<?php
require_once dirname(__DIR__, 3) . '/vendor/autoload.php'; // Torna al livello di public

use Dotenv\Dotenv;

class VisualLimsApiClient
{
    private static $instance = null;
    private $baseUrl;
    private $username;
    private $password;
    private $token = null;

    private function __construct()
    {
        $dotenv = Dotenv::createImmutable(dirname(__DIR__, 3)); // Torna al livello di public
        $dotenv->load();

        $this->baseUrl = $_ENV['API_BASE_URL'];
        $this->username = $_ENV['API_USERNAME'];
        $this->password = $_ENV['API_PASSWORD'];
    }

    public static function getInstance()
    {
        if (self::$instance === null) {
            self::$instance = new VisualLimsApiClient();
        }
        return self::$instance;
    }

    private function authenticate($retryCount = 0, $maxRetries = 3)
    {
        $ch = curl_init("{$this->baseUrl}/api/authentication/authenticate");
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
            'Username' => $this->username,
            'Password' => $this->password
        ]));
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            'Content-Type: application/json',
            'Accept: application/json'
        ]);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($ch, CURLOPT_VERBOSE, true);
        $log = fopen(__DIR__ . '/curl_auth_debug.log', 'a') ?: fopen('php://stderr', 'w');
        curl_setopt($ch, CURLOPT_STDERR, $log);

        $response = curl_exec($ch);
        $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curl_error = curl_error($ch);
        $log_message = date('Y-m-d H:i:s') . " - Auth attempt {$retryCount}: HTTP {$http_code}, Error: {$curl_error}, Response: " . substr($response, 0, 1000) . "\n";
        fwrite($log, $log_message);
        fclose($log);
        curl_close($ch);

        if ($response === false || $http_code != 200) {
            if ($http_code === 400 && strpos($response, 'Cannot persist the object') !== false && $retryCount < $maxRetries) {
                usleep(500000); // Ritardo di 500ms
                return $this->authenticate($retryCount + 1, $maxRetries); // Riprova
            }
            throw new Exception("Autenticazione fallita: HTTP {$http_code}, Errore cURL: {$curl_error}, Risposta: " . substr($response, 0, 1000));
        }

        $token_data = json_decode($response, true);
        $this->token = null;

        if (is_array($token_data) && isset($token_data['token'])) {
            $this->token = $token_data['token'];
        } elseif (is_string($token_data) && !empty($token_data)) {
            $this->token = trim($token_data, '"');
        } elseif (is_string($response) && !empty($response)) {
            $this->token = trim($response, '"');
        }

        if (empty($this->token)) {
            throw new Exception("Token non ricevuto: " . substr($response, 0, 1000));
        }
    }

    private function getToken()
    {
        if ($this->token === null) {
            $this->authenticate();
        }
        return $this->token;
    }

    public function get($endpoint)
    {
        $token = $this->getToken();
        $url = "{$this->baseUrl}/api/odata/{$endpoint}";

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            "Authorization: Bearer {$token}",
            "Accept: application/json"
        ]);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($ch, CURLOPT_VERBOSE, true);
        $log = fopen(__DIR__ . '/curl_request_debug.log', 'w') ?: fopen('php://stderr', 'w');
        curl_setopt($ch, CURLOPT_STDERR, $log);

        $response = curl_exec($ch);
        $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curl_error = curl_error($ch);
        fclose($log);
        curl_close($ch);

        if ($response === false) {
            throw new Exception("Errore nella richiesta: {$curl_error}");
        }

        if ($http_code !== 200) {
            throw new Exception("Errore nel recupero dati: HTTP {$http_code}, Risposta: " . substr($response, 0, 1000));
        }

        $data = json_decode($response, true);
        if (json_last_error() !== JSON_ERROR_NONE) {
            throw new Exception("Risposta non JSON valida: " . substr($response, 0, 1000));
        }

        return $data;
    }

    public function post($endpoint, $payload)
    {
        $token = $this->getToken();
        $url = "{$this->baseUrl}/api/odata/{$endpoint}";

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            "Authorization: Bearer {$token}",
            "Content-Type: application/json",
            "Accept: application/json"
        ]);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

        $response = curl_exec($ch);
        $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curl_error = curl_error($ch);
        curl_close($ch);

        if ($response === false) {
            throw new Exception("Errore nella richiesta POST: {$curl_error}");
        }

        if ($http_code < 200 || $http_code >= 300) {
            throw new Exception("POST fallito: HTTP {$http_code}, Risposta: " . substr($response, 0, 1000));
        }

        return json_decode($response, true);
    }

    public function patch($endpoint, $payload)
    {
        $token = $this->getToken();
        $url = "{$this->baseUrl}/api/odata/{$endpoint}";

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PATCH");
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            "Authorization: Bearer {$token}",
            "Content-Type: application/json",
            "Accept: application/json"
        ]);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

        $response = curl_exec($ch);
        $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curl_error = curl_error($ch);
        curl_close($ch);

        if ($response === false) {
            throw new Exception("Errore nella richiesta PATCH: {$curl_error}");
        }

        if ($http_code < 200 || $http_code >= 300) {
            throw new Exception("PATCH fallito: HTTP {$http_code}, Risposta: " . substr($response, 0, 1000));
        }

        return json_decode($response, true);
    }

    public function getBaseUrl()
    {
        return $this->baseUrl;
    }
}