#include <gtest/gtest.h>
#include "logos_core.h"
#include "qt_test_adapter.h"
#include <nlohmann/json.hpp>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <filesystem>
#include <fstream>
#include <set>
#include <string>
#include <vector>

namespace fs = std::filesystem;

static void clearModuleState() {
    logos_core_terminate_all();
    logos_core_clear();
}

// RAII temporary directory (uses mkdtemp, cleaned up on destruction)
struct TmpDir {
    fs::path path;

    TmpDir() {
        std::string tmpl = (fs::temp_directory_path() / "logos_test_XXXXXX").string();
        char* buf = new char[tmpl.size() + 1];
        memcpy(buf, tmpl.c_str(), tmpl.size() + 1);
        if (!mkdtemp(buf)) {
            delete[] buf;
            throw std::runtime_error("mkdtemp failed");
        }
        path = buf;
        delete[] buf;
    }

    ~TmpDir() {
        std::error_code ec;
        fs::remove_all(path, ec);
    }

    bool isValid() const { return fs::is_directory(path); }

    // Returns path.string().c_str()-compatible value as std::string
    std::string str() const { return path.string(); }
};

static void createFakeModule(const fs::path& parentDir,
                             const std::string& moduleName,
                             const std::string& mainFile,
                             const std::string& type = "core",
                             const std::vector<std::string>& dependencies = {}) {
    fs::path moduleDir = parentDir / moduleName;
    fs::create_directories(moduleDir);

    nlohmann::json manifest;
    manifest["name"] = moduleName;
    manifest["version"] = "1.0.0";
    manifest["type"] = type;
    manifest["main"] = mainFile;
    manifest["description"] = "Fake test module";
    if (!dependencies.empty())
        manifest["dependencies"] = dependencies;

    std::ofstream mf(moduleDir / "manifest.json");
    mf << manifest.dump();
    mf.close();

    std::ofstream bf(moduleDir / mainFile);
    bf << "fake";
    bf.close();
}

// Helpers to free null-terminated char** arrays returned by the C API.
static void freeStringArray(char** arr) {
    if (!arr) return;
    for (int i = 0; arr[i] != nullptr; ++i)
        delete[] arr[i];
    delete[] arr;
}

static int stringArrayLen(char** arr) {
    if (!arr) return 0;
    int n = 0;
    while (arr[n]) ++n;
    return n;
}

static std::set<std::string> stringArrayToSet(char** arr) {
    std::set<std::string> s;
    if (!arr) return s;
    for (int i = 0; arr[i]; ++i)
        s.insert(arr[i]);
    return s;
}

class ModuleManagerTest : public ::testing::Test {
protected:
    void SetUp() override {
        clearModuleState();
    }

    void TearDown() override {
        clearModuleState();
    }
};

// =============================================================================
// Module Query Functions Tests
// =============================================================================

TEST_F(ModuleManagerTest, GetLoadedModules_ReturnsEmptyList) {
    char** result = logos_core_get_loaded_modules();
    ASSERT_NE(result, nullptr);
    EXPECT_EQ(result[0], nullptr);
    delete[] result;
}

TEST_F(ModuleManagerTest, GetKnownModules_ReturnsEmptyHash) {
    char** result = logos_core_get_known_modules();
    ASSERT_NE(result, nullptr);
    EXPECT_EQ(result[0], nullptr);
    delete[] result;
}

TEST_F(ModuleManagerTest, GetKnownModules_ReturnsCorrectHash) {
    logos_core_register_module("module1", "/path/to/module1.dylib");
    logos_core_register_module("module2", "/path/to/module2.dylib");

    char** result = logos_core_get_known_modules();
    ASSERT_NE(result, nullptr);
    ASSERT_EQ(stringArrayLen(result), 2);

    auto moduleSet = stringArrayToSet(result);
    EXPECT_TRUE(moduleSet.count("module1"));
    EXPECT_TRUE(moduleSet.count("module2"));

    char* path1 = logos_core_get_module_path("module1");
    char* path2 = logos_core_get_module_path("module2");
    ASSERT_NE(path1, nullptr);
    ASSERT_NE(path2, nullptr);
    EXPECT_EQ(std::string(path1), "/path/to/module1.dylib");
    EXPECT_EQ(std::string(path2), "/path/to/module2.dylib");
    delete[] path1;
    delete[] path2;
    freeStringArray(result);
}

TEST_F(ModuleManagerTest, IsModuleLoaded_ReturnsFalseForUnloaded) {
    EXPECT_EQ(logos_core_is_module_loaded("nonexistent_module"), 0);
}

TEST_F(ModuleManagerTest, IsModuleKnown_ReturnsFalseForUnknown) {
    EXPECT_EQ(logos_core_is_module_known("nonexistent_module"), 0);
}

TEST_F(ModuleManagerTest, IsModuleKnown_ReturnsTrueForKnown) {
    logos_core_register_module("test_module", "/path/to/module");

    EXPECT_EQ(logos_core_is_module_known("test_module"), 1);
}

// =============================================================================
// C String Array Functions Tests
// =============================================================================

TEST_F(ModuleManagerTest, GetLoadedModulesCStr_ReturnsNullTerminatedArrayWhenEmpty) {
    char** result = logos_core_get_loaded_modules();

    ASSERT_NE(result, nullptr);
    EXPECT_EQ(result[0], nullptr);

    delete[] result;
}

TEST_F(ModuleManagerTest, GetKnownModulesCStr_ReturnsNullTerminatedArrayWhenEmpty) {
    char** result = logos_core_get_known_modules();

    ASSERT_NE(result, nullptr);
    EXPECT_EQ(result[0], nullptr);

    delete[] result;
}

TEST_F(ModuleManagerTest, GetKnownModulesCStr_ReturnsCorrectArray) {
    logos_core_register_module("module1", "/path/to/module1");
    logos_core_register_module("module2", "/path/to/module2");

    char** result = logos_core_get_known_modules();

    ASSERT_NE(result, nullptr);
    ASSERT_NE(result[0], nullptr);
    ASSERT_NE(result[1], nullptr);
    EXPECT_EQ(result[2], nullptr);

    auto modules = stringArrayToSet(result);
    EXPECT_TRUE(modules.count("module1"));
    EXPECT_TRUE(modules.count("module2"));

    freeStringArray(result);
}

// =============================================================================
// loadModule Error Cases Tests
// =============================================================================

TEST_F(ModuleManagerTest, LoadModule_ReturnsFalseForUnknownModule) {
    int result = logos_core_load_module("nonexistent_module", false);
    EXPECT_EQ(result, 0);
}

// =============================================================================
// unloadModule Error Cases Tests
// =============================================================================

TEST_F(ModuleManagerTest, UnloadModule_ReturnsFalseForNotLoaded) {
    int result = logos_core_unload_module("nonexistent_module", false);
    EXPECT_EQ(result, 0);
}

// =============================================================================
// resolveDependencies Function Tests
// =============================================================================

TEST_F(ModuleManagerTest, ResolveDependencies_ReturnsEmptyForEmptyInput) {
    char** result = logos_core_resolve_dependencies(nullptr, 0);
    ASSERT_NE(result, nullptr);
    EXPECT_EQ(result[0], nullptr);
    delete[] result;
}

TEST_F(ModuleManagerTest, ResolveDependencies_ReturnsEmptyForUnknownModule) {
    const char* names[] = {"unknown_module"};
    char** result = logos_core_resolve_dependencies(names, 1);
    ASSERT_NE(result, nullptr);
    EXPECT_EQ(result[0], nullptr);
    delete[] result;
}

TEST_F(ModuleManagerTest, ResolveDependencies_ReturnsSingleModuleWithNoDeps) {
    logos_core_register_module("module_a", "/path/to/module_a");
    logos_core_register_module_dependencies("module_a", nullptr, 0);

    const char* names[] = {"module_a"};
    char** result = logos_core_resolve_dependencies(names, 1);

    ASSERT_EQ(stringArrayLen(result), 1);
    EXPECT_EQ(std::string(result[0]), "module_a");

    freeStringArray(result);
}

TEST_F(ModuleManagerTest, ResolveDependencies_ReturnsCorrectOrder) {
    logos_core_register_module("module_a", "/path/to/module_a");
    logos_core_register_module("module_b", "/path/to/module_b");
    const char* depsA[] = {"module_b"};
    logos_core_register_module_dependencies("module_a", depsA, 1);
    logos_core_register_module_dependencies("module_b", nullptr, 0);

    const char* names[] = {"module_a"};
    char** result = logos_core_resolve_dependencies(names, 1);

    ASSERT_EQ(stringArrayLen(result), 2);
    EXPECT_EQ(std::string(result[0]), "module_b");
    EXPECT_EQ(std::string(result[1]), "module_a");

    freeStringArray(result);
}

TEST_F(ModuleManagerTest, ResolveDependencies_HandlesTransitiveDeps) {
    logos_core_register_module("module_a", "/path/to/module_a");
    logos_core_register_module("module_b", "/path/to/module_b");
    logos_core_register_module("module_c", "/path/to/module_c");
    const char* depsA[] = {"module_b"};
    const char* depsB[] = {"module_c"};
    logos_core_register_module_dependencies("module_a", depsA, 1);
    logos_core_register_module_dependencies("module_b", depsB, 1);
    logos_core_register_module_dependencies("module_c", nullptr, 0);

    const char* names[] = {"module_a"};
    char** result = logos_core_resolve_dependencies(names, 1);

    ASSERT_EQ(stringArrayLen(result), 3);
    EXPECT_EQ(std::string(result[0]), "module_c");
    EXPECT_EQ(std::string(result[1]), "module_b");
    EXPECT_EQ(std::string(result[2]), "module_a");

    freeStringArray(result);
}

// =============================================================================
// C API: logos_core_load_module with_dependencies=true Tests
// =============================================================================

TEST_F(ModuleManagerTest, LoadModuleWithDeps_AbortsForNull) {
    EXPECT_DEATH(logos_core_load_module(nullptr, true), "");
}

TEST_F(ModuleManagerTest, LoadModuleWithDeps_ReturnsZeroForUnknown) {
    int result = logos_core_load_module("unknown_module", true);
    EXPECT_EQ(result, 0);
}

// =============================================================================
// Idempotent-load contract: "already loaded ⇒ success"
//
// logos_core_load_module is an "ensure loaded" guard, not a "load fresh"
// command. Pinning this in tests so the contract documented in
// logos_core.h doesn't quietly regress — basecamp's PluginLoader and
// logoscore-cli's load-module both rely on calling it against modules
// the runtime may have already brought up at startup, and we don't want
// a future refactor to start returning 0 in that case (which previously
// caused UI-plugin loads to abort when a core dep was pre-loaded).
//
// We exercise this without a runtime: register fake modules, mark them
// loaded via the registry adapter, then call the C entry point. The
// short-circuit at the top of ModuleManager::loadModuleInternal never
// reaches the descriptor / runtime path, so no subprocess is spawned.
// =============================================================================

TEST_F(ModuleManagerTest, LoadModule_ReturnsTrueWhenAlreadyLoaded) {
    logos_core_register_module("preloaded", "/fake/path");
    logos_core_mark_module_loaded("preloaded");
    ASSERT_EQ(logos_core_is_module_loaded("preloaded"), 1);

    // First call: module is already loaded ⇒ no-op success.
    EXPECT_EQ(logos_core_load_module("preloaded", false), 1)
        << "loading an already-loaded module must return 1 (no-op success)";

    // Repeating the call must stay idempotent — still success, still loaded.
    EXPECT_EQ(logos_core_load_module("preloaded", false), 1);
    EXPECT_EQ(logos_core_is_module_loaded("preloaded"), 1);
}

TEST_F(ModuleManagerTest, LoadModuleWithDeps_ReturnsTrueWhenAllAlreadyLoaded) {
    // Build a tiny dep graph: parent → child. Both pre-marked loaded.
    logos_core_register_module("parent", "/fake/parent");
    logos_core_register_module("child",  "/fake/child");
    const char* deps[] = {"child"};
    logos_core_register_module_dependencies("parent", deps, 1);
    logos_core_mark_module_loaded("child");
    logos_core_mark_module_loaded("parent");

    // with_dependencies=true walks the resolved order and calls
    // loadModuleInternal for each; every step short-circuits on
    // isLoaded() and returns true, so the overall call returns 1.
    EXPECT_EQ(logos_core_load_module("parent", true), 1)
        << "with_dependencies=true must return 1 when the target and "
           "all of its deps were already loaded before the call";
    EXPECT_EQ(logos_core_is_module_loaded("parent"), 1);
    EXPECT_EQ(logos_core_is_module_loaded("child"),  1);
}

// =============================================================================
// Dependency resolution failure: logos_core_load_module(name, true) must
// return 0 when the dependency graph cannot be fully resolved.
//
// The resolver silently drops unknown modules and detects cycles. Before
// this fix, loadModuleWithDependencies only checked whether the *target*
// appeared in the (possibly partial) resolved order — it didn't verify
// the resolution was clean. A module whose transitive dependency was
// unknown would load successfully, violating the contract in logos_core.h
// ("returns 0 when dependency resolution fails").
// =============================================================================

TEST_F(ModuleManagerTest, LoadModuleWithDeps_FailsWhenDirectDependencyUnknown) {
    logos_core_register_module("parent", "/fake/parent");
    const char* deps[] = {"unknown_dep"};
    logos_core_register_module_dependencies("parent", deps, 1);

    // "unknown_dep" is not registered → resolution has missing deps → fail.
    EXPECT_EQ(logos_core_load_module("parent", true), 0)
        << "must return 0 when a direct dependency is unknown";
}

TEST_F(ModuleManagerTest, LoadModuleWithDeps_FailsWhenTransitiveDependencyUnknown) {
    logos_core_register_module("top", "/fake/top");
    logos_core_register_module("mid", "/fake/mid");
    const char* depsTop[] = {"mid"};
    const char* depsMid[] = {"bottom_unknown"};
    logos_core_register_module_dependencies("top", depsTop, 1);
    logos_core_register_module_dependencies("mid", depsMid, 1);

    // "bottom_unknown" not registered → transitive resolution fails.
    EXPECT_EQ(logos_core_load_module("top", true), 0)
        << "must return 0 when a transitive dependency is unknown";
}

TEST_F(ModuleManagerTest, LoadModuleWithDeps_FailsOnCircularDependency) {
    logos_core_register_module("cyc_a", "/fake/cyc_a");
    logos_core_register_module("cyc_b", "/fake/cyc_b");
    const char* depsA[] = {"cyc_b"};
    const char* depsB[] = {"cyc_a"};
    logos_core_register_module_dependencies("cyc_a", depsA, 1);
    logos_core_register_module_dependencies("cyc_b", depsB, 1);

    // Cycle detected → must return 0.
    EXPECT_EQ(logos_core_load_module("cyc_a", true), 0)
        << "must return 0 when a circular dependency is detected";
}

// =============================================================================
// Module Directory Management Tests
// =============================================================================

TEST_F(ModuleManagerTest, AddModulesDir_SetsFirstDirectory) {
    logos_core_add_modules_dir("/tmp/test_modules");
    ASSERT_EQ(logos_core_get_modules_dirs_count(), 1);
    char* dir = logos_core_get_modules_dir_at(0);
    ASSERT_NE(dir, nullptr);
    EXPECT_EQ(std::string(dir), "/tmp/test_modules");
    delete[] dir;
}

TEST_F(ModuleManagerTest, AddModulesDir_AppendsDirectory) {
    logos_core_add_modules_dir("/tmp/dir1");
    logos_core_add_modules_dir("/tmp/dir2");
    logos_core_add_modules_dir("/tmp/dir3");

    ASSERT_EQ(logos_core_get_modules_dirs_count(), 3);

    char* d0 = logos_core_get_modules_dir_at(0);
    char* d1 = logos_core_get_modules_dir_at(1);
    char* d2 = logos_core_get_modules_dir_at(2);
    ASSERT_NE(d0, nullptr);
    ASSERT_NE(d1, nullptr);
    ASSERT_NE(d2, nullptr);
    EXPECT_EQ(std::string(d0), "/tmp/dir1");
    EXPECT_EQ(std::string(d1), "/tmp/dir2");
    EXPECT_EQ(std::string(d2), "/tmp/dir3");
    delete[] d0;
    delete[] d1;
    delete[] d2;
}

TEST_F(ModuleManagerTest, GetModulesDirs_ReturnsEmptyAfterClear) {
    logos_core_add_modules_dir("/tmp/dir1");
    clearModuleState();
    EXPECT_EQ(logos_core_get_modules_dirs_count(), 0);
}

// =============================================================================
// Discovery Tests — fake installed modules
// =============================================================================

TEST_F(ModuleManagerTest, DiscoverInstalledModules_DoesNotCrashWithEmptyDir) {
    TmpDir tmpDir;
    ASSERT_TRUE(tmpDir.isValid());

    logos_core_add_modules_dir(tmpDir.str().c_str());
    logos_core_refresh_modules();

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr);
    delete[] known;
}

TEST_F(ModuleManagerTest, DiscoverInstalledModules_DoesNotCrashWithNonexistentDir) {
    logos_core_add_modules_dir("/tmp/nonexistent_dir_12345");
    logos_core_refresh_modules();

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr);
    delete[] known;
}

TEST_F(ModuleManagerTest, DiscoverInstalledModules_FindsFakeModulesWithoutCrash) {
    TmpDir tmpDir;
    ASSERT_TRUE(tmpDir.isValid());

    createFakeModule(tmpDir.path, "fake_module_a", "fake_module_a_plugin.so");
    createFakeModule(tmpDir.path, "fake_module_b", "fake_module_b_plugin.so");

    logos_core_add_modules_dir(tmpDir.str().c_str());
    logos_core_refresh_modules();

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr);
    delete[] known;
}

TEST_F(ModuleManagerTest, DiscoverInstalledModules_IgnoresModulesWithoutManifest) {
    TmpDir tmpDir;
    ASSERT_TRUE(tmpDir.isValid());

    fs::path moduleDir = tmpDir.path / "no_manifest_module";
    fs::create_directories(moduleDir);
    std::ofstream bf(moduleDir / "plugin.so");
    bf << "fake";
    bf.close();

    logos_core_add_modules_dir(tmpDir.str().c_str());
    logos_core_refresh_modules();

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr);
    delete[] known;
}

TEST_F(ModuleManagerTest, DiscoverInstalledModules_IgnoresUiTypeModules) {
    TmpDir tmpDir;
    ASSERT_TRUE(tmpDir.isValid());

    createFakeModule(tmpDir.path, "ui_module", "ui_module_plugin.so", "ui");

    logos_core_add_modules_dir(tmpDir.str().c_str());
    logos_core_refresh_modules();

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr);
    delete[] known;
}

TEST_F(ModuleManagerTest, DiscoverInstalledModules_MultipleDirectories) {
    TmpDir tmpDir1;
    TmpDir tmpDir2;
    ASSERT_TRUE(tmpDir1.isValid());
    ASSERT_TRUE(tmpDir2.isValid());

    createFakeModule(tmpDir1.path, "module_in_dir1", "module_in_dir1_plugin.so");
    createFakeModule(tmpDir2.path, "module_in_dir2", "module_in_dir2_plugin.so");

    logos_core_add_modules_dir(tmpDir1.str().c_str());
    logos_core_add_modules_dir(tmpDir2.str().c_str());

    ASSERT_EQ(logos_core_get_modules_dirs_count(), 2);

    logos_core_refresh_modules();

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr);
    delete[] known;
}

TEST_F(ModuleManagerTest, DiscoverInstalledModules_InvalidManifestJson) {
    TmpDir tmpDir;
    ASSERT_TRUE(tmpDir.isValid());

    fs::path moduleDir = tmpDir.path / "bad_manifest_module";
    fs::create_directories(moduleDir);
    std::ofstream mf(moduleDir / "manifest.json");
    mf << "{ this is not valid json }}}";
    mf.close();

    logos_core_add_modules_dir(tmpDir.str().c_str());
    logos_core_refresh_modules();

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr);
    delete[] known;
}

// =============================================================================
// Loaded-flag preservation across re-registration
// =============================================================================

TEST_F(ModuleManagerTest, RegisterModule_PreservesLoadedFlagOnReregister) {
    logos_core_register_module("test_module", "/path/v1");
    logos_core_mark_module_loaded("test_module");
    ASSERT_EQ(logos_core_is_module_loaded("test_module"), 1);

    logos_core_register_module("test_module", "/path/v2");

    EXPECT_EQ(logos_core_is_module_loaded("test_module"), 1)
        << "Re-registering a known module must preserve its loaded flag";

    char* path = logos_core_get_module_path("test_module");
    ASSERT_NE(path, nullptr);
    EXPECT_EQ(std::string(path), "/path/v2");
    delete[] path;
}

TEST_F(ModuleManagerTest, RegisterDependencies_PreservesLoadedFlag) {
    logos_core_register_module("test_module", "/path/to/module");
    logos_core_mark_module_loaded("test_module");
    ASSERT_EQ(logos_core_is_module_loaded("test_module"), 1);

    const char* deps[] = {"dep_a", "dep_b"};
    logos_core_register_module_dependencies("test_module", deps, 2);

    EXPECT_EQ(logos_core_is_module_loaded("test_module"), 1)
        << "Updating dependencies must not wipe the loaded flag";
    EXPECT_EQ(logos_core_get_module_dependencies_count("test_module"), 2);
}

// =============================================================================
// End-to-end regression tests using a real Qt module.
// =============================================================================

class RealModuleRegistryTest : public ::testing::Test {
protected:
    std::string modulePath;

    void SetUp() override {
        clearModuleState();

        const char* envPlugin = std::getenv("TEST_PLUGIN");
        if (envPlugin && std::strlen(envPlugin) > 0 &&
            fs::exists(envPlugin)) {
            modulePath = envPlugin;
            return;
        }

        GTEST_SKIP() << "No real test module available. "
                     << "Set TEST_PLUGIN env var to a built Qt plugin (.so/.dylib).";
    }

    void TearDown() override {
        clearModuleState();
    }
};

TEST_F(RealModuleRegistryTest, ProcessModule_RegistersRealModule) {
    char* name = logos_core_process_module(modulePath.c_str());
    ASSERT_NE(name, nullptr) << "process_module failed for " << modulePath;
    EXPECT_NE(std::string(name), "");
    EXPECT_EQ(logos_core_is_module_known(name), 1);
    EXPECT_EQ(logos_core_is_module_loaded(name), 0);
    delete[] name;
}

// =============================================================================
// Security regression: privileged-name impersonation during discovery (F-022).
//
// Module identity used to be taken from the name embedded in the plugin's own
// Qt metadata, ignoring the trusted package name the package manager scanned.
// That let a package installed under an innocuous name ship a binary whose
// embedded metadata claims a privileged name (e.g. "capability_module"), and
// the registry would key the module under that privileged name — wiring the
// attacker's plugin into the impersonated module's token/trust relationships.
//
// The discovery path (logos_core_refresh_modules → discoverInstalledModules)
// must bind identity to the *trusted package name* (InstalledPackage::name)
// and refuse a plugin whose embedded name disagrees.
//
// These tests use the real TEST_PLUGIN as the impersonating payload: we first
// read its real embedded name via the raw process-module path, then plant a
// package whose manifest name differs from it, and assert the embedded name
// never leaks into the registry.
// =============================================================================

class ImpersonationRegistryTest : public ::testing::Test {
protected:
    std::string modulePath;       // real TEST_PLUGIN on disk
    std::string embeddedName;     // the name baked into TEST_PLUGIN's metadata

    void SetUp() override {
        clearModuleState();

        const char* envPlugin = std::getenv("TEST_PLUGIN");
        if (!envPlugin || std::strlen(envPlugin) == 0 || !fs::exists(envPlugin)) {
            GTEST_SKIP() << "No real test module available. "
                         << "Set TEST_PLUGIN env var to a built Qt plugin (.so/.dylib).";
        }
        modulePath = envPlugin;

        // Discover the plugin's self-asserted embedded name via the raw
        // process-module path (which intentionally trusts the embedded name).
        // This is the name an attacker's binary would carry to impersonate.
        char* name = logos_core_process_module(modulePath.c_str());
        ASSERT_NE(name, nullptr) << "process_module failed for " << modulePath;
        embeddedName = name;
        delete[] name;
        ASSERT_FALSE(embeddedName.empty());

        // Wipe the scratch registration + modules dirs so each test below
        // starts from a clean registry.
        clearModuleState();
    }

    void TearDown() override {
        clearModuleState();
    }

    // Plant a package directory named `packageName` whose manifest declares
    // name=packageName but whose main binary is a byte copy of the real
    // TEST_PLUGIN (embedding `embeddedName`).
    void plantPackage(const fs::path& parentDir, const std::string& packageName) {
        const std::string mainFile = packageName + "_plugin.so";
        createFakeModule(parentDir, packageName, mainFile);  // manifest + placeholder
        std::error_code ec;
        fs::copy_file(modulePath, parentDir / packageName / mainFile,
                      fs::copy_options::overwrite_existing, ec);
        ASSERT_FALSE(ec) << "failed to copy real plugin into package dir: " << ec.message();
    }
};

// The core repro: an "innocent_helper" package carrying a binary that claims
// the privileged embedded name must NOT register under that privileged name,
// and must not silently bind it either. Before the fix the registry keyed the
// module under `embeddedName`, so is_module_known(embeddedName) was 1.
TEST_F(ImpersonationRegistryTest, Discovery_RefusesPrivilegedNameImpersonation) {
    // Only meaningful when the trusted package name differs from the embedded
    // one (true for the capability_module fixture: package "innocent_helper"
    // vs embedded "capability_module").
    const std::string packageName = "innocent_helper";
    ASSERT_NE(packageName, embeddedName);

    TmpDir tmpDir;
    ASSERT_TRUE(tmpDir.isValid());
    plantPackage(tmpDir.path, packageName);

    logos_core_add_modules_dir(tmpDir.str().c_str());
    logos_core_refresh_modules();

    // The impersonated privileged identity must never enter the registry.
    EXPECT_EQ(logos_core_is_module_known(embeddedName.c_str()), 0)
        << "a package must not be able to claim the embedded name '"
        << embeddedName << "' it does not legitimately own";

    // And the lying package is refused outright (its binary's identity does
    // not match its package name), so the innocuous name isn't bound either.
    EXPECT_EQ(logos_core_is_module_known(packageName.c_str()), 0)
        << "a package whose binary impersonates another module must be refused";

    char** known = logos_core_get_known_modules();
    ASSERT_NE(known, nullptr);
    EXPECT_EQ(known[0], nullptr) << "no module should be registered from a lying package";
    freeStringArray(known);
}

// Positive control: an honest package whose manifest name matches the binary's
// embedded name still registers normally. The fix must not break legitimate
// discovery of (even reserved-named) modules installed under their true name.
TEST_F(ImpersonationRegistryTest, Discovery_HonestPackageRegistersUnderItsName) {
    TmpDir tmpDir;
    ASSERT_TRUE(tmpDir.isValid());
    plantPackage(tmpDir.path, embeddedName);  // manifest name == embedded name

    logos_core_add_modules_dir(tmpDir.str().c_str());
    logos_core_refresh_modules();

    EXPECT_EQ(logos_core_is_module_known(embeddedName.c_str()), 1)
        << "an honest package (manifest name == embedded name) must register";

    char* path = logos_core_get_module_path(embeddedName.c_str());
    ASSERT_NE(path, nullptr);
    EXPECT_NE(std::string(path), "");
    delete[] path;
}

// =============================================================================
// Cascading unload: logos_core_unload_module(name, true)
//
// The cascade is exercised without real Qt modules. We:
//   1. Set up fake manifests on disk (PackageManagerLib scan sees the
//      dependency edges).
//   2. Register the same modules directly in ModuleRegistry so it believes
//      they exist (the fake .so files are not loadable Qt plugins, so
//      refresh_modules alone wouldn't populate the registry).
//   3. Register placeholder "processes" + mark loaded so hasProcess() returns
//      true — `terminateProcess` on a placeholder is a no-op but still
//      removes the entry cleanly.
// =============================================================================

class CascadeUnloadTest : public ::testing::Test {
protected:
    TmpDir tmpDir;

    void SetUp() override {
        clearModuleState();
        logos_core_clear_processes();
    }

    void TearDown() override {
        clearModuleState();
        logos_core_clear_processes();
    }

    // Registers a module in both ModuleRegistry and as a loaded fake process.
    void setupLoaded(const std::string& name,
                     const std::vector<std::string>& deps = {}) {
        std::string path = (tmpDir.path / name / (name + "_plugin.so")).string();
        logos_core_register_module(name.c_str(), path.c_str());
        std::vector<const char*> depPtrs;
        depPtrs.reserve(deps.size());
        for (const auto& d : deps) depPtrs.push_back(d.c_str());
        logos_core_register_module_dependencies(
            name.c_str(),
            depPtrs.empty() ? nullptr : depPtrs.data(),
            static_cast<int>(depPtrs.size()));

        logos_core_register_process(name.c_str());
        logos_core_mark_module_loaded(name.c_str());
    }

    void writeManifestsAndScan(
        const std::vector<std::tuple<std::string, std::vector<std::string>>>& modules)
    {
        for (const auto& [name, deps] : modules) {
            createFakeModule(tmpDir.path, name, name + "_plugin.so", "core", deps);
        }
        logos_core_add_modules_dir(tmpDir.str().c_str());
        logos_core_refresh_modules();
    }
};

TEST_F(CascadeUnloadTest, UnloadWithDependents_ReturnsZeroWhenTargetNotLoaded) {
    // Module is known but not loaded.
    logos_core_register_module("foo", "/foo");
    int result = logos_core_unload_module("foo", true);
    EXPECT_EQ(result, 0);
}

TEST_F(CascadeUnloadTest, UnloadWithDependents_NoDependents_UnloadsTargetOnly) {
    // Single loaded module with no dependents on disk → cascade is just the
    // target.
    writeManifestsAndScan({ {"solo", {}} });
    setupLoaded("solo");

    ASSERT_EQ(logos_core_is_module_loaded("solo"), 1);

    int result = logos_core_unload_module("solo", true);
    EXPECT_EQ(result, 1);
    EXPECT_EQ(logos_core_is_module_loaded("solo"), 0);
    EXPECT_EQ(logos_core_has_process("solo"), 0);
}

TEST_F(CascadeUnloadTest, UnloadWithDependents_RecursiveDependentsLeavesFirst) {
    // Graph: a -> b -> c (a depends on b, b depends on c).
    // Unloading c should also bring down b and a, in the order a, b, c.
    writeManifestsAndScan({
        {"c", {}},
        {"b", {"c"}},
        {"a", {"b"}},
    });
    setupLoaded("c", {});
    setupLoaded("b", {"c"});
    setupLoaded("a", {"b"});

    ASSERT_EQ(logos_core_is_module_loaded("a"), 1);
    ASSERT_EQ(logos_core_is_module_loaded("b"), 1);
    ASSERT_EQ(logos_core_is_module_loaded("c"), 1);

    int result = logos_core_unload_module("c", true);
    EXPECT_EQ(result, 1);

    EXPECT_EQ(logos_core_is_module_loaded("a"), 0);
    EXPECT_EQ(logos_core_is_module_loaded("b"), 0);
    EXPECT_EQ(logos_core_is_module_loaded("c"), 0);

    EXPECT_EQ(logos_core_has_process("a"), 0);
    EXPECT_EQ(logos_core_has_process("b"), 0);
    EXPECT_EQ(logos_core_has_process("c"), 0);
}

TEST_F(CascadeUnloadTest, UnloadWithDependents_UnloadedDependentsIgnored) {
    // b depends on c. Only c is loaded; b is known but not loaded. Cascade
    // should only touch c. b stays unloaded (not "failed to unload").
    writeManifestsAndScan({
        {"c", {}},
        {"b", {"c"}},
    });
    setupLoaded("c", {});
    // Register b in registry but don't mark it loaded.
    logos_core_register_module("b", "/b");
    const char* depsB[] = {"c"};
    logos_core_register_module_dependencies("b", depsB, 1);

    int result = logos_core_unload_module("c", true);
    EXPECT_EQ(result, 1);

    EXPECT_EQ(logos_core_is_module_loaded("c"), 0);
    EXPECT_EQ(logos_core_is_module_loaded("b"), 0);
}

TEST_F(CascadeUnloadTest, UnloadWithDependents_DiamondDependents) {
    // Diamond: a -> b -> d ; a -> c -> d. Unloading d should bring down
    // a, b, c in some valid order (a before b and c; b and c before d).
    writeManifestsAndScan({
        {"d", {}},
        {"b", {"d"}},
        {"c", {"d"}},
        {"a", {"b", "c"}},
    });
    setupLoaded("d", {});
    setupLoaded("b", {"d"});
    setupLoaded("c", {"d"});
    setupLoaded("a", {"b", "c"});

    int result = logos_core_unload_module("d", true);
    EXPECT_EQ(result, 1);

    EXPECT_EQ(logos_core_is_module_loaded("a"), 0);
    EXPECT_EQ(logos_core_is_module_loaded("b"), 0);
    EXPECT_EQ(logos_core_is_module_loaded("c"), 0);
    EXPECT_EQ(logos_core_is_module_loaded("d"), 0);
}

TEST_F(CascadeUnloadTest, UnloadWithDependents_AbortsForNull) {
    EXPECT_DEATH(logos_core_unload_module(nullptr, true), "");
}

TEST_F(RealModuleRegistryTest, ProcessModule_PreservesLoadedFlagOnReprocess) {
    char* name1 = logos_core_process_module(modulePath.c_str());
    ASSERT_NE(name1, nullptr) << "process_module failed for " << modulePath;
    std::string modName = name1;
    delete[] name1;

    ASSERT_EQ(logos_core_is_module_known(modName.c_str()), 1);

    logos_core_mark_module_loaded(modName.c_str());
    ASSERT_EQ(logos_core_is_module_loaded(modName.c_str()), 1);

    char* name2 = logos_core_process_module(modulePath.c_str());
    ASSERT_NE(name2, nullptr);
    EXPECT_EQ(std::string(name2), modName);
    delete[] name2;

    EXPECT_EQ(logos_core_is_module_loaded(modName.c_str()), 1)
        << "Re-processing a loaded module must preserve its loaded flag";

    // Verify it still appears in the loaded list
    char** loaded = logos_core_get_loaded_modules();
    auto loadedSet = stringArrayToSet(loaded);
    freeStringArray(loaded);
    EXPECT_TRUE(loadedSet.count(modName))
        << "get_loaded_modules() must still report the module as loaded";
}

// =============================================================================
// Dependency graph queries:
//   logos_core_get_module_dependencies(name, recursive)
//   logos_core_get_module_dependents(name, recursive)
//
// These read from the in-process registry. We populate it with
// logos_core_register_module + logos_core_register_module_dependencies
// (which in turn trigger recomputeDependentsLocked), then check both the
// direct and recursive traversals against known-shaped graphs.
// =============================================================================

class DependencyQueryTest : public ::testing::Test {
protected:
    void SetUp() override {
        clearModuleState();
    }

    void TearDown() override {
        clearModuleState();
    }

    // Register a module with a (possibly empty) direct dependency list. Path
    // value isn't exercised by the queries — anything non-empty is fine.
    void reg(const std::string& name,
             const std::vector<std::string>& deps = {}) {
        logos_core_register_module(name.c_str(), ("/" + name).c_str());
        std::vector<const char*> depPtrs;
        depPtrs.reserve(deps.size());
        for (const auto& d : deps) depPtrs.push_back(d.c_str());
        logos_core_register_module_dependencies(
            name.c_str(),
            depPtrs.empty() ? nullptr : depPtrs.data(),
            static_cast<int>(depPtrs.size()));
    }
};

TEST_F(DependencyQueryTest, GetModuleDependencies_UnknownName_ReturnsEmpty) {
    char** deps = logos_core_get_module_dependencies("ghost", false);
    EXPECT_EQ(stringArrayLen(deps), 0);
    freeStringArray(deps);

    deps = logos_core_get_module_dependencies("ghost", true);
    EXPECT_EQ(stringArrayLen(deps), 0);
    freeStringArray(deps);
}

TEST_F(DependencyQueryTest, GetModuleDependents_UnknownName_ReturnsEmpty) {
    char** d = logos_core_get_module_dependents("ghost", false);
    EXPECT_EQ(stringArrayLen(d), 0);
    freeStringArray(d);

    d = logos_core_get_module_dependents("ghost", true);
    EXPECT_EQ(stringArrayLen(d), 0);
    freeStringArray(d);
}

TEST_F(DependencyQueryTest, GetModuleDependencies_NoDeps_ReturnsEmpty) {
    reg("leaf");
    char** deps = logos_core_get_module_dependencies("leaf", false);
    EXPECT_EQ(stringArrayLen(deps), 0);
    freeStringArray(deps);
    deps = logos_core_get_module_dependencies("leaf", true);
    EXPECT_EQ(stringArrayLen(deps), 0);
    freeStringArray(deps);
}

TEST_F(DependencyQueryTest, GetModuleDependencies_DirectVsRecursive) {
    // Chain: a -> b -> c. Direct deps of a = {b}. Recursive deps of a = {b, c}.
    reg("c");
    reg("b", {"c"});
    reg("a", {"b"});

    char** direct = logos_core_get_module_dependencies("a", false);
    EXPECT_EQ(stringArrayToSet(direct), (std::set<std::string>{"b"}));
    freeStringArray(direct);

    char** recursive = logos_core_get_module_dependencies("a", true);
    EXPECT_EQ(stringArrayToSet(recursive), (std::set<std::string>{"b", "c"}));
    freeStringArray(recursive);
}

TEST_F(DependencyQueryTest, GetModuleDependents_DirectVsRecursive) {
    // Chain: a -> b -> c. Direct dependents of c = {b}. Recursive = {b, a}.
    reg("c");
    reg("b", {"c"});
    reg("a", {"b"});

    char** direct = logos_core_get_module_dependents("c", false);
    EXPECT_EQ(stringArrayToSet(direct), (std::set<std::string>{"b"}));
    freeStringArray(direct);

    char** recursive = logos_core_get_module_dependents("c", true);
    EXPECT_EQ(stringArrayToSet(recursive), (std::set<std::string>{"b", "a"}));
    freeStringArray(recursive);
}

TEST_F(DependencyQueryTest, GetModuleDependencies_Diamond_RecursiveDeduplicates) {
    // Diamond: a -> b -> d ; a -> c -> d. Recursive deps of a must include
    // {b, c, d} with no duplicate entries for d.
    reg("d");
    reg("b", {"d"});
    reg("c", {"d"});
    reg("a", {"b", "c"});

    char** recursive = logos_core_get_module_dependencies("a", true);
    std::set<std::string> got = stringArrayToSet(recursive);
    int n = stringArrayLen(recursive);
    freeStringArray(recursive);

    EXPECT_EQ(got, (std::set<std::string>{"b", "c", "d"}));
    // No duplicate d entries — set and array length must agree.
    EXPECT_EQ(n, static_cast<int>(got.size()));
}

TEST_F(DependencyQueryTest, GetModuleDependents_Diamond_RecursiveDeduplicates) {
    // Same diamond — d has {b, c} as direct dependents and {b, c, a}
    // transitively. The BFS must not report a twice even though both
    // b and c list it as a dependent.
    reg("d");
    reg("b", {"d"});
    reg("c", {"d"});
    reg("a", {"b", "c"});

    char** direct = logos_core_get_module_dependents("d", false);
    EXPECT_EQ(stringArrayToSet(direct), (std::set<std::string>{"b", "c"}));
    freeStringArray(direct);

    char** recursive = logos_core_get_module_dependents("d", true);
    std::set<std::string> got = stringArrayToSet(recursive);
    int n = stringArrayLen(recursive);
    freeStringArray(recursive);
    EXPECT_EQ(got, (std::set<std::string>{"a", "b", "c"}));
    EXPECT_EQ(n, static_cast<int>(got.size()));
}

TEST_F(DependencyQueryTest, GetModuleDependencies_SelfNotIncluded) {
    reg("leaf");
    reg("root", {"leaf"});
    char** recursive = logos_core_get_module_dependencies("root", true);
    std::set<std::string> got = stringArrayToSet(recursive);
    freeStringArray(recursive);
    EXPECT_EQ(got.count("root"), 0u);
    EXPECT_EQ(got, (std::set<std::string>{"leaf"}));
}

TEST_F(DependencyQueryTest, GetModuleDependencies_AbortsForNull) {
    EXPECT_DEATH(logos_core_get_module_dependencies(nullptr, false), "");
}

TEST_F(DependencyQueryTest, GetModuleDependents_AbortsForNull) {
    EXPECT_DEATH(logos_core_get_module_dependents(nullptr, false), "");
}

// =============================================================================
// Derived access-restriction computation (graph + policy -> allowed callers)
// =============================================================================
//
// computeDerivedAllowedCallers() is the registry-backed counterpart of the
// pure derivation seam: it reads the live dependency graph + loaded set + the
// access policy and returns what core would register with capability_module for
// a target — without any RPC. We drive it with the test registry adapters
// (register_module / register_module_dependencies / mark_module_loaded) and the
// ModuleManager::setAccessPolicy entry point.

class DerivedRestrictionsManagerTest : public ::testing::Test {
protected:
    void SetUp() override { clearModuleState(); }
    void TearDown() override {
        // Clear the policy so it doesn't leak into other suites.
        ModuleManager::setAccessPolicy("");
        clearModuleState();
    }

    // Register `name` with `deps` declared as dependencies.
    static void reg(const std::string& name, const std::vector<std::string>& deps) {
        logos_core_register_module(name.c_str(), ("/fake/" + name).c_str());
        std::vector<const char*> d;
        for (const auto& s : deps) d.push_back(s.c_str());
        logos_core_register_module_dependencies(name.c_str(), d.data(),
                                                static_cast<int>(d.size()));
    }

    static std::set<std::string> derived(const std::string& target) {
        auto v = ModuleManager::computeDerivedAllowedCallers(target);
        return std::set<std::string>(v.begin(), v.end());
    }

    // Minimal enforce policy with no explicit restrictions — turns derivation on.
    static const char* enforceEnvelope() {
        return "{\"version\":1,\"mode\":\"enforce\",\"restrictions\":{}}";
    }
};

TEST_F(DerivedRestrictionsManagerTest, LoadedDependentPlusTrusted) {
    // a depends on b; both loaded. b's allowed callers = {a} ∪ trusted.
    reg("b", {});
    reg("a", {"b"});
    logos_core_mark_module_loaded("b");
    logos_core_mark_module_loaded("a");
    ModuleManager::setAccessPolicy(enforceEnvelope());

    EXPECT_EQ(derived("b"),
              (std::set<std::string>{"a", "core", "core_service"}));
}

TEST_F(DerivedRestrictionsManagerTest, UnloadedDependentExcluded) {
    // a declares b but is NOT loaded — a must not appear in b's callers.
    reg("b", {});
    reg("a", {"b"});
    logos_core_mark_module_loaded("b");  // a left unloaded
    ModuleManager::setAccessPolicy(enforceEnvelope());

    EXPECT_EQ(derived("b"), (std::set<std::string>{"core", "core_service"}));
}

TEST_F(DerivedRestrictionsManagerTest, ZeroDependentsIsTrustedOnly) {
    reg("solo", {});
    logos_core_mark_module_loaded("solo");
    ModuleManager::setAccessPolicy(enforceEnvelope());

    EXPECT_EQ(derived("solo"), (std::set<std::string>{"core", "core_service"}));
}

TEST_F(DerivedRestrictionsManagerTest, NoEnforcePolicyDerivesNothing) {
    reg("b", {});
    reg("a", {"b"});
    logos_core_mark_module_loaded("b");
    logos_core_mark_module_loaded("a");
    // No policy set at all -> derivation off -> empty.
    EXPECT_TRUE(derived("b").empty());

    // A non-enforce policy is also inert.
    ModuleManager::setAccessPolicy(
        "{\"version\":1,\"mode\":\"audit\",\"restrictions\":{}}");
    EXPECT_TRUE(derived("b").empty());
}

TEST_F(DerivedRestrictionsManagerTest, ExplicitPolicyOverridesDerived) {
    reg("b", {});
    reg("a", {"b"});
    logos_core_mark_module_loaded("b");
    logos_core_mark_module_loaded("a");
    // Explicit entry for b names only "x" — replaces the derived {a, trusted}.
    ModuleManager::setAccessPolicy(
        "{\"version\":1,\"mode\":\"enforce\",\"restrictions\":{"
        "\"b\":{\"allowedCallers\":[\"x\"]}}}");

    EXPECT_EQ(derived("b"), (std::set<std::string>{"x"}));
}

TEST_F(DerivedRestrictionsManagerTest, ExemptTargetsNeverDerived) {
    reg("capability_module", {});
    logos_core_mark_module_loaded("capability_module");
    ModuleManager::setAccessPolicy(enforceEnvelope());

    EXPECT_TRUE(derived("capability_module").empty());
}

TEST_F(DerivedRestrictionsManagerTest, UnloadDropsDependentFromCallers) {
    reg("b", {});
    reg("a", {"b"});
    logos_core_mark_module_loaded("b");
    logos_core_mark_module_loaded("a");
    ModuleManager::setAccessPolicy(enforceEnvelope());
    EXPECT_TRUE(derived("b").count("a"));

    // Unloading a (it stays known, dependency edge remains) drops it.
    ModuleManager::registry().markUnloaded("a");
    EXPECT_FALSE(derived("b").count("a"));
    EXPECT_EQ(derived("b"), (std::set<std::string>{"core", "core_service"}));
}

TEST_F(DerivedRestrictionsManagerTest, TrustedDependentNotDuplicated) {
    // A loaded dependent that shares a trusted name must appear exactly once in
    // the registered list (the set-based `derived()` helper would hide a dup, so
    // inspect the raw vector here).
    reg("b", {});
    reg("core", {"b"});
    logos_core_mark_module_loaded("b");
    logos_core_mark_module_loaded("core");
    ModuleManager::setAccessPolicy(enforceEnvelope());

    auto callers = ModuleManager::computeDerivedAllowedCallers("b");
    EXPECT_EQ(std::count(callers.begin(), callers.end(), std::string("core")), 1);
}