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#
#    http://www.apache.org/licenses/LICENSE-2.0
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"""Command for adding a term to an existing Route Policy of a Compute Engine router."""

from __future__ import absolute_import
from __future__ import division
from __future__ import unicode_literals

from googlecloudsdk.api_lib.compute import base_classes
from googlecloudsdk.calliope import arg_parsers
from googlecloudsdk.calliope import base
from googlecloudsdk.command_lib.compute import flags as compute_flags
from googlecloudsdk.command_lib.compute.routers import flags


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.ALPHA, base.ReleaseTrack.BETA)
class AddRoutePolicyTerm(base.UpdateCommand):
  """Adds a new term to an existing route policy of a Comute Engine router.

  *{command}* adds a term to a route policy.
  """

  ROUTER_ARG = None

  @classmethod
  def Args(cls, parser):
    AddRoutePolicyTerm.ROUTER_ARG = flags.RouterArgument()
    AddRoutePolicyTerm.ROUTER_ARG.AddArgument(parser, operation_type='update')
    parser.add_argument(
        '--policy-name',
        help="""Name of the route policy to which to add the term.""",
        required=True,
    )
    parser.add_argument(
        '--priority',
        help="""Order of the term within the policy.""",
        required=True,
        type=arg_parsers.BoundedInt(lower_bound=0, upper_bound=2147483647),
    )
    parser.add_argument(
        '--match',
        help="""CEL expression for matching a route.""",
        required=True,
    )
    parser.add_argument(
        '--actions',
        help="""Semicolon separated CEL expressions for the actions to take when the rule matches.""",
        required=True,
        type=arg_parsers.ArgList(custom_delim_char=';'),
        metavar='ACTION',
    )

  def Run(self, args):
    holder = base_classes.ComputeApiHolder(self.ReleaseTrack())
    client = holder.client
    messages = holder.client.messages
    service = holder.client.apitools_client.routers

    router_ref = AddRoutePolicyTerm.ROUTER_ARG.ResolveAsResource(
        args,
        holder.resources,
        scope_lister=compute_flags.GetDefaultScopeLister(client),
    )
    route_policy = service.GetRoutePolicy(
        messages.ComputeRoutersGetRoutePolicyRequest(
            **router_ref.AsDict(), policy=args.policy_name
        )
    ).resource
    new_term = messages.RoutePolicyPolicyTerm(
        priority=args.priority,
        match=messages.Expr(expression=args.match),
        actions=[
            messages.Expr(expression=cel_expression)
            for cel_expression in args.actions
        ],
    )
    route_policy.terms.append(new_term)

    request = (
        service,
        'PatchRoutePolicy',
        messages.ComputeRoutersPatchRoutePolicyRequest(
            **router_ref.AsDict(),
            routePolicy=route_policy,
        ),
    )
    return client.MakeRequests([request])[0]
