syntax = "proto3";

package secsgem.v1;

// =============================================================================
// SECS/GEM Equipment API
//
// The daemon *is* one piece of SEMI equipment: it owns the HSMS link to the
// host (MES) and speaks GEM on your behalf. Your tool software connects as a
// client and only ever does two things:
//
//   • tell the equipment about itself  — set variables, fire events, raise alarms
//   • react to what the host asks for   — receive commands/jobs, answer them
//
// Everything SECS lives inside the daemon: message framing, report definitions,
// the GEM state machines, timers, spooling. You need no SEMI knowledge to use
// this API. Items are addressed by the human names from your equipment config
// (e.g. "chamber_pressure"), never by numeric SVID / CEID / ALID.
//
// CAPABILITY TIERS — wire up only what your equipment is:
//   • Universal  — variables, events, alarms, control state, commands. Every tool.
//   • Carriers   — E87 carrier/load-port flows. Only carrier-based equipment.
//   • Recipes    — S7 process-program transfer. Only recipe-driven equipment.
//   • Jobs       — E40 process jobs. Only job-based process/front-end equipment.
// If a tier doesn't apply, you simply never receive its HostRequest variants and
// never call its report RPCs.
// =============================================================================

service Equipment {
  // ---- Universal: report state to the host --------------------------------

  // Update one or more status/data variables by name. The daemon remembers the
  // values, so the host always sees the latest when it polls (S1F3).
  rpc SetVariables(VariableUpdate) returns (Ack);

  // Read back what the daemon currently holds (useful on tool restart/reconnect).
  rpc GetVariables(VariableQuery) returns (VariableSnapshot);

  // Fire a collection event by name. The daemon assembles the configured report
  // and sends S6F11. Values in `data` override current values for this one event.
  rpc FireEvent(Event) returns (Ack);

  // Raise (S5F1 set) or clear an alarm by name.
  rpc SetAlarm(Alarm) returns (Ack);
  rpc ClearAlarm(Alarm) returns (Ack);

  // ---- Universal: control state -------------------------------------------

  // Current GEM control state (ONLINE/LOCAL/REMOTE/OFFLINE).
  rpc GetControlState(Empty) returns (ControlState);

  // Request a transition — e.g. an operator panel taking the tool OFFLINE for
  // maintenance, or back ONLINE. The daemon applies E30 rules and may decline.
  rpc RequestControlState(ControlStateRequest) returns (Ack);

  // ---- Universal: react to the host ---------------------------------------

  // Subscribe to everything the host asks of this equipment. The daemon streams
  // HostRequest messages for as long as the call stays open.
  //
  // Delivery contract (v1):
  //   - firehose: every subscriber receives every host request;
  //   - NO buffering: a command arriving while no client is subscribed is
  //     answered with its declarative ack from the equipment config (the
  //     pre-daemon behaviour) and is NOT replayed on reconnect — the daemon
  //     never tells the host "will finish later" for work no tool will do;
  //   - when a Command does arrive here, the host has ALREADY been answered
  //     with S2F42 HCACK=4; report the real outcome via FireEvent/SetAlarm.
  rpc Subscribe(SubscribeRequest) returns (stream HostRequest);

  // Report the outcome of a Command delivered on the stream, quoting its `id`.
  // NOTE the contract (SEMI-conformant, non-blocking): the daemon has ALREADY
  // answered the host with S2F42 HCACK=4 ("accepted, will finish later") when
  // it pushed the command onto the stream — the host's transaction is closed.
  // CompleteCommand therefore correlates/audits the command lifecycle; the
  // host learns the real outcome via the events/alarms you fire (FireEvent /
  // SetAlarm), exactly as E30 intends. A synchronous gating mode (tool decides
  // the HCACK before S2F42 goes out) is a possible v2 extension.
  rpc CompleteCommand(CommandResult) returns (Ack);

  // ---- Jobs / Carriers: report progress of work the host asked for --------
  // Keyed by the durable id (job_id / carrier_id), not a per-message id — these
  // are long-lived objects you report against as the physical work proceeds.

  rpc ReportProcessJob(ProcessJobState) returns (Ack);   // E40 — job-based tools
  rpc ReportCarrier(CarrierState) returns (Ack);         // E87 — carrier-based tools

  // ---- Diagnostics --------------------------------------------------------

  // Live daemon/link status: distinguishes "host went offline" from "cable
  // unplugged" from "spool filling up". Streams a snapshot on every change.
  rpc WatchHealth(Empty) returns (stream Health);
}

// ---- Values ----------------------------------------------------------------

// A SECS-II value in plain terms. The daemon converts it to the wire format
// declared for the target item in your config — you never choose U4/F4/ASCII.
message Value {
  oneof kind {
    string text    = 1;
    sint64 integer = 2;
    double real    = 3;
    bool   boolean = 4;
    bytes  binary  = 5;
    List   list    = 6;  // SECS-II nested list
  }
}
message List { repeated Value items = 1; }

message Empty {}

// ---- Universal: tool -> equipment ------------------------------------------

message VariableUpdate {
  map<string, Value> values = 1;   // name -> value
}

message VariableQuery {
  repeated string names = 1;       // empty = all configured variables
}
message VariableSnapshot {
  map<string, Value> values = 1;
}

message Event {
  string name = 1;                 // collection-event name
  map<string, Value> data = 2;     // optional per-fire variable values
}

message Alarm {
  string name = 1;                 // alarm name
}

message SubscribeRequest {
  string client = 1;               // optional label for logging/diagnostics
}

// ---- Control state ---------------------------------------------------------

message ControlState {
  State state = 1;
  enum State {
    EQUIPMENT_OFFLINE = 0;
    ATTEMPT_ONLINE    = 1;
    HOST_OFFLINE      = 2;
    ONLINE_LOCAL      = 3;
    ONLINE_REMOTE     = 4;
  }
}
message ControlStateRequest {
  ControlState.State desired = 1;
}

// ---- Host -> tool stream ---------------------------------------------------

// Everything the host initiates arrives here. Match on the populated variant;
// ignore the variants for tiers your equipment doesn't implement.
message HostRequest {
  oneof request {
    Command            command         = 1;  // S2F41/F21/F49 — universal
    ControlStateChange control_state   = 2;  // control state transitioned — universal
    ConstantChange     constant        = 3;  // host set an equipment constant — universal
    ProcessProgram     process_program = 4;  // S7 recipe downloaded — recipe tools
    CarrierAction      carrier         = 5;  // E87 carrier at a port — carrier tools
    ProcessJob         process_job     = 6;  // E40 job to run/stop — job tools
  }
}

// A remote command (S2F41 / S2F21 / S2F49). Answer with CompleteCommand.
message Command {
  string id   = 1;                 // correlation id — echo in CommandResult
  string name = 2;                 // RCMD, e.g. "START"
  map<string, Value> params = 3;   // CPNAME -> CPVAL
}

// Control state changed (host went online/offline, operator toggled local/remote).
message ControlStateChange {
  ControlState.State state = 1;
}

// The host wrote an equipment constant (S2F15). React if it tunes a process
// parameter you care about; the daemon already stored the new value.
message ConstantChange {
  string name  = 1;
  Value  value = 2;
}

// The host downloaded a recipe (S7F3). Load it into your process engine.
message ProcessProgram {
  string ppid = 1;                 // recipe id
  bytes  body = 2;                 // recipe contents (opaque to the daemon)
}

// E87: a carrier needs attention at a load port. Reply with ReportCarrier.
message CarrierAction {
  string carrier_id = 1;           // CARRIERID
  uint32 port       = 2;           // load-port number
  Action action     = 3;
  enum Action {
    VERIFY_ID = 0;                 // read & confirm the carrier's identity
    PROCEED   = 1;                 // begin access (open / map slots)
    CANCEL    = 2;
  }
}

// E40: the host wants this process job run (or stopped). Report progress with
// ReportProcessJob. `recipe` + `carriers` tell you what to run and on what.
message ProcessJob {
  string job_id = 1;               // PRJobID
  string recipe = 2;               // PPID to run
  Action action = 3;
  repeated string carriers = 4;    // material: carrier ids bound to this job
  enum Action { START = 0; STOP = 1; PAUSE = 2; RESUME = 3; ABORT = 4; }
}

// ---- Tool -> equipment: replies & progress reports -------------------------

message CommandResult {
  string id  = 1;                  // the Command.id you are answering
  Ack    ack = 2;                  // outcome (maps to HCACK on the wire)
}

// Advance an E40 process job as the physical work proceeds; the daemon drives
// the E40 FSM and emits the matching S6F11 / S16F9 to the host.
message ProcessJobState {
  string job_id = 1;
  State  state  = 2;
  enum State {
    SETTING_UP = 0;
    PROCESSING = 1;
    COMPLETE   = 2;
    ABORTED    = 3;
  }
}

// Report a carrier's identity, slot map, and state as the tool reads them.
message CarrierState {
  string carrier_id  = 1;
  uint32 port        = 2;
  State  state       = 3;
  repeated bool slots = 4;         // slot map: true = wafer present
  enum State {
    WAITING   = 0;
    IN_ACCESS = 1;
    COMPLETE  = 2;
  }
}

// ---- Diagnostics -----------------------------------------------------------

message Health {
  LinkState          link          = 1;
  uint32             spool_depth   = 2;   // queued messages waiting for the host
  ControlState.State control_state = 3;
  enum LinkState {
    DISCONNECTED = 0;              // no TCP
    CONNECTED    = 1;              // TCP up, not yet SELECTED
    SELECTED     = 2;              // HSMS selected — actively talking to the host
  }
}

// ---- Acknowledgement -------------------------------------------------------

// Mirrors SEMI HCACK exactly. For non-command RPCs, only ACCEPT vs an error
// code matters; `message` carries human detail ("no variable named 'presure'").
message Ack {
  Code code = 1;
  string message = 2;
  enum Code {
    ACCEPT                     = 0;  // HCACK 0
    INVALID_COMMAND            = 1;  // HCACK 1
    CANNOT_DO_NOW              = 2;  // HCACK 2
    PARAMETER_INVALID          = 3;  // HCACK 3
    ACCEPTED_WILL_FINISH_LATER = 4;  // HCACK 4
    REJECTED                   = 5;  // HCACK 5
    INVALID_OBJECT             = 6;  // HCACK 6
  }
}