syntax = "proto3";
package cosmos.feegrant.v1beta1;

import "gogoproto/gogo.proto";
import "google/protobuf/any.proto";
import "cosmos_proto/cosmos.proto";
import "cosmos/base/v1beta1/coin.proto";
import "google/protobuf/timestamp.proto";
import "google/protobuf/duration.proto";

option go_package = "github.com/cosmos/cosmos-sdk/x/feegrant/types";

// BasicFeeAllowance implements FeeAllowance with a one-time grant of tokens
// that optionally expires. The delegatee can use up to SpendLimit to cover fees.
message BasicFeeAllowance {
  option (cosmos_proto.implements_interface) = "FeeAllowanceI";

  // spend_limit specifies the maximum amount of tokens that can be spent
  // by this allowance and will be updated as tokens are spent. If it is
  // empty, there is no spend limit and any amount of coins can be spent.
  repeated cosmos.base.v1beta1.Coin spend_limit = 1
      [(gogoproto.nullable) = false, (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"];

  // expiration specifies an optional time when this allowance expires
  ExpiresAt expiration = 2 [(gogoproto.nullable) = false];
}

// PeriodicFeeAllowance extends FeeAllowance to allow for both a maximum cap,
// as well as a limit per time period.
message PeriodicFeeAllowance {
  option (cosmos_proto.implements_interface) = "FeeAllowanceI";

  // basic specifies a struct of `BasicFeeAllowance`
  BasicFeeAllowance basic = 1 [(gogoproto.nullable) = false];

  // period specifies the time duration in which period_spend_limit coins can
  // be spent before that allowance is reset
  Duration period = 2 [(gogoproto.nullable) = false];

  // period_spend_limit specifies the maximum number of coins that can be spent
  // in the period
  repeated cosmos.base.v1beta1.Coin period_spend_limit = 3
      [(gogoproto.nullable) = false, (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"];

  // period_can_spend is the number of coins left to be spent before the period_reset time
  repeated cosmos.base.v1beta1.Coin period_can_spend = 4
      [(gogoproto.nullable) = false, (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"];

  // period_reset is the time at which this period resets and a new one begins,
  // it is calculated from the start time of the first transaction after the
  // last period ended
  ExpiresAt period_reset = 5 [(gogoproto.nullable) = false];
}

// Duration is a span of a clock time or number of blocks.
// This is designed to be added to an ExpiresAt struct.
message Duration {
  // sum is the oneof that represents either duration or block
  oneof sum {
    google.protobuf.Duration duration = 1 [(gogoproto.stdduration) = true];
    uint64                   blocks   = 2;
  }
}

// ExpiresAt is a point in time where something expires.
// It may be *either* block time or block height
message ExpiresAt {
  // sum is the oneof that represents either time or height
  oneof sum {
    google.protobuf.Timestamp time   = 1 [(gogoproto.stdtime) = true];
    int64                     height = 2;
  }
}

// FeeAllowanceGrant is stored in the KVStore to record a grant with full context
message FeeAllowanceGrant {

  string              granter   = 1;
  string              grantee   = 2;
  google.protobuf.Any allowance = 3 [(cosmos_proto.accepts_interface) = "FeeAllowanceI"];
}