<?php

namespace App\Services;

use App\Models\Tenants\Payment;
use App\Models\Tenants\Plan;
use App\Models\Tenants\Subscription;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;
use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;

class SubscriptionService extends Service
{
    // =========================================================================
    // 구독 목록/상세
    // =========================================================================

    /**
     * 구독 목록
     */
    public function index(array $params): LengthAwarePaginator
    {
        $tenantId = $this->tenantId();

        $query = Subscription::query()
            ->where('tenant_id', $tenantId)
            ->with(['plan:id,name,code,price,billing_cycle']);

        // 상태 필터
        if (! empty($params['status'])) {
            $query->where('status', $params['status']);
        }

        // 유효한 구독만
        if (! empty($params['valid_only']) && $params['valid_only']) {
            $query->valid();
        }

        // 만료 예정 (N일 이내)
        if (! empty($params['expiring_within'])) {
            $query->expiringWithin((int) $params['expiring_within']);
        }

        // 날짜 범위 필터
        if (! empty($params['start_date'])) {
            $query->where('started_at', '>=', $params['start_date']);
        }
        if (! empty($params['end_date'])) {
            $query->where('started_at', '<=', $params['end_date']);
        }

        // 정렬
        $sortBy = $params['sort_by'] ?? 'started_at';
        $sortDir = $params['sort_dir'] ?? 'desc';
        $query->orderBy($sortBy, $sortDir);

        $perPage = $params['per_page'] ?? 20;

        return $query->paginate($perPage);
    }

    /**
     * 현재 활성 구독
     */
    public function current(): ?Subscription
    {
        $tenantId = $this->tenantId();

        return Subscription::query()
            ->where('tenant_id', $tenantId)
            ->valid()
            ->with(['plan', 'payments' => function ($q) {
                $q->completed()->orderBy('paid_at', 'desc')->limit(5);
            }])
            ->orderBy('started_at', 'desc')
            ->first();
    }

    /**
     * 구독 상세
     */
    public function show(int $id): Subscription
    {
        $tenantId = $this->tenantId();

        return Subscription::query()
            ->where('tenant_id', $tenantId)
            ->with([
                'plan',
                'payments' => function ($q) {
                    $q->orderBy('paid_at', 'desc');
                },
            ])
            ->findOrFail($id);
    }

    // =========================================================================
    // 구독 생성/취소
    // =========================================================================

    /**
     * 구독 생성 (결제 포함)
     */
    public function store(array $data): Subscription
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        // 요금제 확인
        $plan = Plan::active()->findOrFail($data['plan_id']);

        // 이미 활성 구독이 있는지 확인
        $existingSubscription = Subscription::query()
            ->where('tenant_id', $tenantId)
            ->valid()
            ->first();

        if ($existingSubscription) {
            throw new BadRequestHttpException(__('error.subscription.already_active'));
        }

        return DB::transaction(function () use ($data, $plan, $tenantId, $userId) {
            // 구독 생성
            $subscription = Subscription::create([
                'tenant_id' => $tenantId,
                'plan_id' => $plan->id,
                'started_at' => $data['started_at'] ?? now(),
                'status' => Subscription::STATUS_PENDING,
                'created_by' => $userId,
                'updated_by' => $userId,
            ]);

            // 결제 생성 (무료 요금제가 아닌 경우)
            if ($plan->price > 0) {
                $payment = Payment::create([
                    'subscription_id' => $subscription->id,
                    'amount' => $plan->price,
                    'payment_method' => $data['payment_method'] ?? Payment::METHOD_CARD,
                    'status' => Payment::STATUS_PENDING,
                    'created_by' => $userId,
                    'updated_by' => $userId,
                ]);

                // 결제 완료 처리 (실제 PG 연동 시 수정 필요)
                if (! empty($data['auto_complete']) && $data['auto_complete']) {
                    $payment->complete($data['transaction_id'] ?? null);

                    // 구독 활성화
                    $subscription->activate();
                }
            } else {
                // 무료 요금제는 바로 활성화
                Payment::create([
                    'subscription_id' => $subscription->id,
                    'amount' => 0,
                    'payment_method' => Payment::METHOD_FREE,
                    'status' => Payment::STATUS_COMPLETED,
                    'paid_at' => now(),
                    'created_by' => $userId,
                    'updated_by' => $userId,
                ]);

                $subscription->activate();
            }

            return $subscription->fresh(['plan', 'payments']);
        });
    }

    /**
     * 구독 취소
     */
    public function cancel(int $id, ?string $reason = null): Subscription
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        $subscription = Subscription::query()
            ->where('tenant_id', $tenantId)
            ->findOrFail($id);

        if (! $subscription->isCancellable()) {
            throw new BadRequestHttpException(__('error.subscription.not_cancellable'));
        }

        $subscription->cancel($reason);
        $subscription->updated_by = $userId;
        $subscription->save();

        return $subscription->fresh(['plan']);
    }

    /**
     * 구독 갱신
     */
    public function renew(int $id, array $data = []): Subscription
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        $subscription = Subscription::query()
            ->where('tenant_id', $tenantId)
            ->findOrFail($id);

        if ($subscription->status !== Subscription::STATUS_ACTIVE) {
            throw new BadRequestHttpException(__('error.subscription.not_renewable'));
        }

        return DB::transaction(function () use ($subscription, $data, $userId) {
            $plan = $subscription->plan;

            // 결제 생성
            if ($plan->price > 0) {
                $payment = Payment::create([
                    'subscription_id' => $subscription->id,
                    'amount' => $plan->price,
                    'payment_method' => $data['payment_method'] ?? Payment::METHOD_CARD,
                    'status' => Payment::STATUS_PENDING,
                    'created_by' => $userId,
                    'updated_by' => $userId,
                ]);

                // 결제 완료 처리
                if (! empty($data['auto_complete']) && $data['auto_complete']) {
                    $payment->complete($data['transaction_id'] ?? null);
                    $subscription->renew();
                }
            } else {
                // 무료 갱신
                Payment::create([
                    'subscription_id' => $subscription->id,
                    'amount' => 0,
                    'payment_method' => Payment::METHOD_FREE,
                    'status' => Payment::STATUS_COMPLETED,
                    'paid_at' => now(),
                    'created_by' => $userId,
                    'updated_by' => $userId,
                ]);

                $subscription->renew();
            }

            $subscription->updated_by = $userId;
            $subscription->save();

            return $subscription->fresh(['plan', 'payments']);
        });
    }

    // =========================================================================
    // 구독 상태 관리
    // =========================================================================

    /**
     * 구독 일시정지
     */
    public function suspend(int $id): Subscription
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        $subscription = Subscription::query()
            ->where('tenant_id', $tenantId)
            ->findOrFail($id);

        if (! $subscription->suspend()) {
            throw new BadRequestHttpException(__('error.subscription.not_suspendable'));
        }

        $subscription->updated_by = $userId;
        $subscription->save();

        return $subscription->fresh(['plan']);
    }

    /**
     * 구독 재개
     */
    public function resume(int $id): Subscription
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        $subscription = Subscription::query()
            ->where('tenant_id', $tenantId)
            ->findOrFail($id);

        if (! $subscription->resume()) {
            throw new BadRequestHttpException(__('error.subscription.not_resumable'));
        }

        $subscription->updated_by = $userId;
        $subscription->save();

        return $subscription->fresh(['plan']);
    }
}