""" Manage the tags of a repository. """
import json

from datetime import datetime
from flask import request, abort

from app import storage
from auth.auth_context import get_authenticated_user
from data.registry_model import registry_model
from endpoints.api import (resource, nickname, require_repo_read, require_repo_write,
                           RepositoryParamResource, log_action, validate_json_request, path_param,
                           parse_args, query_param, truthy_bool, disallow_for_app_repositories,
                           format_date)
from endpoints.api.image import image_dict
from endpoints.exception import NotFound, InvalidRequest
from util.names import TAG_ERROR, TAG_REGEX


def _tag_dict(tag):
  tag_info = {
    'name': tag.name,
    'reversion': tag.reversion,
  }

  if tag.lifetime_start_ts > 0:
    tag_info['start_ts'] = tag.lifetime_start_ts

  if tag.lifetime_end_ts > 0:
    tag_info['end_ts'] = tag.lifetime_end_ts

  # TODO(jschorr): Remove this once fully on OCI data model.
  if tag.legacy_image_if_present:
    tag_info['docker_image_id'] = tag.legacy_image.docker_image_id
    tag_info['image_id'] = tag.legacy_image.docker_image_id
    tag_info['size'] = tag.legacy_image.aggregate_size

  # TODO(jschorr): Remove this check once fully on OCI data model.
  if tag.manifest_digest:
    tag_info['manifest_digest'] = tag.manifest_digest
    if tag.manifest:
      try:
        tag_info['manifest'] = json.loads(tag.manifest.internal_manifest_bytes.as_unicode())
      except (TypeError, ValueError):
        pass

      tag_info['is_manifest_list'] = tag.manifest.is_manifest_list

      if 'size' not in tag_info:
        tag_info['size'] = tag.manifest.layers_compressed_size

  if tag.lifetime_start_ts > 0:
    last_modified = format_date(datetime.utcfromtimestamp(tag.lifetime_start_ts))
    tag_info['last_modified'] = last_modified

  if tag.lifetime_end_ts is not None:
    expiration = format_date(datetime.utcfromtimestamp(tag.lifetime_end_ts))
    tag_info['expiration'] = expiration

  return tag_info


@resource('/v1/repository/<apirepopath:repository>/tag/')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
class ListRepositoryTags(RepositoryParamResource):
  """ Resource for listing full repository tag history, alive *and dead*. """

  @require_repo_read
  @disallow_for_app_repositories
  @parse_args()
  @query_param('specificTag', 'Filters the tags to the specific tag.', type=str, default='')
  @query_param('limit', 'Limit to the number of results to return per page. Max 100.', type=int,
               default=50)
  @query_param('page', 'Page index for the results. Default 1.', type=int, default=1)
  @query_param('onlyActiveTags', 'Filter to only active tags.', type=truthy_bool, default=False)
  @nickname('listRepoTags')
  def get(self, namespace, repository, parsed_args):
    specific_tag = parsed_args.get('specificTag') or None
    page = max(1, parsed_args.get('page', 1))
    limit = min(100, max(1, parsed_args.get('limit', 50)))
    active_tags_only = parsed_args.get('onlyActiveTags')

    repo_ref = registry_model.lookup_repository(namespace, repository)
    if repo_ref is None:
      raise NotFound()

    history, has_more = registry_model.list_repository_tag_history(repo_ref, page=page,
                                                                   size=limit,
                                                                   specific_tag_name=specific_tag,
                                                                   active_tags_only=active_tags_only)
    return {
      'tags': [_tag_dict(tag) for tag in history],
      'page': page,
      'has_additional': has_more,
    }


@resource('/v1/repository/<apirepopath:repository>/tag/<tag>')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
@path_param('tag', 'The name of the tag')
class RepositoryTag(RepositoryParamResource):
  """ Resource for managing repository tags. """
  schemas = {
    'ChangeTag': {
      'type': 'object',
      'description': 'Makes changes to a specific tag',
      'properties': {
        'image': {
          'type': ['string', 'null'],
          'description': '(If specified) Image identifier to which the tag should point',
        },
        'expiration': {
          'type': ['number', 'null'],
          'description': '(If specified) The expiration for the image',
        },
      },
    },
  }

  @require_repo_write
  @disallow_for_app_repositories
  @nickname('changeTag')
  @validate_json_request('ChangeTag')
  def put(self, namespace, repository, tag):
    """ Change which image a tag points to or create a new tag."""
    if not TAG_REGEX.match(tag):
      abort(400, TAG_ERROR)

    repo_ref = registry_model.lookup_repository(namespace, repository)
    if repo_ref is None:
      raise NotFound()

    if 'expiration' in request.get_json():
      tag_ref = registry_model.get_repo_tag(repo_ref, tag)
      if tag_ref is None:
        raise NotFound()

      expiration = request.get_json().get('expiration')
      expiration_date = None
      if expiration is not None:
        try:
          expiration_date = datetime.utcfromtimestamp(float(expiration))
        except ValueError:
          abort(400)

        if expiration_date <= datetime.now():
          abort(400)

      existing_end_ts, ok = registry_model.change_repository_tag_expiration(tag_ref,
                                                                            expiration_date)
      if ok:
        if not (existing_end_ts is None and expiration_date is None):
          log_action('change_tag_expiration', namespace, {
            'username': get_authenticated_user().username,
            'repo': repository,
            'tag': tag,
            'namespace': namespace,
            'expiration_date': expiration_date,
            'old_expiration_date': existing_end_ts
          }, repo_name=repository)
      else:
        raise InvalidRequest('Could not update tag expiration; Tag has probably changed')

    if 'image' in request.get_json() or 'manifest_digest' in request.get_json():
      existing_tag = registry_model.get_repo_tag(repo_ref, tag, include_legacy_image=True)

      manifest_or_image = None
      image_id = None
      manifest_digest = None

      if 'image' in request.get_json():
        image_id = request.get_json()['image']
        manifest_or_image = registry_model.get_legacy_image(repo_ref, image_id)
      else:
        manifest_digest = request.get_json()['manifest_digest']
        manifest_or_image = registry_model.lookup_manifest_by_digest(repo_ref, manifest_digest)

      if manifest_or_image is None:
        raise NotFound()

      # TODO(jschorr): Remove this check once fully on V22
      existing_manifest_digest = None
      if existing_tag:
        existing_manifest = registry_model.get_manifest_for_tag(existing_tag)
        existing_manifest_digest = existing_manifest.digest if existing_manifest else None

      if not registry_model.retarget_tag(repo_ref, tag, manifest_or_image, storage):
        raise InvalidRequest('Could not move tag')

      username = get_authenticated_user().username

      log_action('move_tag' if existing_tag else 'create_tag', namespace, {
        'username': username,
        'repo': repository,
        'tag': tag,
        'namespace': namespace,
        'image': image_id,
        'manifest_digest': manifest_digest,
        'original_image': (existing_tag.legacy_image.docker_image_id
                           if existing_tag and existing_tag.legacy_image_if_present
                           else None),
        'original_manifest_digest': existing_manifest_digest,
      }, repo_name=repository)

    return 'Updated', 201

  @require_repo_write
  @disallow_for_app_repositories
  @nickname('deleteFullTag')
  def delete(self, namespace, repository, tag):
    """ Delete the specified repository tag. """
    repo_ref = registry_model.lookup_repository(namespace, repository)
    if repo_ref is None:
      raise NotFound()

    registry_model.delete_tag(repo_ref, tag)

    username = get_authenticated_user().username
    log_action('delete_tag', namespace,
               {'username': username,
                'repo': repository,
                'namespace': namespace,
                'tag': tag}, repo_name=repository)

    return '', 204


@resource('/v1/repository/<apirepopath:repository>/tag/<tag>/images')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
@path_param('tag', 'The name of the tag')
class RepositoryTagImages(RepositoryParamResource):
  """ Resource for listing the images in a specific repository tag. """

  @require_repo_read
  @nickname('listTagImages')
  @disallow_for_app_repositories
  @parse_args()
  @query_param('owned', 'If specified, only images wholely owned by this tag are returned.',
               type=truthy_bool, default=False)
  def get(self, namespace, repository, tag, parsed_args):
    """ List the images for the specified repository tag. """
    repo_ref = registry_model.lookup_repository(namespace, repository)
    if repo_ref is None:
      raise NotFound()

    tag_ref = registry_model.get_repo_tag(repo_ref, tag, include_legacy_image=True)
    if tag_ref is None:
      raise NotFound()

    if tag_ref.legacy_image_if_present is None:
      return {'images': []}

    image_id = tag_ref.legacy_image.docker_image_id

    all_images = None
    if parsed_args['owned']:
      # TODO(jschorr): Remove the `owned` image concept once we are fully on V2_2.
      all_images = registry_model.get_legacy_images_owned_by_tag(tag_ref)
    else:
      image_with_parents = registry_model.get_legacy_image(repo_ref, image_id, include_parents=True)
      if image_with_parents is None:
        raise NotFound()

      all_images = [image_with_parents] + image_with_parents.parents

    return {
      'images': [image_dict(image) for image in all_images],
    }


@resource('/v1/repository/<apirepopath:repository>/tag/<tag>/restore')
@path_param('repository', 'The full path of the repository. e.g. namespace/name')
@path_param('tag', 'The name of the tag')
class RestoreTag(RepositoryParamResource):
  """ Resource for restoring a repository tag back to a previous image. """
  schemas = {
    'RestoreTag': {
      'type': 'object',
      'description': 'Restores a tag to a specific image',
      'required': ['image',],
      'properties': {
        'image': {
          'type': 'string',
          'description': 'Image identifier to which the tag should point',
        },
        'manifest_digest': {
          'type': 'string',
          'description': 'If specified, the manifest digest that should be used',
        },
      },
    },
  }

  @require_repo_write
  @disallow_for_app_repositories
  @nickname('restoreTag')
  @validate_json_request('RestoreTag')
  def post(self, namespace, repository, tag):
    """ Restores a repository tag back to a previous image in the repository. """
    repo_ref = registry_model.lookup_repository(namespace, repository)
    if repo_ref is None:
      raise NotFound()

    # Restore the tag back to the previous image.
    image_id = request.get_json()['image']
    manifest_digest = request.get_json().get('manifest_digest', None)

    # Data for logging the reversion/restoration.
    username = get_authenticated_user().username
    log_data = {
      'username': username,
      'repo': repository,
      'tag': tag,
      'image': image_id,
    }

    manifest_or_legacy_image = None
    if manifest_digest is not None:
      manifest_or_legacy_image = registry_model.lookup_manifest_by_digest(repo_ref, manifest_digest,
                                                                          allow_dead=True)
    else:
      manifest_or_legacy_image = registry_model.get_legacy_image(repo_ref, image_id)

    if manifest_or_legacy_image is None:
      raise NotFound()

    if not registry_model.retarget_tag(repo_ref, tag, manifest_or_legacy_image, storage,
                                       is_reversion=True):
      raise InvalidRequest('Could not restore tag')

    log_action('revert_tag', namespace, log_data, repo_name=repository)

    return {
      'image_id': image_id,
    }