/*
 * Minio Client (C) 2015 Minio, Inc.
 *
 * 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 s3

import (
	"net/http"
	"net/http/httputil"
	"regexp"

	"github.com/minio/mc/pkg/console"
	"github.com/minio/minio/pkg/iodine"
)

// Trace - tracing structure
type Trace struct {
}

// NewTrace - initialize Trace structure
func NewTrace() HTTPTracer {
	return Trace{}
}

// Request - Trace HTTP Request
func (t Trace) Request(req *http.Request) (err error) {
	origAuth := req.Header.Get("Authorization")

	// Authorization (S3 v4 signature) Format:
	// Authorization: AWS4-HMAC-SHA256 Credential=AKIAJNACEGBGMXBHLEZA/20150524/us-east-1/s3/aws4_request, SignedHeaders=host;x-amz-content-sha256;x-amz-date, Signature=bbfaa693c626021bcb5f911cd898a1a30206c1fad6bad1e0eb89e282173bd24c

	// Strip out access-key-id from: Credential=<access-key-id>/<date>/<aws-region>/<aws-service>/aws4_request
	regCred := regexp.MustCompile("Credential=([A-Z]+)/")
	newAuth := regCred.ReplaceAllString(origAuth, "Credential=**REDACTED**/")

	// Strip out 256-bit signature from: Signature=<256-bit signature>
	regSign := regexp.MustCompile("Signature=([[0-9a-f]+)")
	newAuth = regSign.ReplaceAllString(newAuth, "Signature=**REDACTED**")

	// Set a temporary redacted auth
	req.Header.Set("Authorization", newAuth)

	reqTrace, err := httputil.DumpRequestOut(req, false) // Only display header
	if err == nil {
		console.Debug(string(reqTrace))
	}

	// Undo
	req.Header.Set("Authorization", origAuth)
	return iodine.New(err, nil)
}

// Response - Trace HTTP Response
func (t Trace) Response(res *http.Response) (err error) {
	resTrace, err := httputil.DumpResponse(res, false) // Only display header
	if err == nil {
		console.Debug(string(resTrace))
	}
	return iodine.New(err, nil)
}