<?php

declare(strict_types=1);

namespace App;

final class RegistrationLdifBuilder
{
    /**
     * @param array<string, mixed> $config
     */
    public function __construct(
        private readonly array $config,
    ) {
    }

    /**
     * @param array<string, mixed> $request
     * @param array<string, mixed> $provisioning
     */
    public function build(array $request, array $provisioning): string
    {
        $username = (string) ($request['username'] ?? '');
        $usersDn = (string) ($this->config['ldap']['users_dn'] ?? '');
        $uidNumber = trim((string) ($provisioning['uid_number'] ?? ''));
        $gidNumber = trim((string) ($provisioning['gid_number'] ?? ''));
        $homeDirectory = trim((string) ($provisioning['home_directory'] ?? ''));
        $loginShell = trim((string) ($provisioning['login_shell'] ?? ($this->config['ldap']['default_login_shell'] ?? '/bin/sh')));
        $memberOf = $this->parseGroupDns((string) ($provisioning['member_of_list'] ?? ''));
        $displayName = trim((string) ($provisioning['display_name'] ?? $request['display_name'] ?? ''));
        $givenName = trim((string) ($request['given_name'] ?? ''));
        $familyName = trim((string) ($request['family_name'] ?? ''));
        $cn = trim((string) ($provisioning['cn'] ?? ($displayName !== '' ? $displayName : $username)));
        $gecos = trim((string) ($provisioning['gecos'] ?? ($displayName !== '' ? $displayName : trim($givenName . ' ' . $familyName))));
        $mail = trim((string) ($request['email'] ?? ''));
        $appleGeneratedUid = trim((string) ($provisioning['apple_generateduid'] ?? $this->generateUuidV4()));
        $sambaSid = trim((string) ($provisioning['samba_sid'] ?? ''));
        $appleSchemaEnabled = (bool) ($this->config['ldap']['apple_schema_enabled'] ?? false);
        $shadowExpire = (string) ($this->config['ldap']['shadow_expire'] ?? 1);
        $shadowFlag = (string) ($this->config['ldap']['shadow_flag'] ?? 0);
        $shadowInactive = (string) ($this->config['ldap']['shadow_inactive'] ?? 0);
        $shadowMax = (string) ($this->config['ldap']['shadow_max'] ?? 99999);
        $shadowMin = (string) ($this->config['ldap']['shadow_min'] ?? 0);
        $shadowWarning = (string) ($this->config['ldap']['shadow_warning'] ?? 7);
        $placeholderPassword = $this->generatePlaceholderPassword();
        $passwordHash = $this->cryptSha512($placeholderPassword);
        $warnings = [];

        if ($uidNumber === '') {
            $warnings[] = '# WARNUNG: uidNumber fehlt und muss vor dem LDAP-Import gesetzt werden.';
        }

        if ($gidNumber === '') {
            $warnings[] = '# WARNUNG: gidNumber fehlt und muss vor dem LDAP-Import gesetzt werden.';
        }

        if ($sambaSid === '') {
            $warnings[] = '# WARNUNG: sambaSID fehlt. Viele NAS-Setups erwarten diesen Wert.';
        }

        if ($memberOf === []) {
            $memberOf = array_values(array_map('strval', (array) ($this->config['ldap']['default_groups'] ?? [])));
        }

        $lines = [
            'version: 1',
            '',
        ];

        foreach ($warnings as $warning) {
            $lines[] = $warning;
        }

        if ($warnings !== []) {
            $lines[] = '# Das Passwort unten ist ein zufälliger Platzhalter für den inaktiven Zustand.';
            $lines[] = '# Platzhalter-Passwort: ' . $placeholderPassword;
            $lines[] = '';
        }

        $lines[] = 'dn: uid=' . $username . ',' . $usersDn;
        $lines[] = 'objectClass: inetOrgPerson';
        $lines[] = 'objectClass: organizationalPerson';
        $lines[] = 'objectClass: person';
        $lines[] = 'objectClass: posixAccount';
        $lines[] = 'objectClass: sambaSamAccount';
        $lines[] = 'objectClass: shadowAccount';
        $lines[] = 'objectClass: top';

        if ($appleSchemaEnabled) {
            $lines[] = 'objectClass: apple-user';
            $lines[] = 'objectClass: extensibleObject';
        }

        $lines[] = 'cn: ' . $cn;

        if ($gidNumber !== '') {
            $lines[] = 'gidNumber: ' . $gidNumber;
        }

        $lines[] = 'homeDirectory: ' . $homeDirectory;

        if ($sambaSid !== '') {
            $lines[] = 'sambaSID: ' . $sambaSid;
        }

        $lines[] = 'sn: ' . ($familyName !== '' ? $familyName : $username);
        $lines[] = 'uid: ' . $username;

        if ($uidNumber !== '') {
            $lines[] = 'uidNumber: ' . $uidNumber;
        }

        $lines[] = 'displayName: ' . ($displayName !== '' ? $displayName : $username);

        if ($appleSchemaEnabled) {
            $lines[] = 'apple-generateduid: ' . strtoupper($appleGeneratedUid);
            $lines[] = 'authAuthority: ;basic;';
        }

        if ($gecos !== '') {
            $lines[] = 'gecos: ' . $gecos;
        }

        if ($givenName !== '') {
            $lines[] = 'givenName: ' . $givenName;
        }

        $lines[] = 'loginShell: ' . $loginShell;
        $lines[] = 'mail: ' . $mail;

        foreach ($memberOf as $groupDn) {
            $lines[] = 'memberOf: ' . $groupDn;
        }

        $lines[] = 'pwdLastSet: 0';
        $lines[] = 'sambaAcctFlags: [U          ]';
        $lines[] = 'sambaLMPassword: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX';
        $lines[] = 'sambaPasswordHistory: 0000000000000000000000000000000000000000000000000000000000000000';
        $lines[] = 'sambaPwdLastSet: 0';
        $lines[] = 'shadowExpire: ' . $shadowExpire;
        $lines[] = 'shadowFlag: ' . $shadowFlag;
        $lines[] = 'shadowInactive: ' . $shadowInactive;
        $lines[] = 'shadowLastChange: 1';
        $lines[] = 'shadowMax: ' . $shadowMax;
        $lines[] = 'shadowMin: ' . $shadowMin;
        $lines[] = 'shadowWarning: ' . $shadowWarning;
        $lines[] = 'userPassword: ' . $passwordHash;

        return implode(PHP_EOL, $lines) . PHP_EOL;
    }

    /**
     * @return array<int, string>
     */
    private function parseGroupDns(string $value): array
    {
        $lines = preg_split('/\r\n|\r|\n/', $value) ?: [];

        return array_values(array_filter(array_map('trim', $lines)));
    }

    private function generateUuidV4(): string
    {
        $bytes = random_bytes(16);
        $bytes[6] = chr((ord($bytes[6]) & 0x0f) | 0x40);
        $bytes[8] = chr((ord($bytes[8]) & 0x3f) | 0x80);

        return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($bytes), 4));
    }

    private function generatePlaceholderPassword(): string
    {
        return bin2hex(random_bytes(12));
    }

    private function cryptSha512(string $password): string
    {
        $salt = '$6$' . bin2hex(random_bytes(8)) . '$';
        $hash = crypt($password, $salt);

        return str_starts_with($hash, '$6$') ? '{CRYPT}' . $hash : $hash;
    }
}