<?php
/**
 * Class represents records from table coupon
 * {autogenerated}
 * @property int $coupon_id 
 * @property int $batch_id 
 * @property string $code 
 * @property int $used_count 
 * @see Am_Table
 */

class Coupon extends Am_Record_WithData {
    
    const DISCOUNT_NUMBER  = 'number';
    const DISCOUNT_PERCENT = 'percent';

    /**
     * @return CouponBatch
     */
    function getBatch(){
        if (! $b = $this->getDi()->couponBatchTable->load($this->batch_id, false))
            throw new Am_Exception_InternalError("Database problem with coupon#{$this->coupon_id}: batch#{$this->batch_id} not found, orphaned record!");
        return $b;
    }
    /**
     * Validate if given coupon is applicable to a customer
     * @param int (optional)$user_id
     * @return string|null error message or null if all OK
     */
    function validate($user_id = null)
    {
        $batch = $this->getBatch();
        if ($batch->is_disabled)
            return ___('Coupon code disabled');
        if ($batch->use_count && ($batch->use_count <= $this->used_count))
            return ___('Coupon usage limit exceeded');
        if ($batch->user_id && $user_id && $batch->user_id != $user_id)
            return ___('This coupon belongs to another customer');
        $tm = $this->getDi()->time;
        if ($batch->begin_date && strtotime($batch->begin_date) > $tm)
            return ___('Coupon is not yet active');
        if ($batch->expire_date && strtotime($batch->expire_date . ' 23:59:59') < $tm)
            return ___('Coupon code expired');
        if ($batch->user_use_count && $user_id)
        {
            $member_used_count = $this->getDi()->invoiceTable->findPaidCountByCouponId($this->coupon_id, $user_id); 
            if ($batch->user_use_count <= $member_used_count)
                return ___('Coupon usage limit exceeded');
        }
        return null;
    }
    
    /**
     * Mark coupon as used by payment (if payment with saved coupon was finished)
     * and saves the coupon record
     * @param Payment
     */
    function setUsed(){
        $this->used_count++;
        $this->updateSelectedFields('used_count');
    }

    /**
     * Return true if discount applies to current productId and 
     * and if that is first payment or coupon is recurring
     * @param string productType (default: 'product')
     * @param int $productId
     * @param bool $isFirstPayment
     * @return bool
     */
    function isApplicable($productType='product', $productId, $isFirstPayment=true)
    {
        $batch = $this->getBatch();
        if (!$isFirstPayment && !$batch->is_recurring)
            return false;
        if ("" != $batch->product_ids)
            if (!in_array($productId, explode(',', $batch->product_ids)))
                return false;
        return true;
    }
}

class CouponTable extends Am_Table_WithData {
    protected $_key = 'coupon_id';
    protected $_table = '?_coupon';
    protected $_recordClass = 'Coupon';

    function generateCouponCode($length, &$new_length)
    {
       $attempt = 0;
       do {
            $code = strtoupper(md5(uniqid('', 1)));
            $code = substr($code, 0, $length);
            //increase lenth of coupon
            //if can not generate unique
            //code for long time
            $attempt++;
            if ($attempt>2) {
                $attempt = 0;
                $length++;
            }
        } while ($this->findByCode($code));

        $new_length = $length;
        return $code;
    }
}