<?php

declare(strict_types=1);

namespace App\Services\VirtualMachine\Rebuild;

use App\DTOs\VirtualMachine\Rebuild\RebuildContext;
use App\Http\Facade\SignRSA;
use App\Models\ModuleVmware;
use App\Models\ReinstallLog;
use App\Models\vCenter as VCenterModel;
use App\Services\VsphereHostSshService;
use Illuminate\Support\Facades\Log;
use RuntimeException;

/**
 * VmRebuildPasswordService
 *
 * Generates a new random password for the rebuilt VM and pushes it through
 * VsphereHostSshService::changePassword(). Uses the same low-level SSH helper
 * as the create flow but never dispatches ChangePasswordViaVsphereJob.
 *
 * The new credential is persisted on the EXISTING ModuleVmware row — the
 * service identity is preserved across rebuild.
 */
final class VmRebuildPasswordService
{
    public function __construct(private readonly VsphereHostSshService $ssh)
    {
    }

    /**
     * @param int|null $reinstallLogId If supplied, the customer-supplied
     *                                 password (if any) is pulled from this
     *                                 log row and the same row is updated
     *                                 with the credential that was applied.
     * @return string the plaintext password actually applied
     */
    public function rotate(RebuildContext $ctx, ?int $reinstallLogId = null): string
    {
        if ($ctx->newVmId === null) {
            throw new RuntimeException('Rebuild password: newVmId is null');
        }

        $vcenter = VCenterModel::find($ctx->vcenterId);
        if (!$vcenter) {
            throw new RuntimeException("Rebuild password: vCenter #{$ctx->vcenterId} not found");
        }

        // Prefer a customer-supplied credential when one was provided.
        $newPassword = null;
        $log         = $reinstallLogId ? ReinstallLog::find($reinstallLogId) : null;
        if ($log && $log->password_supplied_by_customer && $log->password) {
            try {
                $newPassword = SignRSA::DecryptFunc($log->password);
            } catch (\Throwable $e) {
                $newPassword = null;
            }
        }

        if (!is_string($newPassword) || $newPassword === '') {
            $newPassword = $this->generatePassword(16);
        }

        $output = $this->ssh->changePassword(
            $ctx->newVmId,
            $newPassword,
            $ctx->osFamily,
            (string) $vcenter->host,
            (string) $vcenter->user,
            SignRSA::DecryptFunc($vcenter->password),
        );

        if (!str_contains(strtoupper(trim($output)), 'SUCCESS')) {
            throw new RuntimeException(
                "Rebuild password: changePassword script failed — " . trim($output),
            );
        }

        $encrypted = SignRSA::EncryptFunc($newPassword);

        ModuleVmware::where('id', $ctx->moduleVmwareId)->update([
            'password'       => $encrypted,
            'plain_password' => $newPassword,
        ]);

        if ($log) {
            $log->update([
                'password'       => $encrypted,
                'plain_password' => $newPassword,
            ]);
        }

        Log::info('VmRebuildPasswordService: password rotated', [
            'module_vmware_id' => $ctx->moduleVmwareId,
            'new_vm_id'        => $ctx->newVmId,
            'reinstall_log_id' => $log?->id,
        ]);

        return $newPassword;
    }

    private function generatePassword(int $length): string
    {
        $sets = [
            'ABCDEFGHJKLMNPQRSTUVWXYZ',
            'abcdefghjkmnpqrstuvwxyz',
            '23456789',
            '!@#$*',
        ];
        $password = '';
        $allChars = implode('', $sets);
        foreach ($sets as $set) {
            $password .= $set[random_int(0, strlen($set) - 1)];
        }
        for ($i = count($sets); $i < $length; $i++) {
            $password .= $allChars[random_int(0, strlen($allChars) - 1)];
        }
        $chars = str_split($password);
        for ($i = count($chars) - 1; $i > 0; $i--) {
            $j = random_int(0, $i);
            [$chars[$i], $chars[$j]] = [$chars[$j], $chars[$i]];
        }
        return implode('', $chars);
    }
}