#include "utils/delta_timer.hpp"

DeltaTimer::DeltaTimer() noexcept
    : last_counter_(SDL_GetPerformanceCounter()),
      perf_freq_(static_cast<double>(SDL_GetPerformanceFrequency())),
      time_scale_(1.0f) {
}

float DeltaTimer::tick() noexcept {
    const Uint64 now = SDL_GetPerformanceCounter();
    const Uint64 diff = (now > last_counter_) ? (now - last_counter_) : 0;
    last_counter_ = now;
    const double seconds = static_cast<double>(diff) / perf_freq_;
    return static_cast<float>(seconds * static_cast<double>(time_scale_));
}

float DeltaTimer::peek() const noexcept {
    const Uint64 now = SDL_GetPerformanceCounter();
    const Uint64 diff = (now > last_counter_) ? (now - last_counter_) : 0;
    const double seconds = static_cast<double>(diff) / perf_freq_;
    return static_cast<float>(seconds * static_cast<double>(time_scale_));
}

void DeltaTimer::reset(Uint64 counter) noexcept {
    if (counter == 0) {
        last_counter_ = SDL_GetPerformanceCounter();
    } else {
        last_counter_ = counter;
    }
}

void DeltaTimer::setTimeScale(float scale) noexcept {
    time_scale_ = std::max(scale, 0.0f);
}

float DeltaTimer::getTimeScale() const noexcept {
    return time_scale_;
}