frequencies.php

<?php
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Headers: Authorization, Content-Type");
header("Access-Control-Allow-Methods: GET, OPTIONS");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Max-Age: 3600");

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    handleOptionsRequest();
}

require_once 'db_connection.php';
require_once 'functions.php';

if ($_SERVER['REQUEST_METHOD'] === 'GET') {
    handleGetRequest($conn);
} else {
    sendJsonResponse(405, ["message" => "$_SERVER[REQUEST_METHOD] requests are not allowed"]);
}
$conn->close();

function handleGetRequest($conn) {
    global $frequencies_table_name;
    if (isset($_GET['id'])) {
        $id = $_GET['id'];
        $stmt = $conn->prepare("SELECT * FROM $frequencies_table_name WHERE id = ?");
        $stmt->bind_param("i", $id);
        $stmt->execute();
        $result = $stmt->get_result();

        if ($result !== false && $result->num_rows > 0) {
            $frequency = $result->fetch_assoc();
            sendJsonResponse(200, $frequency);
        } else {
            sendJsonResponse(404, ["message" => 'Frequency not found']);
        }
        $stmt->close();
    } else {
        $result = $conn->query("SELECT * FROM $frequencies_table_name");
        $frequency = [];

        while ($row = $result->fetch_assoc()) {
            $frequency[] = $row;
        }
        sendJsonResponse(200, $frequency);
    }
}

function handleOptionsRequest() {
    header("Access-Control-Allow-Origin: *");
    header('Access-Control-Allow-Methods: OPTIONS, GET');
    header('Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With');
    exit;
}