<?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,
]);

$record = "";
$desc = "";

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

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 (!$util->isValidDomain($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 {
            /* Check if such domain name already registered */
            $STH = $pdo->query("SELECT COUNT(*) FROM `hosts` WHERE `host` = '" . $domain . "' LIMIT 1");

            if (isset($parsed["commands"]["action"])) {
                switch ($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 .= ".";
                            }

                            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 (!$pdo->query("SELECT COUNT(*) FROM `hosts` WHERE `host` = '" . $parsed["commands"]["oldname"] . "' AND `base64` = '" . $parsed["commands"]["olddest"] . "' LIMIT 1")->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->exec("INSERT INTO `hosts` (`host`, `base64`, `base32`) VALUES ('" . $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 {
                            if (!$pdo->query("SELECT COUNT(*) FROM `hosts` WHERE `host` = '" . $domain . "' AND `base64` =  '" . $parsed["commands"]["olddest"] . "' LIMIT 1")->fetchColumn()) {
                                $result["error"] = "Error while validating: old base64 and value in olddest field does not match..";

                            } else {
                                $base32 = $util->b32from64($parsed["b64"]);
                                if (!$pdo->exec("UPDATE `hosts` SET `base64` = '" . $parsed["b64"] . "', `base32` = '" . $base32 . "' WHERE `host` = '" . $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"];
                            }

                            if (!$pdo->query("SELECT COUNT(*) FROM `hosts` WHERE `host` = '" . $olddomain . "' AND `base64` =  '" . parsed["b64"] . "' LIMIT 1")->fetchColumn()) {
                                $result["error"] = "Error while validating: base64 does not match for domain in oldname field...";

                            } else {
                                $base32 = $util->b32from64($parsed["b64"]);
                                if (!$pdo->exec("INSERT INTO `hosts` (`host`, `base64`, `base32`) VALUES ('" . $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 {
                if($STH->fetchColumn() == 1) {
                    $result["error"] = "Error while validating: That domain is already registered.";

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

                        /*  Adding to database 2LD domain */
                        if (!$pdo->exec("INSERT INTO `hosts` (`host`, `base64`, `base32`) VALUES ('" . $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]);