<?php

namespace App\Services;

use App\Exceptions\DuplicateGameAccountException;
use Illuminate\Database\ConnectionInterface;
use Illuminate\Database\QueryException;
use Illuminate\Support\Facades\DB;

class VMangosAccountRegistrar
{
    public function __construct(private readonly VMangosSrpService $srp, private readonly AzerothCoreSrpService $siteSrp)
    {
    }

    /**
     * @return array{id: int, username: string}
     */
    public function register(string $username, string $email, string $password): array
    {
        $normalizedUsername = $this->srp->normalizeUsername($username);
        $normalizedPassword = $this->srp->normalizePassword($password);
        $normalizedEmail = $this->srp->normalizeEmail($email);
        [$saltHex, $verifierHex] = $this->srp->makeRegistrationData($normalizedUsername, bin2hex(random_bytes(16)));
        [$siteSaltHex, $siteVerifierHex] = $this->siteSrp->makeRegistrationData($normalizedUsername, $normalizedPassword);

        $connection = DB::connection(config('moonwell.auth_connection'));

        return $connection->transaction(function () use (
            $connection,
            $normalizedEmail,
            $normalizedUsername,
            $saltHex,
            $verifierHex,
            $siteSaltHex,
            $siteVerifierHex,
        ): array {
            if ($this->accountExists($connection, 'username', $normalizedUsername)) {
                throw DuplicateGameAccountException::forUsername();
            }

            if (
                config('moonwell.registration.enforce_unique_email')
                && $normalizedEmail !== ''
                && $this->accountExists($connection, 'email', $normalizedEmail)
            ) {
                throw DuplicateGameAccountException::forEmail();
            }

            try {
                $accountId = (int) $connection->table('account')->insertGetId([
                    'username' => $normalizedUsername,
                    's' => $saltHex,
                    'v' => $verifierHex,
                    'expansion' => 0,
                    'email' => $normalizedEmail,
                    'joindate' => now()->toDateTimeString(),
                ]);
            } catch (QueryException $exception) {
                if ($this->isDuplicateKeyException($exception)) {
                    throw DuplicateGameAccountException::forUsername();
                }

                throw $exception;
            }

            $connection->table('site_credentials')->insert([
                'account_id' => $accountId,
                'salt_hex' => $siteSaltHex,
                'verifier_hex' => $siteVerifierHex,
                'created_at' => now(),
                'updated_at' => now(),
            ]);

            foreach ($connection->table('realmlist')->pluck('id') as $realmId) {
                $connection->table('realmcharacters')->insertOrIgnore([
                    'realmid' => (int) $realmId,
                    'acctid' => $accountId,
                    'numchars' => 0,
                ]);
            }

            $connection->table('account_access')->updateOrInsert(
                ['id' => $accountId, 'RealmID' => (int) config('moonwell.registration.realm_id')],
                ['gmlevel' => (int) config('moonwell.registration.gmlevel')],
            );

            return [
                'id' => $accountId,
                'username' => $normalizedUsername,
            ];
        }, 3);
    }

    private function accountExists(ConnectionInterface $connection, string $column, string $value): bool
    {
        return $connection->table('account')->where($column, $value)->exists();
    }

    private function isDuplicateKeyException(QueryException $exception): bool
    {
        return (string) $exception->getCode() === '23000';
    }
}