// Copyright 2017 Istio Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// THIS FILE IS AUTOMATICALLY GENERATED.

package edge

import (
	"context"
	"time"

	"istio.io/istio/mixer/pkg/adapter"
)

// The `edge` template represents an edge in the mesh graph.

// Fully qualified name of the template
const TemplateName = "edge"

// Instance is constructed by Mixer for the 'edge' template.
//
// The `edge` template represents an edge in the mesh graph
//
// When writing the configuration, the value for the fields associated
// with this template can either be a literal or an
// [expression](https://istio.io/docs/reference/config/policy-and-telemetry/expression-language/). Please
// note that if the datatype of a field is not
// istio.mixer.adapter.model.v1beta1.Value, then the expression's
// [inferred type](https://istio.io/docs/reference/config/policy-and-telemetry/expression-language/#type-checking)
// must match the datatype of the field.
//
// Example config:
// ```yaml
// apiVersion: "config.istio.io/v1alpha2"
// kind: instance
// metadata:
//   name: default
//   namespace: istio-system
// spec:
//   compiledTemplate: edge
//   params:
//     timestamp: request.time
//     sourceUid: source.uid | "Unknown"
//     sourceOwner: source.owner | "Unknown"
//     sourceWorkloadName: source.workload.name | "Unknown"
//     sourceWorkloadNamespace: source.workload.namespace | "Unknown"
//     destinationUid: destination.uid | "Unknown"
//     destinationOwner: destination.owner | "Unknown"
//     destinationWorkloadName: destination.workload.name | "Unknown"
//     destinationWorkloadNamespace: destination.workload.namespace | "Unknown"
//     destinationServiceName: destination.service.name | "Unknown"
//     destinationServiceNamespace: destination.service.namespace | "Unknown"
//     apiProtocol: api.protocol | "Unknown"
//     contextProtocol: context.protocol | "Unknown"
// ```
type Instance struct {
	// Name of the instance as specified in configuration.
	Name string

	// Timestamp of the edge
	Timestamp time.Time

	// Namespace of the source workload
	SourceWorkloadNamespace string

	// Name of the source workload
	SourceWorkloadName string

	// Owner of the source workload (often k8s deployment)
	SourceOwner string

	// UID of the source workload
	SourceUid string

	// Namespace of the destination workload
	DestinationWorkloadNamespace string

	// Name of the destination workload
	DestinationWorkloadName string

	// Owner of the destination workload (often k8s deployment)
	DestinationOwner string

	// UID of the destination workload
	DestinationUid string

	// Namespace of the destination Service
	DestinationServiceNamespace string

	// Name of the destination Service
	DestinationServiceName string

	// Protocol used for communication (http, tcp)
	ContextProtocol string

	// The protocol type of the API call (http, https, grpc)
	ApiProtocol string
}

// HandlerBuilder must be implemented by adapters if they want to
// process data associated with the 'edge' template.
//
// Mixer uses this interface to call into the adapter at configuration time to configure
// it with adapter-specific configuration as well as all template-specific type information.
type HandlerBuilder interface {
	adapter.HandlerBuilder

	// SetEdgeTypes is invoked by Mixer to pass the template-specific Type information for instances that an adapter
	// may receive at runtime. The type information describes the shape of the instance.
	SetEdgeTypes(map[string]*Type /*Instance name -> Type*/)
}

// Handler must be implemented by adapter code if it wants to
// process data associated with the 'edge' template.
//
// Mixer uses this interface to call into the adapter at request time in order to dispatch
// created instances to the adapter. Adapters take the incoming instances and do what they
// need to achieve their primary function.
//
// The name of each instance can be used as a key into the Type map supplied to the adapter
// at configuration time via the method 'SetEdgeTypes'.
// These Type associated with an instance describes the shape of the instance
type Handler interface {
	adapter.Handler

	// HandleEdge is called by Mixer at request time to deliver instances to
	// to an adapter.
	HandleEdge(context.Context, []*Instance) error
}
