/*
   Copyright (c) 2016 VMware, Inc. 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 registry

import (
	"net/http"

	"github.com/vmware/harbor/utils/log"
)

// RequestModifier modifies request
type RequestModifier interface {
	ModifyRequest(*http.Request) error
}

// HeaderModifier adds headers to request
type HeaderModifier struct {
	headers map[string]string
}

// NewHeaderModifier ...
func NewHeaderModifier(headers map[string]string) *HeaderModifier {
	return &HeaderModifier{
		headers: headers,
	}
}

// ModifyRequest adds headers to the request
func (h *HeaderModifier) ModifyRequest(req *http.Request) error {
	for key, value := range h.headers {
		req.Header.Add(key, value)
	}
	return nil
}

// Transport holds information about base transport and modifiers
type Transport struct {
	transport http.RoundTripper
	modifiers []RequestModifier
}

// NewTransport ...
func NewTransport(transport http.RoundTripper, modifiers []RequestModifier) *Transport {
	return &Transport{
		transport: transport,
		modifiers: modifiers,
	}
}

// RoundTrip ...
func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
	for _, modifier := range t.modifiers {
		if err := modifier.ModifyRequest(req); err != nil {
			return nil, err
		}
	}

	resp, err := t.transport.RoundTrip(req)
	if err != nil {
		return nil, err
	}

	log.Debugf("%d | %s %s", resp.StatusCode, req.Method, req.URL.String())

	return resp, err
}