// Copyright 2020 The Exonum Team
//
// 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.

syntax = "proto3";

package exonum.runtime;

option java_package = "com.exonum.messages.core.runtime";

import "exonum/blockchain.proto";
import "exonum/crypto/types.proto";
import "exonum/runtime/base.proto";

// Data that is required for initialization of a service instance.
message InstanceInitParams {
  // Instance specification.
  InstanceSpec instance_spec = 1;
  // Constructor argument for the instance.
  bytes constructor = 2;
}

// Genesis config parameters.
//
// Information from this entity get saved to the genesis block.
message GenesisConfig {
  // Blockchain configuration used to create the genesis block.
  exonum.Config consensus_config = 1;
  // Artifact specification of the built-in services.
  repeated ArtifactSpec artifacts = 2;
  // List of services with their configuration parameters that are created directly
  // in the genesis block.
  repeated InstanceInitParams builtin_instances = 3;
}

// Current state of the artifact in dispatcher.
message ArtifactState {
  // Status of an artifact deployment.
  enum Status {
    // The artifact is pending unload.
    UNLOADING = 0;
    // The artifact is pending deployment.
    DEPLOYING = 1;
    // The artifact has been successfully deployed.
    ACTIVE = 2;
  }

  // Runtime-specific artifact specification.
  bytes deploy_spec = 1;
  // Artifact deployment status.
  Status status = 2;
}

message InstanceStatus {
  enum Simple {
    // The service instance has no status, i.e. this value corresponds to
    // `Option::None` on the Rust code level and other corresponds to
    // `Some(...)`.
    NONE = 0;
    // The service instance is active.
    ACTIVE = 1;
    // The service instance is stopped.
    STOPPED = 2;
    // The service instance is frozen; it can process read-only requests,
    // but not transactions or `before_transactions` / `after_transactions` hooks.
    FROZEN = 3;
  }

  oneof status {
    // Service has a status from the `Simple` enum.
    Simple simple = 1;
    // Service is in process of migration.
    InstanceMigration migration = 2;
  }
}

message InstanceMigration {
  // Migration target to obtain migration scripts from. This artifact
  // must be deployed on the blockchain.
  ArtifactId target = 1;
  // Version of the instance data after the migration is completed.
  // Note that it does not necessarily match the version of `target`,
  // but should be not greater.
  string end_version = 2;
  // Consensus-wide outcome of the migration, in the form of
  // the aggregation hash of the migrated data.
  // The lack of value signifies that the migration is not finished yet.
  exonum.crypto.Hash completed_hash = 3;
}

// Current state of service instance in dispatcher.
message InstanceState {
  // Service instance specification.
  InstanceSpec spec = 1;
  // Service instance activity status.
  //
  // Status can be `NONE` only during the block execution if instance was created,
  // but activation routine for it is not yet completed, and this value can occur no more
  // than once in a service lifetime.
  //
  // If this field is set to `NONE`, the pending_status must have value `ACTIVE`.
  InstanceStatus status = 2;
  // Pending status of the instance.
  //
  // Pending state can be not `NONE` if core is in process of changing service status,
  // e.g. service initialization, resuming or migration. If this field was set to value
  // other than `NONE`, it always will be reset to `NONE` in the next block.
  //
  // The purpose of this field is to keep information about further service status during the
  // block execution because the service status can be changed only after that block is
  // committed. This approach is needed because there is no guarantee that the executed
  // block will be committed.
  InstanceStatus pending_status = 3;
  // Version of the service data. The empty value means that the data version
  // is the same as the `spec.artifact`. Non-empty value means that one or more
  // data migrations have been performed on the service, so that the service data
  // is compatible with a newer artifact.
  string data_version = 4;
}

// Local result of a migration.
message MigrationStatus {
  oneof result {
    // Hash of the successfully migrated data.
    exonum.crypto.Hash hash = 1;
    // Human-readable description of an error that has occurred
    // during migration.
    string error = 2;
  }
}