// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package parse

import (
	"io"

	"android.googlesource.com/platform/tools/gpu/framework/compare"
)

// Branch is a CST node  that can have children.
type Branch struct {
	node
	// Children is the slice of child nodes for this Branch.
	Children []Node
}

func (n *Branch) Token() Token {
	tok := Token{}
	if len(n.Children) > 0 {
		first := n.Children[0].Token()
		last := n.Children[len(n.Children)-1].Token()
		tok = first
		tok.End = last.End
	}
	return tok
}

func (n *Branch) WriteTo(w io.Writer) error {
	if err := n.prefix.WriteTo(w); err != nil {
		return err
	}
	for _, c := range n.Children {
		if err := c.WriteTo(w); err != nil {
			return err
		}
	}
	return n.suffix.WriteTo(w)
}

func compareBranches(c compare.Comparator, reference, value *Branch) {
	c.With(c.Path.Member("node", reference, value)).Compare(reference.node, value.node)
	c.With(c.Path.Member("Children", reference, value)).Compare(reference.Children, value.Children)
}

func init() {
	compare.Register(compareBranches)
}