A start on negative line items

@claudiosmweb

assets/css/admin.less

@@ -695,6 +695,9 @@ ul.wc_coupon_list_block {
 	h3 small {
 		color: #999;
 	}
+	.amount {
+		white-space: nowrap;
+	}
 }
 .woocommerce_order_items_wrapper {
 	margin: 0;

assets/js/admin/meta-boxes-order.js

@@ -582,10 +582,11 @@ jQuery( function ( $ ) {
 			if ( window.confirm( woocommerce_admin_meta_boxes.i18n_do_refund ) ) {
 				var refund_amount = $( 'input#refund_amount' ).val();
 				var refund_reason = $( 'input#refund_reason' ).val();
-				var refund_qty    = $.map( $( 'input[type=number][name^=order_item_refund_qty]' ), function( item ) {
+				var refund_qty    = {};
-				var result        = [];
+				$( 'input[type=number][name^=order_item_refund_qty]' ).each( function( index, item ) {
-				result.push( $( item ).closest( 'tr.item,tr.fee' ).data( 'order_item_id' ), item.value );
+					if ( $( item ).closest( 'tr' ).data( 'order_item_id' ) ) {
-					return result;
+						refund_qty[ $( item ).closest( 'tr' ).data( 'order_item_id' ) ] = item.value;
+					}
 				});
 				var data          = {
 					action:        'woocommerce_refund_line_items',
@@ -602,6 +603,8 @@ jQuery( function ( $ ) {
 					} else if ( response.error ) {
 						window.alert( response.error );
 						removeOrderItemsLoading();
+					} else {
+						console.log(response);
 					}
 				});
 			} else {

includes/class-wc-ajax.php

@@ -1792,11 +1792,10 @@ class WC_AJAX {
 		$order_id      = absint( $_POST['order_id'] );
 		$refund_amount = sanitize_text_field( $_POST['refund_amount'] );
 		$refund_reason = sanitize_text_field( $_POST['refund_reason'] );
-		$refund_qty    = json_decode( sanitize_text_field( stripslashes( $_POST['refund_qty'] ) ) );
+		$refund_qty    = json_decode( sanitize_text_field( stripslashes( $_POST['refund_qty'] ) ), true );
 		$api_refund    = $_POST['api_refund'] === 'true' ? true : false;
 
 		try {
-
 			// Validate that the refund can occur
 			$order      = get_order( $order_id );
 			$max_refund = $order->get_total() - $order->get_total_refunded();
@@ -1807,9 +1806,10 @@ class WC_AJAX {
 
 			// Create the refund object
 			$refund = wc_create_refund( array(
-				'amount'    => $refund_amount,
+				'amount'        => $refund_amount,
-				'reason'    => $refund_reason,
+				'reason'        => $refund_reason,
-				'order_id'  => $order_id
+				'order_id'      => $order_id,
+				'line_item_qty' => $refund_qty
 			) );
 
 			if ( is_wp_error( $refund ) ) {

includes/wc-order-functions.php

@@ -526,10 +526,11 @@ function wc_ship_to_billing_address_only() {
  */
 function wc_create_refund( $args = array() ) {
 	$default_args = array(
-		'amount'    => '',
+		'amount'        => '',
-		'reason'    => null,
+		'reason'        => null,
-		'order_id'  => 0,
+		'order_id'      => 0,
-		'refund_id' => 0
+		'refund_id'     => 0,
+		'line_item_qty' => array()
 	);
 
 	$args        = wp_parse_args( $args, $default_args );
@@ -563,11 +564,50 @@ function wc_create_refund( $args = array() ) {
 		return $refund_id;
 	}
 	
-	// Default refund meta data
 	if ( ! $updating ) {
+		// Default refund meta data
 		update_post_meta( $refund_id, '_refund_amount', wc_format_decimal( $args['amount'] ) );
-	}
 
+		// Negative line items
+		if ( sizeof( $args['line_item_qty'] ) > 0 ) {
+			$order       = get_order( $args['order_id'] );
+			$order_items = $order->get_items();
+			$refund      = get_order( $refund_id );
+			$order_taxes = array();
+			foreach ( $args['line_item_qty'] as $refund_item_id => $refund_qty ) {
+				if ( isset( $order_items[ $refund_item_id ] ) && $refund_qty ) {
+					$refund_item  = $order_items[ $refund_item_id ];
+					$product      = $order->get_product_from_item( $refund_item );
+					$qty          = $refund_item['qty'];
+
+					$args                           = array();
+					$args['totals']['subtotal']     = ( ( $refund_item['line_subtotal'] / $qty ) * $refund_qty ) * -1;
+					$args['totals']['subtotal_tax'] = ( ( $refund_item['line_subtotal_tax'] / $qty ) * $refund_qty ) * -1;
+					$args['totals']['total']        = ( ( $refund_item['line_total'] / $qty ) * $refund_qty ) * -1;
+					$args['totals']['tax']          = ( ( $refund_item['line_tax'] / $qty ) * $refund_qty ) * -1;
+					$args['totals']['tax_data']     = array( 'total' => array(), 'subtotal' => array() );
+
+					if ( isset( $refund_item['line_tax_data'] ) ) {
+						$line_tax_data = maybe_unserialize( $refund_item['line_tax_data'] );
+						foreach ( $line_tax_data['total'] as $key => $tax ) {
+							$args['totals']['tax_data']['total'][ $key ] = ( ( $tax / $qty ) * $refund_qty ) * -1;
+							$order_taxes[ $key ] += ( ( $tax / $qty ) * $refund_qty ) * -1;
+						}
+						foreach ( $line_tax_data['subtotal'] as $key => $tax ) {
+							$args['totals']['tax_data']['subtotal'][ $key ] = ( ( $tax / $qty ) * $refund_qty ) * -1;
+						}
+					}
+
+					$refund->add_product( $product, $refund_qty, $args );
+				}
+			}
+
+			// Save order tax rows
+			foreach ( $order_taxes as $tax_rate_id => $tax_amount ) {
+				$refund->add_tax( $tax_rate_id, $tax_amount );
+			}
+		}
+	}
 	return new WC_Order_Refund( $refund_id );
 }