syntax = "proto3";

package ibc.core.connection.v1;

option go_package = "github.com/cosmos/ibc-go/v10/modules/core/03-connection/types";

import "gogoproto/gogo.proto";
import "ibc/core/commitment/v1/commitment.proto";

// ICS03 - Connection Data Structures as defined in
// https://github.com/cosmos/ibc/blob/master/spec/core/ics-003-connection-semantics#data-structures

// ConnectionEnd defines a stateful object on a chain connected to another
// separate one.
// NOTE: there must only be 2 defined ConnectionEnds to establish
// a connection between two chains.
message ConnectionEnd {
  option (gogoproto.goproto_getters) = false;
  // client associated with this connection.
  string client_id = 1;
  // IBC version which can be utilised to determine encodings or protocols for
  // channels or packets utilising this connection.
  repeated Version versions = 2;
  // current state of the connection end.
  State state = 3;
  // counterparty chain associated with this connection.
  Counterparty counterparty = 4 [(gogoproto.nullable) = false];
  // delay period that must pass before a consensus state can be used for
  // packet-verification NOTE: delay period logic is only implemented by some
  // clients.
  uint64 delay_period = 5;
}

// IdentifiedConnection defines a connection with additional connection
// identifier field.
message IdentifiedConnection {
  option (gogoproto.goproto_getters) = false;
  // connection identifier.
  string id = 1;
  // client associated with this connection.
  string client_id = 2;
  // IBC version which can be utilised to determine encodings or protocols for
  // channels or packets utilising this connection
  repeated Version versions = 3;
  // current state of the connection end.
  State state = 4;
  // counterparty chain associated with this connection.
  Counterparty counterparty = 5 [(gogoproto.nullable) = false];
  // delay period associated with this connection.
  uint64 delay_period = 6;
}

// State defines if a connection is in one of the following states:
// INIT, TRYOPEN, OPEN or UNINITIALIZED.
enum State {
  option (gogoproto.goproto_enum_prefix) = false;

  // Default State
  STATE_UNINITIALIZED_UNSPECIFIED = 0 [(gogoproto.enumvalue_customname) = "UNINITIALIZED"];
  // A connection end has just started the opening handshake.
  STATE_INIT = 1 [(gogoproto.enumvalue_customname) = "INIT"];
  // A connection end has acknowledged the handshake step on the counterparty
  // chain.
  STATE_TRYOPEN = 2 [(gogoproto.enumvalue_customname) = "TRYOPEN"];
  // A connection end has completed the handshake.
  STATE_OPEN = 3 [(gogoproto.enumvalue_customname) = "OPEN"];
}

// Counterparty defines the counterparty chain associated with a connection end.
message Counterparty {
  option (gogoproto.goproto_getters) = false;

  // identifies the client on the counterparty chain associated with a given
  // connection.
  string client_id = 1;
  // identifies the connection end on the counterparty chain associated with a
  // given connection.
  string connection_id = 2;
  // commitment merkle prefix of the counterparty chain.
  ibc.core.commitment.v1.MerklePrefix prefix = 3 [(gogoproto.nullable) = false];
}

// ClientPaths define all the connection paths for a client state.
message ClientPaths {
  // list of connection paths
  repeated string paths = 1;
}

// ConnectionPaths define all the connection paths for a given client state.
message ConnectionPaths {
  // client state unique identifier
  string client_id = 1;
  // list of connection paths
  repeated string paths = 2;
}

// Version defines the versioning scheme used to negotiate the IBC version in
// the connection handshake.
message Version {
  option (gogoproto.goproto_getters) = false;

  // unique version identifier
  string identifier = 1;
  // list of features compatible with the specified identifier
  repeated string features = 2;
}

// Params defines the set of Connection parameters.
message Params {
  // maximum expected time per block (in nanoseconds), used to enforce block delay. This parameter should reflect the
  // largest amount of time that the chain might reasonably take to produce the next block under normal operating
  // conditions. A safe choice is 3-5x the expected time per block.
  uint64 max_expected_time_per_block = 1;
}
