syntax="proto3";
package nu.marginalia.api.searchquery;

option java_package="nu.marginalia.api.searchquery";
option java_multiple_files=true;

service QueryApi {
  rpc query(RpcQsQuery) returns (RpcQsResponse) {}
}
service IndexApi {
  rpc query(RpcIndexQuery) returns (stream RpcDecoratedResultItem) {}
}

message Empty {}

/* Query Service query request */
message RpcQsQuery {
  string humanQuery = 1;
  string nearDomain = 2;
  repeated string tacitIncludes = 3;
  repeated string tacitExcludes = 4;
  repeated string tacitPriority = 5;
  repeated string tacitAdvice = 6;
  RpcSpecLimit quality = 7;
  RpcSpecLimit year = 8;
  RpcSpecLimit size = 9;
  RpcSpecLimit rank = 10;
  repeated int32 domainIds = 12;
  RpcQueryLimits queryLimits = 13;
  string searchSetIdentifier = 14;
  string queryStrategy = 15;      // Named query configuration
  RpcTemporalBias temporalBias = 16;

  RpcQsQueryPagination pagination = 17;
}

/* Query service query response */
message RpcQsResponse {
  RpcIndexQuery specs = 1;
  repeated RpcDecoratedResultItem results = 2;
  repeated string searchTermsHuman = 3;
  repeated string problems = 4;
  string domain = 5;

  RpcQsResultPagination pagination = 6;
}

message RpcQsQueryPagination {
  int32 page = 1;
  int32 pageSize = 2;
}

message RpcQsResultPagination {
  int32 page = 1;
  int32 pageSize = 2;
  int32 totalResults = 3;
}

message RpcTemporalBias {
  enum Bias {
    NONE = 0;
    RECENT = 1;
    OLD = 2;
  }
  Bias bias = 1;
}

/* Index service query request */
message RpcIndexQuery {
  RpcQuery query = 1;
  repeated int32 domains = 2;     // (optional) A list of domain IDs to consider
  string searchSetIdentifier = 3; // (optional) A named set of domains to consider
  string humanQuery = 4;          // The search query as the user entered it
  RpcSpecLimit quality = 5;
  RpcSpecLimit year = 6;
  RpcSpecLimit size = 7;
  RpcSpecLimit rank = 8;
  RpcQueryLimits queryLimits = 10;
  string queryStrategy = 11;      // Named query configuration
  RpcResultRankingParameters parameters = 12;
}

/* A tagged union encoding some limit on a field */
message RpcSpecLimit {
  int32 value = 1;
  TYPE type = 2;

  enum TYPE {
    NONE = 0;
    EQUALS = 1;
    LESS_THAN = 2;
    GREATER_THAN = 3;
  };
}

/** A search result item decorated with title and description metadata from the link database */
message RpcDecoratedResultItem {
  RpcRawResultItem rawItem = 1;
  string url = 2;
  string title = 3;
  string description = 4;
  double urlQuality = 5;
  string format = 6;
  int32 features = 7; // bitmask encoding features of the document
  int32 pubYear = 8;
  int64 dataHash = 9;
  int32 wordsTotal = 10;
  double rankingScore = 11; // The ranking score of this search result item, lower is better
  int64 bestPositions = 12;
  RpcResultRankingDetails rankingDetails = 13; // optional, only present if exportDebugData is true in RpcResultRankingParameters
  int32 resultsFromDomain = 14;
}

/** A raw index-service view of a search result */
message RpcRawResultItem {
  int64 combinedId = 1; // raw ID with bit-encoded ranking information still present
  int64 encodedDocMetadata = 3; // bit encoded document metadata
  int32 htmlFeatures = 4; // bitmask encoding features of the document
  repeated RpcResultKeywordScore keywordScores = 5;
  bool hasPriorityTerms = 6; // true if this word is important to the document
  MATCH_TYPE matchType = 7; // the type of match this result represents

  enum MATCH_TYPE {
    FLAGS = 0;
    PROXIMITY = 1;
    PHRASE = 2;
  };
}

/* Information about how well a keyword matches a query */
message RpcResultKeywordScore {
  string keyword = 1; // the keyword
  int32 flags = 2;
  int32 positions = 3;
}

/* Query execution parameters */
message RpcQueryLimits {
  int32 resultsByDomain = 1;
  int32 resultsTotal = 2;
  int32 timeoutMs = 3;
  int32 fetchSize = 4; // Size of the fetch buffer in the index service
}

/** Parameters for the result ranking function */
message RpcResultRankingParameters {
  double bm25K = 1; // BM25 parameter
  double bm25B = 2; // BM25 parameter

  int32 shortDocumentThreshold = 5;
  double shortDocumentPenalty = 6;
  double domainRankBonus = 7;
  double qualityPenalty = 8;
  int32 shortSentenceThreshold = 9;
  double shortSentencePenalty = 10;
  double bm25Weight = 11;
  // -- 12 unused --
  double tcfFirstPositionWeight = 13;
  double tcfVerbatimWeight = 14;
  double tcfProximityWeight = 15;
  RpcTemporalBias temporalBias = 16;
  double temporalBiasWeight = 17;

  bool exportDebugData = 18;
  bool disablePenalties = 19;

}

message RpcResultRankingDetails {
  RpcResultDocumentRankingOutputs documentOutputs = 1;
  RpcResultTermRankingOutputs termOutputs = 2;
}

message RpcResultRankingInputs {
  int32 rank = 1;
  int32 asl = 2;
  int32 quality = 3;
  int32 size = 4;
  int32 topology = 5;
  int32 year = 6;
  repeated string flags = 7;
}

/** Summary of the output of the ranking function */
message RpcResultDocumentRankingOutputs {
  repeated string factor = 1;
  repeated string value = 2;
}

message RpcResultTermRankingOutputs {
  repeated int64 termId = 1;
  repeated string term = 2;
  repeated string factor = 3;
  repeated string value = 4;
}

/* Defines a single subquery */
message RpcQuery {
  repeated string include = 1;  // These terms must be present
  repeated string exclude = 2;  // These terms must be absent
  repeated string advice = 3;   // These terms must be present, but do not affect ranking
  repeated string priority = 4;  // These terms are not mandatory, but affect ranking positively if they are present
  repeated RpcPhrases phrases = 5; // Groups of terms that must exist in proximity of each other
  string compiledQuery = 6;  // Compiled query in infix notation
}

/* Defines a group of search terms that must exist in the the specified order within the document */
message RpcPhrases {
  repeated string terms = 1;
  TYPE type = 2;

  enum TYPE {
    OPTIONAL = 0;
    MANDATORY = 1;
    FULL = 2;
  };
}