// ==UserScript==
// @name         Linux Do Hub LDC 汇率转换器
// @namespace    https://linux.do/
// @version      2.3.1
// @description  修复关闭转换时表格金额未还原的问题：还原改为按快照属性全局反查
// @author       Tabbit
// @match        https://hub.linux.do/*
// @run-at       document-end
// @grant        none
// @license MIT
// ==/UserScript==

(function () {
    'use strict';

    const EXCHANGE_RATE = 50;               // 1 平台币 = 50 LDC
    const STORAGE_KEY = 'ldc_converter_enabled';

    let isEnabled = localStorage.getItem(STORAGE_KEY) === '1';

    const DOLLAR_REGEX = /(-?)\$([\d,]+(?:\.\d+)?)(?!\s*\/\s*[\d,]+(?:\.\d+)?\s*LDC)/g;
    const CELL_REGEX = /^(-?)(\$?)([\d,]+(?:\.\d+)?)(\s*(?:\/\s*1?[MK万]?|USD|美元)?\s*)$/i;
    const HEADER_HINTS = ['USD', '价格', '金额', '余额', '费用', 'PRICE', 'COST'];

    const btn = document.createElement('button');
    btn.textContent = isEnabled ? '恢复平台币' : '开启 LDC 模式';
    btn.style.cssText =
        'position:fixed;top:10px;right:10px;z-index:2147483647;pointer-events:auto;' +
        'padding:6px 12px;color:#fff;border:none;border-radius:4px;cursor:pointer;font-size:12px;' +
        'box-shadow:0 2px 4px rgba(0,0,0,.1);background:' + (isEnabled ? '#10b981' : '#3b82f6');
    document.body.appendChild(btn);

    const toLdc = s => (parseFloat(String(s).replace(/,/g, '')) * EXCHANGE_RATE).toFixed(4);

    /* ========== 全量还原：按快照属性反查，不依赖表格结构与列号 ========== */
    function restoreAll() {
        document.querySelectorAll('[data-ldc-orig]').forEach(el => {        // 表格单元格
            el.innerText = el.dataset.ldcOrig;
            delete el.dataset.ldcOrig;
        });
        document.querySelectorAll('[data-ldc-orig-html]').forEach(el => {   // 卡片/概览区
            el.innerHTML = el.dataset.ldcOrigHtml;
            delete el.dataset.ldcOrigHtml;
            delete el.dataset.ldcConverted;
        });
        document.querySelectorAll('[data-ldc-orig-header]').forEach(el => { // 表头
            el.innerText = el.dataset.ldcOrigHeader;
            delete el.dataset.ldcOrigHeader;
        });
    }

    /* ========== 1. 表格：按 USD 列转换（仅负责开启方向） ========== */
    function processTables() {
        document.querySelectorAll('table, [role="table"], [role="grid"]').forEach(table => {
            const headerCells = [...new Set(table.querySelectorAll('th, [role="columnheader"]'))];
            const usdCols = new Set();

            headerCells.forEach((th, idx) => {
                if (th.dataset.ldcOrigHeader !== undefined) { usdCols.add(idx); return; } // 已转换过的列
                const text = (th.innerText || '').trim();
                if (HEADER_HINTS.some(k => text.toUpperCase().includes(k))) {
                    th.dataset.ldcOrigHeader = text;
                    th.innerText = text.includes('USD') ? text.replace(/USD/g, 'LDC') : text + ' (LDC)';
                    usdCols.add(idx);
                }
            });

            if (!usdCols.size) return; // 开启方向才受此约束，还原已剥离到 restoreAll

            table.querySelectorAll('tbody tr, [role="row"]').forEach(row => {
                row.querySelectorAll('td, [role="cell"], [role="gridcell"]').forEach((cell, idx) => {
                    if (!usdCols.has(idx)) return;

                    const leaves = [...cell.querySelectorAll('span, div')].filter(e => !e.children.length);
                    const targets = leaves.length ? leaves : [cell];

                    targets.forEach(el => {
                        if (el.dataset.ldcOrig !== undefined) return; // 已转换
                        const text = (el.innerText || '').trim();
                        const m = text.match(CELL_REGEX);
                        if (m && (m[2] === '$' || m[4].trim() === '' || /\/|USD|美元/i.test(m[4]))) {
                            el.dataset.ldcOrig = text;
                            el.innerText = m[1] + toLdc(m[3]) + m[4];
                        }
                    });
                });
            });
        });
    }

    /* ========== 2. 非表格区域：追加 "/ xx LDC"（仅负责开启方向） ========== */
    function processCards() {
        document.querySelectorAll('div, span, p, h2').forEach(el => {
            if (el.children.length || !el.innerText || !el.innerText.includes('$')) return;
            if (el.closest('table, [role="table"], [role="grid"]')) return;
            if (el.dataset.ldcConverted === '1') return;

            DOLLAR_REGEX.lastIndex = 0;
            if (!DOLLAR_REGEX.test(el.innerText)) return;
            DOLLAR_REGEX.lastIndex = 0;

            el.dataset.ldcOrigHtml = el.innerHTML;
            el.innerHTML = el.innerText.replace(DOLLAR_REGEX, (m, sign, amt) =>
                `${m} <span style="font-size:0.85em;opacity:0.6;margin-left:2px;">/ ${sign}${toLdc(amt)} LDC</span>`);
            el.dataset.ldcConverted = '1';
        });
    }

    const run = () => { processTables(); processCards(); };

    btn.addEventListener('click', () => {
        isEnabled = !isEnabled;
        localStorage.setItem(STORAGE_KEY, isEnabled ? '1' : '0');
        btn.textContent = isEnabled ? '恢复平台币' : '开启 LDC 模式';
        btn.style.background = isEnabled ? '#10b981' : '#3b82f6';
        isEnabled ? run() : restoreAll();   // 关闭时走全量快照还原
    });

    if (isEnabled) { setTimeout(run, 300); setTimeout(run, 1000); }

    let t1, t2;
    new MutationObserver(() => {
        if (!btn.isConnected) document.body.appendChild(btn);
        if (!isEnabled) return;
        clearTimeout(t1); clearTimeout(t2);
        t1 = setTimeout(run, 120);
        t2 = setTimeout(run, 600);
    }).observe(document.body, { childList: true, subtree: true, characterData: true });
})();