document.addEventListener('DOMContentLoaded', function(){
const chatDom = document.getElementById("chatDom");
const inputDom = document.getElementById("input-text");
const sendBtn = document.getElementById("send-button");
const uploadBtn = document.getElementById("upload-btn");
const uploadInput = document.getElementById("upload-input");
const composerStatus = document.getElementById("composer-status");
let uploadPending = false;
let uploadVersion = 0;
let uploadController = null;
let historyRequestVersion = 0;
let followLatest = true;
let creatingConv = null;
let sendPreparing = false;
let conversationVersion = 0;
let activeQuickTopic = null;
let humanConvId = null;
let humanStatus = '';
let humanRequestToken = null;
let humanPollTimer = null;
let humanSendingToken = null;
let humanClosing = false;
window.humanSid = 0;
SupportUI.initEmoji(document.getElementById('emoji-toggle'), document.getElementById('emoji-panel'), inputDom, function(){ autoGrow(); });
document.getElementById('notifications-toggle').onclick = function(){ SupportUI.enableNotifications(this); };

function setComposerStatus(message, isError){
    composerStatus.textContent = message || "";
    composerStatus.hidden = !message;
    composerStatus.classList.toggle("is-error", Boolean(isError));
}

async function requestJson(path, options){
    const controller = new AbortController();
    const timer = setTimeout(function(){ controller.abort(); }, 10000);
    try{
        const response = await fetch(path, Object.assign({}, options, {signal:controller.signal}));
        const data = await response.json();
        if(!response.ok){
            const error = new Error(data && (data.e || data.error) || t('networkFail'));
            error.status = response.status;
            throw error;
        }
        return data;
    }finally{ clearTimeout(timer); }
}

function clearAttachment(){
    uploadVersion += 1;
    if(uploadController){
        uploadController.abort();
        uploadController = null;
        uploadPending = false;
        uploadBtn.disabled = false;
        uploadBtn.removeAttribute('aria-busy');
        uploadBtn.textContent = '+';
    }
    window.__pendingImg = "";
    window.__pendingTag = "[图片]";
    const preview = document.getElementById("imgPreview");
    if(preview) preview.remove();
}

function scrollChatToEnd(force){
    if(force) followLatest = true;
    if(followLatest) chatDom.scrollTop = chatDom.scrollHeight;
}

uploadBtn.onclick = ()=> uploadInput.click();
uploadInput.onchange = function(){
    const f = uploadInput.files[0];
    if(!f || uploadPending) return;
    const version = ++uploadVersion;
    const fd = new FormData();
    fd.append("file", f);
    uploadPending = true;
    uploadBtn.disabled = true;
    uploadBtn.setAttribute("aria-busy", "true");
    uploadBtn.textContent = "…";
    setComposerStatus(t("uploading"));
    const controller = new AbortController();
    uploadController = controller;
    const timer = setTimeout(function(){ controller.abort(); }, 15000);
    fetch("/api/upload", {method:"POST", body:fd, signal:controller.signal})
    .then(async function(response){
        const data = await response.json();
        if(!response.ok || !data.ok) throw new Error(data.error || t("uploadFailed"));
        return data;
    })
    .then(data=>{
        if(version === uploadVersion){
            window.__pendingImg = data.url;
            window.__pendingTag = data.is_image ? "[图片]" : "[文件]";
            var old = document.getElementById("imgPreview");
            if(old) old.remove();
            var prev = document.createElement("div");
            prev.id = "imgPreview";
            prev.className = "attachment-preview";
            if(data.is_image){
                var image = document.createElement("img");
                image.src = data.url;
                image.alt = data.name || "待发送图片";
                prev.appendChild(image);
            }else{
                var filename = document.createElement("span");
                filename.className = "attachment-file-icon";
                filename.textContent = data.name.split(".").pop().slice(0,5).toUpperCase();
                prev.appendChild(filename);
            }
            const copy = document.createElement("div");
            copy.className = "attachment-copy";
            const name = document.createElement("strong");
            name.textContent = data.name;
            const hint = document.createElement("small");
            hint.textContent = t("attachmentReady");
            copy.append(name, hint);
            const remove = document.createElement("button");
            remove.type = "button";
            remove.className = "attachment-remove";
            remove.textContent = "×";
            remove.setAttribute("aria-label", t("removeAttachment"));
            remove.onclick = function(){ clearAttachment(); inputDom.focus(); };
            prev.append(copy, remove);
            var area = document.querySelector(".input-area");
            area.before(prev);
            setComposerStatus("");
            inputDom.focus();
        }
    })
    .catch(function(error){
        const message = error.name === 'AbortError' || error instanceof SyntaxError || error instanceof TypeError ? t("uploadFailed") : (error.message || t("uploadFailed"));
        if(version === uploadVersion) setComposerStatus(message, true);
    })
    .finally(function(){
        clearTimeout(timer);
        if(uploadController === controller){
            uploadController = null;
            uploadPending = false;
            uploadBtn.disabled = false;
            uploadBtn.removeAttribute("aria-busy");
            uploadBtn.textContent = "+";
        }
    });
    uploadInput.value = "";
};
const leftHistoryWrap = document.getElementById("historyWrap");
const recentChatWrap = document.getElementById("recentChatWrap");
const clearAllBtn = document.querySelector('.clear-all-btn');
const newChatBtn = document.querySelector('.new-chat-btn');
window.__busy = false;   // 生成中状态，用 window 属性避免作用域问题
// 生成中状态（语言切换等会引用，需提前声明）

// ===== 深色模式 =====
(function initTheme(){
    const KEY = "wuliu-theme";
    const btn = document.getElementById("theme-toggle");
    function apply(mode){
        document.body.classList.toggle("dark", mode === "dark");
        if(btn) btn.textContent = mode === "dark" ? "☀" : "☾";
    }
    let saved = null;
    try{ saved = localStorage.getItem(KEY); }catch(e){}
    if(!saved){
        saved = "light";
    }
    apply(saved);
    if(btn){
        btn.onclick = function(){
            const next = document.body.classList.contains("dark") ? "light" : "dark";
            apply(next);
            try{ localStorage.setItem(KEY, next); }catch(e){}
        }
    }
})();

// ===== 字体大小切换 =====
(function(){
    var KEY = "wuliu-fontsize";
    var SIZES = [14, 16, 18, 20];
    var idx = 1;
    try{ var s = Number(localStorage.getItem(KEY)); if(Number.isInteger(s) && s >= 0 && s < SIZES.length && localStorage.getItem(KEY) !== null) idx = s; }catch(e){}
    var btn = document.getElementById("font-toggle");
    function apply(){
        document.body.style.fontSize = SIZES[idx] + "px";
        if(btn) btn.textContent = SIZES[idx] + "px";
    }
    apply();
    if(btn){
        btn.onclick = function(){
            idx = (idx + 1) % SIZES.length;
            apply();
            try{ localStorage.setItem(KEY, idx); }catch(e){}
        };
    }
})();

// ===== 中英文切换 =====
const I18N = {
    zh: {
        appTitle: "柏悦物流智能助手",
        newChat: "新建对话",
        clearAll: "清空全部历史",
        history: "历史对话",
        searchPh: "搜索历史对话...",
        confirmClear: "确定清空全部历史对话吗？无法恢复！",
        confirmDel: "确定要删除这条历史对话吗？",
        emptySearch: "没有匹配的历史对话",
        emptyHistory: "暂无历史对话",
        thinking: "正在思考中...",
        busyRetry: "服务繁忙，请稍后重试",
        sessionFail: "会话创建失败，请确认服务已启动",
        autoWelcome: "您好！欢迎咨询柏悦物流智能客服，请问有什么可以帮您？输入订单号、入仓码或 Shipment ID 可查订单，或点击下方快捷选项。",
        humanHours: "人工客服工作时间：每天 8:00-22:00。当前为非工作时间，请留言，工作时间会尽快回复您。",
        offlinePrompt: "请输入您的留言：",
        offlineSaved: "留言已提交，工作时间（8:00-22:00）会尽快回复您。",
        humanClosed: "人工客服已结束，您可以继续向 AI 提问。",
        humanReply: "客服回复",
        humanConnecting: "正在为您连接人工客服…",
        humanWaiting: "正在排队，消息将由人工客服接入后回复。您也可以返回 AI 继续咨询。",
        humanActive: "人工客服接待中，消息将发送给人工客服。",
        returnAI: "返回 AI 问答",
        humanSent: "已发送给人工客服",
        humanSending: "正在发送给人工客服…",
        humanSendFailed: "消息未发送成功，内容已保留，请重试。",
        humanConnectFailed: "人工客服连接失败，请稍后重试。",
        humanPollFailed: "人工客服连接中断，正在重试。您可以返回 AI 继续咨询。",
        humanReturnFailed: "暂时无法结束人工会话，请重试。",
        historyLoading: "正在加载这段会话，请稍候…",
        recalled: "该消息已撤回",
        ratingQuestion: "本次服务满意吗？",
        ratingThanks: "感谢您的评价！",
        ratingFailed: "评价未提交，请重试。",
        networkFail: "网络连接中断，请检查网络后重试",
        stopped: "已停止生成",
        stoppedMark: "（已停止生成）",
        inputPh: "请输入问题、订单号或入仓码…（Enter 发送，Shift+Enter 换行）",
        send: "发送",
        stop: "停止",
        copy: "复制",
        copied: "已复制",
        retry: "重答",
        clickRetry: "点击重试",
        welcomeTitle: "物流问题，随时为您解答",
        welcomeSub: "查询订单状态、了解专线报价，或联系人工客服。",
        welcomeEyebrow: "中欧 · 英国物流服务",
        serviceScope: "中欧与英国专线咨询",
        serviceTag: "物流咨询服务",
        quickLabel: "快捷咨询",
        footerTrack: "查订单",
        footerQuote: "专线报价",
        footerException: "异常处理",
        footerHuman: "联系人工",
        disclaimer: "报价与时效仅供参考，请以客服最终确认为准",
        keyboardHint: "Enter 发送 · Shift + Enter 换行",
        inputShort: "输入问题、订单号或入仓码…",
        uploading: "附件正在上传，请稍候…",
        uploadFailed: "附件上传失败，请重新选择文件",
        serviceUnavailable: "服务暂时不可用，请稍后重试，或联系人工客服。",
        attachmentReady: "已准备好，发送后将附在消息中",
        removeAttachment: "移除待发送附件",
        you: "您",
        assistant: "柏悦物流助手",
        humanAgent: "人工客服",
        trackingNo: "运单号",
        orderNo: "订单号",
        orderHistory: "订单业务状态历史",
        noOrderHistory: "未提供订单状态历史",
        legacyTrackingNotice: "历史模拟轨迹，仅供演示，不代表真实订单。",
        order_inbound: "入仓码", order_shipment: "Shipment ID", order_country: "目的国",
        order_warehouse: "目的仓", order_transport: "运输方式", order_packages: "件数",
        order_weight: "申报毛重", order_volume: "申报体积", order_role: "订单层级",
        order_parent: "父订单号", order_updated: "来源更新时间",
        moreTracking: "展开全部轨迹",
        lessTracking: "收起较早轨迹",
        quickSubs: ["输入订单号、入仓码或 Shipment ID", "了解线路、费用与预计时效", "咨询延误、签收或理赔问题", "进一步沟通您的物流需求"],
        welcomeTip: "您可以直接输入问题，也可以点击下面选项快速提问。",
        hot: "热点问题",
        recent: "最近对话记录",
        sideCollapse: "收起侧栏",
        sideExpand: "展开侧栏",
        themeTip: "切换深色/浅色",
        langTip: "中英文切换（Ctrl+L）",
        toBottom: "回到底部",
        quick: [
            "查询订单状态", "欧洲海运专线报价", "包裹异常处理", "转接人工客服"
        ],
        hotList: [
            "如何查询物流轨迹？", "欧洲海运时效是多久？", "包裹显示异常签收怎么办？", "如何申请理赔？"
        ]
    },
    en: {
        appTitle: "Baiyue Logistics AI Assistant",
        newChat: "New Chat",
        clearAll: "Clear All History",
        history: "History",
        searchPh: "Search history...",
        confirmClear: "Clear all conversation history? This cannot be undone.",
        confirmDel: "Delete this conversation?",
        emptySearch: "No matching conversations",
        emptyHistory: "No conversations yet",
        thinking: "Thinking...",
        busyRetry: "Service busy, please try again later",
        sessionFail: "Failed to create session, please check the service is running",
        autoWelcome: "Welcome to Baiyue Logistics. Enter an order number, inbound code or Shipment ID, or choose a quick option below.",
        humanHours: "Our team is available daily, 08:00–22:00. Please leave a message and we will reply during service hours.",
        offlinePrompt: "Please leave your message:",
        offlineSaved: "Message submitted. Our team will reply during service hours (08:00–22:00).",
        humanClosed: "This support session has ended. You can continue chatting with the AI assistant.",
        humanReply: "Support reply",
        humanConnecting: "Connecting you to our support team…",
        humanWaiting: "You are in the queue. A team member will reply after joining, or you can return to AI chat.",
        humanActive: "You are chatting with our support team. Messages will be sent to a team member.",
        returnAI: "Return to AI chat",
        humanSent: "Sent to our support team",
        humanSending: "Sending to our support team…",
        humanSendFailed: "Message not sent. Your text has been kept. Please retry.",
        humanConnectFailed: "Could not connect to our support team. Please try again.",
        humanPollFailed: "Support connection lost. Retrying, or you can return to AI chat.",
        humanReturnFailed: "Could not end the support session. Please try again.",
        historyLoading: "Loading this conversation. Please wait…",
        recalled: "This message was recalled",
        ratingQuestion: "How was your support experience?",
        ratingThanks: "Thank you for your feedback!",
        ratingFailed: "Your rating was not submitted. Please try again.",
        networkFail: "Connection lost, please check your network and retry",
        stopped: "Stopped",
        stoppedMark: "(Generation stopped)",
        inputPh: "Ask a question or enter a tracking number... (Enter to send, Shift+Enter for newline)",
        send: "Send",
        stop: "Stop",
        copy: "Copy",
        copied: "Copied",
        retry: "Regenerate",
        clickRetry: "Retry",
        welcomeTitle: "Your next shipment, made clearer.",
        welcomeSub: "Track a parcel, explore freight options, or speak to our team.",
        welcomeEyebrow: "EUROPE & UK LOGISTICS",
        serviceScope: "Europe & UK freight support",
        serviceTag: "Logistics support",
        quickLabel: "Quick help",
        footerTrack: "Order lookup",
        footerQuote: "Get a quote",
        footerException: "Parcel issue",
        footerHuman: "Human support",
        disclaimer: "Quotes and transit times are subject to final confirmation",
        keyboardHint: "Enter to send · Shift + Enter for a new line",
        inputShort: "Question or tracking number…",
        uploading: "Uploading your attachment…",
        uploadFailed: "Upload failed. Please select the file again.",
        serviceUnavailable: "Service is temporarily unavailable. Please try again later or contact support.",
        attachmentReady: "Ready to attach to your next message",
        removeAttachment: "Remove pending attachment",
        you: "You",
        assistant: "Baiyue Assistant",
        humanAgent: "Support agent",
        trackingNo: "Tracking number",
        orderNo: "Order number",
        orderHistory: "Order workflow history",
        noOrderHistory: "No order status history provided",
        legacyTrackingNotice: "Historical simulated tracking for demonstration only; this is not a real order record.",
        order_inbound: "Inbound code", order_shipment: "Shipment ID", order_country: "Destination country",
        order_warehouse: "Warehouse", order_transport: "Transport", order_packages: "Packages",
        order_weight: "Declared gross weight", order_volume: "Declared volume", order_role: "Order level",
        order_parent: "Parent order", order_updated: "Source updated",
        moreTracking: "View full tracking history",
        lessTracking: "Show recent updates",
        quickSubs: ["Check the latest shipment progress", "Explore routes, rates and transit times", "Get help with delays, delivery or claims", "Discuss your shipping requirements"],
        welcomeTip: "Type your question, or pick a quick option below.",
        hot: "Popular Questions",
        recent: "Recent Conversations",
        sideCollapse: "Collapse sidebar",
        sideExpand: "Expand sidebar",
        themeTip: "Toggle dark/light",
        langTip: "Switch language (Ctrl+L)",
        toBottom: "Back to bottom",
        quick: [
            "Track my shipment", "Europe sea freight quote", "Handle a parcel exception", "Talk to a human agent"
        ],
        hotList: [
            "How do I track my shipment?", "How long does Europe sea freight take?",
            "My parcel shows delivered but I didn't get it", "How do I file a claim?"
        ]
    }
};
let LANG = "zh";
function t(key){
    return (I18N[LANG] || I18N.zh)[key];
}

function applyLanguage(lang){
    LANG = lang === "en" ? "en" : "zh";
    const dict = I18N[LANG];
    document.documentElement.lang = LANG === "en" ? "en" : "zh-CN";
    document.querySelectorAll("[data-i18n]").forEach(function(element){
        const value = dict[element.dataset.i18n];
        if(typeof value === "string") element.textContent = value;
    });
    try{ localStorage.setItem("wuliu-lang", LANG); }catch(e){}

    const titleEl = document.getElementById("app-title");
    if(titleEl) titleEl.textContent = dict.appTitle;
    const langBtn = document.getElementById("lang-toggle");
    if(langBtn){
        langBtn.textContent = LANG === "en" ? "EN" : "中";
        langBtn.title = dict.langTip;
    }
    const themeBtn = document.getElementById("theme-toggle");
    if(themeBtn) themeBtn.title = dict.themeTip;
    document.querySelectorAll(".new-chat-btn").forEach(function(b){ b.textContent = dict.newChat; });
    document.querySelectorAll(".clear-all-btn").forEach(function(b){ b.textContent = dict.clearAll; });
    document.querySelectorAll(".panel-title").forEach(function(e){ e.textContent = dict.history; });
    const hs = document.getElementById("history-search");
    if(hs) hs.placeholder = dict.searchPh;
    if(inputDom) inputDom.placeholder = window.innerWidth > 900 ? dict.inputPh : dict.inputShort;
    sendBtn.textContent = window.__busy ? dict.stop : dict.send;
    const tb = document.getElementById("to-bottom");
    if(tb) tb.title = dict.toBottom;
    const tg = document.querySelector(".toggle-divider");
    if(tg) tg.title = tg.getAttribute('aria-expanded') === 'false' ? dict.sideExpand : dict.sideCollapse;
    updateHumanMode();

    // 欢迎页（若当前显示的是欢迎页则重绘）
    if(chatDom.querySelector(".ai-welcome-card")){
        const scroll = chatDom.scrollTop;
        chatDom.innerHTML = welcomeHTML();
        chatDom.scrollTop = scroll;
    }
    // 历史列表 / 最近对话（空状态与条目都要刷新）
    if(typeof renderSideHistory === 'function'){
        try{
            renderSideHistory();
            renderRecentChat();
        }catch(e){ /* 列表尚未初始化时忽略 */ }
    }
    // 已有消息上的复制/重答按钮
    document.querySelectorAll(".msg-action-btn").forEach(function(b){
        const n = b.dataset.action;
        if(n === "copy") b.textContent = dict.copy;
        if(n === "retry") b.textContent = dict.retry;
    });
    document.querySelectorAll(".retry-btn").forEach(function(b){
        if(!b.dataset.keep) b.textContent = dict.clickRetry;
    });
}

(function initLang(){
    let saved = null;
    try{ saved = localStorage.getItem("wuliu-lang"); }catch(e){}
    if(!saved){
        saved = (navigator.language || "zh").toLowerCase().indexOf("zh") === 0 ? "zh" : "en";
    }
    applyLanguage(saved);
    const btn = document.getElementById("lang-toggle");
    if(btn){
        btn.onclick = function(){ applyLanguage(LANG === "en" ? "zh" : "en"); };
    }
    // 快捷键：Ctrl+L 切换语言（不占用输入框）
    document.addEventListener("keydown", function(e){
        if((e.ctrlKey || e.metaKey) && e.key.toLowerCase() === "l"){
            e.preventDefault();
            applyLanguage(LANG === "en" ? "zh" : "en");
        }
    });
})();

// ===== 历史搜索 =====
const historySearch = document.getElementById("history-search");
if(historySearch){
    historySearch.addEventListener("input", renderSideHistory);
}

let historyList = [];
let sseInstance = null;
let activeBubble = null;      // 正在输出的气泡
let cancelActive = null;      // 中止当前请求（切换对话/重复发送时用）
let currentConvId = null;     // 当前会话 id，null 表示还没建

function formatTime(timeStr) {
    const target = new Date(timeStr);
    const y = target.getFullYear();
    const m = String(target.getMonth() + 1).padStart(2, '0');
    const d = String(target.getDate()).padStart(2, '0');
    const h = String(target.getHours()).padStart(2, '0');
    const min = String(target.getMinutes()).padStart(2, '0');
    return `${y}-${m}-${d} ${h}:${min}`;
}

// 先转义再套格式，防止模型输出里的标签被浏览器执行
function escHtml(s){
    return String(s).replace(/[&<>"]/g, function(c){
        return {"&":"&amp;", "<":"&lt;", ">":"&gt;", '"':"&quot;"}[c];
    });
}

// 轻量 Markdown：加粗、行内代码、无序/有序列表、换行
function mdToHtml(text){
    const inline = function(s){
        return s.replace(/\*\*(.+?)\*\*/g, "<b>$1</b>")
                .replace(/`([^`]+)`/g, "<code>$1</code>");
    };
    const lines = escHtml(text).split("\n");
    let html = "";
    let list = null;
    for (let i = 0; i < lines.length; i++){
        const t = lines[i].trim();
        let m;
        if ((m = t.match(/^[-*•]\s+(.*)$/))){                 // 无序列表
            if (list !== "ul"){ if (list) html += "</" + list + ">"; html += "<ul>"; list = "ul"; }
            html += "<li>" + inline(m[1]) + "</li>";
        } else if ((m = t.match(/^\d+[.、)]\s*(.*)$/))){      // 有序列表
            if (list !== "ol"){ if (list) html += "</" + list + ">"; html += "<ol>"; list = "ol"; }
            html += "<li>" + inline(m[1]) + "</li>";
        } else if (!t){                                        // 空行
            if (list){ html += "</" + list + ">"; list = null; }
            html += "<br>";
        } else {                                               // 普通段落
            if (list){ html += "</" + list + ">"; list = null; }
            html += inline(t) + "<br>";
        }
    }
    if (list) html += "</" + list + ">";
    return html;
}

function parseBold(text){
    return mdToHtml(text);
}

// 空会话时的欢迎内容（新建对话 / 打开空会话都要用）
function welcomeIcon(kind){
    const paths = {
        box: '<path d="m4 7 8-4 8 4v10l-8 4-8-4Z"/><path d="m4 7 8 4 8-4M12 11v10M8 5l8 4"/>',
        track: '<circle cx="10" cy="10" r="6"/><path d="m15 15 5 5M7 10h6M10 7v6"/>',
        quote: '<rect x="5" y="3" width="14" height="18" rx="2"/><path d="M8 7h8M8 11h3M14 11h2M8 15h3M14 15h2M8 18h3M14 18h2"/>',
        issue: '<path d="m12 3 10 18H2L12 3Z M12 9v5M12 17v.1"/>',
        human: '<path d="M4 14v-3a8 8 0 0 1 16 0v3M19 17a4 4 0 0 1-4 4h-3"/><rect x="2" y="11" width="4" height="7" rx="2"/><rect x="18" y="11" width="4" height="7" rx="2"/>'
    };
    return '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">' + paths[kind] + '</svg>';
}

function welcomeHTML(){
    const q = t("quick");
    const h = t("hotList");
    const kinds = ["track", "quote", "issue", "human"];
    const cards = q.map(function(question, index){
        const action = index === 3 ? 'data-human-support' : `data-question="${escHtml(question)}"`;
        return `<button type="button" class="suggest-item" ${action}><span class="suggest-icon">${welcomeIcon(kinds[index])}</span><span class="suggest-copy"><strong>${question}</strong><small>${t("quickSubs")[index]}</small></span><span class="suggest-arrow" aria-hidden="true">↗</span></button>`;
    }).join("");
    return `
            <div class="ai-welcome-card">
                <div class="ai-welcome-top">
                    <div class="ai-avatar">${welcomeIcon("box")}</div>
                    <div class="welcome-eyebrow">${t("welcomeEyebrow")}</div>
                        <h3>${t("welcomeTitle")}</h3>
                        <p>${t("welcomeSub")}</p>
                </div>
                <div class="suggest-grid">${cards}</div>
            </div>

            <div class="hot-questions">
                <h4>${t("hot")}</h4>
                <div class="hot-capsule-wrap">
                    ${h.map(question => `<button type="button" class="hot-capsule" data-question="${escHtml(question)}">${question}</button>`).join("")}
                </div>
            </div>
            <div class="recent-chat" hidden>
                <h4>${t("recent")}</h4>
                <div id="recentChatWrap"></div>
            </div>
    `;
}

// 清空全部历史
if(clearAllBtn){
clearAllBtn.onclick = function(){
    if(openingConv === 'clearing') return;
    if(!confirm(t("confirmClear"))) return;
    const version = resetConversation(null);
    openingConv = 'clearing';
    chatDom.innerHTML = welcomeHTML();
    setComposerStatus(t('historyLoading'));
    requestJson("/api/clear_all", {method:"DELETE"})
    .then(data=>{
        if(!data.ok) throw new Error('Clear failed');
        if(version !== conversationVersion) return;
        openingConv = null;
        setComposerStatus('');
        chatDom.innerHTML = welcomeHTML();
        loadHistory();
    }).catch(function(){
        if(version !== conversationVersion) return;
        openingConv = null;
        setComposerStatus(t('networkFail'), true);
    });
}
}

// 新建对话：只清界面，等用户开口时再建会话
if(newChatBtn){
newChatBtn.onclick = function(){
    if(openingConv === 'clearing') return;
    resetConversation(null);
    inputDom.value = "";
    autoGrow();
    clearAttachment();
    setComposerStatus("");
    chatDom.innerHTML = welcomeHTML();
    chatDom.scrollTop = 0;
    followLatest = true;
    loadHistory();
}
}

function loadHistory(){
    const version = ++historyRequestVersion;
    return requestJson("/api/get_history")
    .then(data=>{
        if(version !== historyRequestVersion || !Array.isArray(data)) return;
        historyList = data;
        renderSideHistory();
        renderRecentChat();
    }).catch(function(){ /* 保留上次成功加载的历史，避免网络错误清空侧栏。 */ });
}

function renderSideHistory(){
    leftHistoryWrap.innerHTML = "";
    const kw = (document.getElementById("history-search")?.value || "").trim().toLowerCase();
    const pinned = pinnedConversations();
    let list = kw
        ? historyList.filter(item => (item.title || "").toLowerCase().indexOf(kw) >= 0)
        : historyList.slice();
    // 置顶的排前面
    list.sort((a,b)=>{
        const ap = pinned.includes(a.id) ? 0 : 1;
        const bp = pinned.includes(b.id) ? 0 : 1;
        return ap - bp;
    });

    if(!list.length){
        const empty = document.createElement("div");
        empty.className = "history-empty";
        empty.innerText = kw ? t("emptySearch") : t("emptyHistory");
        leftHistoryWrap.appendChild(empty);
        return;
    }

    list.forEach((item)=>{
        let div = document.createElement('div');
        div.className = "history-item" + (item.id === currentConvId ? " active" : "");
        div.tabIndex = 0;
        div.setAttribute("role", "button");
        div.addEventListener("keydown", function(event){
            if(event.target === div && (event.key === "Enter" || event.key === " ")){
                event.preventDefault();
                div.click();
            }
        });
        div.dataset.fullText = item.title;
        const isPinned = pinned.includes(item.id);
        const textWrap = document.createElement("div");
        textWrap.className = "history-text-wrap";
        const titleSpan = document.createElement("div");
        titleSpan.className = "history-title";
        titleSpan.innerText = (isPinned ? "📌 " : "") + item.title;
        let timeDiv = document.createElement('div');
        timeDiv.className = "history-time";
        timeDiv.innerText = formatTime(item.utime || item.ctime);
        textWrap.appendChild(titleSpan);
        textWrap.appendChild(timeDiv);
        const pinBtn = document.createElement("button");
        pinBtn.className = "del-history-btn";
        pinBtn.innerText = isPinned ? "📍" : "📌";
        pinBtn.title = isPinned ? "取消置顶" : "置顶";
        pinBtn.style.marginRight = "4px";
        pinBtn.onclick = (e)=>{
            e.stopPropagation();
            let p = pinnedConversations();
            if(p.includes(item.id)){ p = p.filter(x=>x!==item.id); }
            else { p.push(item.id); }
            try{ localStorage.setItem("pinned_conv", JSON.stringify(p)); }catch(error){}
            renderSideHistory();
        };
        const delBtn = document.createElement("button");
        delBtn.className = "del-history-btn";
        delBtn.innerText = "×";
        delBtn.setAttribute("aria-label", LANG === "en" ? "Delete conversation" : "删除对话");
        delBtn.onclick = (e)=>{
            e.stopPropagation();
            if(confirm(t("confirmDel"))){
                const version = conversationVersion;
                return requestJson(`/api/del_history?id=${item.id}`, {method:"DELETE"})
                .then(data=>{
                    if(!data.ok) throw new Error('Delete failed');
                    if(item.id === currentConvId){
                        resetConversation(null);
                        chatDom.innerHTML = welcomeHTML();
                    }
                    return loadHistory();
                }).catch(function(){
                    if(version === conversationVersion) setComposerStatus(t('networkFail'), true);
                });
            }
        }
        div.appendChild(textWrap);
        div.appendChild(pinBtn);
        div.appendChild(delBtn);
        div.onclick = ()=> openConversation(item.id);
        leftHistoryWrap.appendChild(div);
    })
}

function pinnedConversations(){
    try{
        const stored = JSON.parse(localStorage.getItem('pinned_conv') || '[]');
        return Array.isArray(stored) ? stored.filter(Number.isInteger) : [];
    }catch(error){ return []; }
}

function renderRecentChat(){
    const wrap = document.getElementById("recentChatWrap");
    if(!wrap) return;                 // 切过对话后旧节点会失效，每次重新取
    wrap.innerHTML = "";
    wrap.closest('.recent-chat').hidden = historyList.length === 0;
    historyList.slice(0,2).forEach(item=>{
        const div = document.createElement('div');
        div.className = "recent-item";
        div.tabIndex = 0;
        div.setAttribute("role", "button");
        div.addEventListener("keydown", function(event){
            if(event.key === "Enter" || event.key === " "){
                event.preventDefault();
                div.click();
            }
        });
        div.onclick = ()=> openConversation(item.id);
        const titleSpan = document.createElement('span');
        titleSpan.innerText = item.title;
        const timeSpan = document.createElement('span');
        timeSpan.className = "recent-date";
        timeSpan.innerText = formatTime(item.utime || item.ctime);
        div.appendChild(titleSpan);
        div.appendChild(timeSpan);
        wrap.appendChild(div);
    })
}

// 没有会话就先建一个，拿到 conv_id
function ensureConv(){
    if(currentConvId) return Promise.resolve(currentConvId);
    if(creatingConv) return creatingConv;
    const version = conversationVersion;
    const pending = requestJson("/api/new_chat", {method:"POST"})
        .then(function(data){
            if(!data || !data.id) throw new Error('Session failed');
            return data;
        })
        .then(data=>{
            if(version !== conversationVersion){
                const error = new Error('Conversation changed');
                error.name = 'AbortError';
                throw error;
            }
            currentConvId = data.id;
            if(data.welcome) addMsg(t('autoWelcome'), false);
            return currentConvId;
        }).finally(function(){ if(creatingConv === pending) creatingConv = null; });
    creatingConv = pending;
    return pending;
}

function resetConversation(id){
    if(cancelActive){ cancelActive(); cancelActive = null; }
    if(sseInstance){ sseInstance.close(); sseInstance = null; }
    conversationVersion += 1;
    clearAttachment();
    stopHumanMode();
    currentConvId = id;
    openingConv = null;
    creatingConv = null;
    sendPreparing = false;
    activeQuickTopic = null;
    setBusy(false);
    setComposerStatus('');
    return conversationVersion;
}

// 打开历史会话：还原整段对话，而不是把标题重发一遍
let openingConv = null;
function openConversation(id){
    if(openingConv === 'clearing') return;
    if(openingConv === id) return;       // 防连点
    const version = resetConversation(id);
    openingConv = id;
    setComposerStatus(t('historyLoading'));
    renderSideHistory();
    requestJson("/api/get_messages?conv_id=" + id)
    .then(msgs=>{
        if(version !== conversationVersion) return;
        if(!Array.isArray(msgs)) throw new Error('History failed');
        openingConv = null;
        setComposerStatus('');
        chatDom.innerHTML = "";
        if(!msgs.length){
            chatDom.innerHTML = welcomeHTML();
            return;
        }
        msgs.forEach(m=>{
            if(m.role === "assistant" && m.content.indexOf(CARD_PREFIX) === 0){
                try{
                    const bubble = addTrackCard(JSON.parse(m.content.slice(CARD_PREFIX.length)), m.ctime);
                    attachActions(bubble, m.content, '', false);
                }catch(e){
                    addMsg(m.content, false, undefined, m.ctime);
                }
            }else{
                const b = addMsg(m.content, m.role === "user", undefined, m.ctime);
                if(m.role === "assistant" && b) attachActions(b, m.content, "", false);
            }
        });
        // 等渲染完再滚到底部
        requestAnimationFrame(function(){ scrollChatToEnd(true); });
    }).catch(function(){
        if(version !== conversationVersion) return;
        openingConv = null;
        setComposerStatus(t('networkFail'), true);
    });
}

const CARD_PREFIX = "__CARD__";

// 把轨迹数据画成时间轴
function fillTrackCard(el, card){
    el.innerHTML = "";
    const isOrder = card.kind === 'order';
    const head = document.createElement("div");
    head.className = "track-head";
    const no = document.createElement("div");
    no.className = "track-no";
    const numberLabel = isOrder ? 'orderNo' : 'trackingNo';
    no.innerHTML = '<span data-i18n="'+numberLabel+'">' + t(numberLabel) + "</span>" + escHtml(card.no);
    const st = document.createElement("div");
    st.className = "track-status";
    st.textContent = card.status;
    head.appendChild(no);
    head.appendChild(st);
    el.appendChild(head);

    if(!isOrder){
        const legacyNotice = document.createElement('p');
        legacyNotice.className = 'order-data-notice';
        legacyNotice.dataset.i18n = 'legacyTrackingNotice';
        legacyNotice.textContent = t('legacyTrackingNotice');
        el.appendChild(legacyNotice);
    }

    if(isOrder){
        const fields = document.createElement('dl');
        fields.className = 'order-data-fields';
        (card.fields || []).forEach(function(field){
            const label = document.createElement('dt');
            label.dataset.i18n = 'order_'+field.key;
            label.textContent = t('order_'+field.key) || field.key;
            const value = document.createElement('dd');
            value.textContent = field.value;
            fields.append(label, value);
        });
        el.appendChild(fields);
        const title = document.createElement('p');
        title.className = 'order-history-title';
        title.dataset.i18n = 'orderHistory';
        title.textContent = t('orderHistory');
        el.appendChild(title);
        if(!(card.nodes || []).length){
            const empty = document.createElement('p');
            empty.className = 'order-history-empty';
            empty.dataset.i18n = 'noOrderHistory';
            empty.textContent = t('noOrderHistory');
            el.appendChild(empty);
        }
    }

    const timeline = document.createElement("div");
    timeline.className = "track-timeline";
    el.appendChild(timeline);
    const visibleCount = window.matchMedia("(max-width: 520px)").matches ? 2 : 3;
    (card.nodes || []).forEach(function(n, i){
        const node = document.createElement("div");
        node.className = "track-node" + (i === 0 ? " active" : "");
        const dot = document.createElement("span");
        dot.className = "track-dot";
        const text = document.createElement("div");
        text.className = "track-text";
        text.innerHTML = '<span class="track-time">' + escHtml(n.time) + '</span><strong class="track-event">' + escHtml(n.text) + "</strong>" +
                         '<span class="track-place">' + escHtml(n.place || "") + "</span>";
        node.appendChild(dot);
        node.appendChild(text);
        if(i >= visibleCount){ node.classList.add("track-earlier"); node.hidden = true; }
        timeline.appendChild(node);
    });
    if((card.nodes || []).length > visibleCount){
        const toggle = document.createElement("button");
        toggle.type = "button";
        toggle.className = "track-expand";
        toggle.setAttribute("aria-expanded", "false");
        toggle.dataset.i18n = "moreTracking";
        toggle.textContent = t("moreTracking");
        toggle.onclick = function(){
            const expanded = toggle.getAttribute("aria-expanded") !== "true";
            timeline.querySelectorAll(".track-earlier").forEach(node => { node.hidden = !expanded; });
            toggle.setAttribute("aria-expanded", String(expanded));
            toggle.dataset.i18n = expanded ? "lessTracking" : "moreTracking";
            toggle.textContent = t(toggle.dataset.i18n);
        };
        el.appendChild(toggle);
    }
}

function createMessageRow(isUser, authorRole){
    const row = document.createElement("div");
    row.className = "msg-row " + (isUser ? "user-line" : "robot-line");
    const author = document.createElement("div");
    author.className = "message-author";
    const role = isUser ? "you" : (authorRole || "assistant");
    author.innerHTML = (isUser ? "" : '<span class="author-mark">' + welcomeIcon("box") + '</span>') + '<span data-i18n="' + role + '">' + t(role) + '</span>';
    row.appendChild(author);
    return row;
}

function appendMessageTime(row, timeStr){
    const ts = document.createElement('div');
    ts.className = 'msg-time';
    const stored = typeof timeStr === 'string' && timeStr.match(/(?:^|[T\s])(\d{2}:\d{2})/);
    const now = new Date();
    ts.textContent = stored ? stored[1] : String(now.getHours()).padStart(2,'0') + ':' + String(now.getMinutes()).padStart(2,'0');
    if(timeStr) ts.title = timeStr;
    row.appendChild(ts);
}

function addTrackCard(card, timeStr){
    const row = createMessageRow(false);
    const bubble = document.createElement("div");
    bubble.className = "robot-message track-card";
    fillTrackCard(bubble, card);
    row.appendChild(bubble);
    appendMessageTime(row, timeStr);
    chatDom.appendChild(row);
    scrollChatToEnd();
    return bubble;
}

loadHistory();

window.fillInput = function(words){
    inputDom.value = words;
    return doSend();
}

// 点快捷问题：另起一个会话，不同话题就不会堆进同一条历史
window.askNewTopic = function(words){
    if(openingConv === 'clearing') return;
    if(activeQuickTopic === words && (sendPreparing || window.__busy)) return;
    resetConversation(null);
    activeQuickTopic = words;
    // 新话题先重置界面，发送第一条消息时再收起欢迎内容。
    if(!chatDom.querySelector('.ai-welcome-card')){
        chatDom.innerHTML = welcomeHTML();
    }
    inputDom.value = words;
    return doSend();
}

window.sendOrder = function(){
    const no = prompt("请输入运单号：");
    if(no && no.trim()){
        inputDom.value = "我的运单号是 " + no.trim() + "，帮我查一下轨迹";
        doSend();
    }
}

function myOrders(){
    var phone = window.prompt("请输入您的手机号：");
    if(!phone) return;
    addMsg("查询手机号 "+phone+" 的包裹...", false);
    fetch("/api/my_orders?phone="+encodeURIComponent(phone))
    .then(r=>r.json())
    .then(d=>{
        if(!d.orders.length){
            addMsg("手机号 "+phone+" 下暂无运单记录。", false);
        }else{
            var txt = "您名下有 "+d.orders.length+" 个包裹：\n";
            d.orders.forEach(function(o){ txt += "• "+o.track_no+"（"+o.status+"）\n"; });
            addMsg(txt, false);
        }
    })
    .catch(function(){ addMsg("查询失败，请重试", false); });
}

function updateHumanMode(){
    const banner = document.getElementById('human-session');
    const label = document.getElementById('human-session-label');
    const button = document.getElementById('return-ai');
    if(banner) banner.hidden = !window.humanSid && !humanRequestToken;
    const text = t(humanRequestToken ? 'humanConnecting' : humanStatus === 'active' ? 'humanActive' : 'humanWaiting');
    if(label && label.textContent !== text) label.textContent = text;
    if(button){
        button.textContent = t('returnAI');
        button.disabled = Boolean(humanRequestToken || humanClosing || humanSendingToken);
    }
    sendBtn.disabled = Boolean(humanRequestToken || humanClosing || humanSendingToken);
}

function stopHumanMode(){
    if(humanPollTimer !== null) clearInterval(humanPollTimer);
    humanPollTimer = null;
    humanConvId = null;
    humanStatus = '';
    humanRequestToken = null;
    humanSendingToken = null;
    humanClosing = false;
    window.humanSid = 0;
    const typing = document.getElementById('human-typing');
    if(typing) typing.remove();
    updateHumanMode();
}

async function humanRequest(path, data){
    return requestJson(path, {method:data ? 'POST' : 'GET',
        headers:data ? {'Content-Type':'application/json'} : {},
        body:data ? JSON.stringify(data) : undefined});
}

window.showHuman = async function(){
    if(openingConv === 'clearing') return;
    if(humanRequestToken || humanClosing) return;
    if(window.humanSid && humanConvId === currentConvId){ updateHumanMode(); return; }
    if(window.humanSid) stopHumanMode();
    const hour = new Date().getHours();
    if(hour < 8 || hour >= 22) return leaveOfflineMessage();
    const token = {version:conversationVersion};
    humanRequestToken = token;
    if(cancelActive){ cancelActive(); cancelActive = null; }
    setBusy(false);
    updateHumanMode();
    try{
        const cid = await ensureConv();
        if(humanRequestToken !== token || token.version !== conversationVersion) return;
        const data = await humanRequest('/api/human/request', {conv_id:cid});
        if(humanRequestToken !== token || token.version !== conversationVersion) return;
        if(data.closed){ await leaveOfflineMessage(); return; }
        if(!data.ok || !data.session_id) throw new Error('Human session failed');
        window.humanSid = data.session_id;
        humanConvId = cid;
        humanStatus = 'waiting';
        addMsg(t('humanWaiting'), false);
        startHumanPoll();
    }catch(error){
        if(humanRequestToken === token && token.version === conversationVersion) setComposerStatus(t('humanConnectFailed'), true);
    }finally{
        if(humanRequestToken === token){ humanRequestToken = null; updateHumanMode(); }
    }
};

async function returnToAI(){
    if(!window.humanSid || humanClosing || humanSendingToken) return;
    const sid = window.humanSid, version = conversationVersion;
    humanClosing = true;
    updateHumanMode();
    try{
        const result = await humanRequest('/api/human/close', {sid:sid});
        if(!result.ok) throw new Error('Close failed');
        if(version !== conversationVersion || window.humanSid !== sid) return;
        stopHumanMode();
        setComposerStatus('');
        addMsg(t('humanClosed'), false);
        inputDom.focus();
    }catch(error){
        if(version === conversationVersion) setComposerStatus(t('humanReturnFailed'), true);
    }finally{
        if(version === conversationVersion){ humanClosing = false; updateHumanMode(); }
    }
}
const returnAIButton = document.getElementById('return-ai');
if(returnAIButton) returnAIButton.onclick = returnToAI;

async function sendHumanMessage(content){
    if(humanSendingToken || humanClosing) return;
    const sid = window.humanSid, cid = currentConvId, version = conversationVersion;
    const draft = inputDom.value, attachment = window.__pendingImg;
    const token = {};
    humanSendingToken = token;
    updateHumanMode();
    setComposerStatus(t('humanSending'));
    try{
        const result = await humanRequest('/api/human/send', {sid:sid, conv_id:cid, side:'customer', content:content});
        if(!result.ok) throw new Error('Send failed');
        if(version !== conversationVersion || humanSendingToken !== token) return;
        addMsg(content, true);
        if(inputDom.value === draft){ inputDom.value = ''; autoGrow(); }
        if(window.__pendingImg === attachment) clearAttachment();
        setComposerStatus(t(humanStatus === 'active' ? 'humanSent' : 'humanWaiting'));
        inputDom.focus();
    }catch(error){
        if(version !== conversationVersion || humanSendingToken !== token) return;
        if(error.status === 404 || error.status === 409) stopHumanMode();
        setComposerStatus(t('humanSendFailed'), true);
    }finally{
        if(humanSendingToken === token){ humanSendingToken = null; updateHumanMode(); }
    }
}
async function leaveOfflineMessage(){
    const version = conversationVersion;
    addMsg(t('humanHours'), false);
    const message = window.prompt(t('offlinePrompt'));
    if(!message) return;
    try{
        const data = await humanRequest('/api/ticket', {content:message, phone:''});
        if(!data.ok) throw new Error('Ticket failed');
        if(version === conversationVersion) addMsg(t('offlineSaved'), false);
    }catch(error){
        if(version !== conversationVersion) return;
        if(!inputDom.value) inputDom.value = message;
        setComposerStatus(t('networkFail'), true);
    }
}

function startHumanPoll(){
    let last=0;
    let polling=false;
    const sid=window.humanSid;
    const cid=humanConvId, version=conversationVersion;
    let hadPollError=false;
    if(humanPollTimer !== null) clearInterval(humanPollTimer);
    const pollTimer=setInterval(()=>{
        if(window.humanSid !== sid || version !== conversationVersion || currentConvId !== cid){ clearInterval(pollTimer); return; }
        if(polling) return;
        polling=true;
        humanRequest("/api/human/poll?sid="+sid+"&after="+last)
        .then(d=>{
            if(window.humanSid !== sid || version !== conversationVersion || currentConvId !== cid) return;
            if(hadPollError){ setComposerStatus(''); hadPollError=false; }
            humanStatus=d.status;
            updateHumanMode();
            d.messages.forEach(m=>{
                if(m.id <= last) return;
                last = m.id;
                if(m.recalled_id){
                    const recalled = chatDom.querySelector('[data-human-message-id="'+Number(m.recalled_id)+'"]');
                    if(recalled){ recalled.className='human-system-message'; recalled.textContent=t('recalled'); return; }
                }
                if(m.side === 'system'){
                    const system = document.createElement('div');
                    system.className = 'human-system-message';
                    system.setAttribute('data-human-message-id', String(m.id));
                    system.textContent = m.content;
                    chatDom.appendChild(system);
                }else if(m.side === 'agent'){
                    const bubble = addMsg(m.content, false, 'humanAgent');
                    bubble.closest('.msg-row').setAttribute('data-human-message-id', String(m.id));
                    SupportUI.notify(t('humanReply'), m.content.substring(0, 50));
                }
                const typing = document.getElementById('human-typing');
                if(typing) typing.remove();
            });
            if(d.status==="closed"){
                if(humanClosing) return;
                stopHumanMode();
                setBusy(false);
                addMsg(t('humanClosed'), false);
                SupportUI.addRating(chatDom, sid, {question:t('ratingQuestion'), thanks:t('ratingThanks'), failed:t('ratingFailed')});
                scrollChatToEnd();
                return;
            }
            // 客服正在输入
            var oldT = document.getElementById("human-typing");
            if(d.typing && !oldT){
                var td = document.createElement("div");
                td.id = "human-typing";
                td.style.cssText = "font-size:12px;color:#999;padding:4px 0;";
                td.textContent = "客服正在输入...";
                chatDom.appendChild(td);
                scrollChatToEnd();
            }else if(!d.typing && oldT){
                oldT.remove();
            }
        })
        .catch(function(){
            if(version !== conversationVersion || window.humanSid !== sid) return;
            hadPollError=true;
            setComposerStatus(t('humanPollFailed'), true);
        }).finally(function(){ polling=false; });
    }, 1000);
    humanPollTimer = pollTimer;
}

function addMsg(content, isUser, authorRole, timeStr){
    if(chatDom.querySelector('.ai-welcome-card')) chatDom.innerHTML = "";
    const rowDiv = createMessageRow(isUser, authorRole);
    let robotMsg;
    // 检测图片附件
    let imgUrl = null;
    if(content.indexOf("[图片]") >= 0){
        const m = content.match(/\/uploads\/\S+\.(?:jpg|jpeg|png|gif|webp)/i);
        if(m) imgUrl = m[0];
    }
    // 检测文件附件
    let fileUrl = null;
    if(content.indexOf("[文件]") >= 0){
        const m = content.match(/\/uploads\/\S+\.(?:pdf|txt|csv|doc|docx|xls|xlsx|zip)/i);
        if(m) fileUrl = m[0];
    }
    if(isUser){
        rowDiv.classList.add("user-line");
        const userMsg = document.createElement('div');
        userMsg.className = "user-message";
        if(imgUrl){
            var txt = content.replace(/\[图片\]\/uploads\/\S+\.(?:jpg|jpeg|png|gif|webp)/i, "").trim();
            const link = document.createElement("a");
            link.href = imgUrl;
            link.target = "_blank";
            link.rel = "noopener";
            const image = document.createElement("img");
            image.src = imgUrl;
            image.alt = "附件图片";
            image.className = "message-image";
            link.appendChild(image);
            userMsg.appendChild(link);
            if(txt){ const caption = document.createElement("div"); caption.textContent = txt; userMsg.appendChild(caption); }
        }else if(fileUrl){
            var fname = fileUrl.split("/").pop();
            const link = document.createElement("a");
            link.href = fileUrl;
            link.target = "_blank";
            link.rel = "noopener";
            link.className = "message-file";
            link.textContent = "↗ " + fname;
            userMsg.appendChild(link);
            const caption = content.replace("[文件]" + fileUrl, "").trim();
            if(caption){ const text = document.createElement("div"); text.textContent = caption; userMsg.appendChild(text); }
        }else{
            userMsg.innerText = content;
        }
        rowDiv.appendChild(userMsg);
    }else{
        rowDiv.classList.add("robot-line");
        robotMsg = document.createElement('div');
        robotMsg.className = "robot-message";
        robotMsg.innerHTML = parseBold(content);
        rowDiv.appendChild(robotMsg);
    }
    // 时间戳
    appendMessageTime(rowDiv, timeStr);
    chatDom.appendChild(rowDiv);
    scrollChatToEnd(Boolean(isUser));
    if(!isUser){
        return robotMsg;
    }else{
        return rowDiv;
    }
}

function renderError(bubble, text, retry){
    bubble.classList.remove("typing");
    bubble.classList.add("error-bubble");
    if(!bubble.dataset.raw) bubble.innerHTML = "";
    const line = document.createElement("div");
    line.className = "err-line";
    line.textContent = "⚠️ " + (/API Key|DEEPSEEK/i.test(text) ? t("serviceUnavailable") : text);
    const btn = document.createElement("button");
    btn.className = "retry-btn";
    btn.textContent = t("clickRetry");
    btn.onclick = retry;
    bubble.appendChild(line);
    bubble.appendChild(btn);
    scrollChatToEnd();
}

// 复制用：把 Markdown 标记去掉，得到干净纯文本
function mdToPlain(md){
    if(md.indexOf(CARD_PREFIX) === 0){
        try{
            const card = JSON.parse(md.slice(CARD_PREFIX.length));
            if(card.kind === 'order') return card.summary || card.no;
            const lines = ["运单号 " + card.no + "（" + (card.status || "") + "）"];
            (card.nodes || []).forEach(function(n){
                lines.push(n.time + "  " + n.text + (n.place ? "  " + n.place : ""));
            });
            return lines.join("\n");
        }catch(e){ /* 解析失败就走普通处理 */ }
    }
    return String(md)
        .replace(/`([^`]+)`/g, "$1")          // 行内代码
        .replace(/\*\*(.+?)\*\*/g, "$1")      // 加粗
        .replace(/^[-*•]\s+/gm, "· ")          // 列表符号换成 ·
        .replace(/^\d+[.、)]\s*/gm, "")        // 去掉编号前缀
        .replace(/“|”/g, '"');
}

// 给一条回答挂上「复制 / 重答」按钮
function attachActions(bubble, rawText, question, showRetry){
    const old = bubble.querySelector(".msg-actions");
    if(old) old.remove();
    if(!rawText) return;
    const bar = document.createElement("div");
    bar.className = "msg-actions";

    const copyBtn = document.createElement("button");
    copyBtn.className = "msg-action-btn";
    copyBtn.dataset.action = "copy";
    copyBtn.textContent = t("copy");
    copyBtn.onclick = function(){
        const plain = mdToPlain(rawText);
        const done = ()=> {
            copyBtn.textContent = t("copied");
            setTimeout(()=>{ copyBtn.textContent = t("copy"); }, 1200);
        };
        if(navigator.clipboard && navigator.clipboard.writeText){
            navigator.clipboard.writeText(plain).then(done).catch(fallback);
        }else{
            fallback();
        }
        function fallback(){
            const ta = document.createElement("textarea");
            ta.value = plain;
            ta.style.position = "fixed";
            ta.style.opacity = "0";
            document.body.appendChild(ta);
            ta.select();
            try{ document.execCommand("copy"); }catch(e){}
            document.body.removeChild(ta);
            done();
        }
    };
    bar.appendChild(copyBtn);

    if(showRetry){
        const retryBtn = document.createElement("button");
        retryBtn.className = "msg-action-btn";
        retryBtn.dataset.action = "retry";
        retryBtn.textContent = t("retry");
        retryBtn.onclick = function(){
            const row = bubble.closest(".msg-row");
            if(row) row.remove();
            doSend(question);       // 传字符串 = 只重发，不重复插入提问气泡
        };
        bar.appendChild(retryBtn);
    }

    // 👍/👎 反馈
    function addVote(vote, label){
        const b = document.createElement("button");
        b.className = "msg-action-btn";
        b.textContent = label;
        b.onclick = function(){
            if(b.classList.contains("voted")) return;
            bar.querySelectorAll(".msg-action-btn").forEach(function(x){ x.classList.remove("voted"); });
            b.classList.add("voted");
            fetch("/api/feedback", {
                method:"POST", headers:{"Content-Type":"application/json"},
                body: JSON.stringify({question: question, answer: rawText, vote: vote})
            }).catch(function(){});
        };
        bar.appendChild(b);
    }
    addVote("up", "👍");
    addVote("down", "👎");

    bubble.appendChild(bar);
}

// 回答下方的"相关追问"：点一下就接着问
function renderFollowups(bubble){
    let list = [];
    try{ list = JSON.parse(bubble.dataset.suggest || "[]"); }catch(e){ list = []; }
    if(!list.length) return;
    const wrap = document.createElement("div");
    wrap.className = "followup-list";
    list.forEach(function(q){
        const item = document.createElement("div");
        item.className = "followup-item";
        item.innerHTML = "<span></span><span class='arrow'>›</span>";
        item.firstChild.textContent = q;
        item.onclick = function(){
            wrap.remove();
            inputDom.value = q;
            doSend();
        };
        wrap.appendChild(item);
    });
    bubble.appendChild(wrap);
}

async function doSend(retryText){
    const isRetry = typeof retryText === "string";
    const sendWord = (isRetry ? retryText : inputDom.value).trim();
    var imgUrl = isRetry ? "" : (window.__pendingImg || "");
    var tag = window.__pendingTag || "[图片]";
    const draft = inputDom.value, attachmentVersion = uploadVersion;
    if(!sendWord && !imgUrl){
        inputDom.focus();
        return;
    }
    if(uploadPending){ setComposerStatus(t("uploading")); return; }
    if(humanSendingToken || humanClosing) return;
    var fullContent = sendWord;
    if(imgUrl) fullContent += (fullContent ? " " : "") + tag + imgUrl;
    setComposerStatus("");
    if(openingConv !== null){ setComposerStatus(t('historyLoading')); return; }
    if(humanRequestToken || humanClosing){ updateHumanMode(); return; }
    // 人工客服模式：直接发给客服，不走AI
    if(window.humanSid && humanConvId === currentConvId) return sendHumanMessage(fullContent);
    if(window.humanSid) stopHumanMode();

    if(sendPreparing || (window.__busy && !retryText)) return;  // 防连点
    if(cancelActive){ cancelActive(); cancelActive = null; }

    sendPreparing = true;
    const version = conversationVersion;
    let convId;
    try{
        convId = await ensureConv();
    }catch(error){
        if(version === conversationVersion) setComposerStatus(t('sessionFail'), true);
        return;
    }finally{
        if(version === conversationVersion) sendPreparing = false;
    }
    if(version !== conversationVersion || humanRequestToken) return;
    if(!isRetry){
        addMsg(fullContent, true);
        if(inputDom.value === draft){ inputDom.value = ""; autoGrow(); }
        if(attachmentVersion === uploadVersion) clearAttachment();
        inputDom.focus();
    }

    const aiBubble = addMsg(t("thinking"), false);
    aiBubble.classList.add("typing");
    activeBubble = aiBubble;
    setBusy(true);

    let es = null;
    let firstChunk = true;
    let settled = false;      // 已经结束（成功或失败），用它区分"正常关闭"和"真断开"

    const firstTimer = setTimeout(function(){ fail("模型响应超时，请稍后重试"); }, 90000);
    const totalTimer = setTimeout(function(){ fail("生成时间过长，已中断，请重试"); }, 120000);

    function cleanup(){
        clearTimeout(firstTimer);
        clearTimeout(totalTimer);
        const cur = es;
        es = null;
        if(cur){
            cur.close();
            if(sseInstance === cur) sseInstance = null;
        }
    }

    function finish(){
        if(settled) return;
        settled = true;
        cleanup();
        setBusy(false);
        aiBubble.classList.remove("typing");
        if(activeBubble === aiBubble) activeBubble = null;
        inputDom.focus();

        let raw = aiBubble.dataset.raw || "";
        // 模型有时会把卡片标记原样输出，这里兜底转成时间轴
        if(raw.indexOf(CARD_PREFIX) === 0){
            try{
                const card = JSON.parse(raw.slice(CARD_PREFIX.length));
                aiBubble.classList.add("track-card");
                fillTrackCard(aiBubble, card);
                raw = "运单号 " + card.no + "（" + (card.status || "") + "）";
            }catch(e){ /* 解析失败就按普通文本显示 */ }
        }
        attachActions(aiBubble, raw, fullContent, true);
        renderFollowups(aiBubble);
        updateToBottom();
        loadHistory();            // 首条消息会让标题变成问题内容，这里刷新一下
    }

    function fail(text){
        if(settled) return;
        settled = true;
        cleanup();
        setBusy(false);
        if(activeBubble === aiBubble) activeBubble = null;
        renderError(aiBubble, text || t("busyRetry"), function(){
            const row = aiBubble.closest(".msg-row");
            if(row) row.remove();
            doSend(fullContent);
        });
    }

    // 静默中止（用户点了停止 / 开了新对话 / 问了新问题）
    function stop(){
        if(settled) return;
        settled = true;
        cleanup();
        setBusy(false);
        aiBubble.classList.remove("typing");
        if(activeBubble === aiBubble) activeBubble = null;
        const raw = aiBubble.dataset.raw || "";
        if(raw){
            // 已生成的部分保留，并标注已停止
            const hint = document.createElement("div");
            hint.className = "stopped-hint";
            hint.textContent = t("stoppedMark");
            aiBubble.appendChild(hint);
            attachActions(aiBubble, raw, fullContent, false);
        }else{
            aiBubble.innerHTML = t("stopped");
            aiBubble.classList.add("hint-bubble");
        }
    }
    cancelActive = stop;

    function handleFrame(dataText){
        if(settled || version !== conversationVersion) return;
        let obj;
        try{
            obj = JSON.parse(dataText);
        }catch(err){
            obj = {t: dataText};        // 兼容旧的纯文本帧
        }
        if(!obj || typeof obj !== 'object') return;
        if(obj.e){ fail(obj.e); return; }
        if(obj.card){
            clearTimeout(firstTimer);
            aiBubble.classList.add("track-card");
            fillTrackCard(aiBubble, obj.card);
            aiBubble.dataset.raw = obj.card.kind === 'order' ? obj.card.summary : "运单号 " + obj.card.no + "（" + (obj.card.status || "") + "）\n" +
                (obj.card.nodes || []).map(function(n){ return n.time + "  " + n.text + "  " + (n.place || ""); }).join("\n");
            firstChunk = false;
            scrollChatToEnd();
            return;
        }
        if(obj.replace){
            clearTimeout(firstTimer);
            aiBubble.dataset.raw = obj.replace;
            aiBubble.innerHTML = parseBold(obj.replace);
            scrollChatToEnd();
            return;
        }
        if(obj.suggest){
            aiBubble.dataset.suggest = JSON.stringify(obj.suggest);
            return;
        }
        if(obj.d){ finish(); return; }
        if(typeof obj.t !== "string") return;
        clearTimeout(firstTimer);
        if(firstChunk){
            aiBubble.innerHTML = "";
            aiBubble.dataset.raw = "";
            firstChunk = false;
        }
        const raw = (aiBubble.dataset.raw || "") + obj.t;
        aiBubble.dataset.raw = raw;
        aiBubble.innerHTML = parseBold(raw);
        scrollChatToEnd();
    }

    // 用 POST + fetch 流式读取：问题放在请求体里，不受 URL 长度限制
    const controller = new AbortController();
    es = { close: function(){ try{ controller.abort(); }catch(e){} } };
    sseInstance = es;
    // 保留 stop 里的 close 调用
    const prevStop = cancelActive;
    cancelActive = function(){ prevStop && prevStop(); try{ controller.abort(); }catch(e){} };

    fetch("/stream_chat", {
        method: "POST",
        headers: {"Content-Type": "application/json"},
        body: JSON.stringify({msg: fullContent, conv_id: convId}),
        signal: controller.signal
    }).then(async function(res){
        if(!res.ok){
            let data;
            try{ data = await res.json(); }catch(e){}
            fail(data && (data.e || data.error) || t('networkFail'));
            return;
        }
        if(!res.body || typeof res.body.getReader !== 'function'){ fail(t('networkFail')); return; }
        const reader = res.body.getReader();
        const decoder = new TextDecoder("utf-8");
        let buffer = "";
        function drain(final){
            function dispatch(frame){
                const data = frame.split(/\r?\n/).filter(line => line.indexOf('data:') === 0)
                    .map(line => line.slice(5).trimStart()).join('\n');
                if(data) handleFrame(data);
            }
            let boundary;
            while(!settled && (boundary = /\r?\n\r?\n/.exec(buffer))){
                const frame = buffer.slice(0, boundary.index);
                buffer = buffer.slice(boundary.index + boundary[0].length);
                dispatch(frame);
            }
            if(final && !settled && buffer.trim()){ dispatch(buffer); buffer = ''; }
        }
        function pump(){
            return reader.read().then(function(r){
                if(settled) return;
                if(r.done){
                    buffer += decoder.decode();
                    drain(true);
                    if(!settled) fail(t("networkFail"));
                    return;
                }
                buffer += decoder.decode(r.value, {stream: true});
                drain(false);
                if(!settled) return pump();
            });
        }
        return pump();
    }).catch(function(err){
        if(err && err.name === "AbortError") return;   // 用户主动停止
        if(settled) return;
        fail(t("networkFail"));
    });
}

// ===== 发送 / 停止 按钮状态 =====
// 生成中按钮变成“停止”，点击走 cancelActive
function setBusy(on){
    window.__busy = on;
    sendBtn.textContent = on ? t("stop") : t("send");
    sendBtn.classList.toggle("stop", on);
}
sendBtn.addEventListener("click", function(){
    if(window.__busy && cancelActive){
        cancelActive();
        cancelActive = null;
        setBusy(false);
        return;
    }
    doSend();
});

// ===== 多行输入框：自动增高 =====
function autoGrow(){
    inputDom.style.height = "auto";
    inputDom.style.height = Math.min(inputDom.scrollHeight, 140) + "px";
}
inputDom.addEventListener("input", autoGrow);

inputDom.addEventListener("keydown",(e)=>{
    // Enter 发送，Shift+Enter 换行
    if(e.key === 'Enter' && !e.shiftKey && !e.isComposing){
        e.preventDefault();
        if(window.humanSid || !window.__busy) doSend();
    }
});

// ===== 回到底部 =====
const toBottomBtn = document.getElementById("to-bottom");
function updateToBottom(){
    const gap = chatDom.scrollHeight - chatDom.scrollTop - chatDom.clientHeight;
    toBottomBtn.classList.toggle("show", gap > 160);
}
chatDom.addEventListener("scroll", function(){
    followLatest = chatDom.scrollHeight - chatDom.scrollTop - chatDom.clientHeight < 96;
    updateToBottom();
});
toBottomBtn.onclick = ()=>{
    followLatest = true;
    chatDom.scrollTo({top: chatDom.scrollHeight, behavior:"smooth"});
};
if(window.ResizeObserver){
    new ResizeObserver(function(){
        document.querySelector('.main-chat').style.setProperty('--composer-height', document.querySelector('.composer').offsetHeight + 'px');
    }).observe(document.querySelector('.composer'));
}

const sidePanel = document.querySelector('.left-panel');
const toggleBtn = document.querySelector('.toggle-divider');
const chatContainer = document.querySelector('.chat-container');
let wasNarrow = isNarrow();
let sideOpen = !wasNarrow;

function isNarrow(){
    return window.matchMedia("(max-width: 900px)").matches;
}

function renderSidebar(){
    const narrow = isNarrow();
    chatContainer.classList.toggle('side-closed', narrow && !sideOpen);
    sidePanel.classList.toggle('left-panel-hide', !narrow && !sideOpen);
    sidePanel.setAttribute('aria-hidden', String(!sideOpen));
    toggleBtn.setAttribute('aria-expanded', String(sideOpen));
    toggleBtn.title = t(sideOpen ? 'sideCollapse' : 'sideExpand');
    toggleBtn.textContent = "";
    inputDom.placeholder = t(narrow ? 'inputShort' : 'inputPh');
}
renderSidebar();

toggleBtn.onclick = function(){
    sideOpen = !sideOpen;
    renderSidebar();
}
document.querySelector('.sidebar-backdrop').onclick = function(){
    sideOpen = false;
    renderSidebar();
};
document.addEventListener('keydown', function(event){
    if(event.key === 'Escape' && isNarrow() && sideOpen){
        sideOpen = false;
        renderSidebar();
        toggleBtn.focus();
    }
});

// 从窄屏切到宽屏时，还原侧栏状态，避免卡在隐藏
window.addEventListener("resize", function(){
    const narrow = isNarrow();
    if(narrow !== wasNarrow){
        sideOpen = !narrow;
        wasNarrow = narrow;
    }
    renderSidebar();
});

document.querySelectorAll('[data-question-index]').forEach(function(button){
    button.addEventListener('click', function(){
        window.askNewTopic(t('quick')[Number(button.dataset.questionIndex)]);
    });
});
chatDom.addEventListener('click', function(event){
    const question = event.target.closest('button[data-question]');
    if(question) window.askNewTopic(question.dataset.question);
    const human = event.target.closest('button[data-human-support]');
    if(human) window.showHuman();
});

});