// 自动刷新间隔（毫秒）
const REFRESH_INTERVAL = 3000;
let refreshTimer = null;
let countdownTimer = null;
let countdown = 0;
let isCheckingUpdate = false;
let isResettingStats = false;

// 格式化数字，添加千位分隔符
function formatNumber(num) {
    return num.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}

// 格式化百分比
function formatPercent(num) {
    return num.toFixed(2) + '%';
}

// 更新运行时信息
function updateRuntimeStats(runtime) {
    document.getElementById('uptime').textContent = runtime.uptime_str || '-';
    document.getElementById('goroutines').textContent = formatNumber(runtime.goroutines || 0);
    document.getElementById('mem-alloc').textContent = formatNumber(runtime.mem_alloc_mb || 0) + ' MB';
    document.getElementById('mem-sys').textContent = formatNumber(runtime.mem_sys_mb || 0) + ' MB';
    document.getElementById('mem-total').textContent = formatNumber(runtime.mem_total_mb || 0) + ' MB';
    document.getElementById('num-gc').textContent = formatNumber(runtime.num_gc || 0);

    // 更新统计时长
    const statsDuration = runtime.stats_duration_str || '-';
    document.getElementById('stats-duration').textContent = '统计时长: ' + statsDuration;
}

// 更新查询统计
function updateQueryStats(queries) {
    document.getElementById('total-queries').textContent = formatNumber(queries.total || 0);
    document.getElementById('doh-queries').textContent = formatNumber(queries.doh || 0);
    document.getElementById('cache-hits').textContent = formatNumber(queries.cache_hits || 0);
    document.getElementById('cache-misses').textContent = formatNumber(queries.cache_misses || 0);
    document.getElementById('failed-queries').textContent = formatNumber(queries.failed || 0);
    document.getElementById('hit-rate').textContent = formatPercent(queries.hit_rate || 0);
}

// 更新上游服务器表格
function updateUpstreamTable(upstreams) {
    const tbody = document.getElementById('upstream-tbody');

    if (!upstreams || upstreams.length === 0) {
        tbody.innerHTML = '<tr><td colspan="5" class="no-data">暂无数据</td></tr>';
        return;
    }

    let html = '';
    upstreams.forEach(upstream => {
        const errorClass = upstream.error_rate > 10 ? 'error-high' : '';
        html += `
            <tr>
                <td>${upstream.address || '-'}</td>
                <td>${formatNumber(upstream.total_queries || 0)}</td>
                <td class="${errorClass}">${formatNumber(upstream.errors || 0)}</td>
                <td class="${errorClass}">${formatPercent(upstream.error_rate || 0)}</td>
                <td>${upstream.last_used || 'Never'}</td>
            </tr>
        `;
    });
    tbody.innerHTML = html;
}

// 更新 Top 客户端 IP 表格
function updateTopClientsTable(topClients) {
    const tbody = document.getElementById('top-clients-tbody');

    if (!topClients || topClients.length === 0) {
        tbody.innerHTML = '<tr><td colspan="3" class="no-data">暂无数据</td></tr>';
        return;
    }

    let html = '';
    topClients.forEach((client, index) => {
        const rankClass = index < 3 ? `rank-${index + 1}` : '';
        html += `
            <tr class="${rankClass}">
                <td class="rank-cell">${index + 1}</td>
                <td>${client.key || '-'}</td>
                <td>${formatNumber(client.count || 0)}</td>
            </tr>
        `;
    });
    tbody.innerHTML = html;
}

// 更新 Top 查询域名表格
function updateTopDomainsTable(topDomains) {
    const tbody = document.getElementById('top-domains-tbody');

    if (!topDomains || topDomains.length === 0) {
        tbody.innerHTML = '<tr><td colspan="4" class="no-data">暂无数据</td></tr>';
        return;
    }

    let html = '';
    topDomains.forEach((domain, index) => {
        const rankClass = index < 3 ? `rank-${index + 1}` : '';
        const topClient = domain.top_client || '-';
        html += `
            <tr class="${rankClass}">
                <td class="rank-cell">${index + 1}</td>
                <td class="domain-cell" title="${domain.key}">${domain.key || '-'}</td>
                <td>${formatNumber(domain.count || 0)}</td>
                <td>${topClient}</td>
            </tr>
        `;
    });
    tbody.innerHTML = html;
}

// 更新倒计时显示
function updateCountdown() {
    countdown--;
    if (countdown <= 0) {
        countdown = 0;
    }
    document.getElementById('last-update').textContent = `下次刷新: ${countdown}秒`;
}

// 重置倒计时
function resetCountdown() {
    countdown = REFRESH_INTERVAL / 1000;
    if (countdownTimer) {
        clearInterval(countdownTimer);
    }
    countdownTimer = setInterval(updateCountdown, 1000);
    updateCountdown();
}

// 加载统计数据
async function loadStats() {
    try {
        const response = await fetch('/api/stats');
        if (!response.ok) {
            throw new Error('获取统计数据失败');
        }

        const data = await response.json();

        // 更新各部分数据
        updateRuntimeStats(data.runtime);
        updateQueryStats(data.queries);
        updateUpstreamTable(data.upstreams);
        updateTopClientsTable(data.top_clients);
        updateTopDomainsTable(data.top_domains);

        // 重置倒计时
        resetCountdown();

    } catch (error) {
        console.error('加载统计数据出错:', error);
        document.getElementById('last-update').textContent = '加载失败';
    }
}

// 启动自动刷新
function startAutoRefresh() {
    if (refreshTimer) {
        clearInterval(refreshTimer);
    }
    refreshTimer = setInterval(loadStats, REFRESH_INTERVAL);
}

// 停止自动刷新
function stopAutoRefresh() {
    if (refreshTimer) {
        clearInterval(refreshTimer);
        refreshTimer = null;
    }
    if (countdownTimer) {
        clearInterval(countdownTimer);
        countdownTimer = null;
    }
}

// 加载版本号
async function loadVersion() {
    try {
        const response = await fetch('/api/version');
        if (!response.ok) {
            throw new Error('获取版本号失败');
        }
        const data = await response.json();
        document.getElementById('version-display').textContent = 'v' + data.version;
    } catch (error) {
        console.error('加载版本号出错:', error);
        document.getElementById('version-display').textContent = 'v0.0.0';
    }
}

// 检查更新
async function checkUpdate() {
    if (isCheckingUpdate) {
        return;
    }

    const btn = document.getElementById('check-update-btn');
    const originalText = btn.textContent;

    try {
        isCheckingUpdate = true;
        btn.textContent = '⏳';
        btn.disabled = true;

        const response = await fetch('/api/check-update');
        if (!response.ok) {
            throw new Error('检查更新失败');
        }

        const data = await response.json();

        if (data.has_update) {
            alert(`${data.message}\n当前版本: v${data.current_version}\n最新版本: v${data.latest_version}\n\n请访问 GitHub 下载最新版本`);
        } else {
            alert(`${data.message}\n当前版本: v${data.current_version}`);
        }
    } catch (error) {
        console.error('检查更新出错:', error);
        alert('检查更新失败，请稍后再试');
    } finally {
        isCheckingUpdate = false;
        btn.textContent = originalText;
        btn.disabled = false;
    }
}

// 重置统计数据
async function resetStats() {
    if (isResettingStats) {
        return;
    }

    // 确认对话框
    if (!confirm('确定要重置所有统计数据吗？此操作无法撤销。')) {
        return;
    }

    const btn = document.getElementById('reset-stats-btn');
    const originalText = btn.textContent;

    try {
        isResettingStats = true;
        btn.textContent = '⏳ 重置中...';
        btn.disabled = true;

        const response = await fetch('/api/stats/reset', {
            method: 'POST'
        });

        if (!response.ok) {
            throw new Error('重置统计数据失败');
        }

        const data = await response.json();

        if (data.success) {
            alert(data.message || '统计数据已重置');
            // 立即刷新数据
            await loadStats();
        } else {
            alert('重置失败: ' + (data.message || '未知错误'));
        }
    } catch (error) {
        console.error('重置统计数据出错:', error);
        alert('重置统计数据失败，请稍后再试');
    } finally {
        isResettingStats = false;
        btn.textContent = originalText;
        btn.disabled = false;
    }
}

// 页面加载完成后初始化
document.addEventListener('DOMContentLoaded', function() {
    // 立即加载一次数据
    loadStats();
    loadVersion();

    // 启动自动刷新
    startAutoRefresh();

    // 绑定检查更新按钮
    document.getElementById('check-update-btn').addEventListener('click', checkUpdate);

    // 绑定重置统计按钮
    document.getElementById('reset-stats-btn').addEventListener('click', resetStats);

    // 页面可见性变化时控制刷新
    document.addEventListener('visibilitychange', function() {
        if (document.hidden) {
            stopAutoRefresh();
        } else {
            loadStats();
            startAutoRefresh();
        }
    });
});

// 页面卸载时停止刷新
window.addEventListener('beforeunload', function() {
    stopAutoRefresh();
});