如何发送电子邮件与PHP，使用谷歌工作表与JavaScript？

$to = 'recipient@example.com';
$subject = 'Hello from PHP';
$message = 'This is a test email';
$headers = 'From: sender@example.com';

if (mail($to, $subject, $message, $headers)) {
    echo 'Email sent successfully.';
} else {
    echo 'Failed to send email.';
}

// 使用谷歌API加载客户端库
gapi.load('client', initClient);

function initClient() {
    // 在此处设置API密钥或OAuth 2.0授权凭证
    gapi.client.init({
        apiKey: 'YOUR_API_KEY',
        clientId: 'YOUR_CLIENT_ID',
        discoveryDocs: ['https://sheets.googleapis.com/$discovery/rest?version=v4'],
        scope: 'https://www.googleapis.com/auth/spreadsheets.readonly'
    }).then(function() {
        // 初始化成功后执行的代码
        listValues();
    }, function(error) {
        // 初始化失败后执行的代码
        console.error('Error initializing Google Sheets API:', error);
    });
}

function listValues() {
    gapi.client.sheets.spreadsheets.values.get({
        spreadsheetId: 'YOUR_SPREADSHEET_ID',
        range: 'Sheet1!A1:B2'
    }).then(function(response) {
        var values = response.result.values;
        if (values.length > 0) {
            console.log('Data:');
            for (var i = 0; i < values.length; i++) {
                var row = values[i];
                console.log(row[0], row[1]);
            }
        } else {
            console.log('No data found.');
        }
    }, function(error) {
        console.error('Error retrieving data from Google Sheets:', error);
    });
}