// Copyright 2016-2018, Pulumi Corporation.
//
// 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.
package secrets

import (
	"encoding/json"

	"github.com/pulumi/pulumi/pkg/resource/config"
)

// Manager provides the interface for providing stack encryption.
type Manager interface {
	// Type retruns a string that reflects the type of this provider. This is serialized along with the state of
	// the manager into the deployment such that we can re-construct the correct manager when deserializing a
	// deployment into a snapshot.
	Type() string
	// An opaque state, which can be JSON serialized and used later to reconstruct the provider when deserializing
	// the deployment into a snapshot.
	State() interface{}
	// Encrypter returns a `config.Encrypter` that can be used to encrypt values when serializing a snapshot into a
	// deployment, or an error if one can not be constructed.
	Encrypter() (config.Encrypter, error)
	// Decrypter returns a `config.Decrypter` that can be used to decrypt values when deserializing a snapshot from a
	// deployment, or an error if one can not be constructed.
	Decrypter() (config.Decrypter, error)
}

// AreCompatible returns true if the two Managers are of the same type and have the same state.
func AreCompatible(a, b Manager) bool {
	if a == nil || b == nil {
		return a == nil && b == nil
	}

	if a.Type() != b.Type() {
		return false
	}

	as, err := json.Marshal(a.State())
	if err != nil {
		return false
	}
	bs, err := json.Marshal(b.State())
	if err != nil {
		return false
	}
	return string(as) == string(bs)
}
