syntax = "proto3";
package protocol;

option optimize_for = SPEED;
option go_package = "go.miragespace.co/specter/spec/protocol";

import "google/protobuf/duration.proto";

service KVService {
    rpc Put(SimpleRequest) returns (SimpleResponse);
    rpc Get(SimpleRequest) returns (SimpleResponse);
    rpc Delete(SimpleRequest) returns (SimpleResponse);

    rpc Append(PrefixRequest) returns (PrefixResponse);
    rpc List(PrefixRequest) returns (PrefixResponse);
    rpc Contains(PrefixRequest) returns (PrefixResponse);
    rpc Remove(PrefixRequest) returns (PrefixResponse);

    rpc Acquire(LeaseRequest) returns (LeaseResponse);
    rpc Renew(LeaseRequest) returns (LeaseResponse);
    rpc Release(LeaseRequest) returns (LeaseResponse);

    rpc Import(ImportRequest) returns (ImportResponse);

    rpc ListKeys(ListKeysRequest) returns (ListKeysResponse);
}

message SimpleRequest {
    bytes key = 1;
    bytes value = 2;
}

message SimpleResponse {
    bytes value = 1;
}

message PrefixRequest {
    bytes prefix = 1;
    bytes child = 2;
}

message PrefixResponse {
    repeated bytes children = 1;
    bool exists = 2;
}

message LeaseRequest {
    bytes lease = 1;
    uint64 new_token = 2;
    uint64 prev_token = 3;

    google.protobuf.Duration ttl = 5;
}

message LeaseResponse {
    uint64 token = 1;
}

message KVTransfer {
    // Presence distinguishes an empty simple value from no simple value, even
    // when a prefix or lease shares the key. Keep tag 1 for legacy readers.
    optional bytes simple_value = 1;
    repeated bytes prefix_children = 2;
    uint64 lease_token = 3;
}

message ImportRequest {
    repeated bytes keys = 1;
    repeated KVTransfer values = 2;
}

message ImportResponse {}

message ListKeysRequest {
    bytes prefix = 1;
}

message KeyComposite {
    enum Type {
        UNKNOWN = 0;
        SIMPLE = 1;
        PREFIX = 2;
        LEASE  = 3;
    }
    bytes key = 1; 
    Type type = 2;
}

message ListKeysResponse {
    repeated KeyComposite keys = 1;
}