<?php
namespace App\Services;

use Carbon\Carbon;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Schema;
use Illuminate\Support\Str;

class GigaxPremiumService
{
    public const PLANS = [
        'monthly' => ['label'=>'Mensal','days'=>30,'price'=>20.00],
        'quarterly' => ['label'=>'Trimestral','days'=>90,'price'=>50.00],
        'annual' => ['label'=>'Anual','days'=>365,'price'=>100.00],
    ];

    public function accessToken(): string { return trim((string) env('MERCADOPAGO_ACCESS_TOKEN','')); }
    public function webhookSecret(): string { return trim((string) env('MERCADOPAGO_WEBHOOK_SECRET','')); }

    public function createCheckout(int $userId, string $plan): array
    {
        if (!isset(self::PLANS[$plan])) throw new \InvalidArgumentException('Plano Premium inválido.');
        $token=$this->accessToken();
        if ($token==='') throw new \RuntimeException('MERCADOPAGO_ACCESS_TOKEN não configurado no .env.');

        $user=DB::table('users')->where('id',$userId)->first();
        if(!$user) throw new \RuntimeException('Usuário não encontrado.');
        $cfg=self::PLANS[$plan];
        $localRef='GXPREM-'.$userId.'-'.strtoupper($plan).'-'.Str::upper(Str::random(12));
        $idem=(string) Str::uuid();

        $base=rtrim((string) config('app.url'),'/');
        $payload=[
            'type'=>'online',
            'processing_mode'=>'manual',
            'capture_mode'=>'automatic_async',
            'total_amount'=>number_format($cfg['price'],2,'.',''),
            'external_reference'=>$localRef,
            'description'=>'GIGAX Arena Premium '.$cfg['label'],
            'payer'=>['email'=>(string)($user->email ?? '')],
            'items'=>[[
                'title'=>'GIGAX Arena Premium '.$cfg['label'],
                'unit_price'=>number_format($cfg['price'],2,'.',''),
                'quantity'=>1,
            ]],
            'config'=>['online'=>[
                'success_url'=>$base.'/premium/retorno?result=success',
                'failure_url'=>$base.'/premium/retorno?result=failure',
                'pending_url'=>$base.'/premium/retorno?result=pending',
                'auto_return'=>'all',
            ]],
        ];

        $res=Http::timeout(20)->withToken($token)
            ->withHeaders(['X-Idempotency-Key'=>$idem,'Accept'=>'application/json'])
            ->post('https://api.mercadopago.com/v1/orders',$payload);

        if(!$res->successful()){
            throw new \RuntimeException('Mercado Pago recusou a criação do checkout. HTTP '.$res->status().' - '.substr($res->body(),0,500));
        }
        $data=$res->json();
        if(empty($data['id']) || empty($data['checkout_url'])) throw new \RuntimeException('Resposta do Mercado Pago sem order/checkout_url.');

        DB::table('gigax_premium_orders')->insert([
            'user_id'=>$userId,'plan_code'=>$plan,'days'=>$cfg['days'],'amount'=>$cfg['price'],
            'external_reference'=>$localRef,'mp_order_id'=>(string)$data['id'],'status'=>(string)($data['status'] ?? 'created'),
            'idempotency_key'=>$idem,'created_at'=>now(),'updated_at'=>now(),
        ]);
        return $data;
    }

    public function fetchOrder(string $orderId): array
    {
        $token=$this->accessToken();
        if($token==='') throw new \RuntimeException('MERCADOPAGO_ACCESS_TOKEN não configurado.');
        $res=Http::timeout(20)->withToken($token)->acceptJson()->get('https://api.mercadopago.com/v1/orders/'.rawurlencode($orderId));
        if(!$res->successful()) throw new \RuntimeException('Falha ao consultar order Mercado Pago. HTTP '.$res->status());
        return (array)$res->json();
    }

    public function syncOrder(string $orderId): array
    {
        $remote=$this->fetchOrder($orderId);
        $local=DB::table('gigax_premium_orders')->where('mp_order_id',$orderId)->first();
        if(!$local) return ['activated'=>false,'reason'=>'order_local_not_found','remote'=>$remote];

        $remoteRef=(string)($remote['external_reference'] ?? '');
        $remoteAmount=(float)($remote['total_amount'] ?? 0);
        if(!hash_equals((string)$local->external_reference,$remoteRef) || abs($remoteAmount-(float)$local->amount)>0.001){
            throw new \RuntimeException('Order Mercado Pago não corresponde ao pedido local.');
        }

        $status=strtolower((string)($remote['status'] ?? 'unknown'));
        DB::table('gigax_premium_orders')->where('id',$local->id)->update(['status'=>$status,'updated_at'=>now()]);

        if($status!=='processed') return ['activated'=>false,'status'=>$status,'remote'=>$remote];
        if(!empty($local->activated_at)) return ['activated'=>true,'already'=>true,'remote'=>$remote];

        DB::transaction(function() use($local){
            $fresh=DB::table('gigax_premium_orders')->where('id',$local->id)->lockForUpdate()->first();
            if(!$fresh || !empty($fresh->activated_at)) return;
            $u=DB::table('users')->where('id',$fresh->user_id)->lockForUpdate()->first();
            if(!$u) throw new \RuntimeException('Usuário do pedido não encontrado.');
            $now=now();
            $current=!empty($u->premium_until) ? Carbon::parse($u->premium_until) : null;
            $start=($current && $current->greaterThan($now)) ? $current : $now->copy();
            $until=$start->copy()->addDays((int)$fresh->days);
            $upd=['is_premium'=>1,'premium_until'=>$until];
            if(Schema::hasColumn('users','updated_at')) $upd['updated_at']=$now;
            DB::table('users')->where('id',$fresh->user_id)->update($upd);
            DB::table('gigax_premium_orders')->where('id',$fresh->id)->update(['activated_at'=>$now,'updated_at'=>$now]);
        });
        return ['activated'=>true,'remote'=>$remote];
    }

    public function validPremium($user): bool
    {
        if(!$user || empty($user->is_premium)) return false;
        if(!Schema::hasColumn('users','premium_until')) return true;
        if(empty($user->premium_until)) return true; // concessão administrativa sem prazo
        try { return Carbon::parse($user->premium_until)->isFuture(); } catch(\Throwable $e){ return false; }
    }

    public function verifyWebhookSignature(string $signature, string $requestId, string $dataId): bool
    {
        $secret=$this->webhookSecret();
        if($secret==='') return false;
        $parts=[];
        foreach(explode(',',$signature) as $part){ $x=explode('=',trim($part),2); if(count($x)===2)$parts[$x[0]]=$x[1]; }
        if(empty($parts['ts']) || empty($parts['v1'])) return false;
        $manifest='id:'.strtolower($dataId).';request-id:'.$requestId.';ts:'.$parts['ts'].';';
        return hash_equals($parts['v1'],hash_hmac('sha256',$manifest,$secret));
    }
}