// 二维码功能 - 简洁可靠
(function() {
    'use strict';

    // 获取元素
    const btn = document.getElementById('qr-btn');
    const modal = document.getElementById('qr-modal');
    const input = document.getElementById('qr-input');
    const preview = document.getElementById('qr-preview');
    const closeBtn = document.querySelector('.qr-close');
    const cancelBtn = document.querySelector('.qr-cancel');
    const okBtn = document.querySelector('.qr-ok');

    if (!btn || !modal) return;

    let currentQR = null;
    let qrCount = 0;

    // 检查背景图并显示按钮
    function checkBg() {
        const container = document.getElementById('imageContainer');
        if (!container) return;
        // 排除二维码图片，只检查背景图
        const img = container.querySelector('img:not([data-type="qrcode"])');
        if (img && img.src && !img.src.endsWith(window.location.href)) {
            btn.classList.add('show');
        } else {
            btn.classList.remove('show');
        }
    }

    // 监听背景图变化
    const observer = new MutationObserver(checkBg);
    const container = document.getElementById('imageContainer');
    if (container) {
        observer.observe(container, { childList: true, subtree: true });
    }
    setInterval(checkBg, 500);

    // 打开弹窗
    function openModal() {
        modal.classList.add('active');
        input.value = '';
        preview.innerHTML = '';
        currentQR = null;
        input.focus();
    }

    // 关闭弹窗
    function closeModal() {
        modal.classList.remove('active');
    }

    // 生成预览
    function genPreview() {
        const text = input.value.trim();
        if (!text) {
            preview.innerHTML = '';
            currentQR = null;
            return;
        }
        preview.innerHTML = '';
        try {
            currentQR = new QRCode(preview, {
                text: text,
                width: 128,
                height: 128
            });
        } catch (e) {
            console.error('生成失败', e);
        }
    }

    // 添加到画布
    function addToCanvas() {
        if (!currentQR) {
            alert('请输入内容');
            return;
        }
        const canvas = preview.querySelector('canvas');
        if (!canvas) return;

        const img = document.createElement('img');
        img.src = canvas.toDataURL();
        img.className = 'qr-item';
        img.dataset.type = 'qrcode';
        img.style.width = '100px';
        img.style.height = '100px';

        const container = document.getElementById('imageContainer');
        const rect = container.getBoundingClientRect();
        img.style.left = (rect.width / 2 - 50) + 'px';
        img.style.top = (rect.height / 2 - 50) + 'px';

        container.appendChild(img);
        makeDraggable(img);
        closeModal();

        if (typeof saveState === 'function') saveState();
    }

    // 拖拽功能 - 支持鼠标和触摸
    function makeDraggable(el) {
        let dragging = false;
        let startX, startY, startLeft, startTop;

        function startDrag(clientX, clientY) {
            dragging = true;
            startX = clientX;
            startY = clientY;
            startLeft = parseInt(el.style.left) || 0;
            startTop = parseInt(el.style.top) || 0;
        }

        function moveDrag(clientX, clientY) {
            if (!dragging) return;
            el.style.left = (startLeft + clientX - startX) + 'px';
            el.style.top = (startTop + clientY - startY) + 'px';
        }

        function endDrag() {
            if (dragging) {
                dragging = false;
                if (typeof saveState === 'function') saveState();
            }
        }

        // 鼠标事件
        el.addEventListener('mousedown', function(e) {
            e.preventDefault();
            e.stopPropagation();
            startDrag(e.clientX, e.clientY);
        });

        // 触摸事件
        el.addEventListener('touchstart', function(e) {
            e.preventDefault();
            e.stopPropagation();
            if (e.touches.length === 1) {
                startDrag(e.touches[0].clientX, e.touches[0].clientY);
            }
        }, { passive: false });

        // 全局移动事件
        document.addEventListener('mousemove', function(e) {
            moveDrag(e.clientX, e.clientY);
        });

        document.addEventListener('touchmove', function(e) {
            if (dragging && e.touches.length === 1) {
                e.preventDefault();
                moveDrag(e.touches[0].clientX, e.touches[0].clientY);
            }
        }, { passive: false });

        // 全局结束事件
        document.addEventListener('mouseup', endDrag);
        document.addEventListener('touchend', endDrag);
    }

    // 事件绑定
    btn.addEventListener('click', openModal);
    closeBtn.addEventListener('click', closeModal);
    cancelBtn.addEventListener('click', closeModal);
    okBtn.addEventListener('click', addToCanvas);
    modal.addEventListener('click', function(e) {
        if (e.target === modal) closeModal();
    });

    // 输入防抖
    let timer;
    input.addEventListener('input', function() {
        clearTimeout(timer);
        timer = setTimeout(genPreview, 300);
    });

    // 初始检查
    checkBg();
})();