$(document).ready(function () {
    let lastPlayedVideo = null;

    function safePlayVideo(video) {
        if (!video || !video.paused || video.readyState < 2) return;
        video.play().then(() => {
            lastPlayedVideo = video;
        }).catch(error => {
            console.warn("Safe play interrupted:", error);
        });
    }

    // ==============================
    // 1. Header GNB 모션 
    // ==============================
    $(".h_gnb li a, .siteMapItem").hover(
        function () {
            $(this).find(".basic").css("transform", "translateY(-100%)");
            $(this).find(".rolling").css("transform", "translateY(0)");
        },
        function () {
            $(this).find(".basic").css("transform", "translateY(0)");
            $(this).find(".rolling").css("transform", "translateY(100%)");
        }
    );

    // ==============================
    // 2. PC에서 첫 번째 비디오만 로드 
    // ==============================
    function loadFirstPCVideo() {
        if (!isMobile()) {
            var firstVideo = $(".com_slide_videon_box .scroll_videon_montion_box:first-child video.lazy-video")[0];
            if (firstVideo) {
                loadVideoSrc(firstVideo);
            }
        }
    }

    // ==============================
    // 3. Lazy Load 
    // ==============================
    function loadVideoSrc(video) {
        var source = video.querySelector("source");
        if (source && source.dataset.src && !video.getAttribute("data-loaded")) {
            source.src = source.dataset.src;
            video.load();
            video.setAttribute("data-loaded", "true");
        }
    }

    function lazyLoadVideos() {
        const videos = document.querySelectorAll(".scroll_videon_montion_box video.lazy-video");
        videos.forEach(video => loadVideoSrc(video));
    }

    // ==============================
    // 4. 모바일에서 자동 재생
    // ==============================
    function isMobile() {
        return /Mobi|Android|iPhone|iPad|iPod/i.test(navigator.userAgent);
    }

    function checkMobileVideoVisibility() {
        if (!isMobile()) return;

        let centerBox = null;
        let centerDistance = Infinity;
        const viewportCenter = window.innerHeight / 2;

        $(".scroll_videon_montion_box").each(function () {
            var videoBox = $(this);
            var videoElement = videoBox.find("video.lazy-video")[0];
            if (!videoElement) return;

            var rect = videoBox[0].getBoundingClientRect();
            var videoCenter = rect.top + rect.height / 2;
            var distance = Math.abs(viewportCenter - videoCenter);

            if (distance < centerDistance) {
                centerDistance = distance;
                centerBox = videoBox;
            }
        });

        if (centerBox) {
            $(".scroll_videon_montion_box").removeClass("active");
            centerBox.addClass("active");

            var centerVideo = centerBox.find("video.lazy-video")[0];
            if (centerVideo) {
                if (lastPlayedVideo && lastPlayedVideo !== centerVideo) {
                    lastPlayedVideo.pause();
                }

                loadVideoSrc(centerVideo);
                safePlayVideo(centerVideo);
            }
        }
    }

    // ==============================
    // 5. PC Hover 재생
    // ==============================
    $(".scroll_videon_montion_box").on("mouseenter", function () {
        if (!isMobile()) {
            $(".scroll_videon_montion_box video.lazy-video").each(function () {
                this.pause();
                $(this).siblings(".video-thumbnail").show();
            });

            $(".scroll_videon_montion_box").removeClass("active");
            $(this).addClass("active");

            var videoElement = $(this).find("video.lazy-video")[0];
            if (videoElement) {
                loadVideoSrc(videoElement);
                safePlayVideo(videoElement);
            }
        }
    });

    $(".scroll_videon_montion_box").on("mouseleave", function () {
        if (!isMobile()) {
            setTimeout(() => {
                $(".scroll_videon_montion_box.active video.lazy-video").each(function () {
                    safePlayVideo(this);
                });
            }, 100);
        }
    });

    // ==============================
    // 6. PC 자동 재생 Intersection Observer
    // ==============================
    function setupVideoObservers() {
        const videos = document.querySelectorAll(".scroll_videon_montion_box video.lazy-video");

        const observer = new IntersectionObserver(entries => {
            entries.forEach(entry => {
                const video = entry.target;
                if (entry.isIntersecting) {
                    video.muted = true;
                    loadVideoSrc(video);
                    safePlayVideo(video);
                } else {
                    video.pause();
                }
            });
        }, {
            threshold: 0.5
        });

        videos.forEach(video => observer.observe(video));
    }

    // ==============================
    // 7. 타이틀 인터랙션
    // ==============================
    function checkTitleVisibility() {
        $(".com_tit01").each(function () {
            var title = $(this);
            var isMvTitle = title.closest(".mv").length > 0;
            var boundingBox = title[0].getBoundingClientRect();
            var viewportHeight = window.innerHeight;

            var titleMidPoint = boundingBox.top + (boundingBox.height / 2);
            var viewportThreshold = viewportHeight * 0.45;

            if (titleMidPoint <= viewportThreshold && boundingBox.bottom >= 0) {
                if (!title.hasClass("active")) {
                    if (isMvTitle && !title.data("delayed")) return;
                    title.addClass("active");
                }
            }

            var removalThreshold = viewportHeight * 0.2;
            if (boundingBox.bottom < removalThreshold || boundingBox.top > viewportHeight) {
                title.removeClass("active");
            }
        });
    }

    setTimeout(() => {
        $(".mv .com_tit01").data("delayed", true);
        checkTitleVisibility();
    }, 2000);

    $(window).on("scroll", function () {
        requestAnimationFrame(checkTitleVisibility);
    });

    checkTitleVisibility();

    // ==============================
    // 8. 사이트맵 기능 
    // ==============================
    $(".headerMenuBtn").click(function (e) {
        e.stopPropagation();
        $("#header").toggleClass("active");
        $("#siteMap").toggleClass("active");
        $("html, body").toggleClass("active");
    });

    $(document).click(function (e) {
        if (!$(e.target).closest("#header, #siteMap").length) {
            $("#header").removeClass("active");
            $("#siteMap").removeClass("active");
            $("html, body").removeClass("active");
        }
    });

    // ==============================
    // 9. 모바일 스크롤 재생
    // ==============================
    $(window).on("scroll touchmove", function () {
        requestAnimationFrame(checkMobileVideoVisibility);
    });

    setTimeout(checkMobileVideoVisibility, 300);

    // ==============================
    // 10. 초기 실행
    // ==============================
    loadFirstPCVideo();
    setupVideoObservers();

    // ==============================
    // software_con01 영역 전용
    // ==============================
    function checkSoftwareConVideoScroll() {
        let centerBox = null;
        let centerDistance = Infinity;
        const viewportCenter = window.innerHeight / 2;

        $(".software_con01 .scroll_videon_montion_box").each(function () {
            var videoBox = $(this);
            var videoElement = videoBox.find("video.lazy-video")[0];
            if (!videoElement) return;

            var rect = videoBox[0].getBoundingClientRect();
            var videoCenter = rect.top + rect.height / 2;
            var distance = Math.abs(viewportCenter - videoCenter);

            if (distance < centerDistance) {
                centerDistance = distance;
                centerBox = videoBox;
            }
        });

        if (centerBox) {
            $(".software_con01 .scroll_videon_montion_box").removeClass("active");
            centerBox.addClass("active");

            var centerVideo = centerBox.find("video.lazy-video")[0];
            if (centerVideo) {
                if (lastPlayedVideo && lastPlayedVideo !== centerVideo) {
                    lastPlayedVideo.pause();
                }

                loadVideoSrc(centerVideo);
                safePlayVideo(centerVideo);
            }
        }
    }

    // software_con01 영역만 이벤트 등록
    if ($(".software_con01").length > 0) {
        $(window).on("scroll touchmove", function () {
            requestAnimationFrame(checkSoftwareConVideoScroll);
        });

        setTimeout(checkSoftwareConVideoScroll, 300);
    }


});