Get Netherland address details and Calculate distance between two coordinates via Google Destinations API in PHP

address_object.json

{
    "status": "ok",
    "details": [
        {
            "street": "Zaagmolenpad",
            "city": "Doetinchem",
            "municipality": "Doetinchem",
            "province": "Gelderland",
            "postcode": "7008 AJ",
            "pnum": "7008",
            "pchar": "AJ",
            "rd_x": "215930.96446666666666666667",
            "rd_y": "442753.35240000000000000000",
            "lat": "51.9698526620957",
            "lon": "6.2738995722633"
        }
    ]
}

example.php

<?php

// ---------------------------------------------
## Usage Example | ACTION REPLACE WITH YOUR LOGIC
// ---------------------------------------------

// 1. TODO: Replace with your actual Google Maps API Key
$google_api_key = 'YORE_API_KEY_HERE'; // Replace with your actual Google Maps API Key

// 2. Define the origin coordinates (latitude,longitude) Alrady DONE
$origin = '51.97074550279727, 6.271788884654938';  // Albek Witgoed Outlet

// Fill in the postal code and house number you want to look up.
$postcode = "7002TR";
$number = 54;

// Call the function to get address details.
$address_data = getAddressDetails($postcode, $number);

// Output the results.
if ($address_data == null) {
    echo "Failed to retrieve address details.";
    exit;
}

// Extract the first address detail (if available)
$address_details = $address_data['details'][0] ?? null;
if ($address_details == null) {
    echo "No address details found for the provided postal code and house number.";
    exit;
}

// Define the destination coordinates based on the retrieved address details
$destination = $address_details['lat'] . ',' . $address_details['lon']; // Address from postal code lookup

// Calculate the route distance using the retrieved coordinates
$distance_km = get_route_distance_km($origin, $destination, $google_api_key);

if ($distance_km !== null) {
    echo "Real route distance: **" . round($distance_km, 2) . " km** <br><br>";
} else {
    echo "Could not calculate route distance.";
}

echo <<<MULTILINE
    status: {$address_data['status']} <br>
    street: {$address_details['street']} <br>
    City: {$address_details['city']} <br>
    Municipality: {$address_details['municipality']} <br>
    Province: {$address_details['province']} <br>
    Postal Code: {$address_details['postcode']} <br>
    Latitude: {$address_details['lat']} <br>
    Longitude: {$address_details['lon']} <br>
MULTILINE;

?>

index.php

<?php

/**
 * Retrieves address details (including coordinates) for a given Dutch postal code and house number.
 *
 * NOTE: This function is written for a generic public API structure (like PostcodeData.nl's API
 * example, which uses an optional 'ref' parameter). You MUST replace the $api_url
 * and $ref_key with the actual values for the service you are using.
 *
 * @param string $postalCode The Dutch postal code (e.g., "7008AJ").
 * @param int $buildingNumber The house number (e.g., 25).
 * @return array|null The decoded JSON response as a PHP array, or null on failure.
 */
function getAddressDetails(string $postalCode, int $buildingNumber): ?array
{
    // --- Configuration ---
    // 1. Set the correct API URL.
    //    (Example uses the base URL for PostcodeData.nl)
    $api_url = 'http://api.postcodedata.nl/v1/postcode/';

    // 2. Set your unique reference key (which you must register for).
    //    (Example uses the placeholder seen in public documentation)
    $ref_key = 'your_registered_domain.nl';
    // -----------------------

    // Build the query parameters.
    $query_params = http_build_query([
        'postcode' => urlencode(strtoupper($postalCode)),
        'streetnumber' => $buildingNumber,
        'ref' => $ref_key,
        'type' => 'json'
    ]);

    $full_url = $api_url . '?' . $query_params;

    // Use file_get_contents to fetch the JSON data.
    // For production use, you should use cURL for better error handling and control.
    $json_data = @file_get_contents($full_url);

    if ($json_data === FALSE) {
        // Handle API connection or access error.
        error_log("Failed to retrieve data from: " . $full_url);
        return null;
    }

    // Decode the JSON string into a PHP associative array.
    $result = json_decode($json_data, true);

    if ($result === null && json_last_error() !== JSON_ERROR_NONE) {
        // Handle JSON decoding error.
        error_log("Failed to decode JSON response. Error: " . json_last_error_msg());
        return null;
    }

    // The function returns the PHP array, which mirrors your expected JSON structure.
    return $result;
}

/**
 * Calculates the real-route distance between two coordinates using the Google Maps Directions API.
 *
 * NOTE: Ensure you have a valid Google Maps API key with the Directions API enabled and billing set up.
 *
 * @param string $origin_lat_lng The starting latitude and longitude (e.g., '40.712776,-74.005974').
 * @param string $destination_lat_lng The ending latitude and longitude (e.g., '34.052235,-118.243683').
 * @param string $api_key Your Google Maps Platform API Key.
 * @return float|null The distance in kilometers, or null on failure.
 */
function get_route_distance_km(string $origin_lat_lng, string $destination_lat_lng, string $api_key): ?float {
    // The Directions API URL
    $api_url = 'https://maps.googleapis.com/maps/api/directions/json?';

    // Build the request parameters
    $params = [
        'origin' => $origin_lat_lng,
        'destination' => $destination_lat_lng,
        'key' => $api_key,
        'units' => 'metric', // Request distance in meters/kilometers (metric system)
        'mode' => 'driving', // Calculate driving route (you can change this to 'walking', 'bicycling', etc.)
    ];

    // Construct the full URL
    $full_url = $api_url . http_build_query($params);

    // Use cURL to make the API request
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $full_url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $response = curl_exec($ch);
    $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    // Check for cURL errors or bad HTTP response
    if ($http_code !== 200 || $response === false) {
        // Log or handle the error appropriately
        error_log("Google Directions API request failed with HTTP code: $http_code");
        return null;
    }

    // Decode the JSON response
    $data = json_decode($response, true);

    // Check for API errors or no routes found
    if ($data['status'] !== 'OK' || empty($data['routes'])) {
        // Log or handle the API status error (e.g., 'ZERO_RESULTS')
        error_log("Google Directions API returned status: " . $data['status']);
        return null;
    }

    // Extract the distance from the first route's first leg
    // The distance is returned in meters (distance['value'])
    // Distance in meters is found in: routes[0]['legs'][0]['distance']['value']
    $distance_meters = $data['routes'][0]['legs'][0]['distance']['value'] ?? null;

    if ($distance_meters === null) {
        error_log("Could not find distance in Google Directions API response.");
        return null;
    }

    // Convert meters to kilometers and return
    $distance_km = $distance_meters / 1000;

    return (float) $distance_km;
}    
?>