/**
 * 轮播图
 */
document.addEventListener('DOMContentLoaded', function() {
    // 轮播图功能实现
    const slides = document.querySelectorAll('.carousel-slide');
    const prevButton = document.querySelector('.carousel-control.prev');
    const nextButton = document.querySelector('.carousel-control.next');
    const carouselContainer = document.querySelector('#banner-carousel');
    let currentSlide = 0;
    let interval;

    // 检测是否为移动设备
    const isMobile = window.matchMedia('(max-width: 768px)').matches;

    // 触摸事件变量
    let touchStartX = 0;
    let touchEndX = 0;
    let touchStartY = 0;
    let touchEndY = 0;

    // 显示指定幻灯片
    function showSlide(index) {
        // 隐藏所有幻灯片
        slides.forEach(slide => {
            slide.style.opacity = 0;
            slide.style.zIndex = 0;
        });

        // 显示当前幻灯片
        slides[index].style.opacity = 1;
        slides[index].style.zIndex = 1;

        currentSlide = index;
    }

    // 下一张幻灯片
    function nextSlide() {
        let next = currentSlide + 1;
        if (next >= slides.length) {
            next = 0;
        }
        showSlide(next);
    }

    // 上一张幻灯片
    function prevSlide() {
        let prev = currentSlide - 1;
        if (prev < 0) {
            prev = slides.length - 1;
        }
        showSlide(prev);
    }

    // 自动轮播
    function startAutoSlide() {
        interval = setInterval(nextSlide, 5000); // 5秒切换一次
    }

    // 停止自动轮播
    function stopAutoSlide() {
        clearInterval(interval);
    }

    // 显示控制按钮（仅桌面版）
    function showControls() {
        if (!isMobile) {
            prevButton.style.opacity = "1";
            nextButton.style.opacity = "1";
        }
    }

    // 隐藏控制按钮（仅桌面版）
    function hideControls() {
        if (!isMobile) {
            prevButton.style.opacity = "0";
            nextButton.style.opacity = "0";
        }
    }

    // 初始化显示第一张幻灯片
    showSlide(0);

    // 开始自动轮播
    startAutoSlide();

    // 点击上一张按钮
    prevButton.addEventListener('click', function(e) {
        e.stopPropagation(); // 防止事件冒泡
        stopAutoSlide();
        prevSlide();
        startAutoSlide();
    });

    // 点击下一张按钮
    nextButton.addEventListener('click', function(e) {
        e.stopPropagation(); // 防止事件冒泡
        stopAutoSlide();
        nextSlide();
        startAutoSlide();
    });

    // 桌面端鼠标悬停事件
    if (!isMobile) {
        // 鼠标悬停在轮播图上时停止自动轮播并显示控制按钮
        carouselContainer.addEventListener('mouseenter', function() {
            stopAutoSlide();
            showControls();
        });

        // 鼠标离开轮播图时恢复自动轮播并隐藏控制按钮
        carouselContainer.addEventListener('mouseleave', function() {
            startAutoSlide();
            hideControls();
        });
    }

    // 移动端触摸事件支持
    carouselContainer.addEventListener('touchstart', function(e) {
        stopAutoSlide();
        touchStartX = e.changedTouches[0].screenX;
        touchStartY = e.changedTouches[0].screenY;
    }, { passive: true });

    carouselContainer.addEventListener('touchend', function(e) {
        touchEndX = e.changedTouches[0].screenX;
        touchEndY = e.changedTouches[0].screenY;
        handleSwipe();
        startAutoSlide();
    }, { passive: true });

    // 处理滑动手势
    function handleSwipe() {
        const xDiff = touchEndX - touchStartX;
        const yDiff = touchEndY - touchStartY;

        // 确保是水平滑动而不是垂直滚动
        if (Math.abs(xDiff) > Math.abs(yDiff) && Math.abs(xDiff) > 50) {
            if (xDiff > 0) {
                // 右滑 - 上一张
                prevSlide();
            } else {
                // 左滑 - 下一张
                nextSlide();
            }
        }
    }
});