Teacher Bulk Coupon Creation

add_shortcode( 'mycred_create_bulk_coupons', 'mycred_render_bulk_coupon_creation' );
function mycred_render_bulk_coupon_creation() {

    if ( ! current_user_can( 'manage_options' ) ) return 'You do not create coupons.';
    if ( ! function_exists( 'mycred_create_new_coupon' ) ) return 'The Coupon add-on is not enabled!';

    if ( isset( $_POST['mycred_coupon_bulk'] ) && isset( $_POST['cc-token'] ) && wp_verify_nonce( $_POST['cc-token'], 'mycred-coupon-bulk-create' ) ) {

        $number = $_POST['mycred_coupon_bulk']['number'];
        $value = $_POST['mycred_coupon_bulk']['value'];
        $expire = $_POST['mycred_coupon_bulk']['expire'];
        $global_limit = $_POST['mycred_coupon_bulk']['global'];
        $user_limit = $_POST['mycred_coupon_bulk']['user'];
        $min_balance = $_POST['mycred_coupon_bulk']['min'];
        $max_balance = $_POST['mycred_coupon_bulk']['max'];

        $views = array();
        $ids = array();

        add_filter( 'mycred_get_unique_coupon_code', 'mycred_custom_coupon_codes' );

        for ( $i = 0; $i < $number; $i++ ) {
            $post_id = mycred_create_new_coupon( array(
                'value'       => $value,
                'global_max'  => $global_limit,
                'user_max'    => $user_limit,
                'min_balance' => $min_balance,
                'max_balance' => $max_balance,
                'expires'     => $expire
            ) );

            $ids[] = $post_id;
            if ( isset( $_POST['mycred_coupon_bulk']['view'] ) )
                $views[] = get_the_title( $post_id );

        }

    }

    ob_start();
?>
<h3>Bulk Coupon Creator</h3>
<?php if ( ! empty( $ids ) ) : ?>
    <h4><?php printf( '%d Coupons were successfully created.', count( $ids ) ); ?></h4>
    <?php if ( ! empty( $views ) ) : ?>
    <p>Your coupon codes are:</p>
    <pre><?php echo implode( ' ', $views ); ?></pre>
    <?php endif; ?>
<?php else : ?>
    <form method="post" action="">
        <input type="hidden" name="cc-token" value="<?php echo wp_create_nonce( 'mycred-coupon-bulk-create' ); ?>" />
        <p>
            <label for="bulk-number">Teacher Prefix</label><br />
            <input type="text" name="mycred_coupon_bulk[prefix]" id="bulk-number" value="" size="8" />
        </p>
        <p>
            <label for="bulk-number">Number of Coupons to create</label><br />
            <input type="text" name="mycred_coupon_bulk[number]" id="bulk-number" value="1" size="8" />
        </p>
        <p>
            <label for="bulk-view"><input type="checkbox" name="mycred_coupon_bulk[view]" id="bulk-view" value="1" /> View Coupon codes when finished.</label>
        </p>
        <p>
            <label for="bulk-value">Coupon Value</label><br />
            <input type="text" name="mycred_coupon_bulk[value]" id="bulk-value" value="1" size="8" />
        </p>
        <p>
            <label for="bulk-expire">Expiry Date</label><br />
            <input type="text" name="mycred_coupon_bulk[expire]" id="bulk-expire" value="" size="20" placeholder="YYYY-MM-DD" />
        </p>
        <p>
            <label for="bulk-global">Global Limit</label><br />
            <input type="text" name="mycred_coupon_bulk[global]" id="bulk-global" value="1" size="8" />
        </p>
        <p>
            <label for="bulk-user">User Limit</label><br />
            <input type="text" name="mycred_coupon_bulk[user]" id="bulk-user" value="1" size="8" />
        </p>
        <p>
            <label for="bulk-min">Minimum Balance Requirement</label><br />
            <input type="text" name="mycred_coupon_bulk[min]" id="bulk-min" value="0" size="8" />
        </p>
        <p>
            <label for="bulk-max">Maximum Balance Requirement</label><br />
            <input type="text" name="mycred_coupon_bulk[max]" id="bulk-max" value="0" size="8" />
        </p>
        <p><input type="submit" class="button button-primary btn btn-primary btn-lg" value="Generate" /></p>
    </form>
<?php endif; ?>
<?php

    $content = ob_get_contents();
    ob_end_clean();
    return $content;

}

function mycred_custom_coupon_codes( $code ) {
    global $wpdb;

    $prefix = strtoupper( $_POST['mycred_coupon_bulk']['prefix'] );
    do {

        $id = $prefix . rand( 123456, 999999 );
        $query = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$wpdb->posts} WHERE post_title = %s AND post_type = %s;", $id, 'mycred_coupon' ) );

    } while ( ! empty( $query ) );

    return $id;
}