<?php

namespace Longyi\RewardPoints\Services;

use Longyi\RewardPoints\Repositories\RewardPointRepository;
use Longyi\RewardPoints\Models\RewardPointCustomer;
use Webkul\Checkout\Facades\Cart;
use Webkul\Customer\Facades\Customer;

class CartRewardPoints
{
    /**
     * Session key for points used in cart
     */
    const POINTS_USED_KEY = 'reward_points_used';
    
    /**
     * @var RewardPointRepository
     */
    protected $rewardPointRepository;
    
    /**
     * CartRewardPoints constructor.
     */
    public function __construct()
    {
        $this->rewardPointRepository = app(RewardPointRepository::class);
    }
    
    /**
     * Get available points for current customer
     */
    public function getAvailablePoints()
    {
        if (!Customer::check()) {
            return 0;
        }
        
        return $this->rewardPointRepository->getCustomerPoints(Customer::getCustomerId());
    }
    
    /**
     * Get points used in current cart
     */
    public function getPointsUsed()
    {
        if (!session()->has(self::POINTS_USED_KEY)) {
            return 0;
        }
        
        return session()->get(self::POINTS_USED_KEY);
    }
    
    /**
     * Get discount amount from points
     */
    public function getDiscountAmount($points = null)
    {
        $pointsUsed = $points ?: $this->getPointsUsed();
        
        if ($pointsUsed <= 0) {
            return 0;
        }
        
        $pointValue = config('rewardpoints.general.point_value', 0.01);
        
        return $pointsUsed * $pointValue;
    }
    
    /**
     * Apply points to cart
     */
    public function applyPoints($points)
    {
        $cart = Cart::getCart();
        
        if (!$cart) {
            return false;
        }
        
        $availablePoints = $this->getAvailablePoints();
        
        if ($points <= 0) {
            $this->removePoints();
            return false;
        }
        
        if ($points > $availablePoints) {
            return false;
        }
        
        // Calculate maximum points that can be used based on cart total
        $maxPointsByAmount = $this->getMaxPointsByCartTotal();
        
        if ($points > $maxPointsByAmount) {
            return false;
        }
        
        // Save points to session
        session()->put(self::POINTS_USED_KEY, $points);
        
        // Recalculate cart
        Cart::collectTotals();
        
        return true;
    }
    
    /**
     * Remove points from cart
     */
    public function removePoints()
    {
        session()->forget(self::POINTS_USED_KEY);
        Cart::collectTotals();
        
        return true;
    }
    
    /**
     * Calculate discount based on points
     */
    public function calculateDiscount()
    {
        $pointsUsed = $this->getPointsUsed();
        
        if ($pointsUsed <= 0) {
            return 0;
        }
        
        $discountAmount = $this->getDiscountAmount($pointsUsed);
        
        return $discountAmount;
    }
    
    /**
     * Get maximum points that can be used based on cart total
     */
    protected function getMaxPointsByCartTotal()
    {
        $cart = Cart::getCart();
        
        if (!$cart) {
            return 0;
        }
        
        $cartTotal = $cart->grand_total;
        
        // Get maximum discount percentage (default: 100%)
        $maxDiscountPercentage = core()->getConfigData('rewardpoints.general.max_discount_percentage', 100);
        
        // Calculate maximum discount amount
        $maxDiscountAmount = ($cartTotal * $maxDiscountPercentage) / 100;
        
        // Convert discount amount to points
        $pointValue = core()->getConfigData('rewardpoints.general.point_value', 0.01);
        $maxPoints = $pointValue > 0 ? floor($maxDiscountAmount / $pointValue) : 0;
        
        return $maxPoints;
    }
    
    /**
     * Get discount details for cart
     */
    public function getDiscountDetails()
    {
        $pointsUsed = $this->getPointsUsed();
        
        if ($pointsUsed <= 0) {
            return null;
        }
        
        $discountAmount = $this->getDiscountAmount();
        
        return [
            'points_used' => $pointsUsed,
            'discount_amount' => $discountAmount,
            'formatted_discount' => core()->formatPrice($discountAmount),
            'available_points' => $this->getAvailablePoints(),
            'points_remaining' => $this->getAvailablePoints() - $pointsUsed
        ];
    }
    
    /**
     * Process order points
     */
    public function processOrderPoints($order)
    {
        $pointsUsed = $this->getPointsUsed();
        
        if ($pointsUsed <= 0) {
            return false;
        }
        
        $customerId = $order->customer_id;
        
        if (!$customerId) {
            return false;
        }
        
        // Deduct points from customer
        $discountAmount = $this->getDiscountAmount($pointsUsed);
        
        $result = $this->rewardPointRepository->deductPoints(
            $customerId,
            $pointsUsed,
            0,
            "Points redeemed for order #{$order->increment_id} (Discount: " . core()->formatPrice($discountAmount) . ")",
            $order->id
        );
        
        // Clear session
        $this->removePoints();
        
        return $result;
    }
    
    /**
     * Get points value in currency
     */
    public function getPointsValue($points)
    {
        $pointValue = core()->getConfigData('rewardpoints.general.point_value', 0.01);
        return $points * $pointValue;
    }
    
    /**
     * Get currency value in points
     */
    public function getPointsFromValue($value)
    {
        $pointValue = core()->getConfigData('rewardpoints.general.point_value', 0.01);
        return $pointValue > 0 ? floor($value / $pointValue) : 0;
    }
    
    /**
     * Validate if points can be applied to cart
     */
    public function validatePoints($points)
    {
        $cart = Cart::getCart();
        
        if (!$cart) {
            return 'Cart not found';
        }
        
        $availablePoints = $this->getAvailablePoints();
        
        if ($points <= 0) {
            return 'Points must be greater than 0';
        }
        
        if ($points > $availablePoints) {
            return "You only have {$availablePoints} points available";
        }
        
        $maxPoints = $this->getMaxPointsByCartTotal();
        
        if ($points > $maxPoints) {
            return "Maximum {$maxPoints} points can be used for this order";
        }
        
        return true;
    }
}