// Copyright: Ankitects Pty Ltd and contributors
// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html

syntax = "proto3";

option java_multiple_files = true;

package anki.scheduler;

import "anki/generic.proto";
import "anki/cards.proto";
import "anki/decks.proto";
import "anki/collection.proto";
import "anki/config.proto";

service SchedulerService {
  rpc GetQueuedCards(GetQueuedCardsRequest) returns (QueuedCards);
  rpc AnswerCard(CardAnswer) returns (collection.OpChanges);
  rpc SchedTimingToday(generic.Empty) returns (SchedTimingTodayResponse);
  rpc StudiedToday(generic.Empty) returns (generic.String);
  rpc StudiedTodayMessage(StudiedTodayMessageRequest) returns (generic.String);
  rpc UpdateStats(UpdateStatsRequest) returns (generic.Empty);
  rpc ExtendLimits(ExtendLimitsRequest) returns (generic.Empty);
  rpc CountsForDeckToday(decks.DeckId) returns (CountsForDeckTodayResponse);
  rpc CongratsInfo(generic.Empty) returns (CongratsInfoResponse);
  rpc RestoreBuriedAndSuspendedCards(cards.CardIds)
      returns (collection.OpChanges);
  rpc UnburyDeck(UnburyDeckRequest) returns (collection.OpChanges);
  rpc BuryOrSuspendCards(BuryOrSuspendCardsRequest)
      returns (collection.OpChangesWithCount);
  rpc EmptyFilteredDeck(decks.DeckId) returns (collection.OpChanges);
  rpc RebuildFilteredDeck(decks.DeckId) returns (collection.OpChangesWithCount);
  rpc ScheduleCardsAsNew(ScheduleCardsAsNewRequest)
      returns (collection.OpChanges);
  rpc ScheduleCardsAsNewDefaults(ScheduleCardsAsNewDefaultsRequest)
      returns (ScheduleCardsAsNewDefaultsResponse);
  rpc SetDueDate(SetDueDateRequest) returns (collection.OpChanges);
  rpc SortCards(SortCardsRequest) returns (collection.OpChangesWithCount);
  rpc SortDeck(SortDeckRequest) returns (collection.OpChangesWithCount);
  rpc GetSchedulingStates(cards.CardId) returns (SchedulingStates);
  rpc DescribeNextStates(SchedulingStates) returns (generic.StringList);
  rpc StateIsLeech(SchedulingState) returns (generic.Bool);
  rpc UpgradeScheduler(generic.Empty) returns (generic.Empty);
  rpc CustomStudy(CustomStudyRequest) returns (collection.OpChanges);
  rpc CustomStudyDefaults(CustomStudyDefaultsRequest)
      returns (CustomStudyDefaultsResponse);
  rpc RepositionDefaults(generic.Empty) returns (RepositionDefaultsResponse);
  rpc ComputeFsrsWeights(ComputeFsrsWeightsRequest)
      returns (ComputeFsrsWeightsResponse);
  rpc ComputeFsrsWeightsFromItems(ComputeFsrsWeightsFromItemsRequest)
      returns (ComputeFsrsWeightsResponse);
  rpc GetOptimalRetentionParameters(GetOptimalRetentionParametersRequest)
      returns (GetOptimalRetentionParametersResponse);
  rpc ComputeOptimalRetention(ComputeOptimalRetentionRequest)
      returns (ComputeOptimalRetentionResponse);
  rpc EvaluateWeights(EvaluateWeightsRequest) returns (EvaluateWeightsResponse);
  rpc ComputeMemoryState(cards.CardId) returns (ComputeMemoryStateResponse);
}

// Implicitly includes any of the above methods that are not listed in the
// backend service.
service BackendSchedulerService {}

message SchedulingState {
  message New {
    uint32 position = 1;
  }
  message Learning {
    uint32 remaining_steps = 1;
    uint32 scheduled_secs = 2;
    optional cards.FsrsMemoryState memory_state = 6;
  }
  message Review {
    uint32 scheduled_days = 1;
    uint32 elapsed_days = 2;
    float ease_factor = 3;
    uint32 lapses = 4;
    bool leeched = 5;
    optional cards.FsrsMemoryState memory_state = 6;
  }
  message Relearning {
    Review review = 1;
    Learning learning = 2;
  }
  message Normal {
    oneof kind {
      New new = 1;
      Learning learning = 2;
      Review review = 3;
      Relearning relearning = 4;
    }
  }
  message Preview {
    uint32 scheduled_secs = 1;
    bool finished = 2;
  }
  message ReschedulingFilter {
    Normal original_state = 1;
  }
  message Filtered {
    oneof kind {
      Preview preview = 1;
      ReschedulingFilter rescheduling = 2;
    }
  }

  oneof kind {
    Normal normal = 1;
    Filtered filtered = 2;
  }
  // The backend does not populate this field in GetQueuedCards; the front-end
  // is expected to populate it based on the provided Card. If it's not set when
  // answering a card, the existing custom data will not be updated.
  optional string custom_data = 3;
}

message QueuedCards {
  enum Queue {
    NEW = 0;
    LEARNING = 1;
    REVIEW = 2;
  }
  message QueuedCard {
    cards.Card card = 1;
    Queue queue = 2;
    SchedulingStates states = 3;
    SchedulingContext context = 4;
  }

  repeated QueuedCard cards = 1;
  uint32 new_count = 2;
  uint32 learning_count = 3;
  uint32 review_count = 4;
}

message GetQueuedCardsRequest {
  uint32 fetch_limit = 1;
  bool intraday_learning_only = 2;
}

message SchedTimingTodayResponse {
  uint32 days_elapsed = 1;
  int64 next_day_at = 2;
}

message StudiedTodayMessageRequest {
  uint32 cards = 1;
  double seconds = 2;
}

message UpdateStatsRequest {
  int64 deck_id = 1;
  int32 new_delta = 2;
  int32 review_delta = 4;
  int32 millisecond_delta = 5;
}

message ExtendLimitsRequest {
  int64 deck_id = 1;
  int32 new_delta = 2;
  int32 review_delta = 3;
}

message CountsForDeckTodayResponse {
  int32 new = 1;
  int32 review = 2;
}

message CongratsInfoResponse {
  uint32 learn_remaining = 1;
  uint32 secs_until_next_learn = 2;
  bool review_remaining = 3;
  bool new_remaining = 4;
  bool have_sched_buried = 5;
  bool have_user_buried = 6;
  bool is_filtered_deck = 7;
  bool bridge_commands_supported = 8;
  string deck_description = 9;
}

message UnburyDeckRequest {
  enum Mode {
    ALL = 0;
    SCHED_ONLY = 1;
    USER_ONLY = 2;
  }
  int64 deck_id = 1;
  Mode mode = 2;
}

message BuryOrSuspendCardsRequest {
  enum Mode {
    SUSPEND = 0;
    BURY_SCHED = 1;
    BURY_USER = 2;
  }
  repeated int64 card_ids = 1;
  repeated int64 note_ids = 2;
  Mode mode = 3;
}

message ScheduleCardsAsNewRequest {
  enum Context {
    BROWSER = 0;
    REVIEWER = 1;
  }
  repeated int64 card_ids = 1;
  bool log = 2;
  bool restore_position = 3;
  bool reset_counts = 4;
  optional Context context = 5;
}

message ScheduleCardsAsNewDefaultsRequest {
  ScheduleCardsAsNewRequest.Context context = 1;
}

message ScheduleCardsAsNewDefaultsResponse {
  bool restore_position = 1;
  bool reset_counts = 2;
}

message SetDueDateRequest {
  repeated int64 card_ids = 1;
  string days = 2;
  config.OptionalStringConfigKey config_key = 3;
}

message SortCardsRequest {
  repeated int64 card_ids = 1;
  uint32 starting_from = 2;
  uint32 step_size = 3;
  bool randomize = 4;
  bool shift_existing = 5;
}

message SortDeckRequest {
  int64 deck_id = 1;
  bool randomize = 2;
}

message SchedulingStates {
  SchedulingState current = 1;
  SchedulingState again = 2;
  SchedulingState hard = 3;
  SchedulingState good = 4;
  SchedulingState easy = 5;
}

message CardAnswer {
  enum Rating {
    AGAIN = 0;
    HARD = 1;
    GOOD = 2;
    EASY = 3;
  }

  int64 card_id = 1;
  SchedulingState current_state = 2;
  SchedulingState new_state = 3;
  Rating rating = 4;
  int64 answered_at_millis = 5;
  uint32 milliseconds_taken = 6;
}

message CustomStudyRequest {
  message Cram {
    enum CramKind {
      // due cards in due order
      CRAM_KIND_DUE = 0;
      // new cards in added order
      CRAM_KIND_NEW = 1;
      // review cards in random order
      CRAM_KIND_REVIEW = 2;
      // all cards in random order; no rescheduling
      CRAM_KIND_ALL = 3;
    }
    CramKind kind = 1;
    // the maximum number of cards
    uint32 card_limit = 2;
    // cards must match one of these, if unempty
    repeated string tags_to_include = 3;
    // cards must not match any of these
    repeated string tags_to_exclude = 4;
  }
  int64 deck_id = 1;
  oneof value {
    // increase new limit by x
    int32 new_limit_delta = 2;
    // increase review limit by x
    int32 review_limit_delta = 3;
    // repeat cards forgotten in the last x days
    uint32 forgot_days = 4;
    // review cards due in the next x days
    uint32 review_ahead_days = 5;
    // preview new cards added in the last x days
    uint32 preview_days = 6;
    Cram cram = 7;
  }
}

message SchedulingContext {
  string deck_name = 1;
  uint64 seed = 2;
}

message CustomStudyDefaultsRequest {
  int64 deck_id = 1;
}

message CustomStudyDefaultsResponse {
  message Tag {
    string name = 1;
    bool include = 2;
    bool exclude = 3;
  }

  repeated Tag tags = 1;
  uint32 extend_new = 2;
  uint32 extend_review = 3;
  uint32 available_new = 4;
  uint32 available_review = 5;
  // in v3, counts for children are provided separately
  uint32 available_new_in_children = 6;
  uint32 available_review_in_children = 7;
}

message RepositionDefaultsResponse {
  bool random = 1;
  bool shift = 2;
}

message ComputeFsrsWeightsRequest {
  /// The search used to gather cards for training
  string search = 1;
}

message ComputeFsrsWeightsResponse {
  repeated float weights = 1;
  // if less than 1000, should warn user
  uint32 fsrs_items = 2;
}

message ComputeFsrsWeightsFromItemsRequest {
  repeated FsrsItem items = 1;
}

message FsrsItem {
  repeated FsrsReview reviews = 1;
}

message FsrsReview {
  uint32 rating = 1;
  uint32 delta_t = 2;
}

message ComputeOptimalRetentionRequest {
  repeated float weights = 1;
  uint32 deck_size = 2;
  uint32 days_to_simulate = 3;
  uint32 max_minutes_of_study_per_day = 4;
  uint32 max_interval = 5;
  string search = 6;
}

message ComputeOptimalRetentionResponse {
  float optimal_retention = 1;
}

message OptimalRetentionParameters {
  double recall_secs_hard = 6;
  double recall_secs_good = 7;
  double recall_secs_easy = 8;
  double forget_secs = 9;
  double learn_secs = 10;
  double first_rating_probability_again = 11;
  double first_rating_probability_hard = 12;
  double first_rating_probability_good = 13;
  double first_rating_probability_easy = 14;
  double review_rating_probability_hard = 15;
  double review_rating_probability_good = 16;
  double review_rating_probability_easy = 17;
}

message GetOptimalRetentionParametersRequest {
  string search = 1;
}

message GetOptimalRetentionParametersResponse {
  OptimalRetentionParameters params = 1;
}

message EvaluateWeightsRequest {
  repeated float weights = 1;
  string search = 2;
}

message EvaluateWeightsResponse {
  float log_loss = 1;
  float rmse_bins = 2;
}

message ComputeMemoryStateResponse {
  optional cards.FsrsMemoryState state = 1;
  float desired_retention = 2;
}