baseapi/platform/elmapi/elmapi.go

package elmapi

import (
	"crypto/md5"
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"net"
	"net/http"
	"net/url"
	"sort"
	"strings"
	"time"

	"git.rosy.net.cn/baseapi/utils"
	"go.uber.org/zap"
)

const (
	ELM_API_URL_SANDBOX = "https://open-api-sandbox.shop.ele.me/api/v1/"
	ELM_API_URL_PROD    = "https://open-api.shop.ele.me/api/v1/"
)

const (
	sleepSecondWhenLimited            = 6 * time.Second
	maxRetryCountWhenNetworkException = 3
	maxRetryCountWhenReachLimited     = 10
)

var (
	ErrSystemErrMaxRetry  = errors.New("ELM System error reach max retry count!")
	ErrLimitReachMaxRetry = errors.New("ELM Reach max retry count!")
	ErrHttpCode           = errors.New("ELM HTTP Code is not 200")
	ErrELMCode            = errors.New("ELM code is not 0")
)

type ELMResult struct {
	Id     string
	Result map[string]interface{}
	Error  map[string]interface{}
}

type ELMAPI struct {
	token       string
	appKey      string
	secret      string
	sugarLogger *zap.SugaredLogger
	url         *url.URL
	client      http.Client
}

type ELMPayload struct {
	Token     string                 `json:"token"`
	Nop       string                 `json:"nop"`
	Metas     map[string]interface{} `json:"metas"`
	Params    map[string]interface{} `json:"params"`
	Action    string                 `json:"action"`
	Id        string                 `json:"id"`
	Signature string                 `json:"signature"`
}

func NewELMAPI(token, appKey, secret string, sugarLogger *zap.SugaredLogger, isProd bool) *ELMAPI {
	api := &ELMAPI{
		token:       token,
		appKey:      appKey,
		secret:      secret,
		sugarLogger: sugarLogger,
		client:      http.Client{Timeout: time.Second * 10},
	}

	if isProd {
		api.url, _ = url.Parse(ELM_API_URL_PROD)
	} else {
		api.url, _ = url.Parse(ELM_API_URL_SANDBOX)
	}
	return api
}

func (e *ELMAPI) signParams(action string, payload *ELMPayload) string {
	keyValues := make([]string, 0)
	allData := []map[string]interface{}{
		payload.Metas,
		payload.Params,
	}
	for _, data := range allData {
		for k, v := range data {
			vBytes, _ := json.Marshal(v)
			keyValues = append(keyValues, k+"="+string(vBytes))
		}
	}

	sort.Strings(keyValues)
	finalStr := action + e.token + strings.Join(keyValues, "") + e.secret
	// e.sugarLogger.Debugf("sign str:%v", finalStr)
	return fmt.Sprintf("%X", md5.Sum([]byte(finalStr)))
}

func (e *ELMAPI) AccessELM(action string, params map[string]interface{}) (*ELMResult, error) {
	if params == nil {
		params = make(map[string]interface{}, 0)
	}
	metas := map[string]interface{}{
		"app_key":   e.appKey,
		"timestamp": int(utils.GetCurTimestamp()),
	}

	payload := &ELMPayload{
		Token:  e.token,
		Nop:    "1.0.0",
		Metas:  metas,
		Params: params,
		Action: action,
		Id:     utils.GetUUID(),
	}

	payload.Signature = e.signParams(action, payload)
	dataBytes, err := json.Marshal(payload)
	if err != nil {
		e.sugarLogger.Errorf("Error when marshal %v, error:%v", payload, err)
		return nil, err
	}
	dataStr := string(dataBytes)
	exceedLimitRetryCount := 0
	systemErrorRetryCount := 0

	for {
		request := &http.Request{
			Method: "POST",
			URL:    e.url,
			Header: http.Header{
				"Content-Type":     []string{"application/json; charset=utf-8"},
				"Content-Encoding": []string{"gzip, deflate"},
				"User-Agent":       []string{"eleme-golang-api"},
				// "x-eleme-requestid": []string{payload.Id},
			},

			Body: ioutil.NopCloser(strings.NewReader(dataStr)),
		}
		response, err := e.client.Do(request)
		if err != nil {
			e.sugarLogger.Debugf("client.Get return err:%v", err)
			err, ok := err.(net.Error)
			systemErrorRetryCount++
			if ok && err.Timeout() && systemErrorRetryCount <= maxRetryCountWhenNetworkException {
				continue
			} else {
				return nil, err
			}
		}
		defer response.Body.Close()

		if response.StatusCode != 200 {
			e.sugarLogger.Debugf("http code is:%d", response.StatusCode)
			systemErrorRetryCount++
			if systemErrorRetryCount <= maxRetryCountWhenNetworkException {
				continue
			}

			return nil, ErrHttpCode
		}

		jsonResult1, err := utils.HttpResponse2Json(response)
		resultError, _ := jsonResult1["error"].(map[string]interface{})
		result, _ := jsonResult1["result"].(map[string]interface{})
		jsonResult := &ELMResult{
			Id:     jsonResult1["id"].(string),
			Error:  resultError,
			Result: result,
		}
		if err != nil {
			e.sugarLogger.Warnf("HttpResponse2Json return:%v", err)
			return nil, err
		}

		errinfoMap := jsonResult.Error
		if errinfoMap == nil {
			return jsonResult, nil
		}
		errCode := errinfoMap["code"].(string)

		if errCode == "EXCEED_LIMIT" {
			exceedLimitRetryCount++
			if exceedLimitRetryCount <= maxRetryCountWhenReachLimited {
				time.Sleep(sleepSecondWhenLimited)
			} else {
				return jsonResult, ErrLimitReachMaxRetry
			}
		} else if errCode == "SERVER_ERROR" || errCode == "BIZ_SYSTEM_ERROR" || errCode == "BIZ_1006" || errCode == "BUSINESS_ERROR" {
			if systemErrorRetryCount <= maxRetryCountWhenNetworkException {
				continue
			}
			return jsonResult, ErrSystemErrMaxRetry
		} else {
			e.sugarLogger.Debug(jsonResult)
			return jsonResult, ErrELMCode
		}
	}
}