under the given namespace
    is public. If no matching repository was found, returns False.
    """
    pass

  @abstractmethod
  def validate_oauth_token(self, token):
    """ Returns whether the given OAuth token validates. """
    pass

  @abstractmethod
  def get_sorted_matching_repositories(self, search_term, filter_username=None, offset=0, limit=25):
    """
    Returns a sorted list of repositories matching the given search term.
    """
    pass


class PreOCIModel(DockerRegistryV1DataInterface):
  """
  PreOCIModel implements the data model for the v1 Docker Registry protocol using a database schema
  before it was changed to support the OCI specification.
  """
  def placement_locations_and_path_docker_v1(self, namespace_name, repo_name, image_id):
    repo_image = model.image.get_repo_image_extended(namespace_name, repo_name, image_id)
    if not repo_image or repo_image.storage is None:
      return None, None
    return repo_image.storage.locations, model.storage.get_layer_path(repo_image.storage)

  def docker_v1_metadata(self, namespace_name, repo_name, image_id):
    repo_image = model.image.get_repo_image(namespace_name, repo_name, image_id)
    if repo_image is None:
      return None

    return AttrDict({
      'namespace_name': namespace_name,
      'repo_name': repo_name,
      'image_id': image_id,
      'checksum': repo_image.v1_checksum,
      'compat_json': repo_image.v1_json_metadata,
    })

  def update_docker_v1_metadata(self, namespace_name, repo_name, image_id, created_date_str,
                                comment, command, compat_json, parent_image_id=None):
    parent_image = None
    if parent_image_id is not None:
      parent_image = model.image.get_repo_image(namespace_name, repo_name, parent_image_id)

    model.image.set_image_metadata(image_id, namespace_name, repo_name, created_date_str, comment,
                                   command, compat_json, parent=parent_image)

  def storage_exists(self, namespace_name, repo_name, image_id):
    repo_image = model.image.get_repo_image_and_storage(namespace_name, repo_name, image_id)
    if repo_image is None or repo_image.storage is None:
      return False

    if repo_image.storage.uploading:
      return False

    layer_path = model.storage.get_layer_path(repo_image.storage)
    return store.exists(repo_image.storage.locations, layer_path)

  def store_docker_v1_checksums(self, namespace_name, repo_name, image_id, checksum,
                                content_checksum):
    repo_image = model.image.get_repo_image_and_storage(namespace_name, repo_name, image_id)
    if repo_image is None or repo_image.storage is None:
      return

    with db_transaction():
      repo_image.storage.content_checksum = content_checksum
      repo_image.v1_checksum = checksum
      repo_image.storage.save()
      repo_image.save()

  def is_image_uploading(self, namespace_name, repo_name, image_id):
    repo_image = model.image.get_repo_image_and_storage(namespace_name, repo_name, image_id)
    if repo_image is None or repo_image.storage is None:
      return False
    return repo_image.storage.uploading

  def update_image_uploading(self, namespace_name, repo_name, image_id, is_uploading):
    repo_image = model.image.get_repo_image_and_storage(namespace_name, repo_name, image_id)
    if repo_image is None or repo_image.storage is None:
      return

    repo_image.storage.uploading = is_uploading
    repo_image.storage.save()
    return repo_image.storage

  def update_image_sizes(self, namespace_name, repo_name, image_id, size, uncompressed_size):
    model.storage.set_image_storage_metadata(image_id, namespace_name, repo_name, size,
                                             uncompressed_size)

  def get_image_size(self, namespace_name, repo_name, image_id):
    repo_image = model.image.get_repo_image_and_storage(namespace_name, repo_name, image_id)
    if repo_image is None or repo_image.storage is None:
      return None
    return repo_image.storage.image_size

  def create_bittorrent_pieces(self, namespace_name, repo_name, image_id, pieces_bytes):
    repo_image = model.image.get_repo_image_and_storage(namespace_name, repo_name, image_id)
    if repo_image is None or repo_image.storage is None:
      return

    model.storage.save_torrent_info(repo_image.storage, app.config['BITTORRENT_PIECE_SIZE'],
                                    pieces_bytes)

  def image_ancestry(self, namespace_name, repo_name, image_id):
    try:
      image = model.image.get_image_by_id(namespace_name, repo_name, image_id)
    except model.InvalidImageException:
      return None

    parents = model.image.get_parent_images(namespace_name, repo_name, image)
    ancestry_docker_ids = [image.docker_image_id]
    ancestry_docker_ids.extend([parent.docker_image_id for parent in parents])
    return ancestry_docker_ids

  def repository_exists(self, namespace_name, repo_name):
    repo = model.repository.get_repository(namespace_name, repo_name)
    return repo is not None

  def create_or_link_image(self, username, namespace_name, repo_name, image_id, storage_location):
    repo = model.repository.get_repository(namespace_name, repo_name)
    model.image.find_create_or_link_image(image_id, repo, username, {}, storage_location)

  def create_temp_hidden_tag(self, namespace_name, repo_name, image_id, expiration):
    repo_image = model.image.get_repo_image(namespace_name, repo_name, image_id)
    if repo_image is None:
      return

    repo = repo_image.repository
    model.tag.create_temporary_hidden_tag(repo, repo_image, expiration)

  def list_tags(self, namespace_name, repo_name):
    return model.tag.list_repository_tags(namespace_name, repo_name)

  def create_or_update_tag(self, namespace_name, repo_name, image_id, tag_name):
    model.tag.create_or_update_tag(namespace_name, repo_name, tag_name, image_id)

  def find_image_id_by_tag(self, namespace_name, repo_name, tag_name):
    try:
      tag_image = model.tag.get_tag_image(namespace_name, repo_name, tag_name)
    except model.DataModelException:
      return None

    return tag_image.docker_image_id

  def delete_tag(self, namespace_name, repo_name, tag_name):
    model.tag.delete_tag(namespace_name, repo_name, tag_name)

  def load_token(self, token):
    try:
      model.token.load_token_data(token)
      return True
    except model.InvalidTokenException:
      return False

  def verify_robot(self, username, token):
    try:
      return bool(model.user.verify_robot(username, token))
    except model.InvalidRobotException:
      return False

  def change_user_password(self, user, new_password):
    model.user.change_password(user, new_password)

  def get_repository(self, namespace_name, repo_name):
    repo = model.repository.get_repository(namespace_name, repo_name)
    if repo is None:
      return None
    return _repository_for_repo(repo)

  def create_repository(self, namespace_name, repo_name, user=None):
    model.repository.create_repository(namespace_name, repo_name, user)

  def repository_is_public(self, namespace_name, repo_name):
    return model.repository.repository_is_public(namespace_name, repo_name)

  def validate_oauth_token(self, token):
    return bool(model.oauth.validate_access_token(token))

  def get_sorted_matching_repositories(self, search_term, filter_username=None, offset=0, limit=25):
    repos = model.repository.get_filtered_matching_repositories(search_term, filter_username,
                                                                offset, limit)
    return [_repository_for_repo(repo) for repo in repos]


def _repository_for_repo(repo):
  """ Returns a Repository object representing the Pre-OCI data model instance of a repository. """
  return Repository(
    id=repo.id,
    name=repo.name,
    namespace_name=repo.namespace_user.username,
    description=repo.description,
    is_public=model.repository.is_repository_public(repo)
  )


pre_oci_model = PreOCIModel()