<?php
// 引入数据库连接文件
require 'db_connect.php';

// 获取请求参数
$date = $_GET['date'];

// 验证日期格式
if (!preg_match('/^\d{4}-\d{2}-\d{2}$/', $date)) {
    echo json_encode(['error' => 'Invalid date format']);
    exit;
}

try {
    // 查询指定日期的总预约时长，只计算有效预约
    $sql = "SELECT SUM(duration) as total_duration FROM bookings WHERE DATE(start_time) = ? AND status NOT IN ('已完成', '已取消')";
    $stmt = $pdo->prepare($sql);
    $stmt->execute([$date]);
    $row = $stmt->fetch();
    
    // 获取总时长，如果没有预约则返回0
    $total_duration = $row['total_duration'] ? $row['total_duration'] : 0;
    
    // 返回结果
    echo json_encode(['total_duration' => $total_duration]);
} catch (PDOException $e) {
    echo json_encode(['error' => 'Database query failed: ' . $e->getMessage()]);
}