syntax = "proto3";

package moe.nekojimi.friendcloud.protos;

import "google/protobuf/any.proto";

message MessageHeader {
    uint64 sender_id = 1;
    uint64 message_id = 2;
    uint64 reply_to_message_id = 3;
}

message FriendCloudMessage {
    MessageHeader header = 1;
    google.protobuf.Any body = 2;
}

message HelloMessage {
    uint32 protocol_version = 1;        // this is the version of the FriendCloud protocol I speak
}

message CheckInMessage {
    repeated uint64 current_change_heads = 1;
    uint64 current_change = 2;
}

enum Error {
    ERROR_UNSPECIFIED = 0;
    ERROR_WHO_THE_FUCK_ARE_YOU = 1;     // sender unidentified or unauthenticated
    ERROR_PERMISSION_DENIED = 2;        // you can't do that
    ERROR_OBJECT_NOT_FOUND = 3;         // one or more object(s) referenced don't exist
    ERROR_INTERNAL = 4;                 // internal error
    ERROR_OUT_OF_DATE = 5;              // your action is impossible because you have an out-of-date state (in a way that matters)
    ERROR_CHECKSUM_FAILURE = 6;         // a supplied checksum didn't match the relevant data
    ERROR_PIECE_NOT_POSSESSED = 7;      // you asked for a file piece I don't have
    ERROR_INVALID_ARGUMENT = 8;         // an argument specified is outside the expected range
    ERROR_NOT_EXPECTING_REPLY = 9;      // you sent a reply to a message that I wasn't expecting a reply to
    ERROR_INVALID_PROTOBUF = 10;        // your message couldn't be decoded at all
    ERROR_END_OF_HISTORY = 11;          // you're referencing a change ID that I've forgotten (or never had)
    ERROR_MESSAGE_BODY_UNKNOWN = 12;    // I don't know how to handle the type of message in your message body; please stop sending that one
}

message ErrorMessage {
    Error error = 1;
    string text = 2;
}

message MultiObjectConfirmationMessage {
    repeated uint64 expected_return_id = 1;
}