#include <gtest/gtest.h>
#include <XCEngine/Core/RefCounted.h>
#include <XCEngine/Core/SmartPtr.h>
#include <XCEngine/Core/Event.h>
#include <XCEngine/Core/Types.h>

#include <string>
#include <thread>
#include <atomic>

using namespace XCEngine::Core;

namespace {

class TestRefCounted : public RefCounted {
public:
    TestRefCounted() : value(42) {}
    int value;
};

TEST(Core_RefCounted, DefaultConstructor) {
    TestRefCounted* obj = new TestRefCounted();
    EXPECT_EQ(obj->GetRefCount(), 1);
    delete obj;
}

TEST(Core_RefCounted, AddRef) {
    TestRefCounted* obj = new TestRefCounted();
    EXPECT_EQ(obj->GetRefCount(), 1);
    
    obj->AddRef();
    EXPECT_EQ(obj->GetRefCount(), 2);
    
    obj->Release();
    EXPECT_EQ(obj->GetRefCount(), 1);
    delete obj;
}

TEST(Core_RefCounted, Release) {
    TestRefCounted* obj = new TestRefCounted();
    EXPECT_EQ(obj->GetRefCount(), 1);
    
    obj->AddRef();
    EXPECT_EQ(obj->GetRefCount(), 2);
    
    obj->Release();
    EXPECT_EQ(obj->GetRefCount(), 1);
    
    obj->Release();
}

TEST(Core_RefCounted, ChainedRefs) {
    TestRefCounted* obj = new TestRefCounted();
    EXPECT_EQ(obj->GetRefCount(), 1);
    
    for (int i = 0; i < 5; i++) {
        obj->AddRef();
    }
    EXPECT_EQ(obj->GetRefCount(), 6);
    
    for (int i = 0; i < 5; i++) {
        obj->Release();
    }
    EXPECT_EQ(obj->GetRefCount(), 1);
    delete obj;
}

struct TestStruct {
    int value = 100;
    std::string name = "test";
};

TEST(Core_SmartPtr, MakeRef) {
    auto ref = MakeRef<TestStruct>();
    EXPECT_NE(ref, nullptr);
    EXPECT_EQ(ref->value, 100);
    EXPECT_EQ(ref->name, "test");
}

TEST(Core_SmartPtr, Ref_NullCheck) {
    Ref<TestStruct> ref = nullptr;
    EXPECT_EQ(ref, nullptr);
    EXPECT_FALSE(ref);
}

TEST(Core_SmartPtr, Ref_Dereference) {
    auto ref = MakeRef<TestStruct>();
    ref->value = 200;
    EXPECT_EQ(ref->value, 200);
    EXPECT_EQ((*ref).value, 200);
}

TEST(Core_SmartPtr, Ref_Copy) {
    auto ref1 = MakeRef<TestStruct>();
    ref1->value = 300;
    
    auto ref2 = ref1;
    EXPECT_EQ(ref1.use_count(), 2);
    EXPECT_EQ(ref2.use_count(), 2);
    EXPECT_EQ(ref2->value, 300);
    
    ref2->value = 400;
    EXPECT_EQ(ref1->value, 400);
}

TEST(Core_SmartPtr, Ref_Move) {
    auto ref1 = MakeRef<TestStruct>();
    ref1->value = 500;
    
    auto ref2 = std::move(ref1);
    EXPECT_EQ(ref1, nullptr);
    EXPECT_NE(ref2, nullptr);
    EXPECT_EQ(ref2->value, 500);
}

TEST(Core_SmartPtr, MakeUnique) {
    auto unique = MakeUnique<TestStruct>();
    EXPECT_NE(unique, nullptr);
    EXPECT_EQ(unique->value, 100);
}

TEST(Core_SmartPtr, UniqueRef_Ownership) {
    auto unique1 = MakeUnique<TestStruct>();
    unique1->value = 600;
    
    auto unique2 = std::move(unique1);
    EXPECT_EQ(unique1, nullptr);
    EXPECT_NE(unique2, nullptr);
    EXPECT_EQ(unique2->value, 600);
}

TEST(Core_Event, Subscribe) {
    Event<> event;
    bool called = false;
    
    uint64_t id = event.Subscribe([&called]() {
        called = true;
    });
    
    EXPECT_NE(id, 0u);
    
    event.Invoke();
    EXPECT_TRUE(called);
}

TEST(Core_Event, Invoke_NoArgs) {
    Event<> event;
    int count = 0;
    
    event.Subscribe([&count]() { count++; });
    event.Subscribe([&count]() { count++; });
    
    event.Invoke();
    EXPECT_EQ(count, 2);
}

TEST(Core_Event, Invoke_WithArgs) {
    Event<int, std::string> event;
    int result = 0;
    std::string text;
    
    event.Subscribe([&result, &text](int v, const std::string& s) {
        result = v;
        text = s;
    });
    
    event.Invoke(42, "hello");
    EXPECT_EQ(result, 42);
    EXPECT_EQ(text, "hello");
}

TEST(Core_Event, Unsubscribe) {
    Event<> event;
    int count = 0;
    
    uint64_t id = event.Subscribe([&count]() { count++; });
    event.Subscribe([&count]() { count++; });
    
    event.Invoke();
    EXPECT_EQ(count, 2);
    
    event.Unsubscribe(id);
    event.Invoke();
    EXPECT_EQ(count, 3);
}

TEST(Core_Event, Clear) {
    Event<> event;
    int count = 0;
    
    event.Subscribe([&count]() { count++; });
    event.Subscribe([&count]() { count++; });
    
    event.Clear();
    event.Invoke();
    EXPECT_EQ(count, 0);
}

TEST(Core_Event, MultipleListeners) {
    Event<int> event;
    std::vector<int> results;
    
    for (int i = 0; i < 5; i++) {
        event.Subscribe([&results](int v) {
            results.push_back(v);
        });
    }
    
    event.Invoke(10);
    
    EXPECT_EQ(results.size(), 5);
    for (int v : results) {
        EXPECT_EQ(v, 10);
    }
}

TEST(Core_Event, ReturnId) {
    Event<> event;
    
    uint64_t id1 = event.Subscribe([]() {});
    uint64_t id2 = event.Subscribe([]() {});
    
    EXPECT_NE(id1, id2);
}

} // namespace