document.addEventListener("DOMContentLoaded", function () {
  let isScrolling = false;
  let currentSection = 0;
  const sections = document.querySelectorAll(".section");
  const container = document.querySelector(".scroll-container");

  // Navigation dengan keyboard
  document.addEventListener("keydown", function (e) {
    if (isScrolling) return;

    if (e.key === "ArrowDown" || e.key === "PageDown") {
      e.preventDefault();
      scrollToNextSection();
    } else if (e.key === "ArrowUp" || e.key === "PageUp") {
      e.preventDefault();
      scrollToPrevSection();
    }
  });

  // Touch/Wheel events untuk scroll snap yang lebih responsif
  let touchStartY = 0;
  let touchEndY = 0;

  container.addEventListener("touchstart", function (e) {
    touchStartY = e.changedTouches[0].screenY;
  });

  container.addEventListener("touchend", function (e) {
    if (isScrolling) return;

    touchEndY = e.changedTouches[0].screenY;
    handleSwipe();
  });

  function handleSwipe() {
    const swipeThreshold = 50;
    const diff = touchStartY - touchEndY;

    if (Math.abs(diff) > swipeThreshold) {
      if (diff > 0) {
        scrollToNextSection();
      } else {
        scrollToPrevSection();
      }
    }
  }

  function scrollToNextSection() {
    if (currentSection < sections.length - 1) {
      currentSection++;
      scrollToSection(currentSection);
    }
  }

  function scrollToPrevSection() {
    if (currentSection > 0) {
      currentSection--;
      scrollToSection(currentSection);
    }
  }

  function scrollToSection(index) {
    if (index >= 0 && index < sections.length) {
      isScrolling = true;
      sections[index].scrollIntoView({
        behavior: "smooth",
        block: "start",
      });

      setTimeout(() => {
        isScrolling = false;
      }, 800);
    }
  }

  // Update current section berdasarkan scroll position
  container.addEventListener("scroll", function () {
    if (isScrolling) return;

    const scrollTop = container.scrollTop;
    const sectionHeight = window.innerHeight;
    const newCurrentSection = Math.round(scrollTop / sectionHeight);

    if (
      newCurrentSection !== currentSection &&
      newCurrentSection >= 0 &&
      newCurrentSection < sections.length
    ) {
      currentSection = newCurrentSection;
    }
  });

  // API untuk navigasi programmatic
  window.scrollToSection = scrollToSection;
  window.getCurrentSection = () => currentSection;
});