// ==UserScript==
// @name         Colorful Table | Table Data Visualizer
// @name:zh-CN   彩色表格 | 表格数据可视化
// @description  Enhance table readability with interactive gradient-filled columns. Click on any column to apply a color gradient based on cell values.
// @description:zh-CN  通过渐变填充列来增强表格可读性。点击任何列可根据单元格值应用颜色渐变。
// @namespace    http://tampermonkey.net/
// @version      0.5
// @author       Yearly
// @match        *://*/*
// @icon         data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iODAwIiBoZWlnaHQ9IjgwMCIgdmlld0JveD0iMCAwIDExIDExIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjxwYXRoIGZpbGw9IiM0NEMiIGQ9Ik0wIDBoNHYzSDB6Ii8+PHBhdGggZmlsbD0iIzRDNCIgZD0iTTAgNGg0djNIMHoiLz48cGF0aCBmaWxsPSIjQzQ0IiBkPSJNMCA4aDR2M0gweiIvPjxwYXRoIGZpbGw9IiM0Q0MiIGQ9Ik01IDBoMTF2M0g1eiIvPjxwYXRoIGZpbGw9IiNDQzQiIGQ9Ik01IDRoMTF2M0g1eiIvPjxwYXRoIGZpbGw9IiNDNEMiIGQ9Ik01IDhoMTF2M0g1eiIvPjwvc3ZnPg==
// @grant        none
// @license      GPL-3.0
// @downloadURL https://update.greasyfork.icu/scripts/502933/Colorful%20Table%20%7C%20Table%20Data%20Visualizer.user.js
// @updateURL https://update.greasyfork.icu/scripts/502933/Colorful%20Table%20%7C%20Table%20Data%20Visualizer.meta.js
// ==/UserScript==

(function() {
    'use strict';

    const DEBOUNCE_DELAY = 300;
    const POLL_INTERVAL = 1000;
    const HUE_RANGE = 120;
    const SATURATION = '80%';
    const LIGHTNESS = '88%';

    function extractFirstFloat(str) {
        const match = str.match(/[-+]?\d*\.?\d+/);
        return match ? parseFloat(match[0]) : NaN;
    }

    function applyGradient(table, column) {
        const values = Array.from(table.rows)
            .map(row => row.cells[column])
            .filter(cell => cell)
            .map(cell => extractFirstFloat(cell.textContent || cell.innerText))
            .filter(val => !isNaN(val));

        if (values.length === 0) return;

        const min = Math.min(...values);
        const max = Math.max(...values);
        if (min === max) return;

        const headerCell = table.rows[0]?.cells[column];
        if (!headerCell) return;

        headerCell.gradient_fill_increase = !headerCell.gradient_fill_increase;
        const isIncreasing = headerCell.gradient_fill_increase;

        Array.from(table.rows).forEach(row => {
            const cell = row.cells[column];
            if (!cell) return;

            const value = extractFirstFloat(cell.textContent || cell.innerText);
            if (isNaN(value)) return;

            const hue = isIncreasing
                ? HUE_RANGE - ((value - min) / (max - min)) * HUE_RANGE
                : ((value - min) / (max - min)) * HUE_RANGE;

            cell.style.backgroundColor = `hsl(${hue}, ${SATURATION}, ${LIGHTNESS})`;
        });
    }

    function debounce(func, delay) {
        let timeoutId;
        return function(...args) {
            clearTimeout(timeoutId);
            timeoutId = setTimeout(() => func.apply(this, args), delay);
        };
    }

    function initializeTable(table) {
        if (table.hasAttribute('data-gradient-initialized')) return;
        table.setAttribute('data-gradient-initialized', 'true');

        table.addEventListener('click', debounce(event => {
            const column = event.target.cellIndex;
            if (column !== undefined) {
                applyGradient(table, column);
            }
        }, DEBOUNCE_DELAY));
    }

    function initializeTables() {
        document.querySelectorAll('table:not([data-gradient-initialized])').forEach(initializeTable);
    }

    // Initial call and setup interval
    initializeTables();
    setInterval(initializeTables, POLL_INTERVAL);
})();