// ===== 全局状态 =====
let chartInstance = null;
let parsedData = null;
let seriesColors = [];
let seriesOrder = [];
let seriesAxis = []; // 每个系列所属轴：0=左轴 1=右轴
let currentMode = 'chart'; // 'chart' or 'table'
let tableImageBlob = null;

// ===== 预设颜色方案 =====
const colorPalettes = {
    default: ['#5470c6', '#91cc75', '#fac858', '#ee6666', '#73c0de', '#3ba272', '#fc8452', '#9a60b4', '#ea7ccc'],
    dark: ['#4fc3f7', '#81c784', '#fff176', '#ff8a65', '#ba68c8', '#4dd0e1', '#ffab91', '#aed581', '#f48fb1'],
    macarons: ['#2ec7c9', '#b6a2de', '#5ab1ef', '#ffb980', '#d87a80', '#8d98b3', '#e5cf0d', '#97b552', '#95706d'],
    gradient: ['#7f7fd5', '#86a8e7', '#91eae4', '#ff6b6b', '#feca57', '#48dbfb', '#ff9ff3', '#54a0ff', '#5f27cd'],
    retro: ['#d4a5a5', '#95b9c7', '#f6e8c3', '#dfceb4', '#a4c3b5', '#c9b1ff', '#f5c7b8', '#b8d4e3', '#e8c8a0'],
    ocean: ['#0077b6', '#00b4d8', '#90e0ef', '#caf0f8', '#023e8a', '#48cae4', '#ade8f4', '#0096c7', '#03045e'],
    forest: ['#2d6a4f', '#40916c', '#52b788', '#74c69d', '#95d5b2', '#b7e4c7', '#d8f3dc', '#1b4332', '#344e41'],
    sunset: ['#e85d04', '#f48c06', '#faa307', '#ffba08', '#dc2f02', '#d00000', '#9d0208', '#6a040f', '#370617'],
    lavender: ['#7c3aed', '#8b5cf6', '#a78bfa', '#c4b5fd', '#ddd6fe', '#ede9fe', '#5b21b6', '#4c1d95', '#6d28d9'],
    minimal: ['#111827', '#374151', '#6b7280', '#9ca3af', '#d1d5db', '#e5e7eb', '#f3f4f6', '#4b5563', '#1f2937'],
    cherry: ['#e91e63', '#f06292', '#f48fb1', '#f8bbd0', '#fce4ec', '#c2185b', '#ad1457', '#880e4f', '#d81b60'],
    midnight: ['#6c63ff', '#5a52d5', '#483fb5', '#7c79ff', '#3d3d5c', '#8b89ff', '#9d9bff', '#2c2c4a', '#b3b2ff'],
    gold: ['#b8860b', '#daa520', '#f0c040', '#ffd700', '#ffe066', '#996515', '#cc9900', '#e6b800', '#8b6914'],
    coral: ['#ff6f61', '#ff8a70', '#ffa07a', '#ffab91', '#ffccbc', '#e64a19', '#f4511e', '#ff5722', '#d84315'],
    mint: ['#00bfa5', '#26a69a', '#4db6ac', '#80cbc4', '#b2dfdb', '#00897b', '#00796b', '#004d40', '#009688']
};

// ===== 示例数据 =====
const sampleDataSets = [
    {
        name: '季度销售对比',
        data: `产品, Q1, Q2, Q3, Q4
手机, 1200, 1800, 2100, 2500
平板, 800, 950, 1100, 1300
笔记本, 600, 750, 900, 1050
耳机, 400, 520, 680, 800`
    },
    {
        name: '年度增长趋势',
        data: `指标, 2020年, 2021年, 2022年, 2023年, 2024年
营收(万), 500, 680, 820, 1050, 1380
利润(万), 80, 120, 160, 230, 350
用户(千), 50, 85, 130, 200, 320`
    },
    {
        name: '多指标对比（适合区域分割）',
        data: `月份, 方案A-效率, 方案A-成本, 方案B-效率, 方案B-成本
1月, 85, 120, 78, 135
2月, 88, 115, 82, 128
3月, 92, 108, 88, 120
4月, 90, 112, 95, 110
5月, 95, 105, 98, 105
6月, 98, 98, 102, 95`
    }
];

// ===== 初始化 =====
document.addEventListener('DOMContentLoaded', () => {
    // 默认加载第一个示例
    document.getElementById('dataInput').value = sampleDataSets[0].data;
    generateChart();

    // 预填双图合并示例（不提前生成，切到双图模式时由 switchMode 触发）
    document.getElementById('combineData1').value = sampleDataSets[0].data;
    document.getElementById('combineData2').value = sampleDataSets[1].data;
    document.getElementById('combineTitle1').value = '季度销售对比';
    document.getElementById('combineType2').value = 'line';
    document.getElementById('combineTitle2').value = '年度增长趋势';

    // 初始化导出设置
    renderHistory();
    refreshExportHint();
});

// ===== 数据解析 =====
function parseData(rawText) {
    const lines = rawText.trim().split('\n').filter(l => l.trim());
    if (lines.length < 2) {
        alert('数据至少需要包含表头和一行数据');
        return null;
    }

    // 自动检测分隔符
    let delimiter = ',';
    if (lines[0].includes('\t')) {
        delimiter = '\t';
    } else if (lines[0].split('|').length > lines[0].split(',').length) {
        delimiter = '|';
    }

    const rows = lines.map(line => {
        return line.split(delimiter).map(cell => cell.trim());
    });

    const headers = rows[0];
    const categories = [];
    const seriesData = {};

    // 第一列是横坐标，其余列是系列
    for (let i = 1; i < headers.length; i++) {
        seriesData[headers[i]] = [];
    }

    for (let i = 1; i < rows.length; i++) {
        categories.push(rows[i][0]);
        for (let j = 1; j < rows[i].length && j < headers.length; j++) {
            const val = parseFloat(rows[i][j]);
            seriesData[headers[j]].push(isNaN(val) ? 0 : val);
        }
    }

    return {
        categories,
        seriesNames: headers.slice(1),
        seriesData
    };
}

// ===== 生成图表 =====
function generateChart() {
    const rawText = document.getElementById('dataInput').value;
    if (!rawText.trim()) {
        alert('请输入数据');
        return;
    }

    parsedData = parseData(rawText);
    if (!parsedData) return;

    // 初始化系列顺序和颜色
    seriesOrder = parsedData.seriesNames.map((_, i) => i);
    const palette = colorPalettes[document.getElementById('themeStyle').value] || colorPalettes.default;
    seriesColors = parsedData.seriesNames.map((_, i) => palette[i % palette.length]);
    seriesAxis = parsedData.seriesNames.map(() => 0);

    // 渲染系列配置
    renderSeriesConfig();

    // 初始化图表
    initChart();
    updateChart();

    refreshPreview();
}

// ===== 初始化图表实例 =====
function initChart() {
    const chartDom = document.getElementById('chartArea');
    chartDom.innerHTML = '';
    
    if (chartInstance) {
        chartInstance.dispose();
    }
    
    chartInstance = echarts.init(chartDom, null, { renderer: 'canvas' });
    
    // 响应式
    window.addEventListener('resize', () => {
        chartInstance && chartInstance.resize();
    });
}

// ===== 更新图表 =====
function updateChart() {
    if (!parsedData || !chartInstance) return;

    const chartType = document.getElementById('chartType').value;
    const title = document.getElementById('chartTitle').value;
    const theme = document.getElementById('themeStyle').value;
    const showLegend = document.getElementById('showLegend').checked;
    const showGrid = document.getElementById('showGrid').checked;
    const showLabel = document.getElementById('showLabel').checked;
    const stackMode = document.getElementById('stackMode').checked;
    const smoothLine = document.getElementById('smoothLine').checked;
    const enableSplit = document.getElementById('enableSplit').checked;
    const dualAxis = document.getElementById('dualAxis').checked;
    const rightAxisName = document.getElementById('rightAxisName').value;

    // 显示/隐藏分割配置
    document.getElementById('splitConfig').style.display = enableSplit ? 'block' : 'none';

    // 背景色
    const bgColor = theme === 'dark' ? '#1a1a2e' : '#ffffff';
    const textColor = theme === 'dark' ? '#e0e0e0' : '#333333';
    const axisLineColor = theme === 'dark' ? '#444' : '#ddd';

    // 按当前顺序构建系列
    const palette = colorPalettes[theme] || colorPalettes.default;
    const series = seriesOrder.map((origIdx, displayIdx) => {
        const name = parsedData.seriesNames[origIdx];
        const data = parsedData.seriesData[name];
        const color = seriesColors[origIdx] || palette[origIdx % palette.length];
        
        let type = chartType === 'bar-line' 
            ? (displayIdx % 2 === 0 ? 'bar' : 'line') 
            : chartType;

        const seriesItem = {
            name: name,
            type: type,
            data: [...data],
            itemStyle: { color: color },
            emphasis: {
                focus: 'series',
                itemStyle: {
                    shadowBlur: 10,
                    shadowColor: 'rgba(0,0,0,0.3)'
                }
            }
        };

        // 堆叠
        if (stackMode) {
            seriesItem.stack = 'total';
        }

        // 折线图特有
        if (type === 'line') {
            seriesItem.smooth = smoothLine;
            seriesItem.lineStyle = { width: 3 };
            seriesItem.symbolSize = 8;
            seriesItem.areaStyle = theme === 'gradient' ? {
                opacity: 0.15
            } : undefined;
        }

        // 柱状图特有
        if (type === 'bar') {
            seriesItem.barMaxWidth = 40;
            seriesItem.itemStyle.borderRadius = stackMode ? [0, 0, 0, 0] : [4, 4, 0, 0];
            if (theme === 'gradient') {
                seriesItem.itemStyle.color = new echarts.graphic.LinearGradient(0, 0, 0, 1, [
                    { offset: 0, color: color },
                    { offset: 1, color: adjustColor(color, 40) }
                ]);
            }
        }

        // 数据标签
        if (showLabel) {
            seriesItem.label = {
                show: true,
                position: type === 'bar' ? 'top' : 'top',
                fontSize: 11,
                color: textColor,
                formatter: (params) => {
                    if (params.value >= 10000) return (params.value / 10000).toFixed(1) + 'w';
                    if (params.value >= 1000) return (params.value / 1000).toFixed(1) + 'k';
                    return params.value;
                }
            };
        }

        // 双Y轴：按系列指定左右轴
        if (dualAxis) {
            seriesItem.yAxisIndex = (seriesAxis[origIdx] === 1) ? 1 : 0;
        }

        return seriesItem;
    });

    // 区域分割 - 使用 graphic 组件精确画分割线在柱子间隙中
    const graphicElements = [];
    if (enableSplit) {
        const splitIdx = parseInt(document.getElementById('splitIndex').value) || 3;
        const leftLabel = document.getElementById('leftLabel').value || '左侧';
        const rightLabel = document.getElementById('rightLabel').value || '右侧';
        const splitStyle = document.getElementById('splitStyle').value;

        if (splitIdx < parsedData.categories.length) {
            // 区域背景色用 markArea
            const splitLineColor = theme === 'dark' ? '#ff6b6b' : '#e74c3c';

            if (series.length > 0) {
                series[0].markArea = {
                    silent: true,
                    data: [
                        [
                            {
                                name: leftLabel,
                                xAxis: parsedData.categories[0],
                                itemStyle: {
                                    color: theme === 'dark' ? 'rgba(79,195,247,0.06)' : 'rgba(79,70,229,0.05)',
                                    borderWidth: 0
                                },
                                label: {
                                    show: true,
                                    position: 'insideTop',
                                    fontSize: 13,
                                    fontWeight: 'bold',
                                    color: theme === 'dark' ? '#4fc3f7' : '#4f46e5',
                                    offset: [0, 10]
                                }
                            },
                            { xAxis: parsedData.categories[splitIdx - 1] }
                        ],
                        [
                            {
                                name: rightLabel,
                                xAxis: parsedData.categories[splitIdx],
                                itemStyle: {
                                    color: theme === 'dark' ? 'rgba(255,107,107,0.06)' : 'rgba(239,68,68,0.05)',
                                    borderWidth: 0
                                },
                                label: {
                                    show: true,
                                    position: 'insideTop',
                                    fontSize: 13,
                                    fontWeight: 'bold',
                                    color: theme === 'dark' ? '#ff6b6b' : '#ef4444',
                                    offset: [0, 10]
                                }
                            },
                            { xAxis: parsedData.categories[parsedData.categories.length - 1] }
                        ]
                    ]
                };
            }

            // 用 graphic 组件在渲染后画分割线（在柱子间隙中）
            // 先存到全局，在 setOption 后通过 rendered 事件绘制
            window._splitConfig = { splitIdx, splitLineColor, splitStyle, theme };
        } else {
            window._splitConfig = null;
        }
    } else {
        window._splitConfig = null;
    }

    // 图表配置
    const option = {
        backgroundColor: bgColor,
        title: title ? {
            text: title,
            left: 'center',
            top: 15,
            textStyle: {
                color: textColor,
                fontSize: 18,
                fontWeight: 600
            }
        } : undefined,
        tooltip: {
            trigger: 'axis',
            backgroundColor: theme === 'dark' ? 'rgba(30,30,50,0.95)' : 'rgba(255,255,255,0.95)',
            borderColor: theme === 'dark' ? '#555' : '#eee',
            textStyle: { color: textColor },
            axisPointer: {
                type: chartType === 'bar' ? 'shadow' : 'cross',
                crossStyle: { color: '#999' }
            },
            formatter: function(params) {
                let html = `<div style="font-weight:600;margin-bottom:6px">${params[0].axisValue}</div>`;
                params.forEach(p => {
                    html += `<div style="display:flex;align-items:center;gap:6px;margin:3px 0">
                        <span style="display:inline-block;width:10px;height:10px;border-radius:50%;background:${p.color}"></span>
                        <span>${p.seriesName}:</span>
                        <span style="font-weight:600">${p.value.toLocaleString()}</span>
                    </div>`;
                });
                return html;
            }
        },
        legend: showLegend ? {
            show: true,
            top: title ? 50 : 15,
            textStyle: { color: textColor, fontSize: 12 },
            itemGap: 20,
            icon: 'roundRect'
        } : { show: false },
        grid: {
            left: '3%',
            right: '4%',
            bottom: '3%',
            top: showLegend ? (title ? 90 : 60) : (title ? 60 : 30),
            containLabel: true
        },
        xAxis: {
            type: 'category',
            data: parsedData.categories,
            axisLine: { lineStyle: { color: axisLineColor } },
            axisLabel: { 
                color: textColor, 
                fontSize: 12,
                interval: 0,
                rotate: parsedData.categories.length > 10 ? 30 : 0
            },
            axisTick: { show: false }
        },
        yAxis: dualAxis ? [
            {
                type: 'value',
                name: '左轴',
                nameTextStyle: { color: textColor, fontSize: 11, padding: [0, 0, 0, 4] },
                axisLine: { show: false },
                axisTick: { show: false },
                axisLabel: { color: textColor, fontSize: 11 },
                splitLine: {
                    show: showGrid,
                    lineStyle: { color: theme === 'dark' ? '#333' : '#f0f0f0', type: 'dashed' }
                }
            },
            {
                type: 'value',
                name: rightAxisName || '右轴',
                position: 'right',
                nameTextStyle: { color: textColor, fontSize: 11, padding: [0, 4, 0, 0] },
                axisLine: { show: false },
                axisTick: { show: false },
                axisLabel: { color: textColor, fontSize: 11 },
                splitLine: { show: false }
            }
        ] : {
            type: 'value',
            axisLine: { show: false },
            axisTick: { show: false },
            axisLabel: { color: textColor, fontSize: 11 },
            splitLine: {
                show: showGrid,
                lineStyle: {
                    color: theme === 'dark' ? '#333' : '#f0f0f0',
                    type: 'dashed'
                }
            }
        },
        series: series,
        animationDuration: 800,
        animationEasing: 'cubicOut'
    };

    chartInstance.setOption(option, true);

    // 绘制分割线（在 category 间隙中）
    drawSplitLine();

    refreshPreview();
}

// ===== 在柱子间隙中精确绘制分割线 =====
function drawSplitLine() {
    if (!chartInstance || !window._splitConfig) {
        if (chartInstance) {
            chartInstance.setOption({ graphic: { elements: [] } });
        }
        return;
    }

    const { splitIdx, splitLineColor, splitStyle } = window._splitConfig;

    // 使用 convertToPixel 获取 category 的像素坐标（x位置）
    const leftX = chartInstance.convertToPixel({ xAxisIndex: 0 }, splitIdx - 1);
    const rightX = chartInstance.convertToPixel({ xAxisIndex: 0 }, splitIdx);
    const midX = (leftX + rightX) / 2;

    // 使用内部 coordinateSystem 获取精确的绘图区域边界
    // 这是ECharts内部稳定可用的接口
    const gridRect = chartInstance.getModel()
        .getComponent('grid', 0)
        .coordinateSystem.getRect();
    
    const yTop = gridRect.y;
    const yBottom = gridRect.y + gridRect.height;

    // 虚线样式
    let lineDash = null;
    if (splitStyle === 'dashed') lineDash = [8, 4];
    else if (splitStyle === 'dotted') lineDash = [3, 3];

    chartInstance.setOption({
        graphic: {
            elements: [
                {
                    type: 'line',
                    shape: {
                        x1: midX,
                        y1: yTop,
                        x2: midX,
                        y2: yBottom
                    },
                    style: {
                        stroke: splitLineColor,
                        lineWidth: 2,
                        lineDash: lineDash
                    },
                    z: 100
                }
            ]
        }
    });
}

// ===== 渲染系列配置 =====
function renderSeriesConfig() {
    const container = document.getElementById('seriesConfig');
    container.innerHTML = '';

    seriesOrder.forEach((origIdx, displayIdx) => {
        const name = parsedData.seriesNames[origIdx];
        const color = seriesColors[origIdx];
        const dualAxis = document.getElementById('dualAxis').checked;
        const axisSelect = dualAxis ? `
            <select onchange="updateSeriesAxis(${origIdx}, this.value)" title="所属坐标轴">
                <option value="0" ${seriesAxis[origIdx] === 0 ? 'selected' : ''}>左轴</option>
                <option value="1" ${seriesAxis[origIdx] === 1 ? 'selected' : ''}>右轴</option>
            </select>
        ` : '';

        const item = document.createElement('div');
        item.className = 'series-item';
        item.draggable = true;
        item.dataset.index = displayIdx;

        item.innerHTML = `
            <span class="drag-handle">⠿</span>
            <span class="series-name">${name}</span>
            <input type="color" value="${color}" onchange="updateSeriesColor(${origIdx}, this.value)">
            <select onchange="updateSeriesType(${origIdx}, this.value)">
                <option value="auto">自动</option>
                <option value="bar">柱状</option>
                <option value="line">折线</option>
            </select>
            ${axisSelect}
        `;

        // 拖拽事件
        item.addEventListener('dragstart', handleDragStart);
        item.addEventListener('dragover', handleDragOver);
        item.addEventListener('drop', handleDrop);
        item.addEventListener('dragend', handleDragEnd);

        container.appendChild(item);
    });
}

// ===== 拖拽排序 =====
let draggedItem = null;

function handleDragStart(e) {
    draggedItem = this;
    this.classList.add('dragging');
    e.dataTransfer.effectAllowed = 'move';
}

function handleDragOver(e) {
    e.preventDefault();
    e.dataTransfer.dropEffect = 'move';
    
    const rect = this.getBoundingClientRect();
    const midY = rect.top + rect.height / 2;
    
    if (e.clientY < midY) {
        this.style.borderTopColor = 'var(--primary)';
        this.style.borderTopWidth = '2px';
    } else {
        this.style.borderBottomColor = 'var(--primary)';
        this.style.borderBottomWidth = '2px';
    }
}

function handleDrop(e) {
    e.preventDefault();
    
    // 清除样式
    document.querySelectorAll('.series-item').forEach(item => {
        item.style.borderTopColor = '';
        item.style.borderTopWidth = '';
        item.style.borderBottomColor = '';
        item.style.borderBottomWidth = '';
    });

    if (draggedItem === this) return;

    const fromIdx = parseInt(draggedItem.dataset.index);
    const toIdx = parseInt(this.dataset.index);

    // 交换顺序
    const temp = seriesOrder[fromIdx];
    seriesOrder[fromIdx] = seriesOrder[toIdx];
    seriesOrder[toIdx] = temp;

    renderSeriesConfig();
    updateChart();
}

function handleDragEnd() {
    this.classList.remove('dragging');
    document.querySelectorAll('.series-item').forEach(item => {
        item.style.borderTopColor = '';
        item.style.borderTopWidth = '';
        item.style.borderBottomColor = '';
        item.style.borderBottomWidth = '';
    });
}

// ===== 系列操作 =====
function updateSeriesColor(origIdx, color) {
    seriesColors[origIdx] = color;
    updateChart();
}

function updateSeriesType(origIdx, type) {
    // 存储自定义类型覆盖
    if (!window.seriesTypeOverrides) window.seriesTypeOverrides = {};
    window.seriesTypeOverrides[origIdx] = type;
    updateChart();
}

// ===== 双Y轴 =====
function onDualAxisChange() {
    const on = document.getElementById('dualAxis').checked;
    document.getElementById('rightAxisGroup').style.display = on ? 'block' : 'none';
    renderSeriesConfig(); // 显示/隐藏系列轴选择
    updateChart();
}

function updateSeriesAxis(origIdx, axis) {
    seriesAxis[origIdx] = parseInt(axis) || 0;
    updateChart();
}

// ===== 工具函数 =====
function adjustColor(hex, amount) {
    hex = hex.replace('#', '');
    const num = parseInt(hex, 16);
    let r = Math.min(255, ((num >> 16) & 0xff) + amount);
    let g = Math.min(255, ((num >> 8) & 0xff) + amount);
    let b = Math.min(255, (num & 0xff) + amount);
    return `rgb(${r},${g},${b})`;
}

function loadSampleData() {
    // 循环切换示例
    const currentIdx = sampleDataSets.findIndex(s => s.data === document.getElementById('dataInput').value);
    const nextIdx = (currentIdx + 1) % sampleDataSets.length;
    document.getElementById('dataInput').value = sampleDataSets[nextIdx].data;
    generateChart();
}

function clearData() {
    document.getElementById('dataInput').value = '';
    document.getElementById('chartArea').innerHTML = `
        <div class="placeholder">
            <p>📊</p>
            <p>输入数据后点击"生成图表"</p>
        </div>
    `;
    if (chartInstance) {
        chartInstance.dispose();
        chartInstance = null;
    }
    parsedData = null;
    document.getElementById('seriesConfig').innerHTML = '<p class="hint-text">生成图表后可在此调整各系列的顺序和颜色</p>';
}

// ===== 导出图表（SVG 专用） =====
function exportChartSvg() {
    if (!chartInstance) {
        alert('请先生成图表');
        return;
    }
    const svgChart = echarts.init(document.createElement('div'), null, { renderer: 'svg' });
    svgChart.setOption(chartInstance.getOption());
    const url = svgChart.getDataURL({ type: 'svg', pixelRatio: 2 });
    const a = document.createElement('a');
    a.href = url;
    a.download = buildExportFilename('chart', 'svg');
    a.click();
    svgChart.dispose();
}

// ===== 导出设置（分辨率/历史/命名） =====
const EXPORT_PRESETS = {
    'original': { label: '原始大小', w: 0, h: 0 },
    '1920x1080': { label: '1920 × 1080', w: 1920, h: 1080 },
    '1280x720': { label: '1280 × 720', w: 1280, h: 720 },
    '1024x768': { label: '1024 × 768', w: 1024, h: 768 },
    '800x600': { label: '800 × 600', w: 800, h: 600 },
    'custom': { label: '自定义', w: null, h: null }
};
const HISTORY_KEY = 'dct_export_history';
const HISTORY_MAX = 5;

// 当前生效的分辨率 {w, h}（0 表示原始大小）
function getResolution() {
    const preset = document.getElementById('exportPreset').value;
    if (preset === 'original') return { w: 0, h: 0 };
    if (preset === 'custom') {
        const w = parseInt(document.getElementById('customWidth').value) || 0;
        const h = parseInt(document.getElementById('customHeight').value) || 0;
        return { w, h };
    }
    const p = EXPORT_PRESETS[preset];
    return { w: p.w, h: p.h };
}

function onExportPresetChange() {
    const preset = document.getElementById('exportPreset').value;
    document.getElementById('customResGroup').style.display = preset === 'custom' ? 'block' : 'none';
    refreshExportHint();
    refreshPreview();
}

// 导出设置面板展开/折叠（默认折叠）
let exportSettingsOpen = false;
function toggleExportSettings() {
    exportSettingsOpen = !exportSettingsOpen;
    const body = document.getElementById('exportSettingsBody');
    const t = document.getElementById('exportToggle');
    body.style.display = exportSettingsOpen ? 'block' : 'none';
    t.textContent = exportSettingsOpen ? '▾' : '▸';
}

// 一键恢复默认（重置全部设置，历史记录保留）
function resetExportSettings() {
    document.getElementById('exportPreset').value = 'original';
    document.getElementById('customResGroup').style.display = 'none';
    document.getElementById('customWidth').value = '';
    document.getElementById('customHeight').value = '';
    document.getElementById('exportFilename').value = '';
    document.getElementById('exportHistory').value = '';
    refreshExportHint();
    refreshPreview();
}

function onCustomResInput() {
    refreshExportHint();
    refreshPreview();
    const { w, h } = getResolution();
    if (w > 0 && h > 0) saveHistory(w, h);
}

// 历史分辨率管理（最多 5 个，存 localStorage）
function loadHistory() {
    try { return JSON.parse(localStorage.getItem(HISTORY_KEY)) || []; } catch (e) { return []; }
}

function saveHistory(w, h) {
    if (!w || !h) return;
    let hist = loadHistory();
    const key = w + 'x' + h;
    hist = hist.filter(x => x.key !== key);
    hist.unshift({ key, w, h });
    hist = hist.slice(0, HISTORY_MAX);
    localStorage.setItem(HISTORY_KEY, JSON.stringify(hist));
    renderHistory();
}

function renderHistory() {
    const sel = document.getElementById('exportHistory');
    const hist = loadHistory();
    const cur = sel.value;
    sel.innerHTML = hist.length
        ? hist.map(h => `<option value="${h.key}">${h.w} × ${h.h}</option>`).join('')
        : '<option value="">— 暂无历史 —</option>';
    if (cur && hist.some(h => h.key === cur)) sel.value = cur;
}

function onHistorySelect() {
    const v = document.getElementById('exportHistory').value;
    if (!v) return;
    const [w, h] = v.split('x').map(Number);
    const preset = Object.entries(EXPORT_PRESETS).find(([k, p]) => p.w === w && p.h === h);
    document.getElementById('exportPreset').value = preset ? preset[0] : 'custom';
    if (preset) {
        document.getElementById('customResGroup').style.display = 'none';
    } else {
        document.getElementById('customResGroup').style.display = 'block';
        document.getElementById('customWidth').value = w;
        document.getElementById('customHeight').value = h;
    }
    refreshExportHint();
    refreshPreview();
}

// 文件名：手动填写优先，否则按日期时间自动命名（每次不同）
function buildExportFilename(prefix, ext) {
    ext = ext || 'png';
    const manual = document.getElementById('exportFilename').value.trim();
    if (manual) {
        return /\.[a-zA-Z0-9]+$/.test(manual) ? manual : manual + '.' + ext;
    }
    const d = new Date();
    const pad = n => String(n).padStart(2, '0');
    return `${prefix}_${d.getFullYear()}${pad(d.getMonth()+1)}${pad(d.getDate())}_${pad(d.getHours())}${pad(d.getMinutes())}${pad(d.getSeconds())}.${ext}`;
}

// 把源图 contain 居中缩放到目标分辨率画布（自动适配深色背景）
function applyResolution(srcCanvas, tw, th) {
    if (!tw || !th) return srcCanvas;
    let bg = '#ffffff';
    try {
        const d = srcCanvas.getContext('2d').getImageData(0, 0, 1, 1).data;
        if (d[3] > 0 && (d[0] + d[1] + d[2]) / 3 < 100) bg = '#1a1a2e';
    } catch (e) {}
    const c = document.createElement('canvas');
    c.width = tw; c.height = th;
    const ctx = c.getContext('2d');
    ctx.fillStyle = bg;
    ctx.fillRect(0, 0, tw, th);
    const scale = Math.min(tw / srcCanvas.width, th / srcCanvas.height);
    const dw = Math.round(srcCanvas.width * scale);
    const dh = Math.round(srcCanvas.height * scale);
    ctx.drawImage(srcCanvas, Math.round((tw - dw) / 2), Math.round((th - dh) / 2), dw, dh);
    return c;
}

// 获取当前模式源 canvas（异步）
function getSourceCanvas() {
    return new Promise((resolve, reject) => {
        if (currentMode === 'chart') {
            if (!chartInstance) return reject(new Error('请先生成图表'));
            const cvs = chartInstance.getDom().querySelector('canvas');
            if (!cvs) return reject(new Error('图表未渲染'));
            resolve(cvs);
        } else if (currentMode === 'table') {
            if (!tableImageBlob) return reject(new Error('请先生成表格'));
            const url = URL.createObjectURL(tableImageBlob);
            const img = new Image();
            img.onload = () => {
                const c = document.createElement('canvas');
                c.width = img.width; c.height = img.height;
                c.getContext('2d').drawImage(img, 0, 0);
                URL.revokeObjectURL(url);
                resolve(c);
            };
            img.onerror = () => { URL.revokeObjectURL(url); reject(new Error('表格图片加载失败')); };
            img.src = url;
        } else {
            if (!combinedCanvas) return reject(new Error('请先生成合并图'));
            resolve(combinedCanvas);
        }
    });
}

// 生成最终导出 canvas（应用当前分辨率）
function getExportCanvas() {
    return getSourceCanvas().then(src => {
        const { w, h } = getResolution();
        return applyResolution(src, w, h);
    });
}

// 统一下载图片
function exportCurrent(prefix) {
    getExportCanvas().then(canvas => {
        const a = document.createElement('a');
        a.href = canvas.toDataURL('image/png');
        a.download = buildExportFilename(prefix);
        a.click();
        const { w, h } = getResolution();
        if (w > 0 && h > 0) saveHistory(w, h);
    }).catch(err => alert(err.message));
}

// 导出分辨率提示 + 折叠栏摘要
function refreshExportHint() {
    const { w, h } = getResolution();
    const hint = document.getElementById('exportResHint');
    if (hint) hint.textContent = w > 0 && h > 0 ? `导出分辨率：${w} × ${h}（原图居中缩放）` : '导出分辨率：原始大小';
    const sum = document.getElementById('exportSummary');
    if (sum) sum.textContent = w > 0 && h > 0 ? `${w} × ${h}` : '原始大小';
}

// 刷新导出预览：以原图为中心，居中展示保存后的图
function refreshPreview() {
    const box = document.getElementById('exportPreviewBox');
    const inner = document.getElementById('exportPreviewInner');
    const title = document.getElementById('exportPreviewTitle');
    if (!box || !inner) return;
    getExportCanvas().then(canvas => {
        const { w, h } = getResolution();
        const url = canvas.toDataURL('image/png');
        const sizeTag = w > 0 && h > 0 ? ` <span class="export-preview-size">${w} × ${h}</span>` : '';
        title.innerHTML = `📐 导出预览${sizeTag}`;
        inner.innerHTML = `<img src="${url}" alt="导出预览">`;
        box.style.display = 'block';
    }).catch(() => { box.style.display = 'none'; });
}

// ===== 模式切换 =====
function switchMode(mode) {
    currentMode = mode;
    
    // 更新按钮状态
    document.getElementById('btnChartMode').classList.toggle('active', mode === 'chart');
    document.getElementById('btnTableMode').classList.toggle('active', mode === 'table');
    document.getElementById('btnCombineMode').classList.toggle('active', mode === 'combine');
    
    // 显示/隐藏配置区
    document.getElementById('dataInputSection').style.display = mode === 'combine' ? 'none' : 'block';
    document.getElementById('chartConfigSection').style.display = mode === 'chart' ? 'block' : 'none';
    document.getElementById('tableConfigSection').style.display = mode === 'table' ? 'block' : 'none';
    document.getElementById('seriesConfigSection').style.display = mode === 'chart' ? 'block' : 'none';
    document.getElementById('splitConfigSection').style.display = mode === 'chart' ? 'block' : 'none';
    document.getElementById('combineConfigSection').style.display = mode === 'combine' ? 'block' : 'none';
    
    // 更新生成按钮
    const btnGenerate = document.getElementById('btnGenerate');
    if (mode === 'combine') {
        btnGenerate.style.display = 'none'; // 双图模式用自己的按钮
    } else {
        btnGenerate.style.display = '';
        btnGenerate.textContent = mode === 'chart' ? '🎨 生成图表' : '📋 生成表格';
    }
    
    // 更新导出按钮
    const btnExportSvg = document.getElementById('btnExportSvg');
    btnExportSvg.style.display = mode === 'chart' ? 'inline-flex' : 'none';
    
    // 重新生成
    generate();
}

// ===== 统一生成入口 =====
function generate() {
    if (currentMode === 'chart') {
        generateChart();
    } else if (currentMode === 'table') {
        generateTable();
    } else {
        generateCombine();
    }
}

// ===== 更新字体大小显示 =====
function updateFontSize() {
    const val = document.getElementById('tableFontSize').value;
    document.getElementById('fontSizeValue').textContent = val;
}

// ===== 生成表格 =====
function generateTable() {
    const rawText = document.getElementById('dataInput').value;
    if (!rawText.trim()) {
        alert('请输入数据');
        return;
    }

    const params = {
        data: rawText,
        title: document.getElementById('tableTitle').value,
        theme: document.getElementById('tableTheme').value,
        fontSize: parseInt(document.getElementById('tableFontSize').value) || 14,
        stripeRows: document.getElementById('stripeRows').checked,
        borderStyle: document.getElementById('borderStyle').value,
        pixelRatio: 2
    };

    const chartArea = document.getElementById('chartArea');
    chartArea.innerHTML = '<div class="placeholder"><p>⏳</p><p>正在生成表格...</p></div>';

    fetch('/api/table', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(params)
    })
    .then(res => {
        if (!res.ok) throw new Error('表格生成失败');
        return res.blob();
    })
    .then(blob => {
        tableImageBlob = blob;
        const url = URL.createObjectURL(blob);
        chartArea.innerHTML = `<div class="table-preview"><img src="${url}" alt="表格预览"></div>`;
        refreshPreview();
    })
    .catch(err => {
        chartArea.innerHTML = `<div class="placeholder"><p>❌</p><p>${err.message}</p></div>`;
    });
}

// ===== 更新表格（配置变更时） =====
function updateTable() {
    if (currentMode === 'table' && document.getElementById('dataInput').value.trim()) {
        generateTable();
    }
}

// ===== 统一导出图片 =====
function exportImage(format) {
    if (format === 'svg') {
        if (currentMode !== 'chart') {
            alert('SVG 仅图表模式支持');
            return;
        }
        exportChartSvg();
        return;
    }
    const prefix = currentMode === 'chart' ? 'chart' : currentMode === 'table' ? 'table' : 'combine';
    exportCurrent(prefix);
}

// ===== 导出表格（走统一导出） =====
function exportTable(format) {
    exportCurrent('table');
}

// ===== 快速切换风格 =====
function quickSwitchTheme(theme) {
    // 更新按钮状态
    document.querySelectorAll('.theme-btn').forEach(btn => {
        btn.classList.toggle('active', btn.dataset.theme === theme);
    });

    if (currentMode === 'chart') {
        // 图表模式：更新主题选择器并重新渲染
        document.getElementById('themeStyle').value = theme;
        updateChart();
    } else if (currentMode === 'table') {
        // 表格模式：更新主题选择器并重新请求
        document.getElementById('tableTheme').value = theme;
        updateTable();
    }
    // 双图合并模式：仅切换按钮高亮，不联动（两图各自独立主题）
}

// ===== 同步风格按钮状态（下拉框变更时） =====
function syncThemeButtons(theme) {
    document.querySelectorAll('.theme-btn').forEach(btn => {
        btn.classList.toggle('active', btn.dataset.theme === theme);
    });
}

// ===== 初始化风格按钮状态 =====
function initThemeButtons() {
    // 默认激活 default
    document.querySelectorAll('.theme-btn').forEach(btn => {
        btn.classList.toggle('active', btn.dataset.theme === 'default');
    });
}

// 页面加载时初始化
document.addEventListener('DOMContentLoaded', () => {
    initThemeButtons();
});

// ===== 双图合并 =====
let combinedCanvas = null;

// 构建单个子图的 echarts option（不依赖全局状态，双图模式专用）
function buildCombineChartOption(dataText, cfg) {
    const parsed = parseData(dataText);
    if (!parsed) return null;

    const {
        title = '', chartType = 'bar', theme = 'default',
        showLegend = true, showGrid = true, showLabel = false,
        stackMode = false, smoothLine = true
    } = cfg;

    const bgColor = theme === 'dark' ? '#1a1a2e' : '#ffffff';
    const textColor = theme === 'dark' ? '#e0e0e0' : '#333333';
    const axisLineColor = theme === 'dark' ? '#444' : '#ddd';
    const palette = colorPalettes[theme] || colorPalettes.default;

    const series = parsed.seriesNames.map((name, idx) => {
        const color = palette[idx % palette.length];
        let type = chartType === 'bar-line' ? (idx % 2 === 0 ? 'bar' : 'line') : chartType;

        const s = {
            name,
            type,
            data: [...parsed.seriesData[name]],
            itemStyle: { color },
            emphasis: { focus: 'series' }
        };

        if (stackMode) s.stack = 'total';

        if (type === 'line') {
            s.smooth = smoothLine;
            s.lineStyle = { width: 3 };
            s.symbolSize = 8;
            s.areaStyle = theme === 'gradient' ? { opacity: 0.15 } : undefined;
        }

        if (type === 'bar') {
            s.barMaxWidth = 40;
            s.itemStyle.borderRadius = stackMode ? [0, 0, 0, 0] : [4, 4, 0, 0];
            if (theme === 'gradient') {
                s.itemStyle.color = new echarts.graphic.LinearGradient(0, 0, 0, 1, [
                    { offset: 0, color },
                    { offset: 1, color: adjustColor(color, 40) }
                ]);
            }
        }

        if (showLabel) {
            s.label = {
                show: true,
                position: 'top',
                fontSize: 11,
                color: textColor,
                formatter: (p) => {
                    if (p.value >= 10000) return (p.value / 10000).toFixed(1) + 'w';
                    if (p.value >= 1000) return (p.value / 1000).toFixed(1) + 'k';
                    return p.value;
                }
            };
        }

        return s;
    });

    return {
        backgroundColor: bgColor,
        title: title ? {
            text: title,
            left: 'center',
            top: 10,
            textStyle: { color: textColor, fontSize: 16, fontWeight: 600 }
        } : undefined,
        tooltip: {
            trigger: 'axis',
            backgroundColor: theme === 'dark' ? 'rgba(30,30,50,0.95)' : 'rgba(255,255,255,0.95)',
            borderColor: theme === 'dark' ? '#555' : '#eee',
            textStyle: { color: textColor }
        },
        legend: showLegend ? {
            show: true,
            top: title ? 40 : 10,
            textStyle: { color: textColor, fontSize: 12 },
            itemGap: 20,
            icon: 'roundRect'
        } : { show: false },
        grid: {
            left: '3%', right: '4%', bottom: '3%',
            top: showLegend ? (title ? 70 : 45) : (title ? 50 : 30),
            containLabel: true
        },
        xAxis: {
            type: 'category',
            data: parsed.categories,
            axisLine: { lineStyle: { color: axisLineColor } },
            axisLabel: { color: textColor, fontSize: 11, interval: 0, rotate: parsed.categories.length > 10 ? 30 : 0 },
            axisTick: { show: false }
        },
        yAxis: {
            type: 'value',
            axisLine: { show: false },
            axisTick: { show: false },
            axisLabel: { color: textColor, fontSize: 11 },
            splitLine: { show: showGrid, lineStyle: { color: theme === 'dark' ? '#333' : '#f0f0f0', type: 'dashed' } }
        },
        series,
        animation: false
    };
}

// 根据数据量估算子图尺寸
function measureCombineChart(dataText) {
    const p = parseData(dataText);
    if (!p) return { w: 600, h: 400 };
    const w = Math.min(900, Math.max(500, p.categories.length * 70 + 140));
    return { w, h: 400 };
}

// 生成合并图
function generateCombine() {
    const d1 = document.getElementById('combineData1').value.trim();
    const d2 = document.getElementById('combineData2').value.trim();
    if (!d1 || !d2) return;

    const direction = document.querySelector('input[name="combineDirection"]:checked').value;
    const gap = 24;

    const readCfg = (n) => ({
        title: document.getElementById('combineTitle' + n).value,
        chartType: document.getElementById('combineType' + n).value,
        theme: document.getElementById('combineTheme' + n).value,
        showLegend: document.getElementById('combineLegend' + n).checked,
        showGrid: document.getElementById('combineGrid' + n).checked,
        showLabel: document.getElementById('combineLabel' + n).checked,
        stackMode: document.getElementById('combineStack' + n).checked
    });

    const chartArea = document.getElementById('chartArea');
    chartArea.innerHTML = '<div class="placeholder"><p>⏳</p><p>正在合并...</p></div>';

    const renderOne = (dataText, cfg, w, h) => new Promise((resolve, reject) => {
        const option = buildCombineChartOption(dataText, cfg);
        if (!option) { reject(new Error('数据格式错误')); return; }
        const holder = document.createElement('div');
        holder.style.cssText = `position:absolute;left:-9999px;top:0;width:${w}px;height:${h}px;`;
        document.body.appendChild(holder);
        const chart = echarts.init(holder, null, { renderer: 'canvas' });
        chart.setOption(option);
        setTimeout(() => {
            const srcCvs = holder.querySelector('canvas');
            if (!srcCvs) { reject(new Error('子图渲染失败')); return; }
            // 关键：先把内容复制到独立 canvas 再 dispose。
            // 直接 resolve 原 canvas 的话，Promise 微任务在 chart.dispose() 之后才执行，
            // 此时 canvas 内容已被 echarts 清空，合并出来就是白图。
            const copy = document.createElement('canvas');
            copy.width = srcCvs.width;
            copy.height = srcCvs.height;
            copy.getContext('2d').drawImage(srcCvs, 0, 0);
            chart.dispose();
            holder.remove();
            resolve(copy);
        }, 80);
    });

    const m1 = measureCombineChart(d1);
    const m2 = measureCombineChart(d2);

    Promise.all([
        renderOne(d1, readCfg(1), m1.w, m1.h),
        renderOne(d2, readCfg(2), m2.w, m2.h)
    ]).then(([c1, c2]) => {
        let W, H, r1, r2;
        if (direction === 'vertical') {
            // 竖排（上下）：等宽
            const tw = Math.max(c1.width, c2.width);
            r1 = { w: tw, h: Math.round(c1.height * tw / c1.width) };
            r2 = { w: tw, h: Math.round(c2.height * tw / c2.width) };
            W = tw; H = r1.h + r2.h + gap;
        } else {
            // 横排（左右）：等高
            const th = Math.max(c1.height, c2.height);
            r1 = { w: Math.round(c1.width * th / c1.height), h: th };
            r2 = { w: Math.round(c2.width * th / c2.height), h: th };
            W = r1.w + r2.w + gap; H = th;
        }

        const canvas = document.createElement('canvas');
        canvas.width = W;
        canvas.height = H;
        const ctx = canvas.getContext('2d');
        ctx.fillStyle = '#ffffff';
        ctx.fillRect(0, 0, W, H);

        if (direction === 'vertical') {
            ctx.drawImage(c1, 0, 0, r1.w, r1.h);
            ctx.drawImage(c2, 0, r1.h + gap, r2.w, r2.h);
        } else {
            ctx.drawImage(c1, 0, 0, r1.w, r1.h);
            ctx.drawImage(c2, r1.w + gap, 0, r2.w, r2.h);
        }

        combinedCanvas = canvas;
        const url = canvas.toDataURL('image/png');
        chartArea.innerHTML = `<div class="table-preview"><img src="${url}" alt="合并图预览" style="max-width:100%;"></div>`;
        refreshPreview();
    }).catch(err => {
        chartArea.innerHTML = `<div class="placeholder"><p>❌</p><p>${err.message}</p></div>`;
    });
}

// 导出合并图（走统一导出）
function exportCombine() {
    exportCurrent('combine');
}