// ==UserScript==
// @name         Link URL Tooltip
// @namespace    https://github.com/kalekber/libnovel-v2
// @version      1.0.0
// @description  Show the destination URL near the cursor when hovering over any link
// @author       kalekber
// @match        *://*/*
// @run-at       document-idle
// @grant        none
// ==/UserScript==

(function () {
    'use strict';

    // --- Inject styles ---
    const style = document.createElement('style');
    style.textContent = `
        #lnk-tooltip {
            position: fixed;
            display: none;
            background-color: #333;
            color: #fff;
            padding: 5px 10px;
            border-radius: 4px;
            font-size: 12px;
            font-family: monospace;
            pointer-events: none;
            z-index: 2147483647;
            white-space: nowrap;
            max-width: 600px;
            overflow: hidden;
            text-overflow: ellipsis;
            box-shadow: 0 2px 6px rgba(0,0,0,0.4);
        }
    `;
    document.head.appendChild(style);

    // --- Inject tooltip element ---
    const tooltip = document.createElement('div');
    tooltip.id = 'lnk-tooltip';
    document.body.appendChild(tooltip);

    // --- Helpers ---
    function getAnchor(target) {
        // Walk up the DOM to find the nearest <a href="...">
        // (handles clicks on nested elements like <a><span>text</span></a>)
        return target.closest('a[href]');
    }

    function show(anchor, clientX, clientY) {
        tooltip.textContent = anchor.href;
        tooltip.style.display = 'block';
        position(clientX, clientY);
    }

    function hide() {
        tooltip.style.display = 'none';
    }

    function position(clientX, clientY) {
        const offset = 12;
        const tw = tooltip.offsetWidth;
        const th = tooltip.offsetHeight;
        const vw = window.innerWidth;
        const vh = window.innerHeight;

        let x = clientX + offset;
        let y = clientY + offset;

        // Flip horizontally if it would overflow the right edge
        if (x + tw > vw - 4) {
            x = clientX - tw - offset;
        }
        // Flip vertically if it would overflow the bottom edge
        if (y + th > vh - 4) {
            y = clientY - th - offset;
        }

        tooltip.style.left = Math.max(0, x) + 'px';
        tooltip.style.top  = Math.max(0, y) + 'px';
    }

    // --- Event delegation on document ---
    document.addEventListener('mouseover', (e) => {
        const anchor = getAnchor(e.target);
        if (anchor) show(anchor, e.clientX, e.clientY);
    });

    document.addEventListener('mousemove', (e) => {
        if (tooltip.style.display === 'block') {
            position(e.clientX, e.clientY);
        }
    });

    document.addEventListener('mouseout', (e) => {
        const anchor = getAnchor(e.target);
        if (anchor) hide();
    });
})();