syntax = "proto3";

// 32-byte value in bigendian format
message CryptoKey {
    fixed32 u0 = 1;
    fixed32 u1 = 2;
    fixed32 u2 = 3;
    fixed32 u3 = 4;    
    fixed32 u4 = 5;
    fixed32 u5 = 6;
    fixed32 u6 = 7;
    fixed32 u7 = 8;    
}

// 64-byte value in bigendian format
message Signature {
    fixed32 u0 = 1;
    fixed32 u1 = 2;
    fixed32 u2 = 3;
    fixed32 u3 = 4;    
    fixed32 u4 = 5;
    fixed32 u5 = 6;
    fixed32 u6 = 7;
    fixed32 u7 = 8;    
    fixed32 u8 = 9;
    fixed32 u9 = 10;
    fixed32 u10 = 11;
    fixed32 u11 = 12;    
    fixed32 u12 = 13;
    fixed32 u13 = 14;
    fixed32 u14 = 15;
    fixed32 u15 = 16;    
}

// 24-byte value in bigendian format
message Nonce {
    fixed32 u0 = 1;
    fixed32 u1 = 2;
    fixed32 u2 = 3;
    fixed32 u3 = 4;    
    fixed32 u4 = 5;
    fixed32 u5 = 6;
}

// 36-byte typed crpyto key
message TypedKey {
    // CryptoKind FourCC in bigendian format
    fixed32 kind = 1;
    // Key value
    CryptoKey value = 2;
}

// DHTData - represents chunked blob data in the DHT
// Header in subkey 0 follows this structure
//
// stride = descriptor subkey count on first key - 1
// Subkeys 1..=stride on the first key are concatenated chunks
// Subkeys 0..stride on the 'keys' keys are concatenated chunks
//
// Keys must use writable schema in order to make this data mutable

message DHTData {
    // Other keys to concatenate
    repeated TypedKey keys = 1;
    // Hash of reassembled data to verify contents
    TypedKey hash = 2;
    // Chunk size per subkey
    uint32 chunk = 3;
    // Total data size
    uint32 size = 4;
}

// DHTList - represents a re-orderable collection of individual elements
// Header in subkey 0 of first key follows this structure
//
// stride = descriptor subkey count on first key - 1
// Subkeys 1..=stride on the first key are individual elements
// Subkeys 0..stride on the 'keys' keys are also individual elements
//
// Keys must use writable schema in order to make this list mutable
message DHTList {
    // Other keys to concatenate
    repeated TypedKey keys = 1;
    // Item position index
    // Actual item location is:
    //   idx = index[n] + 1 (offset for header at idx 0)
    //   key = idx / stride
    //   subkey = idx % stride
    repeated uint32 index = 2;
    // Free items are not represented in the list but can be
    // calculated through iteration
}

// DHTLog - represents an appendable/truncatable log collection of individual elements
// Header in subkey 0 of first key follows this structure
//
// stride = descriptor subkey count on first key - 1
// Subkeys 1..=stride on the first key are individual elements
// Subkeys 0..stride on the 'keys' keys are also individual elements
// 
// Keys must use writable schema in order to make this list mutable
message DHTLog {
    // Other keys to concatenate
    repeated TypedKey keys = 1;
    // Back link to another DHTLog further back
    TypedKey back = 2;
    // Count of subkeys in all keys in this DHTLog
    repeated uint32 subkey_counts = 3;
    // Total count of subkeys in all keys in this DHTLog including all backlogs
    uint32 total_subkeys = 4;
}

// DataReference
// Pointer to data somewhere in Veilid
// Abstraction over DHTData and BlockStore
message DataReference {
    oneof kind {
        TypedKey dht_data = 1;
        // TypedKey block = 2;
    }
}

// AttachmentKind
// Enumeration of well-known attachment types
enum AttachmentKind {
    ATTACHMENT_KIND_UNSPECIFIED = 0;
    ATTACHMENT_KIND_FILE = 1;
    ATTACHMENT_KIND_IMAGE = 2;
}

// A single attachment
message Attachment {
    // Type of the data
    AttachmentKind kind = 1;
    // MIME type of the data
    string mime = 2;
    // Title or filename
    string name = 3;
    // Pointer to the data content
    DataReference content = 4;
    // Author signature over all attachment fields and content fields and bytes
    Signature signature = 5;
}

// A single message as part of a series of messages
// Messages are stored in an append-only log in DHT
message Message {
    // Author of the message
    TypedKey author = 1;
    // Time the message was sent (us since epoch)
    uint64 timestamp = 2;
    // Text of the message
    string text = 3;
    // Author signature over all of the fields and attachment signatures
    Signature signature = 4;
    // Attachments on the message
    repeated Attachment attachments = 5;
}

// A record of a 1-1 chat that is synchronized between
// two users. Visible and encrypted for the other party
//
// DHT Schema: SMPL(0,1,[identityPublicKey])
// DHT Key (UnicastOutbox): localConversation
// DHT Secret: None
// Encryption: DH(IdentityA, IdentityB)

message Conversation {
    // Profile to publish to friend
    Profile profile = 1;
    // Identity master (JSON) to publish to friend
    string identity = 2;
    // Messages DHTLog
    DHTLog messages = 3;
}

// A record of a contact that has accepted a contact invitation
// Contains a copy of the most recent remote profile as well as
// a locally edited profile.
// Contains a copy of the most recent identity from the contact's
// Master identity dht key
//
// Stored in ContactList DHTList
message Contact {
    // Friend's profile as locally edited
    Profile edited_profile = 1;
    // Copy of friend's profile from remote conversation
    Profile remote_profile = 2;
    // Copy of friend's identity (JSON) from remote conversation
    string remote_identity = 3;
    // Remote conversation key to sync from friend
    TypedKey remote_conversation = 4;
    // Our conversation key for friend to sync
    TypedKey local_conversation = 5;
    // Show availability
    bool show_availability = 6;
}

// Contact availability
enum Availability {
    AVAILABILITY_UNSPECIFIED = 0;
    AVAILABILITY_OFFLINE = 1;
    AVAILABILITY_FREE = 2;
    AVAILABILITY_BUSY = 3;
    AVAILABILITY_AWAY = 4;
}

// Publicly shared profile information for both contacts and accounts
// Contains:
// Name - Friendly name
// Title - Title of user
// Icon - Little picture to represent user in contact list
//
// DHT Key: None
// Encryption: None
message Profile  {
    // Friendy name
    string name = 1;
    // Title of user
    string title = 2;
    // Status/away message
    string status = 3;
    // Availability
    Availability availability = 4;
    // Avatar DHTData
    optional TypedKey avatar = 5;
}

// A record of an individual account
// Pointed to by the identity account map in the identity key
//
// DHT Schema: DFLT(1)
// DHT Key (Private): accountPublicKey
// DHT Secret: accountSecretKey
message Account {
    // The user's profile that gets shared with contacts
    Profile profile = 1;
    // Invisibility makes you always look 'Offline'
    bool invisible = 2;
    // Auto-away sets 'away' mode after an inactivity time
    uint32 auto_away_timeout_sec = 3;
    // The contacts DHTList for this account
    // Schema: SMPL(0,64,[accountPublicKey]) Encryption: accountSecretKey
    TypedKey contact_list = 4;
}