/* common.js —— 全站通用交互
 * 功能：昼/夜主题切换、实时时钟、随机名言刷新、四大板块 hover 浮层、
 *      搜索栏（引擎下拉/清除/回车搜索）、复制到剪贴板、DOM 工具函数
 */
(function (global) {
    'use strict';

    /* ---------- 工具 ---------- */
    function $(sel, root) { return (root || document).querySelector(sel); }
    function $$(sel, root) { return Array.prototype.slice.call((root || document).querySelectorAll(sel)); }

    /* ---------- 主题（昼/夜） ---------- */
    var THEME_KEY = 'hp-theme';

    function currentTheme() {
        var saved = null;
        try { saved = localStorage.getItem(THEME_KEY); } catch (e) { /* ignore */ }
        if (saved === 'light' || saved === 'dark') return saved;
        // 未设置：跟随系统
        return (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) ? 'dark' : 'light';
    }

    function applyTheme(t, persist) {
        document.documentElement.setAttribute('data-theme', t);
        if (persist) {
            try { localStorage.setItem(THEME_KEY, t); } catch (e) { /* ignore */ }
        }
        var icons = $$('.js-theme-icon');
        icons.forEach(function (el) { el.textContent = (t === 'dark') ? '☀' : '☾'; });
        var btn = $('.js-theme-btn');
        if (btn) btn.title = (t === 'dark') ? '切换到白天模式' : '切换到黑夜模式';
    }

    function initTheme() {
        applyTheme(currentTheme(), false);
        $$('.js-theme-btn').forEach(function (btn) {
            btn.addEventListener('click', function () {
                var next = (document.documentElement.getAttribute('data-theme') === 'dark') ? 'light' : 'dark';
                applyTheme(next, true);
            });
        });
        if (window.matchMedia) {
            window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', function () {
                // 用户手动选过则不跟随系统变化
                try {
                    if (!localStorage.getItem(THEME_KEY)) applyTheme(currentTheme(), false);
                } catch (e) { applyTheme(currentTheme(), false); }
            });
        }
    }

    /* ---------- 实时时钟 ---------- */
    function pad(n) { return (n < 10 ? '0' : '') + n; }
    function formatTime(d) {
        return d.getFullYear() + '-' + pad(d.getMonth() + 1) + '-' + pad(d.getDate()) + ' ' +
            pad(d.getHours()) + ':' + pad(d.getMinutes()) + ':' + pad(d.getSeconds());
    }
    function initClocks() {
        function tick() { $$('.js-clock').forEach(function (el) { el.textContent = formatTime(new Date()); }); }
        tick();
        setInterval(tick, 1000);
    }

    /* ---------- 名言条：点击格言本身切换 ---------- */
    function initQuoteRefresh() {
        $$('.js-quote').forEach(function (quote) {
            quote.addEventListener('click', function () {
                var list = $$('.js-quote-pool span', document); // 服务端把所有名言放入隐藏池
                if (!list.length) return;
                // 定位当前展示文本在池中的位置，避免换到下一条仍是同一条
                var currentText = quote.textContent;
                var cur = -1;
                for (var i = 0; i < list.length; i++) {
                    if (list[i].textContent === currentText) { cur = i; break; }
                }
                var n = list.length;
                var idx = Math.floor(Math.random() * n);
                if (n > 1 && cur !== -1) {
                    while (idx === cur) idx = (idx + 1) % n;
                }
                quote.textContent = list[idx].textContent;
            });
        });
    }

    /* ---------- 首页四大板块 hover 展开说明 ---------- */
    function initBoardHover() {
        var section = $('.js-boards');
        if (!section) return;
        var cards = $$('.js-board-card', section);
        var overlay = $('.js-board-panel', section);
        if (!cards.length || !overlay) return;
        var titleEl = $('.js-board-panel-title', overlay);
        var descEl = $('.js-board-panel-desc', overlay);
        var bodyEl = section;

        function showPanel(card) {
            var name = card.getAttribute('data-name') || '';
            var desc = card.getAttribute('data-desc') || '';
            var idx = cards.indexOf(card);
            if (titleEl) titleEl.textContent = name;
            if (descEl) descEl.textContent = desc;
            overlay.classList.remove('panel-left', 'panel-right');
            // 第 0 / 1 块吸附左侧边缘，第 2 / 3 块吸附右侧边缘（实际板块位置不变）
            if (idx === 0 || idx === 1) overlay.classList.add('panel-left');
            else overlay.classList.add('panel-right');
            overlay.classList.add('visible');
        }

        cards.forEach(function (card) {
            card.addEventListener('mouseenter', function () { showPanel(card); });
            card.addEventListener('click', function () { /* 点击由 <a> 包裹，这里无额外处理 */ });
        });
        section.addEventListener('mouseleave', function () { overlay.classList.remove('visible'); });
    }

    /* ---------- 搜索栏 ---------- */
    var DEFAULT_ENGINES = [
        { key: 'bing', name: 'Bing', icon: 'B', url: 'https://www.bing.com/search?q={kw}' },
        { key: 'baidu', name: '百度', icon: '度', url: 'https://www.baidu.com/s?wd={kw}' },
        { key: 'github', name: 'GitHub', icon: 'G', url: 'https://github.com/search?q={kw}' },
        { key: 'google', name: 'Google', icon: 'G', url: 'https://www.google.com/search?q={kw}' }
    ];

    function initSearch() {
        var box = $('.js-search');
        if (!box) return;
        var cfg = null;
        try { cfg = JSON.parse(box.getAttribute('data-engines') || 'null'); } catch (e) { cfg = null; }
        var engines = (cfg && cfg.length) ? cfg : DEFAULT_ENGINES;
        var curKey = box.getAttribute('data-engine') || engines[0].key;
        var cur = engines.filter(function (e) { return e.key === curKey; })[0] || engines[0];

        var input = $('.js-search-input', box);
        var clearBtn = $('.js-search-clear', box);
        var engineBtn = $('.js-engine-btn', box);
        var engineName = $('.js-engine-name', box);
        var menu = $('.js-engine-menu', box);

        function setEngine(e) {
            cur = e;
            // 按钮区域只显示图标（全称在展开下拉列表时展示）
            if (engineName) engineName.textContent = e.icon || '';
            if (engineBtn) engineBtn.title = '搜索引擎：' + e.name;
            box.setAttribute('data-engine', e.key);
            hideMenu();
        }
        function showMenu() {
            if (!menu) return;
            if (!menu.children.length) {
                engines.forEach(function (e) {
                    var li = document.createElement('li');
                    li.textContent = e.icon + ' ' + e.name;
                    li.className = (e.key === cur.key) ? 'active' : '';
                    li.addEventListener('click', function () { setEngine(e); });
                    menu.appendChild(li);
                });
            }
            menu.classList.add('open');
        }
        function hideMenu() { if (menu) menu.classList.remove('open'); }

        function updateClear() {
            if (clearBtn) clearBtn.style.visibility = (input && input.value) ? 'visible' : 'hidden';
        }
        function doSearch() {
            var kw = (input ? input.value : '').trim();
            if (!kw) { if (input) input.focus(); return; }
            window.open(cur.url.replace('{kw}', encodeURIComponent(kw)), '_blank', 'noopener');
        }

        if (engineBtn) engineBtn.addEventListener('click', function (ev) {
            ev.stopPropagation();
            if (menu && menu.classList.contains('open')) hideMenu(); else showMenu();
        });
        if (clearBtn) clearBtn.addEventListener('click', function () {
            if (input) { input.value = ''; input.focus(); }
            updateClear();
        });
        if (input) {
            input.addEventListener('input', updateClear);
            input.addEventListener('keydown', function (ev) { if (ev.key === 'Enter') doSearch(); });
        }
        document.addEventListener('click', function () { hideMenu(); });
        var goBtn = $('.js-search-go', box);
        if (goBtn) goBtn.addEventListener('click', doSearch);
        setEngine(cur);
        updateClear();
    }

    /* ---------- 后台图标控件：文本 / 图片上传（≤200KB → dataURL） ---------- */
    function isIconImage(v) {
        v = String(v || '').trim();
        if (!v) return false;
        if (/^data:image\//i.test(v) || /^https?:\/\//i.test(v)) return true;
        if (/\.(png|jpe?g|gif|svg|webp)(\?|#|$)/i.test(v)) return true;
        return v.charAt(0) === '/' || v.indexOf('./') === 0 || v.indexOf('../') === 0;
    }
    function updateIconPreview(ctl) {
        var input = ctl.querySelector('.icon-input');
        var box = ctl.querySelector('.icon-preview');
        if (!input || !box) return;
        var v = input.value.trim();
        box.innerHTML = '';
        if (!v) return;                 // 空：显示空心占位框
        if (isIconImage(v)) {
            var img = document.createElement('img');
            img.src = v;
            img.alt = '';
            img.loading = 'lazy';
            box.appendChild(img);
        } else {
            box.textContent = v;
        }
    }
    function initIconControls() {
        // 点击“上传”→ 触发隐藏 file
        document.addEventListener('click', function (ev) {
            var btn = ev.target && ev.target.closest ? ev.target.closest('.icon-upload') : null;
            if (!btn) return;
            var ctl = btn.closest('.icon-ctl');
            var file = ctl ? ctl.querySelector('.icon-file') : null;
            if (file) file.click();
        });
        // 选择图片 → 校验并转 dataURL 写入同控件文本框
        document.addEventListener('change', function (ev) {
            var file = ev.target;
            if (!file || !file.classList || !file.classList.contains('icon-file')) return;
            var ctl = file.closest('.icon-ctl');
            var input = ctl ? ctl.querySelector('.icon-input') : null;
            var f = file.files && file.files[0];
            function reset() { file.value = ''; }
            if (!f) return;
            if (f.type.indexOf('image/') !== 0) { alert('请选择图片文件。'); reset(); return; }
            if (f.size > 200 * 1024) { alert('图片不能超过 200KB。'); reset(); return; }
            var rd = new FileReader();
            rd.onload = function () {
                if (input) {
                    input.value = rd.result;
                    updateIconPreview(ctl);
                }
                reset();
            };
            rd.onerror = function () { alert('图片读取失败，请重试。'); reset(); };
            rd.readAsDataURL(f);
        });
        // 手动输入文本 → 实时预览
        document.addEventListener('input', function (ev) {
            var t = ev.target;
            if (t && t.classList && t.classList.contains('icon-input')) {
                updateIconPreview(t.closest('.icon-ctl'));
            }
        });
        // 初始化页面既有控件预览
        $$('.icon-ctl').forEach(updateIconPreview);
    }

    /* ---------- 复制 ---------- */
    function copyText(text, btnEl) {
        function done(ok) {
            if (!btnEl) return;
            var old = btnEl.textContent;
            btnEl.textContent = ok ? '✓ 已复制' : '复制失败';
            setTimeout(function () { btnEl.textContent = old; }, 1500);
        }
        if (navigator.clipboard && navigator.clipboard.writeText) {
            navigator.clipboard.writeText(text).then(function () { done(true); }, function () { fallbackCopy(text, done); });
        } else {
            fallbackCopy(text, done);
        }
    }
    function fallbackCopy(text, done) {
        var ta = document.createElement('textarea');
        ta.value = text;
        ta.style.cssText = 'position:fixed;opacity:0;';
        document.body.appendChild(ta);
        ta.select();
        try { done(document.execCommand('copy')); } catch (e) { done(false); }
        document.body.removeChild(ta);
    }
    function initCopyButtons() {
        document.addEventListener('click', function (ev) {
            var btn = ev.target.closest ? ev.target.closest('.js-copy') : null;
            if (!btn) return;
            var text = btn.getAttribute('data-copy');
            if (text === null || text === undefined) {
                var target = $(btn.getAttribute('data-target') || '');
                text = target ? target.value : '';
            }
            copyText(text, btn);
        });
    }

    /* ---------- 站点风格确认弹窗（回车确认 / Esc 取消 / 点击遮罩取消） ---------- */
    function escHtml(s) {
        return String(s).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
    }
    function siteConfirm(message, opts) {
        opts = opts || {};
        return new Promise(function (resolve) {
            var danger = opts.danger !== false;
            var okText = opts.okText || (danger ? '删除' : '确认');
            var overlay = document.createElement('div');
            overlay.className = 'sc-overlay';
            overlay.innerHTML =
                '<div class="sc-card" role="alertdialog" aria-modal="true">' +
                '<div class="sc-head">' + escHtml(opts.title || '操作确认') + '</div>' +
                '<div class="sc-body">' + escHtml(message || '') + '</div>' +
                '<div class="sc-foot">' +
                '<button type="button" class="btn btn-sm sc-cancel">' + escHtml(opts.cancelText || '取消') + '</button>' +
                '<button type="button" class="btn btn-sm ' + (danger ? 'btn-danger' : 'btn-primary') + ' sc-ok">' + escHtml(okText) + '</button>' +
                '</div></div>';
            var okBtn = overlay.querySelector('.sc-ok');
            var cancelBtn = overlay.querySelector('.sc-cancel');
            var finished = false;
            function close(val) {
                if (finished) return;
                finished = true;
                document.removeEventListener('keydown', onKey, true);
                if (overlay.parentNode) overlay.parentNode.removeChild(overlay);
                resolve(val);
            }
            function onKey(ev) {
                if (ev.key === 'Escape') { ev.preventDefault(); close(false); }
                else if (ev.key === 'Enter') { ev.preventDefault(); close(true); }
            }
            okBtn.addEventListener('click', function () { close(true); });
            cancelBtn.addEventListener('click', function () { close(false); });
            overlay.addEventListener('mousedown', function (ev) { if (ev.target === overlay) close(false); });
            document.addEventListener('keydown', onKey, true);
            document.body.appendChild(overlay);
            okBtn.focus();
        });
    }
    // 统一入口：旧浏览器/异常时回落原生 confirm（仍然以 Promise 风格使用）
    function askConfirm(message, opts) {
        return siteConfirm(message, opts);
    }
    // 表单：带 data-confirm="提示文案" 的表单提交前弹窗确认
    function bindConfirmForms() {
        document.addEventListener('submit', function (ev) {
            var f = ev.target;
            if (!f || !f.getAttribute || !f.hasAttribute('data-confirm')) return;
            ev.preventDefault();
            siteConfirm(f.getAttribute('data-confirm')).then(function (ok) { if (ok) f.submit(); });
        });
    }

    /* ---------- 返回顶部（右下角按钮，滚动后出现；兼容内滚容器页面） ---------- */
    function initToTop() {
        var btn = document.querySelector('.js-to-top');
        if (!btn) return;
        var scrollables = [];
        var doc = document.scrollingElement || document.documentElement;
        if (doc) scrollables.push(doc);
        Array.prototype.forEach.call(document.querySelectorAll('*'), function (el) {
            if (el === doc || el === btn) return;
            if (el.scrollHeight <= el.clientHeight + 40) return;
            var cs;
            try { cs = window.getComputedStyle(el); } catch (e) { cs = null; }
            if (!cs) return;
            if (cs.overflowY === 'auto' || cs.overflowY === 'scroll') scrollables.push(el);
        });
        function measure() {
            var v = 0;
            for (var i = 0; i < scrollables.length; i++) {
                if (scrollables[i].scrollTop > v) v = scrollables[i].scrollTop;
            }
            btn.classList.toggle('show', v > 260);
        }
        for (var s = 0; s < scrollables.length; s++) {
            scrollables[s].addEventListener('scroll', measure, { passive: true });
        }
        window.addEventListener('resize', measure);
        btn.addEventListener('click', function () {
            var root = doc || document.documentElement;
            if (root && root.scrollTop > 0) root.scrollTo({ top: 0, behavior: 'smooth' });
            else window.scrollTo({ top: 0, behavior: 'smooth' });
        });
        measure();
    }

    /* ---------- 自动初始化 ---------- */
    document.addEventListener('DOMContentLoaded', function () {
        initTheme();
        initClocks();
        initQuoteRefresh();
        initBoardHover();
        initSearch();
        initIconControls();
        initCopyButtons();
        bindConfirmForms();
        initToTop();
    });

    global.HomePage = {
        $: $, $$: $$, copyText: copyText, applyTheme: applyTheme, currentTheme: currentTheme,
        confirm: siteConfirm, ask: askConfirm
    };
})(window);