syntax = "proto3";
package resource;

option go_package = "github.com/grafana/grafana/pkg/storage/unified/resourcepb";

import "resource.proto";


// Unlike the ResourceStore, this service can be exposed to clients directly
// It should be implemented with efficient indexes and does not need read-after-write semantics
service ResourceIndex {
  // Query for documents
  rpc Search(ResourceSearchRequest) returns (ResourceSearchResponse);

  // Get the resource stats
  rpc GetStats(ResourceStatsRequest) returns (ResourceStatsResponse);

  // Rebuild the search index
  rpc RebuildIndexes(RebuildIndexesRequest) returns (RebuildIndexesResponse);
}

// Get statistics across multiple resources
// For these queries, we do not need authorization to see the actual values
message ResourceStatsRequest {
  // Namespace (tenant)
  string namespace = 1;

  // An optional list of group/resource identifiers
  // when empty, we assume searching across everything
  // NOTE, this query may need to federate across a few storage instances
  repeated string kinds = 2;

  // Limit the stats within a folder (not recursive!)
  string folder = 3;
}

message ResourceStatsResponse {
  message Stats {
    // Resource group
    string group = 1;
    // Resource name
    string resource = 2;
    // Number of items
    int64 count = 3;
  }

  // Error details
  ErrorResult error = 1;

  // All results exist within this key
  repeated Stats stats = 2;
}

// This controls what query and analyzers are applied to the specified field
// See: https://blevesearch.com/docs/Analyzers/
enum QueryFieldType {
  // Picks a reasonable analyzer given the input.  Currently this always uses TEXT
  // In the future, it may change to depend on the indexed field type
  DEFAULT = 0;
  // Use free text analyzer.  The query is broken into a normalized set of tokens
  TEXT = 1;
  // The query must exactly match the indexed token
  KEYWORD = 2;
  // Like a text query, but the position and offsets influence the score
  PHRASE = 3; 
}

// Search within a single resource
message ResourceSearchRequest {
  message Sort {
    string field = 1;
    bool desc = 2; // defaults to ascending
  }

  message Facet {
    string field = 1;
    int64 limit = 2;
    // For now, only term queries, eventually?
    // numeric queries
    // date queries
  }

  // Defines the field in the index to query
  // Boost is optional, and allows weighting the field higher in the results
  message QueryField {
    // The field name in the index to query
    string name = 1;

    QueryFieldType type = 2;

    // Boost value for this field
    float boost = 3;
  }

  // The key must include namespace + group + resource
  ListOptions options = 1;

  // To search additional resource types, add additional keys to this list
  // NOTE: queries will only support federation across kinds with common fields
  repeated ResourceKey federated = 2;

  // When a query exists, it is parsed and used to influence
  // query string for chosen implementation (currently just bleve)
  // The score is only relevant when a query exists
  string query = 3;

  // max results
  int64 limit = 4;

  // where to start the query (eg, From)
  int64 offset = 5;

  // sorting
  repeated Sort sortBy = 6;

  // calculate field statistics
  map<string,Facet> facet = 7;

  // the return fields (empty will return everything)
  repeated string fields = 8;

  // explain each result (added to the each row)
  bool explain = 9;

  bool is_deleted = 10;

  int64 page = 11;

  int64 permission = 12;

  // Optionally specify which fields are included in the query
  repeated QueryField query_fields = 13;
}

message ResourceSearchResponse {
  message Facet {
    string field = 1;
    // The distinct terms
    int64 total = 2;
    // The number of documents that do *not* have this field
    int64 missing = 3;
    // Top term stats
    repeated TermFacet terms = 4;
    // numeric range
    // date range facets
  }

  message TermFacet {
    string term = 1;
    int64 count = 2;
  }

  // Error details
  ErrorResult error = 1;

  // All results exist within this key
  ResourceKey key = 2;

  // Query results
  ResourceTable results = 3;

  // The total hit count
  int64 total_hits = 4;

  // indicates how expensive was the query with respect to bytes read
  double query_cost = 5;

  // maximum score across all fields
  double max_score = 6;

  // Facet results
  map<string,Facet> facet = 7;
}

message RebuildIndexesRequest {
  // Namespace (tenant) must be the same as all keys' namespace
  string namespace = 1;

  // List of ResourceKeys (Namespace + Group + Resource)
  repeated ResourceKey keys = 2;
}

message RebuildIndexesResponse {
  // Total count of rebuilt indexes
  int64 rebuildCount = 1;

  // Result message
  string details = 2;

  // Error details
  ErrorResult error = 3;
}