syntax = "proto3";

package telemetry;

// Top-level wrapper. Every message on the WebSocket is an Envelope.
// `oneof` enforces mutual exclusivity at the schema level.
message Envelope {
  oneof payload {
    DataPacket data = 1;
    LogPacket  log  = 2;
  }
}

// One sample packet covering all channels and all status fields.
// All fields optional: any field absent means "no update for this field
// in this packet" — the UI renders missing channel data as a gap and
// missing status fields walk back to find the most recent value.
message DataPacket {
  optional int64 timestamp_us = 1;

  optional double ch1  = 2;
  optional double ch2  = 3;
  optional double ch3  = 4;
  optional double ch4  = 5;
  optional double ch5  = 6;
  optional double ch6  = 7;
  optional double ch7  = 8;
  optional double ch8  = 9;
  optional double ch9  = 10;
  optional double ch10 = 11;
  optional double ch11 = 12;
  optional double ch12 = 13;
  optional double ch13 = 14;
  optional double ch14 = 15;
  optional double ch15 = 16;
  optional double ch16 = 17;

  // True = pause requested by server. UI button OR-composes with this.
  optional bool pause = 18;

  // 4-state status indicators. Defined values: 0=gray, 1=red, 2=yellow, 3=green.
  // Other values render as gray with a one-time warning logged.
  optional uint32 status1 = 19;
  optional uint32 status2 = 20;
  optional uint32 status3 = 21;
  optional uint32 status4 = 22;
  optional uint32 status5 = 23;
  optional uint32 status6 = 24;
  optional uint32 status7 = 25;
  optional uint32 status8 = 26;
}

// One log entry. Description is taken verbatim and is the single source
// of truth for the human-readable text — the app does not maintain a
// separate error_number → description mapping.
message LogPacket {
  optional int64    timestamp_us = 1;
  optional Severity severity     = 2;
  optional uint32   error_number = 3;
  optional string   description  = 4;
}

enum Severity {
  SEVERITY_UNKNOWN = 0;
  DEBUG            = 1;
  INFO             = 2;
  WARN             = 3;
  ERROR            = 4;
  FATAL            = 5;
}