#include <doctest/doctest.h>

#include <chrono>
#include <cstdlib>
#include <filesystem>
#include <sys/types.h>
#include <unistd.h>

#include "secsgem/gem/data_model.hpp"

using namespace secsgem::gem;

// ---- Status variables ----------------------------------------------------

TEST_CASE("SVID add / get / list / set value") {
  StatusVariableStore svids;
  svids.add({1, "Clock", "", s2::Item::ascii("19700101000000")});
  svids.add({2, "EventsEnabled", "", s2::Item::boolean(true)});

  CHECK(svids.get(1).has_value());
  CHECK_FALSE(svids.get(99).has_value());
  CHECK(svids.all().size() == 2);

  svids.set_value(2, s2::Item::boolean(false));
  CHECK(svids.get(2)->value == s2::Item::boolean(false));
}

// ---- Equipment constants -------------------------------------------------

TEST_CASE("ECID set rejects unknown id and out-of-range values") {
  EquipmentConstantStore ecids;
  ecids.add({10, "MaxSpool", "msgs", s2::Item::u4(uint32_t{100}),
             s2::Item::u4(uint32_t{100}), "0", "1000"});
  CHECK(ecids.set_value(10, s2::Item::u4(uint32_t{50})) == EquipmentAck::Accept);
  CHECK(ecids.get(10)->value == s2::Item::u4(uint32_t{50}));
  CHECK(ecids.set_value(999, s2::Item::u4(uint32_t{1})) == EquipmentAck::Denied_UnknownEcid);

  // Out-of-range rejected (closes COMPLIANCE.md gap).
  CHECK(ecids.set_value(10, s2::Item::u4(uint32_t{5000})) == EquipmentAck::Denied_OutOfRange);
  CHECK(ecids.get(10)->value == s2::Item::u4(uint32_t{50}));  // unchanged
}

TEST_CASE("ECID with no min/max accepts any value") {
  EquipmentConstantStore ecids;
  ecids.add({1, "n", "", s2::Item::u4(uint32_t{0}), s2::Item::u4(uint32_t{0}), "", ""});
  CHECK(ecids.set_value(1, s2::Item::u4(uint32_t{99999999})) == EquipmentAck::Accept);
}

TEST_CASE("ECID range validation skipped for non-numeric formats") {
  EquipmentConstantStore ecids;
  ecids.add({1, "label", "", s2::Item::ascii("a"), s2::Item::ascii("a"), "0", "10"});
  CHECK(ecids.set_value(1, s2::Item::ascii("foo")) == EquipmentAck::Accept);
}

// ---- Clock ---------------------------------------------------------------

TEST_CASE("clock string has 16 characters") {
  Clock c;
  auto s = c.current_time_string();
  REQUIRE(s.size() == 16);
}

TEST_CASE("set_time_string accepts well-formed and rejects malformed") {
  Clock c;
  CHECK(c.set_time_string("20260101000000") == TimeAck::Accept);
  CHECK(c.set_time_string("2026010100000000") == TimeAck::Accept);
  CHECK(c.set_time_string("not-a-date-12345") == TimeAck::Error);
  CHECK(c.set_time_string("short") == TimeAck::Error);
}

TEST_CASE("Clock: E148 sync quality starts Unsynchronized") {
  Clock c;
  CHECK(c.sync_quality() == TimeSyncQuality::Unsynchronized);
  CHECK(c.sync_count() == 0);
}

TEST_CASE("Clock: consecutive set_time_string updates record drift") {
  Clock c;
  // First sync: drift measured against the (zero) initial offset.
  REQUIRE(c.set_time_string("20260101000000") == TimeAck::Accept);
  CHECK(c.sync_count() == 1);

  // Second sync, far in the future: drift should be a large positive number.
  REQUIRE(c.set_time_string("20270101000000") == TimeAck::Accept);
  CHECK(c.sync_count() == 2);
  CHECK(c.last_drift_seconds() > 60 * 60 * 24);  // > 1 day
  CHECK(c.sync_quality() == TimeSyncQuality::Unsynchronized);
}

TEST_CASE("Clock: same-value resync registers as Synchronized") {
  Clock c;
  REQUIRE(c.set_time_string("20260601000000") == TimeAck::Accept);
  // Apply the same target again; the offset doesn't move materially.
  REQUIRE(c.set_time_string("20260601000000") == TimeAck::Accept);
  CHECK(std::abs(c.last_drift_seconds()) <= 1);
  CHECK(c.sync_quality() == TimeSyncQuality::Synchronized);
}

// ---- Host command registry ----------------------------------------------

TEST_CASE("host command registry returns spec + result") {
  HostCommandRegistry r;
  r.register_command("START", {HostCmdAck::Accept,      300, std::nullopt});
  r.register_command("STOP",  {HostCmdAck::CannotDoNow, std::nullopt, std::nullopt});
  r.register_command("FAULT", {HostCmdAck::Accept,      std::nullopt, 1});

  CHECK(r.has("START"));
  CHECK_FALSE(r.has("PAUSE"));

  auto start = r.dispatch("START", {});
  CHECK(start.ack == HostCmdAck::Accept);
  CHECK(start.emit_ceid.value_or(0) == 300);

  auto fault = r.dispatch("FAULT", {});
  CHECK(fault.set_alarm.value_or(0) == 1);

  CHECK(r.dispatch("UNKNOWN", {}).ack == HostCmdAck::InvalidCommand);
}

// ---- Event reports -------------------------------------------------------

TEST_CASE("define reports rejects unknown VID") {
  EventReportSubscriptions ev;
  ev.register_event({100, "x"});
  auto exists = [](uint32_t id) { return id == 1 || id == 2; };

  CHECK(ev.define_reports({{1000, {1, 2}}}, exists) == DefineReportAck::Accept);
  CHECK(ev.define_reports({{1001, {1, 999}}}, exists) == DefineReportAck::InvalidVid);
}

TEST_CASE("full event-report pipeline") {
  StatusVariableStore svids;
  svids.add({1, "ControlState", "", s2::Item::ascii("OnlineRemote")});
  svids.add({2, "Clock", "", s2::Item::ascii("19700101000000")});

  EventReportSubscriptions ev;
  ev.register_event({100, "ControlStateChanged"});
  ev.register_event({200, "AlarmSetEvent"});

  auto exists = [&](uint32_t id) { return svids.has(id); };
  auto value  = [&](uint32_t id) { return svids.value(id); };

  REQUIRE(ev.define_reports({{1000, {1}}, {1001, {1, 2}}}, exists) == DefineReportAck::Accept);
  REQUIRE(ev.link_event_reports({{100, {1000, 1001}}, {200, {1001}}}) == LinkEventAck::Accept);
  CHECK_FALSE(ev.is_enabled(100));

  REQUIRE(ev.enable_events(true, {100}) == EnableEventAck::Accept);
  CHECK(ev.is_enabled(100));
  CHECK_FALSE(ev.is_enabled(200));

  auto reports = ev.compose_for(100, value);
  REQUIRE(reports.size() == 2);
  CHECK(reports[0].rptid == 1000);
  REQUIRE(reports[0].values.size() == 1);
  CHECK(reports[0].values[0] == s2::Item::ascii("OnlineRemote"));
  CHECK(reports[1].rptid == 1001);
  REQUIRE(reports[1].values.size() == 2);
}

TEST_CASE("enable_events with empty CEID list enables all registered events") {
  EventReportSubscriptions ev;
  ev.register_event({1, "a"});
  ev.register_event({2, "b"});
  CHECK(ev.enable_events(true, {}) == EnableEventAck::Accept);
  CHECK(ev.is_enabled(1));
  CHECK(ev.is_enabled(2));
  CHECK(ev.enable_events(false, {}) == EnableEventAck::Accept);
  CHECK_FALSE(ev.is_enabled(1));
}

TEST_CASE("link_event_reports rejects unknown CEID or RPTID") {
  EventReportSubscriptions ev;
  ev.register_event({100, "x"});
  ev.define_reports({{500, {1}}}, [](uint32_t) { return true; });

  CHECK(ev.link_event_reports({{999, {500}}}) == LinkEventAck::UnknownCeid);
  CHECK(ev.link_event_reports({{100, {999}}}) == LinkEventAck::UnknownRptid);
  CHECK(ev.link_event_reports({{100, {500}}}) == LinkEventAck::Accept);
}

// ---- Alarms --------------------------------------------------------------

TEST_CASE("alarm enable / set / clear / list") {
  AlarmRegistry r;
  r.add({1, "Chiller Temp High", 4});
  r.add({2, "Door Open", 1});

  CHECK(r.set_enabled(1, true) == AlarmAck::Accept);
  CHECK(r.enabled(1));
  CHECK(r.set_enabled(999, true) == AlarmAck::Error);

  auto alcd_set = r.set_active(1);
  REQUIRE(alcd_set.has_value());
  CHECK((*alcd_set & 0x80) != 0);
  CHECK((*alcd_set & 0x7F) == 4);
  CHECK(r.active(1));

  auto alcd_clr = r.clear_active(1);
  REQUIRE(alcd_clr.has_value());
  CHECK((*alcd_clr & 0x80) == 0);
  CHECK_FALSE(r.active(1));

  CHECK(r.all().size() == 2);
}

TEST_CASE("AlarmSeverity bit-flag helpers (E5 §10.3 / E30 §6.13)") {
  // Single-category alarms.
  Alarm safety{1, "door open", static_cast<uint8_t>(AlarmSeverity::PersonalSafety)};
  CHECK(safety.has(AlarmSeverity::PersonalSafety));
  CHECK_FALSE(safety.has(AlarmSeverity::EquipmentSafety));
  CHECK(safety.is_safety());

  Alarm temp_warn{2, "chiller high",
                  static_cast<uint8_t>(AlarmSeverity::ParameterWarning)};
  CHECK_FALSE(temp_warn.is_safety());
  CHECK(temp_warn.has(AlarmSeverity::ParameterWarning));

  // Multi-category alarms: combine Irrecoverable + EquipmentSafety.
  Alarm combo{3, "spindle seized",
              static_cast<uint8_t>(
                  static_cast<uint8_t>(AlarmSeverity::EquipmentSafety) |
                  static_cast<uint8_t>(AlarmSeverity::Irrecoverable))};
  CHECK(combo.is_safety());
  CHECK(combo.has(AlarmSeverity::Irrecoverable));
  CHECK(combo.has(AlarmSeverity::EquipmentSafety));
  CHECK_FALSE(combo.has(AlarmSeverity::PersonalSafety));

  // The ALCD set-bit is *not* part of the category bitmap.
  const uint8_t set_alcd = static_cast<uint8_t>(combo.severity_category | 0x80);
  CHECK(severity_bits(set_alcd) == combo.severity_category);
  CHECK(has_severity(set_alcd, AlarmSeverity::Irrecoverable));
}

// ---- Process programs ----------------------------------------------------

TEST_CASE("recipe CRUD") {
  RecipeStore r;
  r.add("RECIPE-A", "step1\nstep2\n");
  r.add("RECIPE-B", "alt body");
  CHECK(r.list().size() == 2);
  CHECK(r.get("RECIPE-A").value() == "step1\nstep2\n");
  CHECK_FALSE(r.get("UNKNOWN").has_value());

  CHECK(r.remove("RECIPE-A") == ProcessProgramAck::Accept);
  CHECK_FALSE(r.get("RECIPE-A").has_value());
  CHECK(r.remove("RECIPE-A") == ProcessProgramAck::PpidNotFound);
}

// ---- Composite EquipmentDataModel ---------------------------------------

TEST_CASE("EquipmentDataModel composes the eight stores") {
  EquipmentDataModel m;
  m.svids.add({1, "Clock", "", s2::Item::ascii("")});
  m.dvids.add({2, "Temp", "C", s2::Item::u4(uint32_t{25})});
  CHECK(m.vid_exists(1));
  CHECK(m.vid_exists(2));
  CHECK_FALSE(m.vid_exists(3));
  CHECK(m.vid_value(2) == s2::Item::u4(uint32_t{25}));
}

// ---- Spool ---------------------------------------------------------------

TEST_CASE("spool enqueue respects spoolable_streams whitelist") {
  SpoolStore s;
  s.set_spoolable_streams({5, 6});
  CHECK(s.enqueue(s2::Message(6, 11, false)) == SpoolStore::EnqueueResult::Queued);
  CHECK(s.enqueue(s2::Message(5, 1, false))  == SpoolStore::EnqueueResult::Queued);
  CHECK(s.enqueue(s2::Message(1, 2, false))  == SpoolStore::EnqueueResult::Dropped_NotSpoolable);
  CHECK(s.size() == 2);
}

TEST_CASE("spool FIFO eviction when max_size reached") {
  SpoolStore s;
  s.set_spoolable_streams({6});
  s.set_max_size(3);
  for (int i = 0; i < 5; ++i)
    s.enqueue(s2::Message(6, 11, false, s2::Item::u4(static_cast<uint32_t>(i))));
  CHECK(s.size() == 3);
  // Oldest two (0, 1) were evicted; remaining are 2, 3, 4.
  auto drained = s.drain();
  REQUIRE(drained.size() == 3);
  auto first_u4 = [](const s2::Message& m) -> uint32_t {
    return std::get<std::vector<uint32_t>>(m.body->storage()).front();
  };
  CHECK(first_u4(drained[0]) == 2);
  CHECK(first_u4(drained[2]) == 4);
}

TEST_CASE("spool drain returns FIFO order and empties the queue") {
  SpoolStore s;
  s.set_spoolable_streams({6});
  s.enqueue(s2::Message(6, 11, false, s2::Item::u4(uint32_t{1})));
  s.enqueue(s2::Message(6, 11, false, s2::Item::u4(uint32_t{2})));
  auto out = s.drain();
  CHECK(out.size() == 2);
  CHECK(s.empty());
  CHECK(s.drain().empty());
}

TEST_CASE("spool force flag controls whether enqueue is taken") {
  SpoolStore s;
  s.set_spoolable_streams({6});
  CHECK_FALSE(s.force_spool());
  s.set_force_spool(true);
  CHECK(s.force_spool());
}

TEST_CASE("spool persistence: write, restart, replay") {
  namespace fs = std::filesystem;
  // Unique temp dir per test run.
  auto dir = fs::temp_directory_path() /
             ("spool_test_" + std::to_string(::getpid()) + "_" +
              std::to_string(std::chrono::steady_clock::now().time_since_epoch().count()));
  fs::remove_all(dir);

  {
    SpoolStore s;
    s.set_spoolable_streams({5, 6});
    s.enable_persistence(dir);
    CHECK(s.empty());
    s.enqueue(s2::Message(6, 11, false, s2::Item::u4(uint32_t{42})));
    s.enqueue(s2::Message(5, 1,  false, s2::Item::ascii("ALARM")));
    CHECK(s.size() == 2);
    // Two journal files written.
    std::size_t count = 0;
    for (auto& e : fs::directory_iterator(dir)) {
      if (e.path().extension() == ".spool") ++count;
    }
    CHECK(count == 2);
  }

  // Simulate restart: fresh store rehydrates from the same dir.
  {
    SpoolStore s;
    s.set_spoolable_streams({5, 6});
    s.enable_persistence(dir);
    REQUIRE(s.size() == 2);
    auto drained = s.drain();
    REQUIRE(drained.size() == 2);
    CHECK(drained[0].stream == 6);
    CHECK(drained[1].stream == 5);
    // FIFO: first-enqueued comes out first.
    REQUIRE(drained[0].body.has_value());
    CHECK(std::get<std::vector<uint32_t>>(drained[0].body->storage()).front() == 42);
    CHECK(drained[1].body->as_ascii() == "ALARM");
    // Files removed after drain.
    std::size_t count = 0;
    for (auto& e : fs::directory_iterator(dir)) {
      if (e.path().extension() == ".spool") ++count;
    }
    CHECK(count == 0);
  }

  fs::remove_all(dir);
}

TEST_CASE("spool persistence: clear deletes files") {
  namespace fs = std::filesystem;
  auto dir = fs::temp_directory_path() /
             ("spool_clear_" + std::to_string(::getpid()) + "_" +
              std::to_string(std::chrono::steady_clock::now().time_since_epoch().count() + 1));
  fs::remove_all(dir);

  SpoolStore s;
  s.set_spoolable_streams({6});
  s.enable_persistence(dir);
  s.enqueue(s2::Message(6, 11, false));
  s.enqueue(s2::Message(6, 11, false));
  CHECK(s.size() == 2);
  s.clear();
  CHECK(s.empty());
  std::size_t count = 0;
  for (auto& e : fs::directory_iterator(dir)) {
    if (e.path().extension() == ".spool") ++count;
  }
  CHECK(count == 0);

  fs::remove_all(dir);
}