// 地表水环境质量监测方案 - 主要JavaScript逻辑

// 页面初始化
document.addEventListener('DOMContentLoaded', function() {
    console.log('🌊 环保订单班水质监测页面加载完成');

    // 初始化Lucide图标
    if (typeof lucide !== 'undefined') {
        lucide.createIcons();
    }

    // 初始化组件
    initNavigation();
    initAnimations();
    initLazyLoading();
    initSmoothScroll();
    updateStats();
    initThemeToggle();
});

// 导航功能
function initNavigation() {
    const navItems = document.querySelectorAll('.nav-item');
    const sections = document.querySelectorAll('.section');

    // 点击导航项滚动到对应区块
    navItems.forEach((item, index) => {
        item.addEventListener('click', () => {
            // 移除所有活跃状态
            navItems.forEach(nav => nav.classList.remove('active'));
            // 添加当前活跃状态
            item.classList.add('active');

            // 滚动到对应区块
            if (sections[index]) {
                const targetSection = sections[index];
                const offsetTop = targetSection.offsetTop - 100;

                window.scrollTo({
                    top: offsetTop,
                    behavior: 'smooth'
                });
            }
        });
    });

    // 滚动时更新导航活跃状态
    window.addEventListener('scroll', () => {
        let current = '';
        sections.forEach((section, index) => {
            const sectionTop = section.offsetTop - 150;
            if (scrollY >= sectionTop) {
                current = index;
            }
        });

        navItems.forEach((item, index) => {
            item.classList.remove('active');
            if (index === current) {
                item.classList.add('active');
            }
        });
    });
}

// 动画初始化
function initAnimations() {
    // 使用 Intersection Observer 实现滚动动画
    const observerOptions = {
        root: null,
        rootMargin: '0px',
        threshold: 0.1
    };

    const observer = new IntersectionObserver((entries) => {
        entries.forEach(entry => {
            if (entry.isIntersecting) {
                entry.target.classList.add('fade-in');
                observer.unobserve(entry.target);
            }
        });
    }, observerOptions);

    // 观察所有需要动画的元素
    const animatedElements = document.querySelectorAll('.card, .expert-intro');
    animatedElements.forEach(el => {
        el.style.opacity = '0';
        observer.observe(el);
    });
}

// 图片懒加载
function initLazyLoading() {
    const images = document.querySelectorAll('img[data-src]');

    const imageObserver = new IntersectionObserver((entries, observer) => {
        entries.forEach(entry => {
            if (entry.isIntersecting) {
                const img = entry.target;
                const src = img.getAttribute('data-src');

                // 创建新图片对象来预加载
                const tempImg = new Image();
                tempImg.onload = function() {
                    img.src = src;
                    img.classList.add('loaded');
                };
                tempImg.onerror = function() {
                    // 如果图片加载失败，使用占位图
                    img.src = 'data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" width="400" height="300" viewBox="0 0 400 300"%3E%3Crect width="400" height="300" fill="%23e0f2fe"/%3E%3Ctext x="50%25" y="50%25" dominant-baseline="middle" text-anchor="middle" font-family="system-ui" font-size="20" fill="%230284c7"%3E图片加载中%3C/text%3E%3C/svg%3E';
                    img.classList.add('error');
                };
                tempImg.src = src;

                img.removeAttribute('data-src');
                observer.unobserve(img);
            }
        });
    });

    images.forEach(img => {
        imageObserver.observe(img);
    });
}

// 平滑滚动
function initSmoothScroll() {
    // 为所有锚点链接添加平滑滚动
    document.querySelectorAll('a[href^="#"]').forEach(anchor => {
        anchor.addEventListener('click', function (e) {
            e.preventDefault();
            const targetId = this.getAttribute('href');
            if (targetId === '#') return;

            const target = document.querySelector(targetId);
            if (target) {
                target.scrollIntoView({
                    behavior: 'smooth',
                    block: 'start'
                });
            }
        });
    });
}

// 更新统计数据 - 环保监测数据
function updateStats() {
    // 动画数字增长效果 - 环保水质监测相关数据
    const stats = [
        { selector: '.monitoring-points', value: 144, suffix: '个' },
        { selector: '.quality-indicators', value: 26, suffix: '项' },
        { selector: '.sampling-frequency', value: 12, suffix: '次/年' },
        { selector: '.data-accuracy', value: 95, suffix: '%' },
        { selector: '.quality-control', value: 10, suffix: '%' },
        { selector: '.project-budget', value: 45, suffix: '万元' },
        { selector: '.team-members', value: 10, suffix: '人' },
        { selector: '.monitoring-cycle', value: 12, suffix: '个月' }
    ];

    stats.forEach(stat => {
        const element = document.querySelector(stat.selector);
        if (element) {
            animateValue(element, 0, stat.value, 2000, stat.suffix);
        }
    });
}

// 数字动画函数
function animateValue(element, start, end, duration, suffix = '') {
    const startTime = performance.now();

    function update(currentTime) {
        const elapsed = currentTime - startTime;
        const progress = Math.min(elapsed / duration, 1);

        // 使用缓动函数
        const easeOutQuad = progress * (2 - progress);
        const current = Math.floor(start + (end - start) * easeOutQuad);

        element.textContent = current + suffix;

        if (progress < 1) {
            requestAnimationFrame(update);
        }
    }

    requestAnimationFrame(update);
}

// 错误处理
window.addEventListener('error', function(e) {
    if (e.target.tagName === 'IMG') {
        console.warn('图片加载失败:', e.target.src);
        e.target.src = 'data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" width="400" height="300" viewBox="0 0 400 300"%3E%3Crect width="400" height="300" fill="%23e0f2fe"/%3E%3Ctext x="50%25" y="50%25" dominant-baseline="middle" text-anchor="middle" font-family="system-ui" font-size="20" fill="%230284c7"%3E图片暂时无法显示%3C/text%3E%3C/svg%3E';
        e.target.classList.add('error');
    }
}, true);

// 移动端优化
if ('ontouchstart' in window) {
    document.body.classList.add('touch-device');

    // 移动端点击优化
    let touchStartTime;
    document.addEventListener('touchstart', () => {
        touchStartTime = Date.now();
    });

    document.addEventListener('touchend', (e) => {
        const touchEndTime = Date.now();
        if (touchEndTime - touchStartTime < 200) {
            // 快速点击
            e.preventDefault();
        }
    });
}

// 性能监控
if (window.performance && window.performance.timing) {
    window.addEventListener('load', () => {
        setTimeout(() => {
            const timing = window.performance.timing;
            const loadTime = timing.loadEventEnd - timing.navigationStart;
            console.log(`页面加载时间: ${loadTime}ms`);

            // 如果加载时间过长，提示用户
            if (loadTime > 3000) {
                console.warn('页面加载时间较长，可能需要优化');
            }
        }, 0);
    });
}

// 主题切换功能
function initThemeToggle() {
    const themeToggleBtn = document.getElementById('themeToggleBtn');

    // 从localStorage读取用户的主题偏好
    const savedTheme = localStorage.getItem('theme');
    // 如果没有保存的偏好，默认使用暗色主题
    if (savedTheme === 'dark' || savedTheme === null) {
        document.body.classList.add('dark-theme');
    }

    // 点击切换主题
    if (themeToggleBtn) {
        themeToggleBtn.addEventListener('click', () => {
            document.body.classList.toggle('dark-theme');

            // 保存用户偏好
            if (document.body.classList.contains('dark-theme')) {
                localStorage.setItem('theme', 'dark');
            } else {
                localStorage.setItem('theme', 'light');
            }

            // 重新初始化图标以确保正确显示
            if (typeof lucide !== 'undefined') {
                lucide.createIcons();
            }
        });
    }
}