syntax = "proto3";

/*
  Layer defines some default layers for compositing animations onto for 
  various purposes.
*/
enum Layer {
  NONE = 0;
  // Well-known layers
  LIGHT = 1;
  COLOR = 2;
  NOTIFICATIONS = 8;
  PRIORITY = 9;
}

/*
  FrameData represents an ARGB array of dots.
*/
message FrameData {
  // ARGB
  repeated fixed32 dots = 1;
}

/*
  FrameBuffer represents an entire frame together with a layer tag. It also
  defines a timestamp that can be used within a FrameSequence to define the 
  duration a frame will be shown. 
*/
message FrameBuffer {
  FrameData frame = 1;
  // Time offset from start of frame in milliseconds
  fixed32 timestamp = 2;
  // Layer to apply the frame to
  Layer layer = 3;
}

/*
  FrameSequence buffers a series of frames to be drawn one by one at intervals
  defined by the timestamp included in the FrameBuffers. Useful for running 
  smooth animations. 

  In the future, this should have more metadata like looping counts and async
  animations. 
*/
message FrameSequence {
  repeated FrameBuffer frames = 1;
  // Number of times to loop the sequence
  int32 loop = 2; 
}

message DrawResponse {
}

message LengthRequest {
}

message LengthResponse {
  fixed32 length = 1;
}

service Drawer {
  // DrawFrame draws one frame
  rpc DrawFrame (FrameBuffer) returns (DrawResponse) {}
  // DrawFrames draws a series of frames
  rpc DrawFrames (FrameSequence) returns (DrawResponse) {}
  // GetLength returns the length of the strip
  rpc GetLength (LengthRequest) returns (LengthResponse) {}
}