/*
Copyright 2021 The Kubernetes 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 common

import (
	"bytes"
	"compress/flate"
	"compress/gzip"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"time"

	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/tencentcloud/tencentcloud-sdk-go/common/errors"
	tchttp "k8s.io/autoscaler/cluster-autoscaler/cloudprovider/tencentcloud/tencentcloud-sdk-go/common/http"
)

const (
	codeLimitExceeded = "RequestLimitExceeded"
	tplRateLimitRetry = "[WARN] rate limit exceeded, retrying (%d/%d) in %f seconds: %s"
)

func (c *Client) sendWithRateLimitRetry(req *http.Request, retryable bool) (resp *http.Response, err error) {
	// make sure maxRetries is more than 0
	maxRetries := maxInt(c.profile.RateLimitExceededMaxRetries, 0)
	durationFunc := safeDurationFunc(c.profile.RateLimitExceededRetryDuration)

	var shadow []byte
	for idx := 0; idx <= maxRetries; idx++ {
		resp, err = c.sendWithNetworkFailureRetry(req, retryable)
		if err != nil {
			return
		}

		shadow, err = shadowRead(resp)
		if err != nil {
			return resp, err
		}

		err = tchttp.ParseErrorFromHTTPResponse(shadow)
		// should not sleep on last request
		if err, ok := err.(*errors.TencentCloudSDKError); ok && err.Code == codeLimitExceeded && idx < maxRetries {
			duration := durationFunc(idx)
			if c.debug {
				c.logger.Printf(tplRateLimitRetry, idx, maxRetries, duration.Seconds(), err.Error())
			}

			time.Sleep(duration)
			continue
		}

		return resp, err
	}

	return resp, err
}

func shadowRead(resp *http.Response) ([]byte, error) {
	var reader io.ReadCloser
	var err error
	var val []byte

	enc := resp.Header.Get("Content-Encoding")
	switch enc {
	case "":
		reader = resp.Body
	case "deflate":
		reader = flate.NewReader(resp.Body)
	case "gzip":
		reader, err = gzip.NewReader(resp.Body)
		if err != nil {
			return nil, err
		}
	default:
		return nil, fmt.Errorf("Content-Encoding not support: %s", enc)
	}

	val, err = ioutil.ReadAll(reader)
	if err != nil {
		return nil, err
	}

	err = resp.Body.Close()
	if err != nil {
		return nil, err
	}

	resp.Body = ioutil.NopCloser(bytes.NewReader(val))

	// delete the header in case the caller mistake the body being encoded
	delete(resp.Header, "Content-Encoding")

	return val, nil
}