<?php


function valid($msg, $key, $regex) {
    //if(!isset($msg[$key])) {
    /*
    if(!array_key_exists($key,$msg)) {
        echo "{\"error_message\": \"Key " . $key . " does not exist in msg.\"}";
        return false;
    }
    else if(!preg_match($regex,$msg[$key])) {
        echo "{\"error_message\": \"" . $msg[$key] . "  does not match regex " . $regex . "\"}";
        return false;
    }
    else {
        return true;
    }
    */
    return array_key_exists($key,$msg) && preg_match($regex,$msg[$key]);
}

// Update device configuration
$router->post('/api/config', function($req) use($db) {
    $msg = $req->getJSONBody();

    if(!valid($msg,'mac_address',        '/^[0-9a-f][0-9a-f]:[0-9a-f][0-9a-f]:[0-9a-f][0-9a-f]:[0-9a-f][0-9a-f]:[0-9a-f][0-9a-f]:[0-9a-f][0-9a-f]$/i') ||
       !valid($msg,'ip_address',         '/^[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*$/i') ||
       !valid($msg,'firmware_version',   '/^[0-9]+$/') ||
       !valid($msg,'temperature_offset', '/^[0-9]+\.*[0-9]*$/') ||
       !valid($msg,'humidity_offset',    '/^[0-9]+\.*[0-9]*$/') ||
       !valid($msg,'id','/^[0-9]+$/')
    ) {
        echo '{"error_message": "Field verification failed."}';
        http_response_code(400);
        return;
    }

    $deviceData = $msg['id'] == 0 ?  null : $db->getDeviceByID($msg['id']);
    // If device is not registered yet, register...
    if($deviceData == null) {
        // All fields are set and no ID was given. Register new device and return new ID...
        $config = [
            'mac_address'        => $msg['mac_address'],
            'ip_address'         => $msg['ip_address'],
            'ip_address_seen'    => $_SERVER['REMOTE_ADDR'],
            'firmware_version'   => $msg['firmware_version'],
            'temperature_offset' => $msg['temperature_offset'],
            'humidity_offset'    => $msg['humidity_offset'],
            'last_seen'          => date('Y-m-d H:i:s')
        ];
        $deviceID = $db->addDevice($config);
        $config['deviceID'] = $deviceID;
        echo json_encode($config);
        http_response_code(200);
        return;
    }
    // If device is registered...
    // Update database entry based on post data received.
    $db->updateDevice($deviceData['id'],
    [
        'mac_address'        => $msg['mac_address'],
        'ip_address'         => $msg['ip_address'],
        'ip_address_seen'    => $_SERVER['REMOTE_ADDR'],
        'firmware_version'   => $msg['firmware_version'],
        'last_seen'          => date('Y-m-d H:i:s')
    ]);
    // Return stored device data so device may update its settings.
    echo json_encode($deviceData);
    http_response_code(200);
    return;
});

// Device reports temperature back on this endpoint.
$router->post('/api/report', function($req) use($db) {
    $msg = $req->getJSONBody();

    if(!valid($msg,'id',          '/^[0-9]+$/') ||
       !valid($msg,'temperature', '/^[0-9]+\.*[0-9]*$/') ||
       !valid($msg,'humidity',    '/^[0-9]+\.*[0-9]*$/')
    ) {
        echo '{"error_message": "Field verification failed."}';
        http_response_code(400);
    }
    else if($db->getDeviceByID($msg['id']) == null) {
        echo '{"error_message": "ID '.$msg['id'].' not found"}';
        http_response_code(400);
    }
    else {
        $data = [
            "temperature" => $msg['temperature'],
            "humidity"    => $msg['humidity'],
            "read_at"     => date('Y-m-d H:i:s')
        ];
        $db->updateDevice($msg['id'], $data);
        http_response_code(200);
    }
});

$router->get('/api/update', function() {
    if ( $_SERVER['HTTP_USER_AGENT'] == 'ESP8266-http-Update' && isset($_SERVER['HTTP_X_ESP8266_SKETCH_MD5']) ) {
        $user_agent        = $_SERVER['HTTP_USER_AGENT'];
        $curr_firmware_md5 = $_SERVER['HTTP_X_ESP8266_SKETCH_MD5'];
        $firmware_file     = __DIR__ . '/firmware.bin';
        $firmware_md5      = md5_file($firmware_file);
        echo "USER_AGENT -> ESP8266-http-Update\n";
	echo 'X_ESP8266_SKETCH_MD5 -> ' . $_SERVER['HTTP_X_ESP8266_SKETCH_MD5'] . "\n";
	echo 'MD5 file hash of ' . $firmware_file . ': ' . $firmware_md5;
	if ( $curr_firmware_md5 == $firmware_md5 ) {
            http_response_code(204);
        }
        else {
            $fwdata = file_get_contents($firmware_file);
            header('Content-Length:' . strlen($fwdata));
            echo $fwdata;
            http_response_code(200);
        }
        return;
    }

    http_response_code(400);
});