<?php
declare(strict_types=1);

namespace App;

use PDO;
use RuntimeException;

class AmiClient
{
    public function __construct(
        private string $host,
        private int $port,
        private string $username,
        private string $secret,
        private int $timeout = 3
    ) {}

    public static function fromDatabase(PDO $db): self
    {
        $row = $db->query('SELECT ami_host, ami_port, ami_user, ami_secret FROM settings WHERE id = 1')->fetch();
        return new self(
            (string)($row['ami_host'] ?? '127.0.0.1'),
            (int)($row['ami_port'] ?? 5038),
            (string)($row['ami_user'] ?? 'pbxgui'),
            (string)($row['ami_secret'] ?? 'AsteriskAmi2026!')
        );
    }

    /**
     * Teste la connexion et l'authentification AMI
     */
    public function testConnection(): array
    {
        $fp = $this->connectAndLogin($banner);
        $versionOutput = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'core show version',
        ]);
        $this->logoff($fp);

        return [
            'connected' => true,
            'banner'    => trim($banner),
            'version'   => $this->extractCommandOutput($versionOutput),
        ];
    }

    /**
     * Recharge à chaud l'ensemble des modules PJSIP, force le Re-Register SIP immédiat des Trunks, et recharge le Dialplan via AMI
     */
    public function reloadPjsipAndDialplan(): array
    {
        $fp = $this->connectAndLogin($banner);

        // Recharge l'intégralité de la pile PJSIP (res_pjsip.so, res_pjsip_outbound_registration.so, res_pjsip_endpoint_identifier_ip.so, etc.)
        $pjsipRes = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'pjsip reload',
        ]);

        // Force l'envoi immédiat d'une requête SIP REGISTER vers tous les opérateurs (reprend immédiatement la main si un autre PBX était enregistré)
        $regRes = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'pjsip send register *all',
        ]);

        // Recharge le dialplan (extensions.conf / extensions.custom.conf)
        $dialplanRes = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'dialplan reload',
        ]);

        // Recharge les classes de musique d'attente (musiconhold.conf)
        $mohRes = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'moh reload',
        ]);

        // Recharge le module RTP (plages de ports rtpstart/rtpend & NAT)
        $rtpRes = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'module reload res_rtp_asterisk.so',
        ]);

        // Recharge les touches en cours d'appel (features.conf : transferts ##, *2, etc.)
        $featuresRes = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'module reload features',
        ]);

        // Recharge la messagerie vocale (voicemail.conf & voicemail.custom.conf)
        $voicemailRes = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'voicemail reload',
        ]);

        $this->logoff($fp);

        // Laisse 1.25s au scheduler PJSIP (1s) + registrar opérateur (OVH) pour répondre 200 OK avant le rafraîchissement de l'état UI
        usleep(1250000);

        return [
            'banner'   => trim($banner),
            'pjsip'    => $this->extractCommandOutput($pjsipRes),
            'register' => $this->extractCommandOutput($regRes),
            'dialplan' => $this->extractCommandOutput($dialplanRes),
            'moh'      => $this->extractCommandOutput($mohRes),
        ];
    }

    /**
     * Force l'envoi immédiat d'un paquet SIP REGISTER sur un trunk précis ou tous les trunks (*all)
     */
    public function forceRegister(string $regObject = '*all'): string
    {
        $fp = $this->connectAndLogin($banner);
        $raw = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => 'pjsip send register ' . $regObject,
        ]);
        $this->logoff($fp);
        usleep(1250000);
        return $this->extractCommandOutput($raw);
    }

    /**
     * Exécute une commande CLI Asterisk via AMI (ex: "pjsip show endpoints")
     */
    public function runCommand(string $cliCommand): string
    {
        $fp = $this->connectAndLogin($banner);
        $raw = $this->sendAction($fp, [
            'Action'  => 'Command',
            'Command' => $cliCommand,
        ]);
        $this->logoff($fp);
        return $this->extractCommandOutput($raw);
    }

    /**
     * @return resource
     */
    private function connectAndLogin(?string &$banner = null)
    {
        $errno  = 0;
        $errstr = '';
        $fp = @fsockopen($this->host, $this->port, $errno, $errstr, $this->timeout);
        if (!$fp) {
            throw new RuntimeException("Connexion socket AMI refusée sur {$this->host}:{$this->port} ({$errstr} [{$errno}]). Vérifiez qu'Asterisk et manager.conf sont actifs.");
        }

        stream_set_timeout($fp, $this->timeout);
        $banner = (string)fgets($fp, 1024);

        $loginResp = $this->sendAction($fp, [
            'Action'   => 'Login',
            'Username' => $this->username,
            'Secret'   => $this->secret,
            'Events'   => 'off',
        ]);

        if (!preg_match('/Response:\s*Success/i', $loginResp)) {
            fclose($fp);
            throw new RuntimeException("Échec d'authentification AMI pour l'utilisateur '{$this->username}' sur {$this->host}:{$this->port}.");
        }

        return $fp;
    }

    /**
     * @param resource $fp
     */
    private function sendAction($fp, array $headers): string
    {
        $packet = '';
        foreach ($headers as $k => $v) {
            $packet .= "{$k}: {$v}\r\n";
        }
        $packet .= "\r\n";

        fwrite($fp, $packet);

        $response = '';
        while (!feof($fp)) {
            $line = fgets($fp, 4096);
            if ($line === false) {
                break;
            }
            $response .= $line;
            if (str_ends_with($response, "\r\n\r\n") || str_ends_with($response, "\n\n")) {
                break;
            }
        }

        return $response;
    }

    /**
     * @param resource $fp
     */
    private function logoff($fp): void
    {
        @fwrite($fp, "Action: Logoff\r\n\r\n");
        @fclose($fp);
    }

    private function extractCommandOutput(string $raw): string
    {
        $lines = preg_split('/\r?\n/', trim($raw)) ?: [];
        $clean = [];
        foreach ($lines as $line) {
            if (preg_match('/^(Response|Privilege|ActionID|Message):/i', $line)) {
                continue;
            }
            if (str_starts_with($line, 'Output:')) {
                $val = ltrim(substr($line, 7));
                if ($val !== '') {
                    $clean[] = $val;
                }
            } elseif ($line !== '--END COMMAND--') {
                $clean[] = $line;
            }
        }
        return trim(implode("\n", $clean));
    }
}