<?php
namespace App\Services;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Crypt;
use Illuminate\Support\Str;
class LicenseService {
 public function issue(int $userId,int $purchaseId): void {
  if(DB::table('licenses')->where('purchase_id',$purchaseId)->exists()){return;}
  $key='TNX-'.Str::upper(bin2hex(random_bytes(20)));
  DB::table('licenses')->insert(['user_id'=>$userId,'purchase_id'=>$purchaseId,'key_hash'=>hash('sha256',$key),'key_encrypted'=>Crypt::encryptString($key),'status'=>'active','device_limit'=>2,'created_at'=>now(),'updated_at'=>now()]);
 }
 public function activate(string $key,string $device): array {
  return DB::transaction(function()use($key,$device){
   $license=DB::table('licenses')->where('key_hash',hash('sha256',$key))->lockForUpdate()->first();
   abort_unless($license && $license->status==='active',403,'Invalid or revoked license.');
   $deviceHash=hash('sha256',$device);$existing=DB::table('activations')->where('license_id',$license->id)->where('device_hash',$deviceHash)->first();
   abort_if(!$existing && DB::table('activations')->where('license_id',$license->id)->count()>=$license->device_limit,409,'Device limit reached.');
   $token=bin2hex(random_bytes(32));
   DB::table('activations')->updateOrInsert(['license_id'=>$license->id,'device_hash'=>$deviceHash],['token_hash'=>hash('sha256',$token),'last_seen_at'=>now(),'created_at'=>now(),'updated_at'=>now()]);
   return ['activation_token'=>$token,'valid'=>true,'check_again_in'=>86400];
  },3);
 }
 public function check(string $token,bool $deactivate=false): array {
  return DB::transaction(function()use($token,$deactivate){
   $activation=DB::table('activations')->where('token_hash',hash('sha256',$token))->first();
   abort_unless($activation,403,'Invalid activation.');
   $license=DB::table('licenses')->where('id',$activation->license_id)->lockForUpdate()->first();
   if($deactivate){DB::table('activations')->where('id',$activation->id)->delete();return ['deactivated'=>true];}
   abort_unless($license->status==='active',403,'License revoked.');
   DB::table('activations')->where('id',$activation->id)->update(['last_seen_at'=>now()]);
   return ['valid'=>true,'check_again_in'=>86400];
  },3);
 }
}