<?php

namespace App\Services;

use App\Enums\CartStatusEnum;
use App\Enums\PaymentStatusEnum;
use App\Models\Cart;
use App\Models\CartItem;
use App\Models\Payment;
use App\Models\Schedule;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

class CartItemService
{
    public function getAll(): Collection
    {
        return CartItem::query()
            ->orderBy('created_at', 'desc')
            ->get();
    }

    public function findById(int $id): ?CartItem
    {
        return CartItem::find($id);
    }

    public function create(array $data): CartItem
    {
        return DB::transaction(function () use ($data) {
            [$cart, $schedule] = $this->validateItem($data['cart_id'], $data['schedule_id']);

            if (! $cart->provider_id) {
                $cart->update(['provider_id' => $schedule->provider_id]);
            }

            return CartItem::create($data);
        });
    }

    public function update(int $id, array $data): ?CartItem
    {
        return DB::transaction(function () use ($id, $data): ?CartItem {
            $model = $this->findById($id);

            if (! $model) {
                return null;
            }

            $cartId     = $data['cart_id']     ?? $model->cart_id;
            $scheduleId = $data['schedule_id'] ?? $model->schedule_id;

            [$cart, $schedule] = $this->validateItem($cartId, $scheduleId);

            if (! $cart->provider_id) {
                $cart->update(['provider_id' => $schedule->provider_id]);
            }

            $model->update($data);

            return $model->fresh();
        });
    }

    public function delete(int $id): bool
    {
        $model = $this->findById($id);

        if (!$model) {
            return false;
        }

        return DB::transaction(function () use ($model): bool {
            $this->validateItem($model->cart_id, $model->schedule_id);

            return $model->delete();
        });
    }

    private function validateItem(int $cartId, int $scheduleId): array
    {
        $cart     = Cart::query()->lockForUpdate()->findOrFail($cartId);
        $schedule = Schedule::query()->findOrFail($scheduleId);

        if ($cart->status !== CartStatusEnum::OPEN) {
            throw ValidationException::withMessages([
                'cart_id' => 'Somente carrinhos abertos podem ser alterados.',
            ]);
        }

        if ($schedule->client_id !== $cart->client_id) {
            throw ValidationException::withMessages([
                'schedule_id' => 'O agendamento precisa pertencer ao mesmo cliente do carrinho.',
            ]);
        }

        if (! $schedule->provider_id || ($cart->provider_id && $schedule->provider_id !== $cart->provider_id)) {
            throw ValidationException::withMessages([
                'schedule_id' => 'Todos os agendamentos do carrinho precisam ser do mesmo prestador.',
            ]);
        }

        $belongsToAnotherCart = CartItem::query()
            ->where('schedule_id', $scheduleId)
            ->where('cart_id', '!=', $cartId)
            ->exists();

        if ($belongsToAnotherCart) {
            throw ValidationException::withMessages([
                'schedule_id' => 'O agendamento já pertence a outro carrinho.',
            ]);
        }

        $hasActivePayment = Payment::query()
            ->where('schedule_id', $scheduleId)
            ->whereIn('status', [
                PaymentStatusEnum::PENDING->value,
                PaymentStatusEnum::PROCESSING->value,
                PaymentStatusEnum::AUTHORIZED->value,
                PaymentStatusEnum::PAID->value,
            ])
            ->exists();

        if ($hasActivePayment) {
            throw ValidationException::withMessages([
                'schedule_id' => 'O agendamento já possui um pagamento e não pode ser adicionado ao carrinho.',
            ]);
        }

        return [$cart, $schedule];
    }
}