syntax = "proto3";

package protobuf;

import "google/protobuf/timestamp.proto";

message QueueName {
    // chain_id is which chain this queue is
    // associated with
    string chain_id = 1;
    enum Purpose {
        SEND = 0;
        RECEIPT = 1;
    }
    Purpose purpose = 2;
}

// StateKey is a key for the head/tail of a given queue
message StateKey {
    QueueName queue = 1;
    // both encode into one byte with varint encoding
    // never clash with 8 byte message indexes
    enum State {
        HEAD = 0;
        TAIL = 0x7f;
    }
    State state = 2;
}

// StateValue is the type stored under a StateKey
message StateValue {
   fixed64 index = 1;
}

// MessageKey is the key for message *index* in a given queue
message MessageKey {
    QueueName queue = 1;
    fixed64 index = 2;
}

// SendValue is stored under a MessageKey in the SEND queue
message SendValue {
    uint64 maxHeight = 1;
    google.protobuf.Timestamp maxTime = 2;
    // use kind instead of type to avoid keyword conflict
    bytes kind = 3;
    bytes data = 4;
}

// ReceiptValue is stored under a MessageKey in the RECEIPT queue
message ReceiptValue {
    // 0 is success, others are application-defined errors
    int32 errorCode = 1;
    // contains result on success, optional info on error
    bytes data = 2;
}