{% extends "base.html" %}
{% block title %}Web 终端 - Squid Manager{% endblock %}
{% block content %}
<div class="page-header">
    <h1>💻 Web SSH 终端</h1>
    <p class="page-desc">直接在浏览器中打开远程 Squid 主机的 SSH 会话,所有输入输出都会被审计记录。</p>
</div>

{% if not ssh_target %}
<div class="banner banner-warn">
    ⚠ 当前未配置 SSH 目标 (没有活跃实例或活跃实例未启用 SSH)。
    请先在
    <a href="{{ url_for('instances_view') }}">多实例管理</a>
    中为实例填写 <code>ssh_host</code> / <code>ssh_user</code> / <code>ssh_key_path</code>。
</div>
{% endif %}

<div class="banner banner-danger">
    <strong>🔒 审计提示:</strong>
    所有 SSH 会话的开启、关闭、resize 事件以及输入数据
    (经过编辑保留关键字符) 都会写入 <code>audit_log</code> 表,
    操作记录可在
    <a href="{{ url_for('audit_view') }}">审计日志</a>
    中查询。非法操作将被追责。
</div>

{% if paramiko_missing %}
<div class="banner banner-error" id="paramiko-error-banner">
    <strong>❌ 后端依赖缺失:</strong>
    检测到当前 Python 环境未安装 <code>paramiko</code>,WebSSH 功能不可用。
    请在服务器上执行
    <code>pip install paramiko flask-sock</code>
    后重启服务。当前页面仅供布局预览。
</div>
{% endif %}

<div class="terminal-config">
    <div class="terminal-config-row">
        <span class="meta-text">SSH 目标:</span>
        {% if ssh_target %}
            <code class="terminal-ssh-host">{{ ssh_target }}</code>
        {% else %}
            <code class="meta-text">(未配置)</code>
        {% endif %}
        <span class="meta-text">| 用户:</span>
        <code>{{ ssh_user if ssh_user else '-' }}</code>
        <span class="meta-text">| 端口:</span>
        <code>{{ ssh_port }}</code>
        <span class="meta-text">| 密钥:</span>
        <code title="{{ ssh_key_path or '' }}">{{ ssh_key_short or '-' }}</code>
        <span class="meta-text">| 实例:</span>
        <code>{{ instance_name }}</code>
    </div>
</div>

<div class="card terminal-card">
    <h3 class="card-title">🖥️ 终端</h3>
    <div id="terminal-error" class="banner banner-error" style="display:none;"></div>
    <div id="terminal" class="terminal-host" data-testid="terminal-host"></div>
    <div class="terminal-statusbar">
        <span>状态:</span>
        <span id="terminal-status" class="badge badge-gray">未连接</span>
        <span class="meta-text">|</span>
        <span>目标:</span>
        <code id="terminal-target">{% if ssh_target %}{{ ssh_target }}{% else %}(未配置){% endif %}</code>
        <span class="terminal-statusbar-spacer"></span>
        <span id="terminal-bytes" class="meta-text">0 B in / 0 B out</span>
        <button id="terminal-exit" type="button" class="btn btn-danger btn-small">⏹ 断开/退出</button>
    </div>
</div>

<div class="card">
    <h3 class="card-title">📘 使用说明</h3>
    <ul class="card-list">
        <li>终端会在页面加载时自动建立 WebSocket → paramiko SSH 通道,默认 80×24。</li>
        <li>支持 <kbd>Ctrl+C</kbd> / <kbd>Ctrl+D</kbd> / <kbd>Ctrl+L</kbd> 等组合键,窗口大小变化会自动 resize。</li>
        <li>顶部"断开/退出"按钮会主动关闭 SSH 会话并写入审计记录。</li>
        <li>为安全起见,本功能仅 <code>admin</code> 角色可见可用,其他用户不会显示此入口。</li>
        {% if ssh_key_path %}
        <li>实例配置的密钥文件:
            <code>{{ ssh_key_path }}</code>
            <span class="meta-text">(如服务端读不到,UI 会显示错误)</span>
        </li>
        {% endif %}
    </ul>
</div>
{% endblock %}

{% block scripts %}
{# xterm.js + addon-fit from CDN. We pin to a known-good version; the
   addon-fit script is shipped as part of xterm-addon-fit. #}
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/xterm@5.3.0/css/xterm.css" crossorigin="anonymous">
<script src="https://cdn.jsdelivr.net/npm/xterm@5.3.0/lib/xterm.js" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/xterm-addon-fit@0.8.0/lib/xterm-addon-fit.js" crossorigin="anonymous"></script>

<style>
/* --- terminal layout --- */
.terminal-config {
    margin: 12px 0;
    padding: 8px 12px;
    background: rgba(0,0,0,0.18);
    border-radius: 6px;
    border: 1px solid rgba(255,255,255,0.06);
    font-size: 0.85rem;
}
.terminal-config-row > * { margin-right: 6px; }
.terminal-ssh-host { color: #4ec9b0; font-weight: 600; }
.terminal-card { padding: 12px; }
.terminal-host {
    width: 100%;
    height: 480px;
    background: #1e1e1e;
    border-radius: 6px;
    overflow: hidden;
    padding: 4px;
}
.terminal-host .xterm,
.terminal-host .xterm-viewport,
.terminal-host .xterm-screen { height: 100% !important; }
.terminal-statusbar {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 10px;
    padding: 8px 10px;
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 6px;
    background: rgba(0,0,0,0.12);
    font-size: 0.85rem;
    flex-wrap: wrap;
}
.terminal-statusbar-spacer { flex: 1; }
.banner-danger {
    background: rgba(220, 53, 69, 0.12);
    border-left: 4px solid #dc3545;
    padding: 10px 14px;
    margin: 12px 0;
    border-radius: 4px;
}
.banner-error {
    background: rgba(255, 80, 80, 0.18);
    border: 1px solid #ff5252;
    color: #ffb3b3;
    padding: 10px 14px;
    margin: 8px 0;
    border-radius: 4px;
}
.banner-warn {
    background: rgba(255, 193, 7, 0.10);
    border-left: 4px solid #ffc107;
    padding: 10px 14px;
    margin: 12px 0;
    border-radius: 4px;
}
.card-list { margin-left: 20px; }
.card-list li { margin: 4px 0; }
</style>

<script>
(function() {
    "use strict";

    const ERR_BANNER = document.getElementById('terminal-error');
    const ERR_BANNER_PARAMIKO = document.getElementById('paramiko-error-banner');
    const STATUS_EL = document.getElementById('terminal-status');
    const BYTES_EL = document.getElementById('terminal-bytes');
    const TARGET_EL = document.getElementById('terminal-target');
    const EXIT_BTN = document.getElementById('terminal-exit');

    function setStatus(text, cls) {
        STATUS_EL.textContent = text;
        STATUS_EL.className = 'badge ' + (cls || 'badge-gray');
    }
    function showError(msg) {
        ERR_BANNER.style.display = 'block';
        ERR_BANNER.textContent = '❌ ' + msg;
    }
    function clearError() {
        ERR_BANNER.style.display = 'none';
    }

    /* Initialise xterm.js */
    let term;
    try {
        term = new Terminal({
            cursorBlink: true,
            fontSize: 13,
            fontFamily: 'Menlo, Monaco, Consolas, "DejaVu Sans Mono", monospace',
            scrollback: 5000,
            cols: 80,
            rows: 24,
            theme: {
                background: '#1e1e1e',
                foreground: '#d4d4d4',
                cursor: '#ffffff',
            },
        });
    } catch (e) {
        showError('xterm.js 加载失败,请检查网络 (CDN 被拦截): ' + e);
        setStatus('加载失败', 'badge-red');
        return;
    }
    const fitAddon = (window.FitAddon && window.FitAddon.FitAddon)
        ? new window.FitAddon.FitAddon()
        : null;
    term.open(document.getElementById('terminal'));
    if (fitAddon) { try { fitAddon.fit(); } catch (_) {} }
    term.writeln('\x1b[33m正在连接 SSH 服务,请稍候...\x1b[0m');

    /* WebSocket */
    const wsScheme = (window.location.protocol === 'https:') ? 'wss' : 'ws';
    const wsUrl = wsScheme + '://' + window.location.host + '/ws/terminal';
    let ws = null;
    let bytesIn = 0, bytesOut = 0;
    let closing = false;

    function updateBytes() {
        BYTES_EL.textContent = `${bytesIn} B in / ${bytesOut} B out`;
    }

    function connect() {
        if (closing) return;
        try {
            ws = new WebSocket(wsUrl);
        } catch (e) {
            showError('无法创建 WebSocket: ' + e);
            setStatus('异常', 'badge-red');
            return;
        }
        setStatus('连接中...', 'badge-orange');
        ws.onopen = function() {
            setStatus('已连接', 'badge-green');
            clearError();
            // send resize
            const cols = term.cols || 80;
            const rows = term.rows || 24;
            ws.send(JSON.stringify({type: 'resize', cols: cols, rows: rows}));
        };
        ws.onmessage = function(ev) {
            let msg;
            try { msg = JSON.parse(ev.data); }
            catch (_) { term.write(ev.data); return; }
            if (msg.type === 'output') {
                term.write(msg.data);
                bytesIn += (msg.data && msg.data.length) || 0;
                updateBytes();
            } else if (msg.type === 'status') {
                term.writeln('\r\n\x1b[36m[状态] ' + (msg.msg || '') + '\x1b[0m');
            } else if (msg.type === 'error') {
                showError(msg.msg || 'unknown error');
                setStatus('错误', 'badge-red');
                term.writeln('\r\n\x1b[31m[错误] ' + (msg.msg || '') + '\x1b[0m');
                // server forced close; close ws
                try { ws.close(); } catch (_) {}
            }
        };
        ws.onerror = function() {
            setStatus('连接失败', 'badge-red');
            showError('WebSocket 出现错误,请检查服务器日志。');
        };
        ws.onclose = function() {
            setStatus('已断开', 'badge-gray');
            term.writeln('\r\n\x1b[33m[提示] WebSocket 已关闭\x1b[0m');
        };
    }

    /* input -> server */
    term.onData(function(data) {
        if (!ws || ws.readyState !== 1) return;
        try {
            ws.send(JSON.stringify({type: 'input', data: data}));
            bytesOut += data.length;
            updateBytes();
        } catch (_) {}
    });

    /* resize */
    function sendResize() {
        if (!ws || ws.readyState !== 1) return;
        try { ws.send(JSON.stringify({type: 'resize', cols: term.cols, rows: term.rows})); }
        catch (_) {}
    }
    if (fitAddon) {
        window.addEventListener('resize', function() {
            try { fitAddon.fit(); sendResize(); } catch (_) {}
        });
    }

    /* exit button */
    EXIT_BTN.addEventListener('click', function() {
        if (ws && ws.readyState === 1) {
            try { ws.close(1000, 'user-exit'); } catch (_) {}
        }
        closing = true;
        setStatus('已主动断开', 'badge-gray');
        term.writeln('\r\n\x1b[33m[用户操作] 已请求断开 SSH 会话\x1b[0m');
    });

    /* kick off */
    connect();
})();
</script>
{% endblock %}