// Persistence tests for CarrierStore + LoadPortStore.
//
// Mirrors the pattern from test_data_model.cpp:spool-persistence: enable
// a journal directory, mutate state, "restart" by constructing a fresh
// store pointed at the same directory, and assert replay reproduces the
// in-memory state.  Plus negative paths: partial-write files are
// dropped, remove deletes the file, persistence-disabled is a no-op.

#include <doctest/doctest.h>

#include <filesystem>
#include <fstream>
#include <random>
#include <string>

#include "secsgem/gem/store/carriers.hpp"

using namespace secsgem::gem;
namespace fs = std::filesystem;

namespace {

fs::path scratch_dir(const char* tag) {
  std::random_device rd;
  auto p = fs::temp_directory_path() /
           (std::string("secsgem-carrier-") + tag + "-" +
            std::to_string(rd()));
  fs::remove_all(p);
  fs::create_directories(p);
  return p;
}

std::size_t count_with_ext(const fs::path& dir, const std::string& ext) {
  std::size_t n = 0;
  std::error_code ec;
  for (auto& e : fs::directory_iterator(dir, ec)) {
    if (e.is_regular_file() && e.path().extension() == ext) ++n;
  }
  return n;
}

}  // namespace

TEST_CASE("CarrierStore persistence: write + restart + replay") {
  auto dir = scratch_dir("write-replay");
  {
    CarrierStore s;
    s.enable_persistence(dir);
    REQUIRE(s.create("CAR-1", /*port=*/2, /*capacity=*/4) ==
            CarrierStore::CreateResult::Created);
    REQUIRE(s.create("CAR-2", /*port=*/3, /*capacity=*/4) ==
            CarrierStore::CreateResult::Created);

    // Drive each FSM axis through a transition so we can prove every
    // byte makes it through the journal.
    REQUIRE(s.fire_id_event("CAR-1", CarrierIDEvent::ProceedWithCarrier));
    REQUIRE(s.fire_slot_map_event("CAR-1", SlotMapEvent::Read));
    REQUIRE(s.fire_access_event("CAR-1", CarrierAccessEvent::BeginAccess));
    s.set_slot_state("CAR-1", 0, 1);  // slot 1 occupied
    s.set_slot_state("CAR-1", 1, 0);  // slot 2 empty

    CHECK(count_with_ext(dir, ".car") == 2);
  }

  // Restart: fresh store, same dir.
  {
    CarrierStore s;
    s.enable_persistence(dir);
    REQUIRE(s.has("CAR-1"));
    REQUIRE(s.has("CAR-2"));

    const auto* c1 = s.get("CAR-1");
    REQUIRE(c1);
    CHECK(c1->port_id == 2);
    CHECK(c1->slots.size() == 4);
    CHECK(c1->slots[0].state == 1);
    CHECK(c1->slots[1].state == 0);
    CHECK(c1->fsm->id_status() == CarrierIDStatus::Confirmed);
    CHECK(c1->fsm->slot_map_status() == SlotMapStatus::Read);
    CHECK(c1->fsm->access_status() == CarrierAccessStatus::InAccess);

    const auto* c2 = s.get("CAR-2");
    REQUIRE(c2);
    CHECK(c2->port_id == 3);
    CHECK(c2->fsm->id_status() == CarrierIDStatus::NotConfirmed);

    // Continued mutation after replay still writes through.
    REQUIRE(s.fire_id_event("CAR-2", CarrierIDEvent::Bind));
  }

  // Second restart shows the post-replay mutation is durable.
  {
    CarrierStore s;
    s.enable_persistence(dir);
    REQUIRE(s.has("CAR-2"));
    CHECK(s.get("CAR-2")->fsm->id_status() == CarrierIDStatus::Confirmed);
  }
  fs::remove_all(dir);
}

TEST_CASE("CarrierStore persistence: remove deletes the journal file") {
  auto dir = scratch_dir("remove");
  CarrierStore s;
  s.enable_persistence(dir);
  REQUIRE(s.create("CAR-A") == CarrierStore::CreateResult::Created);
  REQUIRE(s.create("CAR-B") == CarrierStore::CreateResult::Created);
  CHECK(count_with_ext(dir, ".car") == 2);

  REQUIRE(s.remove("CAR-A"));
  CHECK(count_with_ext(dir, ".car") == 1);

  // Restart and confirm CAR-A is gone, CAR-B remains.
  CarrierStore s2;
  s2.enable_persistence(dir);
  CHECK_FALSE(s2.has("CAR-A"));
  CHECK(s2.has("CAR-B"));
  fs::remove_all(dir);
}

TEST_CASE("CarrierStore persistence: malformed file is dropped, not poisonous") {
  auto dir = scratch_dir("malformed");
  {
    CarrierStore s;
    s.enable_persistence(dir);
    REQUIRE(s.create("CAR-OK") == CarrierStore::CreateResult::Created);
  }

  // Inject a corrupt record (wrong magic byte at offset 0).
  {
    std::ofstream f(dir / "9999999999.car", std::ios::binary);
    const char garbage[] = {0x00, 0x01, 0x02, 0x03};
    f.write(garbage, sizeof(garbage));
  }
  // And a truncated record (magic+version only).
  {
    std::ofstream f(dir / "9999999998.car", std::ios::binary);
    const char hdr[] = {static_cast<char>(0xC4), 0x01};
    f.write(hdr, sizeof(hdr));
  }

  CHECK(count_with_ext(dir, ".car") == 3);

  CarrierStore s;
  s.enable_persistence(dir);
  CHECK(s.has("CAR-OK"));
  CHECK(s.size() == 1);
  // The two malformed files were removed during replay.
  CHECK(count_with_ext(dir, ".car") == 1);
  fs::remove_all(dir);
}

TEST_CASE("CarrierStore: persistence disabled is a no-op") {
  auto dir = scratch_dir("disabled");
  CarrierStore s;
  // Note: enable_persistence NOT called.
  REQUIRE(s.create("CAR-X") == CarrierStore::CreateResult::Created);
  REQUIRE(s.fire_id_event("CAR-X", CarrierIDEvent::ProceedWithCarrier));
  CHECK_FALSE(s.persistence_enabled());

  // No journal file should exist anywhere — but to be safe also check
  // that pointing a fresh store at `dir` doesn't see CAR-X (since we
  // never wrote it).
  CarrierStore s2;
  s2.enable_persistence(dir);
  CHECK_FALSE(s2.has("CAR-X"));
  CHECK(s2.size() == 0);
  fs::remove_all(dir);
}

TEST_CASE("LoadPortStore persistence: write + restart + replay") {
  auto dir = scratch_dir("lp-write-replay");
  {
    LoadPortStore lp;
    lp.enable_persistence(dir);
    REQUIRE(lp.create(1));
    REQUIRE(lp.create(2));
    REQUIRE(lp.associate(1, "CAR-1"));
    REQUIRE(lp.fire_transfer_event(1, LoadPortTransferEvent::StartLoading));
    REQUIRE(lp.fire_reservation_event(2, LoadPortReservationEvent::Reserve));
    CHECK(count_with_ext(dir, ".lp") == 2);
  }
  {
    LoadPortStore lp;
    lp.enable_persistence(dir);
    REQUIRE(lp.has(1));
    REQUIRE(lp.has(2));
    const auto* p1 = lp.get(1);
    CHECK(p1->carrierid == "CAR-1");
    CHECK(p1->fsm->transfer_state() == LoadPortTransferState::Loading);
    CHECK(p1->fsm->association_state() == LoadPortAssociationStatus::Associated);
    const auto* p2 = lp.get(2);
    CHECK(p2->fsm->reservation_state() == LoadPortReservationStatus::Reserved);
  }
  fs::remove_all(dir);
}

TEST_CASE("LoadPortStore persistence: malformed file dropped") {
  auto dir = scratch_dir("lp-malformed");
  {
    std::ofstream f(dir / "001.lp", std::ios::binary);
    const char junk[] = {0x00, 0x01, 0x02};
    f.write(junk, sizeof(junk));
  }
  LoadPortStore lp;
  lp.enable_persistence(dir);
  CHECK(lp.size() == 0);
  CHECK(count_with_ext(dir, ".lp") == 0);
  fs::remove_all(dir);
}