/*
   Copyright The containerd Authors.

   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 content

import (
	"strings"

	"github.com/containerd/containerd/filters"
)

// AdaptInfo returns `filters.Adaptor` that handles `content.Info`.
func AdaptInfo(info Info) filters.Adaptor {
	return filters.AdapterFunc(func(fieldpath []string) (string, bool) {
		if len(fieldpath) == 0 {
			return "", false
		}

		switch fieldpath[0] {
		case "digest":
			return info.Digest.String(), true
		case "size":
			// TODO: support size based filtering
		case "labels":
			return checkMap(fieldpath[1:], info.Labels)
		}

		return "", false
	})
}

func checkMap(fieldpath []string, m map[string]string) (string, bool) {
	if len(m) == 0 {
		return "", false
	}

	value, ok := m[strings.Join(fieldpath, ".")]
	return value, ok
}