<?php
namespace Sodino\Services;

use Sodino\Repositories\RuleRepository;
use Sodino\Services\TrackingService;

class PricingService {
    private $ruleRepository;
    private $trackingService;
    private $rulesCache = null;

    public function __construct(RuleRepository $ruleRepository, TrackingService $trackingService) {
        $this->ruleRepository = $ruleRepository;
        $this->trackingService = $trackingService;
    }

    public function applyDynamicPricing($price, $product) {
        $settings = $this->getSettings();
        if (empty($settings['plugin_enabled']) || empty($settings['pricing_enabled'])) {
            return $price;
        }

        if (!$price || !is_numeric($price)) {
            return $price;
        }

        $price = $this->normalizePrice($price);
        if (!$settings['cart_pricing_enabled'] && is_cart()) {
            return $price;
        }

        $originalPrice = $price;
        $rules = $this->getEnabledRules();
        $matchedRules = [];

        foreach ($rules as $rule) {
            if ($this->ruleMatches($rule, $product)) {
                $matchedRules[] = $rule;
            }
        }

        if (empty($matchedRules)) {
            return $price;
        }

        if (!$settings['allow_multiple_rules']) {
            $chosenRule = $this->chooseRule($matchedRules, $price, $settings['strategy']);
            $matchedRules = $chosenRule ? [$chosenRule] : [];
        }

        foreach ($matchedRules as $rule) {
            $oldPrice = $price;
            $price = $this->applyActions($rule, $price);
            if ($price < $oldPrice) {
                $this->trackingService->recordDiscountApplied($product, $oldPrice, $price, $rule->id);
            }
        }

        $price = $this->enforceLimits($originalPrice, $price, $settings);

        return max(0, $price);
    }

    private function chooseRule(array $rules, $price, $strategy) {
        if ($strategy === 'highest_discount') {
            usort($rules, function ($a, $b) use ($price) {
                return $this->estimateRuleDiscount($b, $price) <=> $this->estimateRuleDiscount($a, $price);
            });
            return $rules[0] ?? null;
        }

        if ($strategy === 'first_valid') {
            return $rules[0] ?? null;
        }

        usort($rules, function ($a, $b) {
            return $b->priority <=> $a->priority;
        });
        return $rules[0] ?? null;
    }

    private function getSettings() {
        $defaults = [
            'plugin_enabled' => 1,
            'pricing_enabled' => 1,
            'upsell_enabled' => 1,
            'allow_multiple_rules' => 0,
            'strategy' => 'priority',
            'max_discount_percent' => 100,
            'min_product_price' => 0,
            'ab_testing_enabled' => 0,
            'cart_pricing_enabled' => 1,
            'scheduled_campaigns_enabled' => 1,
        ];

        return wp_parse_args(get_option('sodino_settings', []), $defaults);
    }

    private function getEnabledRules() {
        if ($this->rulesCache === null) {
            $this->rulesCache = $this->ruleRepository->getEnabled();
        }
        return $this->rulesCache;
    }

    private function normalizePrice($price) {
        if ($price === '' || $price === null) {
            return 0.0;
        }

        return floatval($price);
    }

    private function ruleMatches($rule, $product = null) {
        if (!$rule->enabled) {
            return false;
        }

        if ($rule->usage_limit > 0 && $this->trackingService->getRuleUsageCount($rule->id) >= $rule->usage_limit) {
            return false;
        }

        if (!empty($rule->user_roles) && is_array($rule->user_roles)) {
            if (!$this->userHasAllowedRole($rule->user_roles)) {
                return false;
            }
        }

        if (!$this->isRuleActive($rule)) {
            return false;
        }

        if (empty($rule->conditions)) {
            return true;
        }

        foreach ($rule->conditions as $condition) {
            if (!$this->evaluateCondition($condition, $product)) {
                return false;
            }
        }

        return true;
    }

    private function isRuleActive($rule) {
        $now = current_time('Y-m-d H:i:s');

        if (!empty($rule->start_date) && $now < $rule->start_date) {
            return false;
        }

        if (!empty($rule->end_date) && $now > $rule->end_date) {
            return false;
        }

        return true;
    }

    private function evaluateCondition($condition, $product = null) {
        $type = $condition['type'] ?? '';
        $value = $condition['value'] ?? null;

        switch ($type) {
            case 'user_type':
                return $this->getUserType() === $value;
            case 'cart_total_min':
                return $this->getCartTotal() >= floatval($value);
            case 'cart_total_max':
                return $this->getCartTotal() <= floatval($value);
            case 'cart_item_count_min':
                return $this->getCartItemCount() >= intval($value);
            case 'cart_item_count_max':
                return $this->getCartItemCount() <= intval($value);
            case 'product_category':
                return $this->productHasCategory($product, (array) $value);
            case 'product_ids':
                return $this->productIsInIds($product, (array) $value);
            default:
                return true;
        }
    }

    private function getUserType() {
        if (!is_user_logged_in()) {
            return 'guest';
        }

        $user_id = get_current_user_id();
        $order_count = wc_get_customer_order_count($user_id);

        return $order_count > 0 ? 'returning' : 'new';
    }

    private function userHasAllowedRole($roles) {
        if (!is_user_logged_in()) {
            return false;
        }

        $user = wp_get_current_user();
        foreach ($roles as $role) {
            if (in_array($role, $user->roles, true)) {
                return true;
            }
        }

        return false;
    }

    private function getCartTotal() {
        if (!WC()->cart) {
            return 0;
        }

        return floatval(WC()->cart->get_cart_contents_total());
    }

    private function getCartItemCount() {
        if (!WC()->cart) {
            return 0;
        }

        return WC()->cart->get_cart_contents_count();
    }

    private function productHasCategory($product, $categories) {
        if (!$product || empty($categories)) {
            return false;
        }

        $product_cats = wp_get_post_terms($product->get_id(), 'product_cat', ['fields' => 'ids']);
        return (bool) array_intersect($product_cats, $categories);
    }

    private function productIsInIds($product, $ids) {
        if (!$product || empty($ids)) {
            return false;
        }

        return in_array($product->get_id(), $ids, true);
    }

    private function applyActions($rule, $price) {
        foreach ($rule->actions as $action) {
            $price = $this->applyAction($action, $price);
        }

        return $price;
    }

    private function applyAction($action, $price) {
        $type = $action['type'] ?? '';
        $value = isset($action['value']) ? floatval($action['value']) : 0;

        switch ($type) {
            case 'discount_percent':
                if ($value <= 0) {
                    return $price;
                }
                return $price * (1 - $value / 100);
            case 'discount_fixed':
                if ($value <= 0) {
                    return $price;
                }
                return $price - $value;
            case 'free_shipping':
                return $price;
            default:
                return $price;
        }
    }

    private function enforceLimits($originalPrice, $price, array $settings) {
        $minPrice = max(0, floatval($settings['min_product_price']));
        $price = max($price, $minPrice);

        $maxDiscountPercent = floatval($settings['max_discount_percent']);
        if ($maxDiscountPercent > 0 && $maxDiscountPercent < 100) {
            $limit = $originalPrice * ($maxDiscountPercent / 100);
            $price = max($originalPrice - $limit, $price);
        }

        return $price;
    }

    private function estimateRuleDiscount($rule, $price) {
        foreach ($rule->actions as $action) {
            if (($action['type'] ?? '') === 'discount_percent') {
                return $price * floatval($action['value']) / 100;
            }
            if (($action['type'] ?? '') === 'discount_fixed') {
                return floatval($action['value']);
            }
        }
        return 0;
    }
}