// Copyright 2016 Prometheus 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 prometheus;

option go_package = "prompb";

import "types.proto";

message WriteRequest {
  repeated prometheus.TimeSeries timeseries = 1;
  // Cortex uses this field to determine the source of the write request.
  // We reserve it to avoid any compatibility issues.
  reserved  2;
  repeated prometheus.MetricMetadata metadata = 3;
}

// ReadRequest represents a remote read request.
message ReadRequest {
  repeated Query queries = 1;

  enum ResponseType {
    // Server will return a single ReadResponse message with matched series that includes list of raw samples.
    // It's recommended to use streamed response types instead.
    //
    // Response headers:
    // Content-Type: "application/x-protobuf"
    // Content-Encoding: "snappy"
    SAMPLES = 0;
    // Server will stream a delimited ChunkedReadResponse message that contains XOR encoded chunks for a single series.
    // Each message is following varint size and fixed size bigendian uint32 for CRC32 Castagnoli checksum.
    //
    // Response headers:
    // Content-Type: "application/x-streamed-protobuf; proto=prometheus.ChunkedReadResponse"
    // Content-Encoding: ""
    STREAMED_XOR_CHUNKS = 1;
  }

  // accepted_response_types allows negotiating the content type of the response.
  //
  // Response types are taken from the list in the FIFO order. If no response type in `accepted_response_types` is
  // implemented by server, error is returned.
  // For request that do not contain `accepted_response_types` field the SAMPLES response type will be used.
  repeated ResponseType accepted_response_types = 2;
}

// ReadResponse is a response when response_type equals SAMPLES.
message ReadResponse {
  // In same order as the request's queries.
  repeated QueryResult results = 1;
}

message Query {
  int64 start_timestamp_ms = 1;
  int64 end_timestamp_ms = 2;
  repeated prometheus.LabelMatcher matchers = 3;
  prometheus.ReadHints hints = 4;
}

message QueryResult {
  // Samples within a time series must be ordered by time.
  repeated prometheus.TimeSeries timeseries = 1;
}

// ChunkedReadResponse is a response when response_type equals STREAMED_XOR_CHUNKS.
// We strictly stream full series after series, optionally split by time. This means that a single frame can contain
// partition of the single series, but once a new series is started to be streamed it means that no more chunks will
// be sent for previous one. Series are returned sorted in the same way TSDB block are internally.
message ChunkedReadResponse {
  repeated prometheus.ChunkedSeries chunked_series = 1;

  // query_index represents an index of the query from ReadRequest.queries these chunks relates to.
  int64 query_index = 2;
}