// 状态
let currentUser = "";
let conversations = [];
let currentKfid = "";

// 初始化
document.addEventListener("DOMContentLoaded", () => {
    fetchAccounts();
});

// Toast
function showToast(msg, type = "success") {
    const el = document.getElementById("toast");
    el.textContent = msg;
    el.className = "toast toast-" + type;
    el.style.display = "block";
    el.style.opacity = "1";
    setTimeout(() => { el.style.opacity = "0"; setTimeout(() => el.style.display = "none", 300); }, 2000);
}

// 获取客服账号列表，填充下拉框
async function fetchAccounts() {
    const select = document.getElementById("accountSelect");
    select.innerHTML = '<option value="">加载中...</option>';
    try {
        const resp = await fetch("/api/accounts");
        const data = await resp.json();
        if (data.errcode === 0 && data.account_list && data.account_list.length > 0) {
            const accounts = data.account_list;
            select.innerHTML = accounts.map((a, i) =>
                `<option value="${a.open_kfid}" ${i === 0 ? 'selected' : ''}>${a.name || a.open_kfid}</option>`
            ).join("");
            currentKfid = accounts[0].open_kfid;
            showToast(`已加载 ${accounts.length} 个客服账号`);
            // 自动加载会话
            loadConversations();
        } else {
            select.innerHTML = '<option value="">获取失败</option>';
            showToast("获取账号列表失败: " + (data.errmsg || "未知错误"), "error");
        }
    } catch (e) {
        select.innerHTML = '<option value="">请求失败</option>';
        showToast("获取账号列表失败: " + e.message, "error");
    }
}

function onAccountChange() {
    const select = document.getElementById("accountSelect");
    currentKfid = select.value;
    if (currentKfid) {
        currentUser = "";
        document.getElementById("msgHeader").textContent = "请选择会话";
        document.getElementById("messageList").innerHTML = '<div class="empty-state">选择左侧会话查看消息</div>';
        document.getElementById("sendBtn").disabled = true;
        loadConversations();
    }
}

// 加载会话列表
async function loadConversations() {
    try {
        const resp = await fetch("/api/conversations?open_kfid=" + encodeURIComponent(currentKfid));
        const data = await resp.json();
        conversations = data.conversations || [];
        renderConversations();

        if (conversations.length === 0) {
            showToast('暂无会话，请先点击 同步拉取 获取消息', "error");
        }
    } catch (e) {
        showToast("加载会话失败: " + e.message, "error");
    }
}

// 渲染会话列表
function renderConversations() {
    const list = document.getElementById("conversationList");
    if (conversations.length === 0) {
        list.innerHTML = '<div style="padding:20px;color:#999;text-align:center;">暂无会话</div>';
        return;
    }
    list.innerHTML = conversations.map(c => `
        <div class="conv-item ${c.external_userid === currentUser ? 'active' : ''}"
             onclick="selectConversation('${c.external_userid}')">
            <div class="userid">${c.external_userid}</div>
            <div class="preview">${escapeHtml(c.latest_content || '[非文本消息]')}</div>
            <div class="time">${formatTime(c.latest_time)}</div>
        </div>
    `).join("");
}

// 选择会话
async function selectConversation(userid) {
    currentUser = userid;
    document.getElementById("msgHeader").textContent = "客户: " + userid;
    document.getElementById("sendBtn").disabled = false;
    document.getElementById("msgInput").disabled = false;
    renderConversations();
    await loadMessages(userid);
}

// 加载消息
async function loadMessages(userid) {
    try {
        const resp = await fetch(`/api/messages?external_userid=${userid}&open_kfid=${encodeURIComponent(currentKfid)}`);
        const data = await resp.json();
        const msgs = data.messages || [];
        renderMessages(msgs);
    } catch (e) {
        showToast("加载消息失败: " + e.message, "error");
    }
}

// 渲染消息
function renderMessages(msgs) {
    const container = document.getElementById("messageList");
    if (msgs.length === 0) {
        container.innerHTML = '<div class="empty-state">暂无消息</div>';
        return;
    }
    container.innerHTML = msgs.map(m => `
        <div class="msg-bubble ${m.direction === 'outbound' ? 'msg-outbound' : 'msg-inbound'}">
            <div>${escapeHtml(m.content || `[${m.msgtype}]`)}</div>
            <div class="msg-time">${formatTime(m.send_time)}</div>
        </div>
    `).join("");
    container.scrollTop = container.scrollHeight;
}

// 发送消息
async function sendMessage() {
    if (!currentUser) return;
    const input = document.getElementById("msgInput");
    const content = input.value.trim();
    if (!content) return;

    const btn = document.getElementById("sendBtn");
    btn.disabled = true;
    btn.textContent = "发送中...";

    try {
        const resp = await fetch("/api/send", {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({ external_userid: currentUser, content, open_kfid: currentKfid }),
        });
        const result = await resp.json();
        if (result.errcode === 0) {
            input.value = "";
            showToast("发送成功");
            await loadMessages(currentUser);
        } else {
            showToast("发送失败: " + (result.errmsg || JSON.stringify(result)), "error");
        }
    } catch (e) {
        showToast("发送失败: " + e.message, "error");
    } finally {
        btn.disabled = false;
        btn.textContent = "发送";
    }
}

// 同步拉取
async function syncMessages() {
    const statusEl = document.getElementById("syncStatus");
    statusEl.textContent = "同步中...";
    try {
        const resp = await fetch("/api/sync", {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({ open_kfid: currentKfid }),
        });
        const data = await resp.json();
        if (data.errcode === 0) {
            showToast(`同步成功，获取 ${data.total} 条消息，新增入库 ${data.saved} 条`);
            await loadConversations();
            if (currentUser) await loadMessages(currentUser);
        } else {
            showToast("同步失败: " + (data.errmsg || JSON.stringify(data)), "error");
        }
    } catch (e) {
        showToast("同步失败: " + e.message, "error");
    } finally {
        statusEl.textContent = "";
    }
}

// 格式化时间
function formatTime(iso) {
    if (!iso) return "";
    const d = new Date(iso);
    const pad = (n) => String(n).padStart(2, "0");
    return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())} ${pad(d.getHours())}:${pad(d.getMinutes())}`;
}

// HTML 转义
function escapeHtml(text) {
    const div = document.createElement("div");
    div.textContent = text;
    return div.innerHTML;
}