// Copyright 2018 Google LLC All Rights Reserved.
//
// 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 remote

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"

	"github.com/google/go-containerregistry/authn"
	"github.com/google/go-containerregistry/name"
	"github.com/google/go-containerregistry/v1/remote/transport"
)

// DeleteOptions are used to expose optional information to guide or
// control the image deletion.
type DeleteOptions struct {
	// TODO(mattmoor): Fail on not found?
	// TODO(mattmoor): Delete tag and manifest?
}

// Delete removes the specified image reference from the remote registry.
func Delete(ref name.Reference, auth authn.Authenticator, t http.RoundTripper, do DeleteOptions) error {
	scopes := []string{ref.Scope(transport.DeleteScope)}
	tr, err := transport.New(ref.Context().Registry, auth, t, scopes)
	if err != nil {
		return err
	}
	c := &http.Client{Transport: tr}

	u := url.URL{
		Scheme: transport.Scheme(ref.Context().Registry),
		Host:   ref.Context().RegistryStr(),
		Path:   fmt.Sprintf("/v2/%s/manifests/%s", ref.Context().RepositoryStr(), ref.Identifier()),
	}

	req, err := http.NewRequest(http.MethodDelete, u.String(), nil)
	if err != nil {
		return err
	}

	resp, err := c.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	switch resp.StatusCode {
	case http.StatusOK, http.StatusAccepted:
		return nil
	default:
		b, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return err
		}
		return fmt.Errorf("unrecognized status code during DELETE: %v; %v", resp.Status, string(b))
	}
}