// Copyright 2016 Google Inc.
//
// 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 google.datastore.v1;

import "google/api/annotations.proto";
import "google/protobuf/struct.proto";
import "google/protobuf/timestamp.proto";
import "google/type/latlng.proto";

option java_multiple_files = true;
option java_outer_classname = "EntityProto";
option java_package = "com.google.datastore.v1";


// A partition ID identifies a grouping of entities. The grouping is always
// by project and namespace, however the namespace ID may be empty.
//
// A partition ID contains several dimensions:
// project ID and namespace ID.
//
// Partition dimensions:
//
// - May be `""`.
// - Must be valid UTF-8 bytes.
// - Must have values that match regex `[A-Za-z\d\.\-_]{1,100}`
// If the value of any dimension matches regex `__.*__`, the partition is
// reserved/read-only.
// A reserved/read-only partition ID is forbidden in certain documented
// contexts.
//
// Foreign partition IDs (in which the project ID does
// not match the context project ID ) are discouraged.
// Reads and writes of foreign partition IDs may fail if the project is not in an active state.
message PartitionId {
  // The ID of the project to which the entities belong.
  string project_id = 2;

  // If not empty, the ID of the namespace to which the entities belong.
  string namespace_id = 4;
}

// A unique identifier for an entity.
// If a key's partition ID or any of its path kinds or names are
// reserved/read-only, the key is reserved/read-only.
// A reserved/read-only key is forbidden in certain documented contexts.
message Key {
  // A (kind, ID/name) pair used to construct a key path.
  //
  // If either name or ID is set, the element is complete.
  // If neither is set, the element is incomplete.
  message PathElement {
    // The kind of the entity.
    // A kind matching regex `__.*__` is reserved/read-only.
    // A kind must not contain more than 1500 bytes when UTF-8 encoded.
    // Cannot be `""`.
    string kind = 1;

    // The type of ID.
    oneof id_type {
      // The auto-allocated ID of the entity.
      // Never equal to zero. Values less than zero are discouraged and may not
      // be supported in the future.
      int64 id = 2;

      // The name of the entity.
      // A name matching regex `__.*__` is reserved/read-only.
      // A name must not be more than 1500 bytes when UTF-8 encoded.
      // Cannot be `""`.
      string name = 3;
    }
  }

  // Entities are partitioned into subsets, currently identified by a project
  // ID and namespace ID.
  // Queries are scoped to a single partition.
  PartitionId partition_id = 1;

  // The entity path.
  // An entity path consists of one or more elements composed of a kind and a
  // string or numerical identifier, which identify entities. The first
  // element identifies a _root entity_, the second element identifies
  // a _child_ of the root entity, the third element identifies a child of the
  // second entity, and so forth. The entities identified by all prefixes of
  // the path are called the element's _ancestors_.
  //
  // An entity path is always fully complete: *all* of the entity's ancestors
  // are required to be in the path along with the entity identifier itself.
  // The only exception is that in some documented cases, the identifier in the
  // last path element (for the entity) itself may be omitted. For example,
  // the last path element of the key of `Mutation.insert` may have no
  // identifier.
  //
  // A path can never be empty, and a path can have at most 100 elements.
  repeated PathElement path = 2;
}

// An array value.
message ArrayValue {
  // Values in the array.
  // The order of this array may not be preserved if it contains a mix of
  // indexed and unindexed values.
  repeated Value values = 1;
}

// A message that can hold any of the supported value types and associated
// metadata.
message Value {
  // Must have a value set.
  oneof value_type {
    // A null value.
    google.protobuf.NullValue null_value = 11;

    // A boolean value.
    bool boolean_value = 1;

    // An integer value.
    int64 integer_value = 2;

    // A double value.
    double double_value = 3;

    // A timestamp value.
    // When stored in the Datastore, precise only to microseconds;
    // any additional precision is rounded down.
    google.protobuf.Timestamp timestamp_value = 10;

    // A key value.
    Key key_value = 5;

    // A UTF-8 encoded string value.
    // When `exclude_from_indexes` is false (it is indexed) , may have at most 1500 bytes.
    // Otherwise, may be set to at least 1,000,000 bytes.
    string string_value = 17;

    // A blob value.
    // May have at most 1,000,000 bytes.
    // When `exclude_from_indexes` is false, may have at most 1500 bytes.
    // In JSON requests, must be base64-encoded.
    bytes blob_value = 18;

    // A geo point value representing a point on the surface of Earth.
    google.type.LatLng geo_point_value = 8;

    // An entity value.
    //
    // - May have no key.
    // - May have a key with an incomplete key path.
    // - May have a reserved/read-only key.
    Entity entity_value = 6;

    // An array value.
    // Cannot contain another array value.
    // A `Value` instance that sets field `array_value` must not set fields
    // `meaning` or `exclude_from_indexes`.
    ArrayValue array_value = 9;
  }

  // The `meaning` field should only be populated for backwards compatibility.
  int32 meaning = 14;

  // If the value should be excluded from all indexes including those defined
  // explicitly.
  bool exclude_from_indexes = 19;
}

// A Datastore data object.
//
// An entity is limited to 1 megabyte when stored. That _roughly_
// corresponds to a limit of 1 megabyte for the serialized form of this
// message.
message Entity {
  // The entity's key.
  //
  // An entity must have a key, unless otherwise documented (for example,
  // an entity in `Value.entity_value` may have no key).
  // An entity's kind is its key path's last element's kind,
  // or null if it has no key.
  Key key = 1;

  // The entity's properties.
  // The map's keys are property names.
  // A property name matching regex `__.*__` is reserved.
  // A reserved property name is forbidden in certain documented contexts.
  // The name must not contain more than 500 characters.
  // The name cannot be `""`.
  map<string, Value> properties = 3;
}
