#include <gtest/gtest.h>
#include <atomic>
#include <cstdint>
#include <memory>
#include "renderive/base/observer/Observer.hpp"
struct Observer_Test_Observation {
    int value{};
};
struct Observer_Test_Time_Source {
    std::shared_ptr<std::atomic<std::uint64_t>> time{std::make_shared<std::atomic<std::uint64_t>>(10)};
    std::uint64_t now_ns() const noexcept {
        return time->fetch_add(5, std::memory_order_relaxed);
    }
};
struct Observer_Test_Recorder {
    static constexpr bool enabled = true;
    std::shared_ptr<int> value{std::make_shared<int>()};
    void observe(const Observer_Test_Observation& observation) noexcept {
        *value = observation.value;
    }
};
using Observer_Test_State = Observer_State<Observer_Test_Recorder, Observer_Test_Time_Source>;
static_assert(Observation_Struct<Observer_Test_Observation>);
static_assert(Observer_Time_Source<Observer_Test_Time_Source>);
static_assert(Struct_Observer<Observer_Test_Recorder, Observer_Test_Observation>);
static_assert(Timed_Struct_Observer<Observer_Test_State, Observer_Test_Observation>);
TEST(observer_state_test, forwards_observation_structure) {
    Observer_Test_Recorder recorder;
    Observer_Test_State observer(recorder, Observer_Test_Time_Source{});
    observer.observe(Observer_Test_Observation{7});
    EXPECT_EQ(*recorder.value, 7);
}
TEST(observer_state_test, owns_time_source) {
    Observer_Test_State observer;
    EXPECT_EQ(observer.now_ns(), 10);
    EXPECT_EQ(observer.now_ns(), 15);
}
TEST(disabled_observer_test, accepts_any_observation_structure) {
    Observer_State<> observer;
    EXPECT_NO_THROW(observer.observe(Observer_Test_Observation{7}));
    EXPECT_GT(observer.now_ns(), 0);
}