// ================================================================
// Ozon Seller Kit - 应用逻辑
// 水印图片：web/imgs/watermark.jpg（需通过本地服务访问，否则画布会被污染无法导出）
// 作为经典脚本加载（非 module）。
// ================================================================
        const calculateBtn = document.getElementById('calculateBtn');
        const purchasePriceInput = document.getElementById('purchasePrice');
        const profitRateInput = document.getElementById('profitRate');
        const weightInput = document.getElementById('weight');
        const TDPriceInput = document.getElementById('tiedanPrice');
        const lengthInput = document.getElementById('length');
        const widthInput = document.getElementById('width');
        const heightInput = document.getElementById('height');
        const recordBtn = document.getElementById('recordBtn');
        const recordCurrentBtn = document.getElementById('recordCurrentBtn');
        const toggleOptionalColsBtn = document.getElementById('toggleOptionalColsBtn');
        const historyTable = document.getElementById('historyTable');
        const modelCodeInput = document.getElementById('modelCode');
        const skuSuffixInput = document.getElementById('skuSuffix');
        const skuPrefixEl = document.getElementById('skuPrefix');
        const skuFullPreview = document.getElementById('skuFullPreview');
        const productNameInput = document.getElementById('productName');
        const purchaseUrlInput = document.getElementById('purchaseUrl');
        const copyPurchaseUrlBtn = document.getElementById('copyPurchaseUrlBtn');
        const openPurchaseUrlBtn = document.getElementById('openPurchaseUrlBtn');
        const copyModelBtn = document.getElementById('copyModelBtn');
        const historyTableBody = document.getElementById('historyTableBody');
        const clearHistoryBtn = document.getElementById('clearHistoryBtn');
        const logisticsFeeElement = document.getElementById('logisticsFee');
        const receivedPriceElement = document.getElementById('receivedPrice');
        const profitElement = document.getElementById('profitElement');
        const commission = document.getElementById('commission');
        const sellingPriceElement = document.getElementById('sellingPrice');
        const logisticsCard = document.getElementById('logisticsCard');
        const receivedCard = document.getElementById('receivedCard');
        const sellingCard = document.getElementById('sellingCard');
        const dimensionAlert = document.getElementById('dimensionAlert');
        const dimensionWarning = document.getElementById('dimensionWarning');
        const dimensionError = document.getElementById('dimensionError');
        const dimensionWarningMsg = document.getElementById('dimensionWarningMsg');
        const dimensionErrorMsg = document.getElementById('dimensionErrorMsg');
        const logisticsLevelAlert = document.getElementById('logisticsLevelAlert');
        const logisticsLevelMsg = document.getElementById('logisticsLevelMsg');
        const priceRangeAlert = document.getElementById('priceRangeAlert');
        const priceRangeMsg = document.getElementById('priceRangeMsg');
        const resultOutput = document.getElementById('resultOutput');
        const copyBtn = document.getElementById('copyBtn');
        const transferDataBtn = document.getElementById('transferDataBtn');
        const exportHistoryBtn = document.getElementById('exportHistoryBtn');
        const clearPurchasePriceBtn = document.getElementById('clearPurchasePriceBtn');
        let historyData = JSON.parse(localStorage.getItem('priceCalculatorHistory')) || [];
        const baseUrl = 'https://www.ozon.ru/highlight/tovary-iz-kitaya-935133/';
        const copySkuBtn = document.getElementById('copySkuBtn');
        const copyProductNameBtn = document.getElementById('copyProductNameBtn');

        function getModelPrefix() {
            // 型号后默认加 "-"，型号为空时不显示孤立的连字符
            const model = (modelCodeInput.value || '').trim();
            return model ? model + '-' : '';
        }
        function getFullSku() {
            return (getModelPrefix() + (skuSuffixInput.value || '')).trim();
        }
        function syncSkuPrefix() {
            skuPrefixEl.textContent = getModelPrefix();
            const full = getFullSku();
            skuFullPreview.textContent = full || '--';
        }
        const uploadArea = document.getElementById('uploadArea');
        const fileInput = document.getElementById('fileInput');
        const previewContainer = document.getElementById('previewContainer');
        const addWatermarkBtn = document.getElementById('addWatermarkBtn');
        const exportAllBtn = document.getElementById('exportAllBtn');
        const watermarkOpacityInput = document.getElementById('watermarkOpacity');
        const watermarkTextInput = document.getElementById('watermarkText');
        const whiteBgToleranceInput = document.getElementById('whiteBgTolerance');
        const watermarkTypeRadios = document.querySelectorAll('input[name="watermarkType"]');
        const watermarkImageOptions = document.getElementById('watermarkImageOptions');
        const watermarkTextOptions = document.getElementById('watermarkTextOptions');
        const imageToggleBtn = document.getElementById('imageToggleBtn');
        const imageBody = document.getElementById('imageBody');
        // 水印图片地址
        const watermarkUrl = 'imgs/watermark.jpg';
        const WATERMARK_SCALE = 0.15;   // 水印直径占原图宽度的比例
        const WATERMARK_MARGIN = 10;    // 默认位置距右下角的间距（原图像素）
        const WATERMARK_TEXT_SCALE = 0.06; // 文字水印字号占原图宽度的比例
        const DEFAULT_WHITE_BG_TOLERANCE = 60; // 白底颜色容差，越大清除得越狠
        const PREVIEW_MAX_WIDTH = 400;  // 预览画布宽度
        const DEFAULT_WATERMARK_OPACITY = 30;
        // 存储上传的图片信息（原图 + 水印状态）
        let imageList = [];
        let watermarkImg = null;
        let watermarkImgPromise = null;
        renderHistoryTable();
        transferDataBtn.addEventListener('click', () => {
            let output = '';
            historyData.forEach((record) => {
                const sku = (record.sku || '').trim();
                // 优先导出卢布预留价（挂牌价），旧记录回退到人民币现价
                const price = record.sellingPriceRubReserved || record.sellingPrice;
                if (sku && price !== undefined && price !== '' && !isNaN(parseFloat(price))) {
                    output += `${sku} ${parseFloat(price).toFixed(2)}\n`;
                }
            });
            resultOutput.value = output;
        });
        function normalizeUrl(value) {
            // 采买链接常常是直接粘贴的，可能缺少协议头
            const text = (value || '').trim();
            if (!text) return '';
            return /^https?:\/\//i.test(text) ? text : `https://${text}`;
        }
        async function copyText(text, btn) {
            const value = (text || '').trim();
            if (!value) return;
            try {
                if (navigator.clipboard && navigator.clipboard.writeText) {
                    await navigator.clipboard.writeText(value);
                } else {
                    const ta = document.createElement('textarea');
                    ta.value = value;
                    ta.style.position = 'fixed';
                    ta.style.left = '-9999px';
                    document.body.appendChild(ta);
                    ta.select();
                    document.execCommand('copy');
                    document.body.removeChild(ta);
                }
                const originalHtml = btn.innerHTML;
                btn.innerHTML = '<i class="fa fa-check"></i>';
                btn.classList.add('text-secondary');
                setTimeout(() => {
                    btn.innerHTML = originalHtml;
                    btn.classList.remove('text-secondary');
                }, 1200);
            } catch (e) {
                console.error('复制失败', e);
            }
        }
        copyModelBtn.addEventListener('click', () => {
            copyText(modelCodeInput.value, copyModelBtn);
        });
        copySkuBtn.addEventListener('click', () => {
            copyText(getFullSku(), copySkuBtn);
        });
        copyProductNameBtn.addEventListener('click', () => {
            copyText(productNameInput.value, copyProductNameBtn);
        });
        copyPurchaseUrlBtn.addEventListener('click', () => {
            copyText(purchaseUrlInput.value, copyPurchaseUrlBtn);
        });
        openPurchaseUrlBtn.addEventListener('click', () => {
            const url = normalizeUrl(purchaseUrlInput.value);
            if (url) window.open(url, '_blank', 'noopener');
        });
        modelCodeInput.addEventListener('input', syncSkuPrefix);
        skuSuffixInput.addEventListener('input', syncSkuPrefix);
        clearPurchasePriceBtn.addEventListener('click', () => {
            purchasePriceInput.value = '';
            purchasePriceInput.focus();
        });
        calculateBtn.addEventListener('click', calculateAndDisplay);
        copyBtn.addEventListener('click', copyToClipboard);
        recordBtn.addEventListener('click', recordData);
        if (recordCurrentBtn) {
            recordCurrentBtn.addEventListener('click', recordData);
        }
        if (toggleOptionalColsBtn && historyTable) {
            toggleOptionalColsBtn.addEventListener('click', () => {
                const shown = historyTable.classList.toggle('show-optional-cols');
                toggleOptionalColsBtn.setAttribute('aria-pressed', shown ? 'true' : 'false');
                toggleOptionalColsBtn.textContent = shown ? '隐藏型号/重量/尺寸' : '显示型号/重量/尺寸';
            });
        }
        clearHistoryBtn.addEventListener('click', clearHistory);
        document.addEventListener('DOMContentLoaded', function () {
            const weightInput = document.getElementById('weight');
            const weightPresetBtns = document.querySelectorAll('.weight-preset-btn');
            weightPresetBtns.forEach(btn => {
                btn.addEventListener('click', function () {
                    const weight = this.getAttribute('data-weight');
                    weightInput.value = weight;
                    weightPresetBtns.forEach(b => b.classList.remove('bg-primary', 'text-white'));
                    this.classList.add('bg-primary', 'text-white');
                });
            });
        });
        exportHistoryBtn.addEventListener('click', exportHistory);
        [purchasePriceInput, profitRateInput, weightInput, lengthInput, widthInput, heightInput, TDPriceInput].forEach(input => {
            input.addEventListener('keyup', function (event) {
                if (event.key === 'Enter') {
                    calculateAndDisplay();
                }
            });
        });
        document.addEventListener('DOMContentLoaded', function () {
            purchasePriceInput.value = '30';
            profitRateInput.value = '100';
            weightInput.value = '600';
            lengthInput.value = '20';
            widthInput.value = '15';
            heightInput.value = '10';
            TDPriceInput.value = '3';
            document.querySelector('input[name="logisticsLevel"][value="low"]').checked = true;
            syncSkuPrefix();
            calculateAndDisplay();
        });

        uploadArea.addEventListener('click', () => {
            fileInput.click();
        });

        // 拖拽上传处理
        uploadArea.addEventListener('dragover', (e) => {
            e.preventDefault();
            uploadArea.classList.add('border-primary');
        });

        uploadArea.addEventListener('dragleave', () => {
            uploadArea.classList.remove('border-primary');
        });

        uploadArea.addEventListener('drop', (e) => {
            e.preventDefault();
            uploadArea.classList.remove('border-primary');
            if (e.dataTransfer.files.length) {
                handleFiles(e.dataTransfer.files);
            }
        });

        // 文件选择后处理
        fileInput.addEventListener('change', (e) => {
            if (e.target.files.length) {
                handleFiles(e.target.files);
            }
        });

        // 处理上传的文件
        function handleFiles(files) {
            imageList = [];
            if (files.length === 0) return;

            // 清空预览容器
            previewContainer.innerHTML = '';

            // 遍历文件并加载图片
            Array.from(files).forEach((file, index) => {
                if (!file.type.startsWith('image/')) return;

                const reader = new FileReader();
                reader.onload = (e) => {
                    const img = new Image();
                    img.onload = () => {
                        // 存储图片信息
                        const item = {
                            index,
                            original: img,
                            whiteBg: null, // 白底处理后的 Canvas（与原图同尺寸）
                            whiteBgRatio: 0, // 被判定为背景的像素占比
                            fileName: file.name,
                            hasWatermark: false,
                            pos: { x: 0, y: 0 } // 水印左上角在原图中的坐标
                        };
                        imageList.push(item);
                        // 显示原始图片预览
                        renderPreview(item);
                    };
                    img.src = e.target.result;
                };
                reader.readAsDataURL(file);
            });

            // 启用导出按钮（先显示原始图片，添加水印后更新）
            exportAllBtn.disabled = false;
            exportAllBtn.classList.remove('opacity-50', 'cursor-not-allowed');
        }

        // 预加载水印图片，避免拖动时才开始加载
        function loadWatermarkImage() {
            if (!watermarkImgPromise) {
                watermarkImgPromise = new Promise((resolve, reject) => {
                    const img = new Image();
                    img.onload = () => {
                        watermarkImg = img;
                        resolve(img);
                    };
                    img.onerror = reject;
                    img.src = watermarkUrl;
                });
            }
            return watermarkImgPromise;
        }
        loadWatermarkImage().catch(err => console.error('水印加载失败：', err));

        // 当前水印类型：'image' | 'text'
        function getWatermarkType() {
            const checked = document.querySelector('input[name="watermarkType"]:checked');
            return checked ? checked.value : 'image';
        }

        // 透明度输入框的值（0~1），图片水印和文字水印共用
        function getWatermarkOpacity() {
            const value = parseFloat(watermarkOpacityInput.value);
            if (!isFinite(value)) return DEFAULT_WATERMARK_OPACITY / 100;
            return Math.min(100, Math.max(0, value)) / 100;
        }

        function getWatermarkText() {
            return (watermarkTextInput.value || '').trim();
        }

        // 文字水印字体（按原图宽度等比缩放）
        function getWatermarkFontSize(item) {
            return Math.max(12, Math.round(item.original.width * WATERMARK_TEXT_SCALE));
        }
        function getWatermarkFont(fontSize) {
            return `bold ${fontSize}px "PingFang SC", "Microsoft YaHei", Arial, sans-serif`;
        }

        // 量文字宽度用的离屏画布
        const measureCtx = document.createElement('canvas').getContext('2d');

        // 水印在原图坐标系中的尺寸
        function getWatermarkSize(item) {
            if (getWatermarkType() === 'text') {
                const fontSize = getWatermarkFontSize(item);
                measureCtx.font = getWatermarkFont(fontSize);
                return {
                    width: measureCtx.measureText(getWatermarkText()).width,
                    height: fontSize * 1.25
                };
            }
            // 图片水印固定为正方形，绘制时裁成圆形
            const diameter = item.original.width * WATERMARK_SCALE;
            return { width: diameter, height: diameter };
        }

        // 限制水印不被拖出图片范围
        function clampWatermarkPos(item, x, y) {
            const size = getWatermarkSize(item);
            const maxX = Math.max(0, item.original.width - size.width);
            const maxY = Math.max(0, item.original.height - size.height);
            return {
                x: Math.min(Math.max(0, x), maxX),
                y: Math.min(Math.max(0, y), maxY)
            };
        }

        // 默认位置：右下角
        function defaultWatermarkPos(item) {
            const size = getWatermarkSize(item);
            return clampWatermarkPos(
                item,
                item.original.width - size.width - WATERMARK_MARGIN,
                item.original.height - size.height - WATERMARK_MARGIN
            );
        }

        // 圆形图片水印：取水印图中间的正方形，裁成圆形后绘制
        function drawImageWatermark(ctx, x, y, size) {
            const source = Math.min(watermarkImg.width, watermarkImg.height);
            const sx = (watermarkImg.width - source) / 2;
            const sy = (watermarkImg.height - source) / 2;
            ctx.save();
            ctx.beginPath();
            ctx.arc(x + size / 2, y + size / 2, size / 2, 0, Math.PI * 2);
            ctx.closePath();
            ctx.clip();
            ctx.globalAlpha = getWatermarkOpacity();
            ctx.drawImage(watermarkImg, sx, sy, source, source, x, y, size, size);
            ctx.restore();
        }

        // 文字水印：白字 + 半透明描边，保证深浅背景上都能看清。
        // 先画在离屏画布上再整体合成，避免透明度让描边透过字面显脏。
        const textLayerCanvas = document.createElement('canvas');
        function drawTextWatermark(ctx, x, y, fontSize) {
            const text = getWatermarkText();
            if (!text) return;
            const font = getWatermarkFont(fontSize);
            measureCtx.font = font;
            const padding = Math.ceil(fontSize / 4);
            textLayerCanvas.width = Math.ceil(measureCtx.measureText(text).width) + padding * 2;
            textLayerCanvas.height = Math.ceil(fontSize * 1.5) + padding * 2;

            const layerCtx = textLayerCanvas.getContext('2d');
            layerCtx.font = font;
            layerCtx.textBaseline = 'top';
            layerCtx.lineWidth = Math.max(1, fontSize / 8);
            layerCtx.lineJoin = 'round';
            layerCtx.strokeStyle = 'rgba(0, 0, 0, 0.55)';
            layerCtx.strokeText(text, padding, padding);
            layerCtx.fillStyle = '#ffffff';
            layerCtx.fillText(text, padding, padding);

            ctx.save();
            ctx.globalAlpha = getWatermarkOpacity();
            ctx.drawImage(textLayerCanvas, x - padding, y + fontSize * 0.1 - padding);
            ctx.restore();
        }

        // 水印所需资源是否就绪
        function isWatermarkReady() {
            return getWatermarkType() === 'text' ? true : !!watermarkImg;
        }

        function getWhiteBgTolerance() {
            const value = parseFloat(whiteBgToleranceInput.value);
            if (!isFinite(value)) return DEFAULT_WHITE_BG_TOLERANCE;
            return Math.min(200, Math.max(5, value));
        }

        // 取边框像素每个通道的中位数作为背景基准色。
        // 用中位数而不是均值：商品压到画面边缘时，均值会被商品颜色带偏。
        function pickBorderColor(data, width, height) {
            const histR = new Uint32Array(256);
            const histG = new Uint32Array(256);
            const histB = new Uint32Array(256);
            let count = 0;
            function sample(x, y) {
                const i = (y * width + x) * 4;
                histR[data[i]]++;
                histG[data[i + 1]]++;
                histB[data[i + 2]]++;
                count++;
            }
            for (let x = 0; x < width; x++) {
                sample(x, 0);
                sample(x, height - 1);
            }
            for (let y = 1; y < height - 1; y++) {
                sample(0, y);
                sample(width - 1, y);
            }
            function median(hist) {
                const half = count / 2;
                let acc = 0;
                for (let v = 0; v < 256; v++) {
                    acc += hist[v];
                    if (acc >= half) return v;
                }
                return 255;
            }
            return { r: median(histR), g: median(histG), b: median(histB) };
        }

        // 白底处理：从四条边做区域生长，只把与边缘连通的背景像素刷白。
        // 判定同时看两个条件：与相邻背景像素的局部色差（容忍渐变和噪点），
        // 以及与背景基准色的整体色差（防止顺着渐变一路吃进商品）。
        // 商品内部的浅色区域不与边缘连通，因此不会被误伤。
        function applyWhiteBackground(source, tolerance) {
            const width = source.width;
            const height = source.height;
            const canvas = document.createElement('canvas');
            canvas.width = width;
            canvas.height = height;
            const ctx = canvas.getContext('2d', { willReadFrequently: true });
            ctx.drawImage(source, 0, 0);

            const imageData = ctx.getImageData(0, 0, width, height);
            const data = imageData.data;
            const origin = new Uint8ClampedArray(data); // 判定始终基于原始像素
            const ref = pickBorderColor(origin, width, height);

            const globalLimit = tolerance;
            const localLimit = Math.max(6, tolerance / 3);
            const visited = new Uint8Array(width * height);
            const stack = new Int32Array(width * height);
            let top = 0;
            let filled = 0;

            function distanceTo(i, r, g, b) {
                const dr = origin[i] - r;
                const dg = origin[i + 1] - g;
                const db = origin[i + 2] - b;
                return Math.sqrt(dr * dr + dg * dg + db * db);
            }

            function accept(p) {
                visited[p] = 1;
                stack[top++] = p;
                const i = p * 4;
                data[i] = 255;
                data[i + 1] = 255;
                data[i + 2] = 255;
                filled++;
            }

            // 种子：四条边上颜色接近基准色的像素
            function trySeed(x, y) {
                const p = y * width + x;
                if (visited[p]) return;
                if (distanceTo(p * 4, ref.r, ref.g, ref.b) > globalLimit) return;
                accept(p);
            }
            for (let x = 0; x < width; x++) {
                trySeed(x, 0);
                trySeed(x, height - 1);
            }
            for (let y = 1; y < height - 1; y++) {
                trySeed(0, y);
                trySeed(width - 1, y);
            }

            // 生长：与来源像素颜色接近，且没有整体偏离基准色太远
            function tryGrow(x, y, fromIndex) {
                const p = y * width + x;
                if (visited[p]) return;
                const i = p * 4;
                if (distanceTo(i, origin[fromIndex], origin[fromIndex + 1], origin[fromIndex + 2]) > localLimit) return;
                if (distanceTo(i, ref.r, ref.g, ref.b) > globalLimit) return;
                accept(p);
            }
            while (top > 0) {
                const p = stack[--top];
                const i = p * 4;
                const x = p % width;
                const y = (p - x) / width;
                if (x > 0) tryGrow(x - 1, y, i);
                if (x < width - 1) tryGrow(x + 1, y, i);
                if (y > 0) tryGrow(x, y - 1, i);
                if (y < height - 1) tryGrow(x, y + 1, i);
            }

            ctx.putImageData(imageData, 0, 0);
            return { canvas, ratio: filled / (width * height) };
        }

        // 按指定宽度把原图和水印合成到 Canvas
        function drawItemToCanvas(canvas, item, targetWidth) {
            const scale = targetWidth / item.original.width;
            canvas.width = Math.max(1, Math.round(targetWidth));
            canvas.height = Math.max(1, Math.round(item.original.height * scale));
            const ctx = canvas.getContext('2d');
            ctx.clearRect(0, 0, canvas.width, canvas.height);
            ctx.drawImage(item.whiteBg || item.original, 0, 0, canvas.width, canvas.height);
            if (item.hasWatermark && isWatermarkReady()) {
                const drawX = item.pos.x * scale;
                const drawY = item.pos.y * scale;
                if (getWatermarkType() === 'text') {
                    drawTextWatermark(ctx, drawX, drawY, getWatermarkFontSize(item) * scale);
                } else {
                    drawImageWatermark(ctx, drawX, drawY, getWatermarkSize(item).width * scale);
                }
            }
            return canvas;
        }

        // 让预览图上的水印可拖动
        function attachWatermarkDrag(canvas, item) {
            let dragging = false;
            let grabOffsetX = 0;
            let grabOffsetY = 0;

            // 把指针位置换算成原图坐标（预览画布可能被 CSS 再次缩放）
            function toImageCoords(e) {
                const rect = canvas.getBoundingClientRect();
                const scale = item.original.width / rect.width;
                return { x: (e.clientX - rect.left) * scale, y: (e.clientY - rect.top) * scale };
            }

            canvas.addEventListener('pointerdown', (e) => {
                if (!item.hasWatermark || !isWatermarkReady()) return;
                const point = toImageCoords(e);
                const size = getWatermarkSize(item);
                const inside = point.x >= item.pos.x && point.x <= item.pos.x + size.width
                    && point.y >= item.pos.y && point.y <= item.pos.y + size.height;
                if (!inside) return;
                dragging = true;
                grabOffsetX = point.x - item.pos.x;
                grabOffsetY = point.y - item.pos.y;
                canvas.setPointerCapture(e.pointerId);
                e.preventDefault();
            });

            canvas.addEventListener('pointermove', (e) => {
                if (!dragging) return;
                const point = toImageCoords(e);
                item.pos = clampWatermarkPos(item, point.x - grabOffsetX, point.y - grabOffsetY);
                drawItemToCanvas(canvas, item, PREVIEW_MAX_WIDTH);
                e.preventDefault();
            });

            function stopDrag(e) {
                if (!dragging) return;
                dragging = false;
                if (canvas.hasPointerCapture(e.pointerId)) canvas.releasePointerCapture(e.pointerId);
            }
            canvas.addEventListener('pointerup', stopDrag);
            canvas.addEventListener('pointercancel', stopDrag);
        }

        // 单张图片：切换是否贴水印
        function toggleItemWatermark(item) {
            if (item.hasWatermark) {
                item.hasWatermark = false;
            } else {
                item.hasWatermark = true;
                item.pos = defaultWatermarkPos(item);
            }
            renderPreview(item);
        }

        // 单张图片：切换白底处理（再次点击还原原始底色）
        function toggleItemWhiteBackground(item, btn) {
            if (item.whiteBg) {
                item.whiteBg = null;
                renderPreview(item);
                return;
            }
            // 大图区域生长是同步的，先让按钮进入处理中状态再开工
            btn.disabled = true;
            btn.textContent = '处理中…';
            setTimeout(() => {
                try {
                    const result = applyWhiteBackground(item.original, getWhiteBgTolerance());
                    item.whiteBg = result.canvas;
                    item.whiteBgRatio = result.ratio;
                    if (result.ratio < 0.02) {
                        alert('几乎没有识别到背景，这张图的背景可能不是纯色。可以把「白底容差」调大一些再试');
                    }
                } catch (err) {
                    alert('白底处理失败，请重试或换一张图');
                    console.error('白底处理失败：', err);
                }
                renderPreview(item);
            }, 0);
        }

        // 按当前状态刷新预览图右上角按钮的文案
        function syncPreviewActions(previewItem, item) {
            const watermarkBtn = previewItem.querySelector('[data-role="toggle-watermark"]');
            const whiteBgBtn = previewItem.querySelector('[data-role="toggle-white-bg"]');
            watermarkBtn.textContent = item.hasWatermark ? '清除水印' : '加水印';
            watermarkBtn.title = item.hasWatermark ? '这张图不加水印' : '给这张图加上水印';
            whiteBgBtn.disabled = false;
            whiteBgBtn.textContent = item.whiteBg ? '还原底色' : '白底';
            whiteBgBtn.title = item.whiteBg
                ? `已把 ${(item.whiteBgRatio * 100).toFixed(0)}% 的画面刷成白底，点击还原`
                : '把这张图的背景刷成纯白';
        }

        // 渲染（或更新）单张图片的预览
        function renderPreview(item) {
            let previewItem = previewContainer.querySelector(`[data-index="${item.index}"]`);
            if (!previewItem) {
                previewItem = document.createElement('div');
                previewItem.dataset.index = item.index;
                previewItem.className = 'flex flex-col items-center';

                const frame = document.createElement('div');
                frame.className = 'preview-frame mb-2';

                const canvas = document.createElement('canvas');
                canvas.className = 'preview-img';
                attachWatermarkDrag(canvas, item);
                frame.appendChild(canvas);

                const actions = document.createElement('div');
                actions.className = 'preview-actions';

                const watermarkBtn = document.createElement('button');
                watermarkBtn.type = 'button';
                watermarkBtn.className = 'preview-action-btn';
                watermarkBtn.dataset.role = 'toggle-watermark';
                watermarkBtn.onclick = () => toggleItemWatermark(item);
                actions.appendChild(watermarkBtn);

                const whiteBgBtn = document.createElement('button');
                whiteBgBtn.type = 'button';
                whiteBgBtn.className = 'preview-action-btn';
                whiteBgBtn.dataset.role = 'toggle-white-bg';
                whiteBgBtn.onclick = () => toggleItemWhiteBackground(item, whiteBgBtn);
                actions.appendChild(whiteBgBtn);

                frame.appendChild(actions);
                previewItem.appendChild(frame);

                const exportBtn = document.createElement('button');
                exportBtn.className = 'bg-primary/20 hover:bg-primary/30 text-primary px-2 py-1 rounded-lg text-xs';
                exportBtn.innerHTML = '<i class="fa fa-download mr-1"></i>导出';
                exportBtn.onclick = () => exportImage(item.index);
                previewItem.appendChild(exportBtn);

                previewContainer.appendChild(previewItem);
            }

            const canvas = previewItem.querySelector('canvas');
            canvas.classList.toggle('preview-img-draggable', item.hasWatermark);
            drawItemToCanvas(canvas, item, PREVIEW_MAX_WIDTH);
            syncPreviewActions(previewItem, item);
        }

        function renderAllPreviews() {
            imageList.forEach(renderPreview);
        }

        // 添加水印到图片
        addWatermarkBtn.addEventListener('click', async () => {
            if (imageList.length === 0) {
                alert('请先上传图片');
                return;
            }

            if (getWatermarkType() === 'text' && !getWatermarkText()) {
                alert('请先填写水印文字');
                watermarkTextInput.focus();
                return;
            }

            if (getWatermarkType() === 'image') {
                try {
                    await loadWatermarkImage();
                } catch (err) {
                    alert('水印图片加载失败，请重试');
                    console.error('水印加载失败：', err);
                    return;
                }
            }

            imageList.forEach(item => {
                if (!item.hasWatermark) {
                    item.hasWatermark = true;
                    item.pos = defaultWatermarkPos(item);
                }
                renderPreview(item);
            });
        });

        // 切换水印类型：显示对应的表单项，并把已有水印重新约束回图片范围内
        function syncWatermarkTypeUI() {
            const isText = getWatermarkType() === 'text';
            watermarkImageOptions.classList.toggle('hidden', isText);
            watermarkTextOptions.classList.toggle('hidden', !isText);
            imageList.forEach(item => {
                if (item.hasWatermark) item.pos = clampWatermarkPos(item, item.pos.x, item.pos.y);
            });
            renderAllPreviews();
        }
        watermarkTypeRadios.forEach(radio => radio.addEventListener('change', syncWatermarkTypeUI));

        // 调整透明度 / 修改文字后实时刷新预览
        watermarkOpacityInput.addEventListener('input', renderAllPreviews);
        watermarkTextInput.addEventListener('input', () => {
            imageList.forEach(item => {
                if (item.hasWatermark) item.pos = clampWatermarkPos(item, item.pos.x, item.pos.y);
            });
            renderAllPreviews();
        });

        // 收起 / 展开整个图片处理面板
        imageToggleBtn.addEventListener('click', () => {
            const collapsed = imageBody.classList.toggle('hidden');
            imageToggleBtn.textContent = collapsed ? '展开' : '收起';
            imageToggleBtn.setAttribute('aria-expanded', collapsed ? 'false' : 'true');
        });

        // 导出单张图片
        function exportImage(index) {
            const targetImage = imageList.find(item => item.index === index);
            if (!targetImage) return;

            // 按原图尺寸重新合成，保证导出的是全分辨率图片
            const canvas = drawItemToCanvas(document.createElement('canvas'), targetImage, targetImage.original.width);
            const baseName = targetImage.fileName.replace(/\.\w+$/, '');
            const suffix = (targetImage.whiteBg ? '_white' : '') + (targetImage.hasWatermark ? '_watermark' : '');

            // 创建下载链接
            let dataUrl;
            try {
                dataUrl = canvas.toDataURL('image/png');
            } catch (err) {
                // 以 file:// 打开时水印图会污染画布，导致无法导出
                alert('导出失败，请通过本地服务访问页面（start.command）后重试');
                console.error('导出失败：', err);
                return;
            }
            const link = document.createElement('a');
            link.href = dataUrl;
            link.download = baseName + suffix + '.png';
            link.click();
        }

        // 导出所有图片
        exportAllBtn.addEventListener('click', () => {
            if (imageList.length === 0) {
                alert('暂无图片可导出');
                return;
            }
            // 批量导出（逐个触发下载）
            imageList.forEach((item, i) => {
                setTimeout(() => exportImage(item.index), i * 300); // 延迟避免浏览器拦截
            });
        });

        function validateDimensions(weight, length, width, height, level) {
            const dimensions = [length, width, height].sort((a, b) => b - a);
            const longestSide = dimensions[0];
            const sumOfSides = dimensions.reduce((sum, side) => sum + side, 0);
            let warning = '';
            let error = '';
            if (level === 'low') {
                if (weight <= 500) {
                    if (sumOfSides > 90 || longestSide > 60) {
                        error = '低等级物流重量≤500g时，要求三边之和≤90厘米且最长边≤60厘米。当前商品三边之和为' +
                            sumOfSides.toFixed(2) + '厘米，最长边为' + longestSide.toFixed(2) + '厘米，不符合要求。';
                    }
                } else {
                    if (sumOfSides > 150) {
                        error = '低等级物流重量>500g时，要求三边之和≤150厘米。当前商品三边之和为' +
                            sumOfSides.toFixed(2) + '厘米，不符合要求。';
                    } else if (longestSide > 60) {
                        error = '低等级物流重量>500g时，要求最长边≤60厘米。当前商品最长边为' +
                            longestSide.toFixed(2) + '厘米，不符合要求。';
                    }
                }
            } else {
                if (weight <= 2000) {
                    if (sumOfSides > 150) {
                        error = '高等级物流重量≤2000g时，要求三边之和≤150厘米。当前商品三边之和为' +
                            sumOfSides.toFixed(2) + '厘米，不符合要求。';
                    } else if (longestSide > 60) {
                        error = '高等级物流重量≤2000g时，要求最长边≤60厘米。当前商品最长边为' +
                            longestSide.toFixed(2) + '厘米，不符合要求。';
                    }
                } else {
                    if (sumOfSides > 250) {
                        error = '高等级物流重量>2000g时，要求三边之和≤250厘米。当前商品三边之和为' +
                            sumOfSides.toFixed(2) + '厘米，不符合要求。';
                    } else if (longestSide > 150) {
                        error = '高等级物流重量>2000g时，要求最长边≤150厘米。当前商品最长边为' +
                            longestSide.toFixed(2) + '厘米，不符合要求。';
                    }
                }
            }
            return { warning, error };
        }
        function validateLogisticsLevel(sellingPrice, logisticsLevel) {
            let message = '';
            if (sellingPrice > 140 && logisticsLevel === 'low') {
                message = '当前销售价格为' + sellingPrice.toFixed(2) + '元，超过140元，建议选择高等级物流以提供更好的服务体验。';
            } else if (sellingPrice < 135 && logisticsLevel === 'high') {
                message = '当前销售价格为' + sellingPrice.toFixed(2) + '元，低于135元，建议选择低等级物流以降低成本。';
            }
            return message;
        }
        function validatePriceRange(sellingPrice) {
            let message = '';
            if (sellingPrice >= 135 && sellingPrice <= 140) {
                message = '当前销售价格为' + sellingPrice.toFixed(2) + '元，处于135-140元的区间。由于汇率波动，建议尽量避免此价格区间。';
            }
            return message;
        }
        function calculateLogisticsFee(weight, length, width, height, level, TDPrice) {
            let logisticsFee = 0;
            let usedWeight = weight;
            if (level === 'low') {
                if (weight <= 500) {
                    logisticsFee = 3.12 + 0.026 * weight;
                } else {
                    logisticsFee = 23.92 + 0.01768 * usedWeight;
                }
            } else if (level === 'high2') {
                if (weight <= 5000) {
                    logisticsFee = 22.88 + 0.026 * weight;
                } else {
                    logisticsFee = 64.48 + 0.024 * usedWeight;
                }
            } else {
                if (weight <= 2000) {
                    logisticsFee = 16.64 + 0.026 * weight;
                } else {
                    logisticsFee = 37.44 + 0.01768 * usedWeight;
                }
            }
            logisticsFee += TDPrice;
            return { fee: logisticsFee };
        }
        function calculateAndDisplay() {
            const purchasePrice = parseFloat(purchasePriceInput.value) || 0;
            console.log('222', purchasePrice)
            const profitRate = parseFloat(profitRateInput.value) || 0;
            const TDPrice = parseFloat(TDPriceInput.value) || 0;
            const weight = parseFloat(weightInput.value) || 0;
            const length = parseFloat(lengthInput.value) || 0;
            const width = parseFloat(widthInput.value) || 0;
            const height = parseFloat(heightInput.value) || 0;
            const logisticsLevel = document.querySelector('input[name="logisticsLevel"]:checked').value;
            if (purchasePrice <= 0 || weight <= 0 || length <= 0 || width <= 0 || height <= 0) {
                alert('请输入有效的商品信息（所有数值必须大于0）');
                return;
            }
            const { warning, error } = validateDimensions(weight, length, width, height, logisticsLevel, TDPrice);
            dimensionAlert.classList.remove('hidden');
            if (error) {
                dimensionErrorMsg.textContent = error;
                dimensionError.classList.remove('hidden');
            } else {
                dimensionError.classList.add('hidden');
            }
            if (warning) {
                dimensionWarningMsg.textContent = warning;
                dimensionWarning.classList.remove('hidden');
            } else {
                dimensionWarning.classList.add('hidden');
            }
            if (error) {
                logisticsFeeElement.textContent = '--';
                receivedPriceElement.textContent = '--';
                profitElement.textContent = '--'
                commission.textContent = '--';
                sellingPriceElement.textContent = '--';
                logisticsLevelAlert.classList.add('hidden');
                priceRangeAlert.classList.add('hidden');
                return;
            }
            const profitRateDecimal = profitRate / 100;
            const { fee: logisticsFee } = calculateLogisticsFee(
                weight, length, width, height, logisticsLevel, TDPrice
            );
            const receivedPrice = purchasePrice * (1 + profitRateDecimal);
            const profitPrice = purchasePrice * profitRateDecimal;
            let commissionPrice
            let sellingPrice;
            if (logisticsLevel === 'low') {
                sellingPrice = (receivedPrice + logisticsFee) / 0.845;
                commissionPrice = sellingPrice * 0.12;
            } else {
                sellingPrice = (receivedPrice + logisticsFee) / 0.785;
                commissionPrice = sellingPrice * 0.18;
            }
            const logisticsLevelMessage = validateLogisticsLevel(sellingPrice, logisticsLevel);
            const priceRangeMessage = validatePriceRange(sellingPrice);
            if (logisticsLevelMessage) {
                logisticsLevelMsg.textContent = logisticsLevelMessage;
                logisticsLevelAlert.classList.remove('hidden');
            } else {
                logisticsLevelAlert.classList.add('hidden');
            }
            if (priceRangeMessage) {
                priceRangeMsg.textContent = priceRangeMessage;
                priceRangeAlert.classList.remove('hidden');
            } else {
                priceRangeAlert.classList.add('hidden');
            }
            setTimeout(() => {
                dimensionAlert.classList.add('opacity-100');
            }, 10);
            logisticsFeeElement.textContent = `¥ ${logisticsFee.toFixed(2)}`;
            receivedPriceElement.textContent = `¥ ${receivedPrice.toFixed(2)}`;
            sellingPriceElement.textContent = `¥ ${sellingPrice.toFixed(2)}`;
            profitElement.textContent = `¥ ${profitPrice.toFixed(2)}`
            commission.textContent = `¥ ${commissionPrice.toFixed(2)}`;
            [logisticsCard, receivedCard, sellingCard].forEach((card, index) => {
                setTimeout(() => {
                    card.classList.remove('opacity-0', 'translate-y-4');
                }, index * 100);
            });
        }
        function copyToClipboard() {
            resultOutput.select();
            document.execCommand('copy');
            const originalText = copyBtn.innerHTML;
            copyBtn.innerHTML = '复制成功';
            copyBtn.classList.add('bg-green-600');
            setTimeout(() => {
                copyBtn.innerHTML = originalText;
                copyBtn.classList.remove('bg-green-600');
            }, 2000);
        }
        function parseDisplayMoney(text) {
            const n = parseFloat(String(text || '').replace(/[^\d.]/g, ''));
            return isNaN(n) ? '' : n.toFixed(2);
        }
        function formatCny(value) {
            const n = parseFloat(value);
            return isNaN(n) ? '--' : `¥ ${n.toFixed(2)}`;
        }
        function formatRub(value) {
            const n = parseFloat(value);
            return isNaN(n) ? '--' : `₽ ${n.toFixed(2)}`;
        }
        function isFormValueEmpty(value) {
            return value === undefined || value === null || String(value).trim() === '';
        }
        function validateProductInfoForm() {
            const fields = [
                { label: '进货价', el: purchasePriceInput, value: purchasePriceInput && purchasePriceInput.value },
                { label: '利润率', el: profitRateInput, value: profitRateInput && profitRateInput.value },
                { label: '商品重量', el: weightInput, value: weightInput && weightInput.value },
                { label: '贴单费用', el: TDPriceInput, value: TDPriceInput && TDPriceInput.value },
                { label: '外包装长度', el: lengthInput, value: lengthInput && lengthInput.value },
                { label: '外包装宽度', el: widthInput, value: widthInput && widthInput.value },
                { label: '外包装高度', el: heightInput, value: heightInput && heightInput.value },
                { label: '型号', el: modelCodeInput, value: modelCodeInput && modelCodeInput.value },
                { label: '货号 (sku)', el: skuSuffixInput, value: skuSuffixInput && skuSuffixInput.value },
                { label: '商品名', el: productNameInput, value: productNameInput && productNameInput.value },
                { label: '采买地址', el: purchaseUrlInput, value: purchaseUrlInput && purchaseUrlInput.value }
            ];
            const missing = fields.filter((f) => isFormValueEmpty(f.value));
            if (missing.length === 0) {
                return true;
            }
            alert(`请完整填写「输入商品信息」，以下项不能为空：\n${missing.map((f) => f.label).join('、')}`);
            const first = missing[0].el;
            if (first && typeof first.focus === 'function') {
                first.focus();
            }
            return false;
        }
        function recordData() {
            if (!validateProductInfoForm()) {
                return;
            }
            const sku = getFullSku();
            if (!sku) {
                alert('请先填写货号 (sku)');
                if (skuSuffixInput) skuSuffixInput.focus();
                return;
            }
            const sellingPrice = parseDisplayMoney(sellingPriceElement.textContent);
            if (!sellingPrice) {
                alert('请先点击「计价」，再录入商品');
                return;
            }
            const skuKey = sku.toLowerCase();
            const duplicated = historyData.findIndex(
                (item) => ((item && item.sku) || '').trim().toLowerCase() === skuKey
            );
            if (duplicated !== -1) {
                alert(`货号「${sku}」已存在于上品登记表（第 ${duplicated + 1} 条），请勿重复录入`);
                return;
            }
            const productName = productNameInput.value.trim();
            const logisticsFee = parseDisplayMoney(logisticsFeeElement.textContent);
            const receivedPrice = parseDisplayMoney(receivedPriceElement.textContent);
            const purchasePrice = purchasePriceInput.value;
            const weight = weightInput.value;
            const length = lengthInput.value;
            const width = widthInput.value;
            const height = heightInput.value;
            const logisticsLevel = document.querySelector('input[name="logisticsLevel"]:checked').value;
            const discountReserveEl = document.getElementById('discountReserve');
            let discountReserve = parseFloat(discountReserveEl && discountReserveEl.value);
            if (isNaN(discountReserve) || discountReserve < 0) discountReserve = 0;
            if (discountReserve > 95) discountReserve = 95;
            const purchaseNum = parseFloat(purchasePrice);
            const receivedNum = parseFloat(receivedPrice);
            const profit = (!isNaN(receivedNum) && !isNaN(purchaseNum))
                ? (receivedNum - purchaseNum).toFixed(2)
                : '';
            const profitRate = (!isNaN(purchaseNum) && purchaseNum > 0 && profit !== '')
                ? ((parseFloat(profit) / purchaseNum) * 100).toFixed(0)
                : '';
            const record = {
                sku,
                modelCode: (modelCodeInput.value || '').trim(),
                skuSuffix: (skuSuffixInput.value || '').trim(),
                productName,
                purchaseUrl: (purchaseUrlInput.value || '').trim(),
                sellingPrice,
                sellingPriceReserved: parseDisplayMoney(document.getElementById('sellingPriceReserved').textContent),
                sellingPriceRub: parseDisplayMoney(document.getElementById('sellingPriceRub').textContent),
                sellingPriceRubReserved: parseDisplayMoney(document.getElementById('sellingPriceRubReserved').textContent),
                discountReserve: discountReserve.toFixed(0),
                exchangeRate: cnyToRubRate ? cnyToRubRate.toFixed(4) : '',
                logisticsFee,
                receivedPrice,
                purchasePrice,
                profit,
                profitRate,
                weight,
                dimensions: `${length}x${width}x${height}`,
                logisticsLevel: logisticsLevel === 'high' ? '高' : (logisticsLevel === 'high2' ? 'Premium' : '低')
            };
            historyData.unshift(record);
            localStorage.setItem('priceCalculatorHistory', JSON.stringify(historyData));
            renderHistoryTable();
        }
        function createLinkCell(url, label) {
            const cell = document.createElement('td');
            cell.className = 'px-4 py-3 whitespace-nowrap';
            if (!url) {
                cell.classList.add('text-sm', 'text-gray-500');
                cell.textContent = '--';
                return cell;
            }
            const link = document.createElement('a');
            link.href = url;
            link.className = 'text-sm text-primary hover:underline block max-w-[14rem] truncate';
            link.textContent = label || url;
            link.title = label || url;
            link.target = '_blank';
            link.rel = 'noopener';
            cell.appendChild(link);
            return cell;
        }
        function getRecordProfit(record) {
            const purchaseNum = parseFloat(record.purchasePrice);
            const receivedNum = parseFloat(record.receivedPrice);
            if (record.profit !== undefined && record.profit !== '') {
                return String(record.profit);
            }
            if (!isNaN(receivedNum) && !isNaN(purchaseNum)) {
                return (receivedNum - purchaseNum).toFixed(2);
            }
            return '';
        }
        function getRecordProfitRate(record, profit) {
            const purchaseNum = parseFloat(record.purchasePrice);
            if (record.profitRate !== undefined && record.profitRate !== '') {
                return `${record.profitRate}%`;
            }
            if (!isNaN(purchaseNum) && purchaseNum > 0 && profit !== '') {
                return `${((parseFloat(profit) / purchaseNum) * 100).toFixed(0)}%`;
            }
            return '';
        }
        function renderHistoryTable() {
            const colCount = 15;
            if (historyData.length === 0) {
                historyTableBody.innerHTML = `<tr class="text-center"><td colspan="${colCount}" class="px-6 py-10 text-gray-500"></td></tr>`;
                return;
            }
            historyTableBody.innerHTML = '';
            historyData.forEach((record, index) => {
                const profit = getRecordProfit(record);
                const profitRate = getRecordProfitRate(record, profit) || '--';
                const weightNum = parseFloat(record.weight);
                const weightText = isNaN(weightNum) ? '--' : `${weightNum.toFixed(0)} g`;
                const dimensionsText = record.dimensions ? `${record.dimensions} cm` : '--';

                const row = document.createElement('tr');
                const deleteCell = document.createElement('td');
                deleteCell.className = 'px-4 py-3 whitespace-nowrap';
                const deleteButton = document.createElement('button');
                deleteButton.type = 'button';
                deleteButton.classList.add('bg-danger/10', 'hover:bg-danger/20', 'text-danger', 'px-3', 'py-1', 'rounded-lg', 'text-sm', 'flex', 'items-center', 'transition-colors', 'duration-200');
                deleteButton.textContent = '删除';
                deleteButton.addEventListener('click', () => {
                    deleteRecord(index);
                });
                deleteCell.appendChild(deleteButton);

                const ozonUrl = record.sku ? `https://www.ozon.ru/product/${record.sku}` : '';
                const purchaseUrl = normalizeUrl(record.purchaseUrl);

                row.append(
                    deleteCell,
                    createCell(record.sku || '--'),
                    createCell(record.modelCode || '--', true),
                    createCell(record.productName || '--'),
                    createCell(formatCny(record.purchasePrice)),
                    createCell(formatCny(record.logisticsFee)),
                    createCell(formatCny(record.sellingPrice)),
                    createCell(formatCny(record.receivedPrice)),
                    createCell(profit !== '' ? formatCny(profit) : '--'),
                    createCell(profitRate),
                    createCell(formatRub(record.sellingPriceRub)),
                    createCell(weightText, true),
                    createCell(dimensionsText, true),
                    createLinkCell(ozonUrl, ozonUrl),
                    createLinkCell(purchaseUrl, record.purchaseUrl || purchaseUrl)
                );
                historyTableBody.appendChild(row);
            });
        }
        function createCell(content, optional) {
            const cell = document.createElement('td');
            cell.className = (optional ? 'history-col-optional ' : '') + 'px-4 py-3 whitespace-nowrap';
            const div = document.createElement('div');
            div.className = 'text-sm text-gray-100';
            div.textContent = content;
            cell.appendChild(div);
            return cell;
        }
        function deleteRecord(index) {
            historyData.splice(index, 1);
            localStorage.setItem('priceCalculatorHistory', JSON.stringify(historyData));
            renderHistoryTable();
        }
        function clearHistory() {
            if (confirm('确认表格已经导出！此操作将清空已有数据。')) {
                historyData = [];
                localStorage.removeItem('priceCalculatorHistory');
                renderHistoryTable();
            }
        }
        function csvEscape(value) {
            const text = value === undefined || value === null ? '' : String(value);
            if (/[",\n]/.test(text)) {
                return `"${text.replace(/"/g, '""')}"`;
            }
            return text;
        }
        function exportHistory() {
            if (historyData.length === 0) {
                return;
            }
            const headers = [
                '货号(sku)', '型号', '商品名', '进货价', '物流费', '销售价', '实收价',
                '利润', '利润率', '卢布销价', '重量', '尺寸', 'Ozon地址', '采买地址'
            ];
            let csvContent = '\uFEFF' + headers.join(',') + '\n';
            historyData.forEach(record => {
                const profit = getRecordProfit(record);
                const profitRate = getRecordProfitRate(record, profit);
                const row = [
                    record.sku || '',
                    record.modelCode || '',
                    record.productName || '',
                    record.purchasePrice || '',
                    record.logisticsFee || '',
                    record.sellingPrice || '',
                    record.receivedPrice || '',
                    profit,
                    profitRate,
                    record.sellingPriceRub || '',
                    record.weight || '',
                    record.dimensions || '',
                    record.sku ? `https://www.ozon.ru/product/${record.sku}` : '',
                    record.purchaseUrl || ''
                ].map(csvEscape);
                csvContent += row.join(',') + '\n';
            });
            const blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8;' });
            const url = URL.createObjectURL(blob);
            const link = document.createElement('a');
            link.setAttribute('href', url);
            const currentDate = new Date();
            const month = String(currentDate.getMonth() + 1).padStart(2, '0');
            const day = String(currentDate.getDate()).padStart(2, '0');
            const hours = String(currentDate.getHours()).padStart(2, '0');
            const minutes = String(currentDate.getMinutes()).padStart(2, '0');
            const formattedDate = `${month}-${day} ${hours}:${minutes}`;
            link.setAttribute('download', `${formattedDate}.csv`);
            link.style.visibility = 'hidden';
            document.body.appendChild(link);
            link.click();
            document.body.removeChild(link);
            URL.revokeObjectURL(url);
        }

        // ===== 汇兑与折扣空间 =====
        // 按优先级排列：FloatRates 每小时更新，最接近 Wise 中间价；
        // 俄央行是 Ozon 结算参考的官方牌价；er-api 每日 00:00 UTC 才更新一次，仅作兜底。
        const FX_SOURCES = [
            {
                name: 'FloatRates',
                url: 'https://www.floatrates.com/daily/cny.json',
                parse: (data) => data && data.rub && { rate: data.rub.rate, time: data.rub.date }
            },
            {
                name: '俄央行',
                url: 'https://www.cbr-xml-daily.ru/daily_json.js',
                parse: (data) => {
                    const cny = data && data.Valute && data.Valute.CNY;
                    return cny && { rate: cny.Value / cny.Nominal, time: data.Date };
                }
            },
            {
                name: 'ExchangeRate-API',
                url: 'https://open.er-api.com/v6/latest/CNY',
                parse: (data) => data && data.rates && { rate: data.rates.RUB, time: data.time_last_update_utc }
            }
        ];
        const FX_FALLBACK_RATE = 11.5;
        // 汇率明显越界时视为脏数据，换下一个源
        const FX_MIN_RATE = 5;
        const FX_MAX_RATE = 25;
        const fxCnyInput = document.getElementById('fxCny');
        const fxRubInput = document.getElementById('fxRub');
        const fxRateText = document.getElementById('fxRateText');
        const fxRateSource = document.getElementById('fxRateSource');
        const fxRefreshBtn = document.getElementById('fxRefreshBtn');
        const discountReserveInput = document.getElementById('discountReserve');
        const sellingPriceReserved = document.getElementById('sellingPriceReserved');
        const cnyReserveLabel = document.getElementById('cnyReserveLabel');
        const cnyReserveGap = document.getElementById('cnyReserveGap');
        const sellingPriceRub = document.getElementById('sellingPriceRub');
        const sellingPriceRubReserved = document.getElementById('sellingPriceRubReserved');
        const rubReserveLabel = document.getElementById('rubReserveLabel');
        const rubReserveGap = document.getElementById('rubReserveGap');
        const rubCardRate = document.getElementById('rubCardRate');
        const sellingCardRub = document.getElementById('sellingCardRub');
        let cnyToRubRate = null;

        async function loadFxRate() {
            fxRateText.textContent = '加载中…';
            fxRateSource.textContent = '';
            for (const source of FX_SOURCES) {
                try {
                    const res = await fetch(source.url, { cache: 'no-store' });
                    if (!res.ok) continue;
                    const result = source.parse(await res.json());
                    const rate = result && Number(result.rate);
                    if (rate >= FX_MIN_RATE && rate <= FX_MAX_RATE) {
                        applyFxRate(rate, source.name, result.time);
                        return;
                    }
                    console.warn('汇率数据异常：', source.name, result);
                } catch (err) {
                    console.warn('汇率获取失败：', source.name, err);
                }
            }
            applyFxRate(FX_FALLBACK_RATE, '默认（获取失败）');
        }

        function formatFxTime(time) {
            const date = new Date(time);
            if (!time || isNaN(date)) return '';
            return date.toLocaleString('zh-CN', { month: '2-digit', day: '2-digit', hour: '2-digit', minute: '2-digit' });
        }

        function applyFxRate(rate, source, time) {
            cnyToRubRate = rate;
            fxRateText.textContent = rate.toFixed(4);
            rubCardRate.textContent = rate.toFixed(4);
            const updatedAt = formatFxTime(time);
            fxRateSource.textContent = updatedAt ? `${source} · ${updatedAt}` : source;
            fxRateSource.title = updatedAt ? `数据源：${source}，更新于 ${updatedAt}` : `数据源：${source}`;
            if (fxCnyInput.value !== '') {
                syncFxFrom('cny');
            } else if (fxRubInput.value !== '') {
                syncFxFrom('rub');
            }
            updateDerivedPrices();
        }

        function syncFxFrom(origin) {
            if (!cnyToRubRate) return;
            if (origin === 'cny') {
                const cny = parseFloat(fxCnyInput.value);
                fxRubInput.value = isNaN(cny) ? '' : (cny * cnyToRubRate).toFixed(2);
            } else {
                const rub = parseFloat(fxRubInput.value);
                fxCnyInput.value = isNaN(rub) ? '' : (rub / cnyToRubRate).toFixed(2);
            }
        }

        function getReserveRate() {
            let percent = parseFloat(discountReserveInput.value);
            if (isNaN(percent) || percent < 0) percent = 0;
            if (percent > 95) percent = 95;
            return percent;
        }

        function updateDerivedPrices() {
            const percent = getReserveRate();
            cnyReserveLabel.textContent = percent + '%';
            rubReserveLabel.textContent = percent + '%';

            const cnyPrice = parseFloat(sellingPriceElement.textContent.replace(/[^\d.]/g, ''));
            if (isNaN(cnyPrice) || cnyPrice <= 0) {
                sellingPriceReserved.textContent = '--';
                cnyReserveGap.textContent = '--';
                sellingPriceRub.textContent = '--';
                sellingPriceRubReserved.textContent = '--';
                rubReserveGap.textContent = '--';
                return;
            }

            const cnyReserved = cnyPrice / (1 - percent / 100);
            sellingPriceReserved.textContent = `¥ ${cnyReserved.toFixed(2)}`;
            cnyReserveGap.textContent = `¥ ${(cnyReserved - cnyPrice).toFixed(2)}`;

            if (!cnyToRubRate) {
                sellingPriceRub.textContent = '--';
                sellingPriceRubReserved.textContent = '--';
                rubReserveGap.textContent = '--';
                return;
            }
            const rubPrice = cnyPrice * cnyToRubRate;
            const rubReserved = cnyReserved * cnyToRubRate;
            sellingPriceRub.textContent = `₽ ${rubPrice.toFixed(2)}`;
            sellingPriceRubReserved.textContent = `₽ ${rubReserved.toFixed(2)}`;
            rubReserveGap.textContent = `₽ ${(rubReserved - rubPrice).toFixed(2)}`;
            sellingCardRub.classList.remove('opacity-0', 'translate-y-4');
        }

        fxCnyInput.addEventListener('input', () => syncFxFrom('cny'));
        fxRubInput.addEventListener('input', () => syncFxFrom('rub'));
        fxRefreshBtn.addEventListener('click', loadFxRate);
        discountReserveInput.addEventListener('input', updateDerivedPrices);
        new MutationObserver(updateDerivedPrices)
            .observe(sellingPriceElement, { childList: true, characterData: true, subtree: true });
        loadFxRate();