<?php

require_once __DIR__ . '/../vendor/autoload.php';
require_once __DIR__ . '/../config.php';

/* Initialize Twig engine */
$loader = new \Twig\Loader\FilesystemLoader(__DIR__ . '/../templates');
$twig = new \Twig\Environment($loader, [
    'cache' => __DIR__ . '/../cache',
    'auto_reload' => true,
]);

$all = false;
$record = "";
$desc = "";

$error = "";
$result = [];

if (isset($_POST["all"]) || isset($_GET["all"]))
    $all = true;

if (isset($_POST["record"]) && !empty($_POST["record"])) {
    $record = (string) $_POST["record"];

    if (isset($_POST["desc"]) && !empty($_POST["desc"])) {
        $desc = (string) $_POST["desc"];
    }

    $pdo = (new App\DB($options))->pdo;
    $util = new App\Utils;

    $parsed = $util->parseHostRecord($record);

    if (!isset($parsed['host'])) {
        $result["error"] = "Error while validating: Incorrect Auth string";

    } else if (!$util->isValidDomain($parsed['host'], $error)) {
        $result["error"] = "Error while validating: " . $error;

    } else {
        if ($util->isPunycodeDomain($parsed['host'])) {
            $domain = idn_to_utf8($parsed['host'], 0, INTL_IDNA_VARIANT_UTS46);

        } else {
            $domain = $parsed['host'];
        }

        if (!isset($parsed["commands"]) || !isset($parsed["commands"]["sig"])) {
            $result["error"] = "Error while validating: No extended record fields or signature is found.";

        } else if (!$util->verifyHostRecord($record, $error)) {
            $result["error"] = "Error while validating: " . $error[0];

        } else {
            if (isset($parsed["commands"]["action"])) {
                /* Check if such domain name already registered */
                $STH = $pdo->prepare('SELECT COUNT(*) FROM `hosts` WHERE `host` = ? LIMIT 1');
                $STH->execute([$domain]);

                switch ($parsed["commands"]["action"]) {
                    case 'addsubdomain':
                        if ($STH->fetchColumn() == 1) {
                            $result["error"] = "Error while validating: That subdomain is already registered.";

                        } else if (!isset($parsed["commands"]["oldname"]) || !isset($parsed["commands"]["olddest"]) || !isset($parsed["commands"]["oldsig"])) {
                            $result["error"] = "Error while validating: required fields not found. Re-check your registration string.";

                        } else {
                            /* Getting domain at higher level (2LD for registering 3LD and etc.) and validating that domain is lower than 2LD. */
                            $darr = explode(".", $domain);
                            $dtop = "";

                            for ($i = 1; $i < sizeof ($darr); $i++) {
                                $dtop .= $darr[$i];
                                if ((sizeof ($darr) - 1) != $i) $dtop .= ".";
                            }

                            $STH = $pdo->prepare('SELECT COUNT(*) FROM `hosts` WHERE `host` = ? AND `base64` = ? LIMIT 1');

                            if (sizeof($darr) < 3) {
                                $result["error"] = "Error while validating: you can't register second level domain (example.i2p) using addsubdomain action.";

                            } else if ($dtop != $parsed["commands"]["oldname"]) {
                                $result["error"] = "Error while validating: oldname value is not same as your higher level domain.";

                            } else if (!$STH->execute([$parsed["commands"]["oldname"], $parsed["commands"]["olddest"]]) || !$STH->fetchColumn()) {
                                $result["error"] = "Error while validating: can't find higher level domain with values from oldname and olddest.";

                            } else {
                                $base32 = $util->b32from64($parsed["b64"]);

                                if (!$pdo->prepare('INSERT INTO `hosts` (`host`, `base64`, `base32`) VALUES (?, ?, ?)')->execute([$domain, $parsed["b64"], $base32])) {
                                    $result["error"] = "Error happened while inserting record to database. Please try again later.";

                                } else {
                                    $result["command"] = 'addsubdomain';
                                    $result["host"]    = $domain;
                                    $result["base64"]  = $parsed["b64"];
                                    $result["base32"]  = $base32;
                                }
                            }
                        }
                    break;
                    case 'adddest':
                    case 'changedest':
                        if($STH->fetchColumn() == 0) {
                            $result["error"] = "Error while validating: That domain is not registered.";

                        } else if (!isset($parsed["commands"]["olddest"]) || !isset($parsed["commands"]["oldsig"])) {
                            $result["error"] = "Error while validating: required fields not found. Re-check your registration string.";

                        } else {
                            $STH = $pdo->prepare('SELECT COUNT(*) FROM `hosts` WHERE `host` = ? AND `base64` = ? LIMIT 1');

                            if (!$STH->execute([$domain, $parsed["commands"]["olddest"]]) || !$STH->fetchColumn()) {
                                $result["error"] = "Error while validating: old base64 and value in olddest field does not match..";

                            } else {
                                $base32 = $util->b32from64($parsed["b64"]);

                                if (!$pdo->prepare('UPDATE `hosts` SET `base64` = ?, `base32` = ? WHERE `host` = ?')->execute([$parsed["b64"], $base32, $domain])) {
                                    $result["error"] = "Error happened while updating record in database. Please try again later.";

                                } else {
                                    $result["command"] = 'changedest';
                                    $result["host"]    = $domain;
                                    $result["base64"]  = $parsed["b64"];
                                    $result["base32"]  = $base32;
                                }
                            }
                        }
                    break;
                    case 'addname':
                        if($STH->fetchColumn() == 1) {
                            $result["error"] = "Error while validating: That domain is already registered.";

                        /* Getting domain level (2LD, 3LD and etc.) and validating that domain at higher level is registered (2LD if registering 3LD). */
                        } else if (sizeof(explode(".", $domain)) > 2) {
                            $result["error"] = "Error while validating: you can't register subdomain (sub.example.i2p) as domain alias using addname action.";

                        } else if (!isset($parsed["commands"]["oldname"])) {
                            $result["error"] = "Error while validating: required fields not found. Re-check your registration string.";

                        } else {
                            if ($util->isPunycodeDomain($parsed["commands"]["oldname"])) {
                                $olddomain = idn_to_utf8($parsed["commands"]["oldname"], 0, INTL_IDNA_VARIANT_UTS46);

                            } else {
                                $olddomain = $parsed["commands"]["oldname"];
                            }

                            $STH = $pdo->prepare('SELECT COUNT(*) FROM `hosts` WHERE `host` = ? AND `base64` = ? LIMIT 1');

                            if (!$STH->execute([$olddomain, parsed["b64"]]) || !$STH->fetchColumn()) {
                                $result["error"] = "Error while validating: base64 does not match for domain in oldname field...";

                            } else {
                                $base32 = $util->b32from64($parsed["b64"]);

                                if (!$pdo->prepare('INSERT INTO `hosts` (`host`, `base64`, `base32`) VALUES (?, ?, ?)')->execute([$domain, $parsed["b64"], $base32])) {
                                    $result["error"] = "Error happened while updating record in database. Please try again later.";

                                } else {
                                    $result["command"] = 'addname';
                                    $result["host"]    = $domain;
                                    $result["base64"]  = $parsed["b64"];
                                    $result["base32"]  = $base32;
                                }
                            }
                        }
                    break;
                    default:
                        $result["error"] = "Error while validating: extended record fields are NOT supported.";
                    break;
                }

            } else {
                /* Check if such domain name already registered */
                $STH = $pdo->prepare('SELECT `host`, `base32`, `base64`, `initial`, `disabled` FROM `hosts` WHERE `host` = ? LIMIT 1');
                $STH->execute([$domain]);
                $row = $STH->fetch(PDO::FETCH_ASSOC);

                if($row && !$row['disabled']) {
                    $result["error"] = "Error while validating: That domain is already registered.";

                } else if($row && $row['disabled'] && $row['initial']) {
                    $result["error"] = "Error while validating: That domain is reserved and can't be re-registered automatically. Please contact service support team.";

                } else {
                    if (isset($parsed["commands"]["oldname"]) || isset($parsed["commands"]["olddest"]) || isset($parsed["commands"]["oldsig"])) {
                        $result["error"] = "Error while validating: unexpected fields found.";

                    } else if (sizeof(explode(".", $domain)) > 2) {
                        $result["error"] = "Error while validating: you can't register subdomain without specific action field.";

                    } else {
                        $result["reregister"] = false;
                        if($row && $row['disabled']) { /* processing disabled domain */
                            $log = "[" . date("d-M-Y H:i:s e") . "] Re-registering attempt for " . $row['host'] . "! Next records will be deleted:" . PHP_EOL;

                            /* print all records, which will be deleted*/
                            $STH = $pdo->prepare('SELECT `host`, `base32`, `base64` FROM `hosts` WHERE `host` = ? OR `host` LIKE ?');
                            $STH->execute([$domain, '%'.$domain]);
                            $hosts = $STH->fetchAll(PDO::FETCH_ASSOC);
                            foreach ($hosts as $host) {
                                $log .= "Host: " . $host['host'] . PHP_EOL . "Base32: " . $host['base32'] . PHP_EOL . "Base64: " . $host['base64'] . PHP_EOL;
                            }

                            file_put_contents(__DIR__ . '/../logs/reg.log', $log, FILE_APPEND);

                            /* remove domain and subdomains if any found */
                            $pdo->prepare('DELETE FROM `hosts` WHERE `host` = ? OR `host` LIKE ?')->execute([$domain, '%'.$domain]);
                            $result["reregister"] = true;
                        }

                        $base32 = $util->b32from64($parsed["b64"]);

                        /*  Adding to database 2LD domain */
                        if (!$pdo->prepare('INSERT INTO `hosts` (`host`, `base64`, `base32`) VALUES (?, ?, ?)')->execute([$domain, $parsed["b64"], $base32])) {
                            $result["error"] = "Error happened while inserting record to database. Please try again later.";

                        } else {
                            $result["command"] = 'added';
                            $result["host"]    = $domain;
                            $result["base64"]  = $parsed["b64"];
                            $result["base32"]  = $base32;
                        }
                    }
                }
            }
        }
    }

} else if (isset($_POST["desc"]) && !empty($_POST["desc"])) {
    $result["error"] = "Authentication string is required for registering record.";
}

if (!empty($result)) {
    $record = $desc = ""; // clear them if any result present
}

$pdo = null;

$template = $twig->load('add.twig');
echo $template->render(['record' => $record, 'desc' => $desc, 'result' => $result, 'all' => $all]);