// You should use the field numbers 1 through 15 
// for the most-frequently-set fields. 
// Lower field number values take less space in the wire format. 
// For example, field numbers in the range 1 through 15 take one byte to encode. 
// Field numbers in the range 16 through 2047 take two bytes. 
/**
 * Meow messages
 *
 * This is the Meow protocol protobuf messages description.
 * 
 */
syntax = "proto3";
package meowlib;
option go_package = "forge.redroom.link/yves/meowlib";

// structure definnig a message as received by a server in protobuf format
message PackedServerMessage {
	string from = 1; // The client public key for that server to get an answer 
	bytes payload = 2; // The ToServerMessage encrypted with the server public key |or| symetrical encryption as agreed earlier
	bytes signature = 3; // The message signature with the client public key |eo| the reference to teh symetrical key used
}

// structure to hold an invitation through a server
message Invitation {
    bytes payload = 1; // invitation payload, encrypted after step 2 
    int32 timeout = 2; // how long do I want the invitation to remain available on the server
    int32 shortcodeLen = 3; // len of the shortcode you wish for short url transmission
    string shortcode = 4; // shortcode that the friend shall request to get the invitation
    string password = 5; // password to set for accessing invitation (optional)
    string uuid = 6; // id that the friend gave you, that you should include to your reply to get recognized
    int64 expiry = 7; // the server allowed expiry date, it may be samller than the requested timeout according to server policy
    int32 step = 8; // progress in the inviattion process : 1=invite friend, 2=friend requests invitation, 3=friend's answer
    string from=9; // used in step 3 the answer public key to check the signature in user message
}

// structure for requesting incoming messages
message ConversationRequest {  
    string lookup_key = 1; // lookup key for a conversation
    bool delivery_request = 2; // look for for delivery tracking, key is implicit, "from" field is used
    int64 send_timestamp = 3;
    string lookup_signature = 4; // prove that I own the private key by signing that block
} 

message Meet {
    string public_status = 1; // Publish my online status, if the server is a meeting server 
    ContactCard contact_card = 2; // mine or the requester
    string message = 3; // short description
}

// structure defining a message for a server, that will be encrypted, then sent in a "packedmessage" payload
message ToServerMessage {
	string type = 1; // Type 1 : final destination / 2 : forward 
	string from = 2 ; // My pub key for the server to send me an encrypter answer
	bytes payload = 3 ; // optional payload for server

    repeated ConversationRequest pull_request = 4; 

	repeated PackedUserMessage messages = 5; 

    repeated ServerCard known_servers = 6; 

    Matriochka matriochka_message = 7;
    
    string uuid = 8;

    Invitation invitation = 9; // invitation for the 2 first steps of a "through server" invitation process

    repeated PackedUserMessage device_messages = 10; // messages to another device belonging to the same user

    int64 timeout = 11; // timeout expected by the client for the server to answer (long polling)

    VideoData video_data = 12; // video call data
}


// structure defining a from server receiver message decrypted from a "packedmessage" payload
message FromServerMessage {
	string type = 1; // Type 
	string server_public_key = 2 ; // Pub key from the server
	bytes payload = 3 ; // 
	string uuid_ack = 4 ; // Ack for the last received ToServerMessage Uuid
	string server_uuid = 5 ; // Provides the server uuid that replaced the client uuid 

	repeated PackedUserMessage chat = 6; 

    repeated ServerCard known_servers = 7; 

    Invitation invitation = 8; // invitation answer, for the third steps of any invitation

    repeated PackedUserMessage device_messages = 9; // messages from other devices belonging to the same user

    VideoData video_data = 10; // video call data

    repeated ContactCard contactCard = 11;  // contact list for a personae
}

message MatriochkaServer {
    string url = 1; // Server Url
    string publicKey = 2; // Server Public Key
    string uuid = 3 ; // Optional, uuid for delivery confirmation
    int32 delay = 4; // Max delay requested for message forwarding or delivery tracking
}

message Matriochka {
    string lookupKey = 1; // Optional, only if you want delivery tracking, less stealth
    MatriochkaServer prev = 2; // Optional, like above   
    MatriochkaServer next = 3; // Next server to deliver the message to
    bytes data = 4; // Matriochka data
}

// structure describing required server attributes
message ServerCard {
    string	name = 1; // friendly server name
    string description=2; // description : owner type (company/private/university...), 
    string public_key = 3; // public key you must use to send encrypted messages to that server
    string url = 4; // meow server url
    string login = 5; // required login to access the server
    string password = 6; // password associated to the login
    string signature = 7; // signature of all previous fields by the server itself
    }

// structure describing a user contact card ie the minimum set of attributes for exchanging identities
message ContactCard {
    string name=1; // contact nickname 
	string contact_public_key =2; // contact public key, will be used to authenticate her/his messages
	string encryption_public_key= 3; // public key you must use to to write encrypted messages to that contact
	string lookup_public_key  =4; // public key you will use as "destination identifier" for her/him to lookup for your messages on the servers
	repeated ServerCard pull_servers =5; // list the servers where the contact will look for messages from you
    uint32 version = 6;
    string invitation_id=7;
    string invitation_message=8;
}

// structure for sending a message to be forwarded to another user in protobuf format
message PackedUserMessage {
	string destination=1; // the peer's current conversation lookup public key
    bytes payload=2;  // the message UserMessage encrypted with the destination peer's public key
	bytes signature=3; // the payload signature with the client identity private key
    repeated int64 serverTimestamp=4; // server time stamp, might be several in matriochka mode
    string server_delivery_uuid=5; // message uuid, for server delivery tracking, omitted if not delivery tracking desired
}

message ConversationStatus {
    string uuid = 1; 
    string answer_to_uuid=2; // message is an answer to another one, specify uuid here
    uint64 localSequence = 3 ; // seq number in local conversation for custom reordering
    uint64 sent = 4 ; // timestamp of the message sent
    uint64 received = 5; // timestamp of the message received
    uint64 processed = 6; // timestamp of the message processed
    ContactCard my_next_identity = 7;
    int32  peer_next_identityAck = 8; // version of the new peer accepted id
    }

message Group{
    string name=1;
    repeated ContactCard members = 2;
}


// structure defining information that might be exchanged between two peers.
message UserMessage {
	string destination = 1; // Lookupkey
	string from = 2; // My public key for that contact
	string type = 3; // Message type
	bytes data = 4; 
    ConversationStatus status = 5;
    ContactCard contact = 6;
    ServerCard knownServers = 7;
    Group group = 8;
    repeated File files = 9;
    Location currentLocation = 10;
    bytes appdata = 11; 
    Invitation invitation = 12;
    VideoData video_data = 13;
}

// UserMessage types :
// 1 : normal message (test, image, video, audio, file, etc)
// 2 : status message (online, offline, busy, etc)
// 3 : send avatar as file[0]
// 4 : location request
// 5 : location response


message File {
    string filename=1; // the proposed filename
    uint64 size=2; // the file size
    uint32 chunk=3; // the chunk counter if file is sent by chunks
    bytes data=4; // the file/chunk content
}

message Location {
    uint64 time=1;
    float latitude=2;
    float longitude=3;
    int32 altitude=4;
}

message DbMessage {
	bool outbound = 1; // direction of the message
	string type = 2; 
	bytes data = 3; // text data
    ConversationStatus status = 4;
    ContactCard contact = 5;
    Group group = 6;
    repeated string file_paths = 7;
    Location current_location = 8;
    bytes appdata = 9; 
    Invitation invitation = 10;
    string from = 11; // source peer uid, used when storing group conversations with more than one peer
}

message VideoData {
    string url  = 1;
    string room = 2;
    uint64 duration = 3;
    repeated VideoCredential credentials = 4;
    repeated string media_query = 5;
}

message VideoCredential {
    string username = 1; 
    string shared_key = 2;
    string token = 3;
}