<?php
if (!function_exists('yak_allowed_promo')) {
    /**
     * return true if the current user is allowed access to a promo.
     * Note: defaults to true if the promo has no users assigned.
     */
    function yak_allowed_promo($promo) {
        global $wpdb, $user_ID;
        
        if (count($promo->users) > 0) {
            if (!isset($user_ID) || $user_ID == null) {
                return false;
            }
            $sql = $wpdb->prepare("select user_nicename
                                   from $wpdb->users
                                   where ID = %d", $user_ID);
            $row = $wpdb->get_row($sql);
            if (!in_array($row->user_nicename, $promo->users)) {
                return false;
            }
        }
        $rtn = apply_filters('yak-allowed-promo', $promo);
        return $rtn != null;
    }
}

if (!function_exists('yak_calc_discount_price')) {
    /**
     * Calculate a price discount, or return 0 if not a pricing promotion
     */
    function yak_calc_price_discount($product_id, $item_quantity, $price, $total_items, $total_price, $promo=null) {
        if ($promo != null && ($promo->products == null || count($promo->products) == 0 || in_array($product_id, $promo->products))) {
            if (yak_str_contains($promo->promo_type, 'pricing_perc')) {
                return ($promo->value / 100.0) * $price;
            }
            else if (yak_str_contains($promo->promo_type, 'pricing_val')) {
                if ($total_price > 0) {
                    $item_perc_of_total = $price / $total_price;
                    return $promo->value * $item_perc_of_total;
                }
            }
        }
        return 0;
    }
}

if (!function_exists('yak_calc_discount_shipping')) {
    /**
     * Calculate a shipping discount, or return 0 if not a shipping discount
     */
    function yak_calc_shipping_discount($shipping_cost, $promo=null, $items) {
        if ($promo != null && ($promo->products == null || yak_contains_product($items, $promo->products))) {
            if (yak_str_contains($promo->promo_type, 'shipping_perc')) {
                return ($promo->value / 100.0) * $shipping_cost;
            }
            else if (yak_str_contains($promo->promo_type, 'shipping_val')) {
                return min($promo->value, $shipping_cost);
            }
        }
        
        return 0;
    }
}


if (!function_exists('yak_get_promotion')) {
    function yak_get_promotion($code) {
        // find by code
        $promos = yak_get_promotions($code, true);
        if (sizeof($promos) >= 1) {
            return $promos[0];
        }
        
        // find by coupon
        $set = yak_get_coupon_by_code($code);
        if ($coupon_set != null && $set->used_datetime == null) {
            $promos = yak_get_promotions($set->coupon_set, true);
            if (sizeof($promos) >= 1) {
                return $promos[0];
            }
        }
        
        // no promo found
        return new YakPromotion('', null, null, null, 0, '', '');
    }
}


if (!function_exists('yak_get_promotion_by_threshold')) {
    function yak_get_promotion_by_threshold($price_threshold, $qty_threshold = null) {
        $promos = yak_get_promotions(null, true, $price_threshold, null);
        if (sizeof($promos) >= 1) {
            return $promos[0];
        }
        if ($qty_threshold != null) {
            $promos = yak_get_promotions(null, true, null, $qty_threshold);
        }
        
        if (sizeof($promos) >= 1) {
            return $promos[0];
        }
        else {
            return null;
        }
    }
}


if (!function_exists('yak_get_promotions')) {
    function yak_get_promotions($code = null, $valid = false, $price_threshold = null, $qty_threshold = null, $types = null) {
        global $wpdb, $promo_table, $promo_users_table, $coupon_table;
                
        $args = array();
        $sql = "select promo_id, code, promo_type, description, threshold, value, expiry_date, products
                from $promo_table 
                where 1 = 1 ";
        
        // search by code        
        if (!empty($code)) {
            $sql .= "and ((code = %s ";
            $sql .= "and promo_type in ('shipping_perc', 'shipping_val', 'pricing_perc', 'pricing_val')) ";
            $args[] = $code;
            
            $sql .= "or code in (select coupon_set from $coupon_table where coupon_code = %s and used_datetime is null)) ";
            $args[] = $code;
        }
        // or search by price threshold
        else if (!empty($price_threshold)) {
            $sql .= "and (threshold is not null and %f >= threshold ";
            $sql .= "and promo_type in ('shipping_perc_threshold', 'shipping_val_threshold', 'pricing_perc_threshold', 'pricing_val_threshold')) ";
            $args[] = $price_threshold;
        }
        // or search by qty threshold
        else if (!empty($qty_threshold)) {
            $sql .= "and (threshold is not null and %d >= threshold ";
            $sql .= "and promo_type in ('pricing_perc_qty_threshold', 'pricing_val_qty_threshold', 'shipping_perc_qty_threshold', 'shipping_val_qty_threshold')) ";
            $args[] = $qty_threshold;
        }
        
        // check for validity
        if ($valid) {
            $sql .= "and (expiry_date is null or expiry_date >= current_date) ";
        }
        
        if ($types != null) {
            $sql .= "and promo_type in (";
            
            $count = count($types);
            for ($i = 0; $i < $count; $i++) {
                $sql .= '"' . $types[$i] . '"';
                if ($i < $count - 1) {
                    $sql .= ',';
                }
            }
            $sql .= ") ";
        }
        
        // final sql
        if (!empty($price_threshold) || !empty($qty_threshold)) {
            $sql .= "order by threshold desc limit 1";
        }
        else {
            $sql .= "order by promo_id asc";
        }
        
        $sql = $wpdb->prepare($sql, $args);
        $results = $wpdb->get_results($sql);
        
        $promos = array();
        foreach ($results as $result) {
            $sql = $wpdb->prepare("select user_nicename
                                   from $wpdb->users u
                                   where exists (select 1
                                                 from $promo_users_table pu 
                                                 where pu.promo_id = %d
                                                 and pu.user_id = u.ID)", $result->promo_id);
            $rows = $wpdb->get_results($sql);
            $users = array();
            foreach ($rows as $row) {
                $users[] = $row->user_nicename;
            }
            
            if (!empty($result->products)) {
                $products = explode(',', $result->products);
            }
            else {
                $products = null;
            }
            
            $promo = new YakPromotion($result->promo_id, $result->code, $result->promo_type, $result->threshold, $result->value, 
                                      $result->description, $result->expiry_date, $users, $products);
            $promos[] = $promo;
        }
        
        return $promos;
    }
}
?>