secs-gem/apps/secs_server.cpp

// Passive SECS/GEM equipment. Capabilities (SVIDs, ECIDs, CEIDs, alarms,
// recipes, host commands) come from data/equipment.yaml; the E30 control
// state machine comes from data/control_state.yaml. Dispatch is a Router
// table.  No imperative if-ladder; no in-code device data dictionary.

#include <asio.hpp>
#include <chrono>
#include <cstdint>
#include <iostream>
#include <memory>
#include <optional>
#include <string>
#include <vector>

#include "secsgem/config/loader.hpp"
#include "secsgem/endpoint.hpp"
#include "secsgem/gem/control_state.hpp"
#include "secsgem/gem/data_model.hpp"
#include "secsgem/gem/messages.hpp"
#include "secsgem/gem/router.hpp"
#include "secsgem/secs2/message.hpp"

using namespace secsgem;
namespace s2 = secsgem::secs2;
namespace gem = secsgem::gem;

namespace {

std::string arg(int argc, char** argv, const std::string& key, const std::string& def) {
  for (int i = 1; i + 1 < argc; ++i)
    if (key == argv[i]) return argv[i + 1];
  return def;
}

constexpr uint32_t kSvidControlState = 1;
constexpr uint32_t kSvidClock        = 2;

void refresh(gem::EquipmentDataModel& m, const gem::ControlStateMachine& sm) {
  m.set_status_value(kSvidControlState, s2::Item::ascii(gem::control_state_name(sm.state())));
  m.set_status_value(kSvidClock, s2::Item::ascii(m.current_time_string()));
}

}  // namespace

int main(int argc, char** argv) {
  const auto port = static_cast<uint16_t>(std::stoi(arg(argc, argv, "--port", "5000")));
  const auto equipment_yaml = arg(argc, argv, "--config", "/app/data/equipment.yaml");
  const auto state_yaml     = arg(argc, argv, "--state-table", "/app/data/control_state.yaml");

  auto logfn = [](const std::string& m) { std::cout << "[equip] " << m << std::endl; };

  auto model = std::make_shared<gem::EquipmentDataModel>();
  config::EquipmentDescriptor desc;
  config::ControlStateConfig sm_cfg;
  try {
    desc = config::load_equipment(equipment_yaml, *model);
    sm_cfg = config::load_control_state(state_yaml);
  } catch (const std::exception& e) {
    std::cerr << "[equip] config error: " << e.what() << std::endl;
    return 1;
  }
  logfn("loaded " + std::to_string(model->all_status_variables().size()) + " SVIDs, " +
        std::to_string(model->all_equipment_constants().size()) + " ECIDs, " +
        std::to_string(model->all_events().size()) + " CEIDs, " +
        std::to_string(model->all_alarms().size()) + " alarms");

  auto sm = std::make_shared<gem::ControlStateMachine>(sm_cfg.table, sm_cfg.initial);

  asio::io_context io;
  Server::Config server_cfg{port, desc.device_id, {}};
  Server server(io, server_cfg);
  server.on_log(logfn);

  auto active_conn = std::make_shared<std::weak_ptr<Connection>>();

  auto emit_event = [&io, active_conn, model, logfn](uint32_t ceid) {
    asio::post(io, [active_conn, model, logfn, ceid]() {
      auto conn = active_conn->lock();
      if (!conn) return;
      if (!model->is_event_enabled(ceid)) {
        logfn("CEID " + std::to_string(ceid) + " not enabled; suppressed");
        return;
      }
      auto reports = model->compose_reports_for(ceid);
      logfn("emit S6F11 CEID=" + std::to_string(ceid) + " (" +
            std::to_string(reports.size()) + " reports)");
      conn->send_request(gem::s6f11_event_report(0, ceid, reports),
                         [](std::error_code, const s2::Message&) {});
    });
  };

  auto emit_alarm_set = [&io, active_conn, model, logfn, emit_event](uint32_t alid) {
    asio::post(io, [active_conn, model, logfn, emit_event, alid]() {
      auto conn = active_conn->lock();
      if (!conn) return;
      auto alarm = model->alarm(alid);
      if (!alarm) return;
      auto alcd = model->alarm_set(alid);
      if (!alcd) return;
      if (model->alarm_enabled(alid)) {
        logfn("emit S5F1 alarm set ALID=" + std::to_string(alid));
        conn->send_request(gem::s5f1_alarm_report(*alcd, alid, alarm->text),
                           [](std::error_code, const s2::Message&) {});
      } else {
        logfn("alarm " + std::to_string(alid) + " not enabled; suppressed");
      }
      // E30: an AlarmSetEvent CEID also fires (if linked + enabled).
    });
  };

  sm->set_state_change_handler(
      [logfn, emit_event, desc](gem::ControlState from, gem::ControlState to, gem::ControlEvent ev) {
        logfn(std::string("control: ") + gem::control_state_name(from) + " -> " +
              gem::control_state_name(to) + "  (" + gem::control_event_name(ev) + ")");
        if (desc.emit_on_control_change) emit_event(*desc.emit_on_control_change);
      });

  // ---- Build the SECS dispatch table once -------------------------------
  gem::Router router;

  router.on(1, 1, [desc, logfn](const s2::Message&) {
    logfn("S1F1 -> S1F2");
    return gem::s1f2_on_line_data(desc.model_name, desc.software_rev);
  });
  router.on(1, 3, [model, sm, logfn](const s2::Message& msg) -> std::optional<s2::Message> {
    refresh(*model, *sm);
    auto svids = gem::parse_s1f3(msg);
    if (!svids) return s2::Message(1, 0, false);
    std::vector<std::optional<s2::Item>> values;
    if (svids->empty()) {
      for (const auto& sv : model->all_status_variables()) values.push_back(sv.value);
    } else {
      for (auto id : *svids) {
        auto sv = model->status_variable(id);
        values.push_back(sv ? std::optional<s2::Item>(sv->value) : std::nullopt);
      }
    }
    logfn("S1F3 -> S1F4 (" + std::to_string(values.size()) + " values)");
    return gem::s1f4_selected_status_data(values);
  });
  router.on(1, 11, [model, logfn](const s2::Message&) {
    logfn("S1F11 -> S1F12 (namelist)");
    return gem::s1f12_status_namelist_data(model->all_status_variables());
  });
  router.on(1, 13, [desc, logfn](const s2::Message&) {
    logfn("S1F13 -> S1F14");
    return gem::s1f14_establish_comms_ack(gem::CommAck::Accept, desc.model_name, desc.software_rev);
  });
  router.on(1, 15, [sm, logfn](const s2::Message&) {
    auto ack = sm->on_host_request_offline();
    logfn("S1F15 -> S1F16 OFLACK=" + std::to_string(static_cast<int>(ack)));
    return gem::s1f16_offline_ack(ack);
  });
  router.on(1, 17, [sm, logfn](const s2::Message&) {
    auto ack = sm->on_host_request_online();
    logfn("S1F17 -> S1F18 ONLACK=" + std::to_string(static_cast<int>(ack)));
    return gem::s1f18_online_ack(ack);
  });

  router.on(2, 13, [model, logfn](const s2::Message& msg) -> std::optional<s2::Message> {
    auto ids = gem::parse_u4_list_body(msg);
    if (!ids) return s2::Message(2, 0, false);
    std::vector<s2::Item> values;
    for (auto id : *ids) {
      auto ec = model->equipment_constant(id);
      values.push_back(ec ? ec->value : s2::Item::list({}));
    }
    logfn("S2F13 -> S2F14 (" + std::to_string(values.size()) + " values)");
    return gem::s2f14_ec_data(values);
  });
  router.on(2, 15, [model, logfn](const s2::Message& msg) {
    auto sets = gem::parse_s2f15(msg);
    auto eac = gem::EquipmentAck::Accept;
    if (!sets) eac = gem::EquipmentAck::Denied_OutOfRange;
    else
      for (const auto& [id, val] : *sets) {
        auto r = model->set_equipment_constant_value(id, val);
        if (r != gem::EquipmentAck::Accept) eac = r;
      }
    logfn("S2F15 -> S2F16 EAC=" + std::to_string(static_cast<int>(eac)));
    return gem::s2f16_ec_ack(eac);
  });
  router.on(2, 17, [model, logfn](const s2::Message&) {
    logfn("S2F17 -> S2F18 (clock)");
    return gem::s2f18_date_time_data(model->current_time_string());
  });
  router.on(2, 29, [model, logfn](const s2::Message& msg) {
    auto ids = gem::parse_u4_list_body(msg);
    std::vector<gem::EquipmentConstant> ecs;
    if (ids && ids->empty()) ecs = model->all_equipment_constants();
    else if (ids)
      for (auto id : *ids) {
        auto ec = model->equipment_constant(id);
        if (ec) ecs.push_back(*ec);
      }
    logfn("S2F29 -> S2F30 (" + std::to_string(ecs.size()) + " ECs)");
    return gem::s2f30_ec_namelist_data(ecs);
  });
  router.on(2, 31, [model, logfn](const s2::Message& msg) {
    auto t = gem::parse_s2f31(msg);
    auto ack = t ? model->set_time_string(*t) : gem::TimeAck::Error;
    logfn("S2F31 -> S2F32 TIACK=" + std::to_string(static_cast<int>(ack)));
    return gem::s2f32_date_time_ack(ack);
  });
  router.on(2, 33, [model, logfn](const s2::Message& msg) {
    auto req = gem::parse_s2f33(msg);
    auto ack = req ? model->define_reports(req->reports)
                   : gem::DefineReportAck::InvalidFormat;
    logfn("S2F33 -> S2F34 DRACK=" + std::to_string(static_cast<int>(ack)));
    return gem::s2f34_define_report_ack(ack);
  });
  router.on(2, 35, [model, logfn](const s2::Message& msg) {
    auto req = gem::parse_s2f35(msg);
    auto ack = req ? model->link_event_reports(req->links) : gem::LinkEventAck::InvalidFormat;
    logfn("S2F35 -> S2F36 LRACK=" + std::to_string(static_cast<int>(ack)));
    return gem::s2f36_link_event_report_ack(ack);
  });
  router.on(2, 37, [model, logfn](const s2::Message& msg) {
    auto req = gem::parse_s2f37(msg);
    auto ack = req ? model->enable_events(req->enable, req->ceids)
                   : gem::EnableEventAck::UnknownCeid;
    logfn(std::string("S2F37 ") + (req && req->enable ? "enable" : "disable") +
          " -> S2F38 ERACK=" + std::to_string(static_cast<int>(ack)));
    return gem::s2f38_enable_event_ack(ack);
  });
  router.on(2, 41, [model, logfn, emit_event, emit_alarm_set](const s2::Message& msg) {
    auto cmd = gem::parse_s2f41(msg);
    if (!cmd) return gem::s2f42_host_command_ack(gem::HostCmdAck::ParameterInvalid);
    auto result = model->dispatch_command(cmd->rcmd, cmd->params);
    logfn("S2F41 RCMD=" + cmd->rcmd + " -> S2F42 HCACK=" +
          std::to_string(static_cast<int>(result.ack)));
    if (result.ack == gem::HostCmdAck::Accept) {
      if (result.emit_ceid) emit_event(*result.emit_ceid);
      if (result.set_alarm) emit_alarm_set(*result.set_alarm);
    }
    return gem::s2f42_host_command_ack(result.ack);
  });

  router.on(5, 3, [model, logfn](const s2::Message& msg) {
    auto req = gem::parse_s5f3(msg);
    auto ack = req ? model->set_alarm_enabled(req->alid, req->enable)
                   : gem::AlarmAck::Error;
    logfn(std::string("S5F3 -> S5F4 ACKC5=") + std::to_string(static_cast<int>(ack)));
    return gem::s5f4_enable_alarm_ack(ack);
  });
  router.on(5, 5, [model, logfn](const s2::Message& msg) {
    auto ids = gem::parse_u4_list_body(msg);
    std::vector<gem::Alarm> alarms;
    if (ids && ids->empty()) alarms = model->all_alarms();
    else if (ids)
      for (auto id : *ids) {
        auto a = model->alarm(id);
        if (a) alarms.push_back(*a);
      }
    logfn("S5F5 -> S5F6 (" + std::to_string(alarms.size()) + " alarms)");
    return gem::s5f6_list_alarms_data(
        alarms, [model](uint32_t id) { return model->alarm_active(id); });
  });

  router.on(7, 3, [model, logfn](const s2::Message& msg) {
    auto pp = gem::parse_s7f3(msg);
    if (!pp) return gem::s7f4_process_program_ack(gem::ProcessProgramAck::LengthError);
    model->add_process_program(pp->ppid, pp->ppbody);
    logfn("S7F3 PPID=" + pp->ppid + " -> S7F4 (Accept)");
    return gem::s7f4_process_program_ack(gem::ProcessProgramAck::Accept);
  });
  router.on(7, 5, [model, logfn](const s2::Message& msg) {
    auto ppid = gem::parse_s7f5(msg);
    if (!ppid) return gem::s7f6_process_program_data("", "");
    auto body = model->process_program(*ppid);
    logfn("S7F5 PPID=" + *ppid + " -> S7F6");
    return gem::s7f6_process_program_data(*ppid, body ? *body : "");
  });
  router.on(7, 19, [model, logfn](const s2::Message&) {
    auto list = model->process_program_list();
    logfn("S7F19 -> S7F20 (" + std::to_string(list.size()) + " PPIDs)");
    return gem::s7f20_current_eppd_data(list);
  });

  router.on(10, 1, [logfn](const s2::Message& msg) {
    auto td = gem::parse_terminal_display(msg);
    if (td) logfn("TERMINAL[" + std::to_string(td->tid) + "] " + td->text);
    return gem::s10f2_terminal_display_ack(gem::TerminalAck::Accepted);
  });

  logfn("registered " + std::to_string(router.size()) + " (stream,function) handlers");

  // ---- Wire the router into accepted connections -----------------------
  server.on_connection([sm, model, logfn, active_conn, &router, desc](
                           std::shared_ptr<Connection> conn) {
    *active_conn = conn;
    conn->set_closed_handler([active_conn](const std::string&) { active_conn->reset(); });

    conn->set_selected_handler([logfn, sm]() {
      logfn(std::string("host is online; control=") + gem::control_state_name(sm->state()));
    });

    conn->set_message_handler(
        [&router](const s2::Message& msg) { return router.dispatch(msg); });
  });

  server.start();
  io.run();
  return 0;
}