package platformapi

import (
	"bytes"
	"errors"
	"io"
	"io/ioutil"
	"net"
	"net/http"
	"time"

	"git.rosy.net.cn/baseapi"
	"git.rosy.net.cn/baseapi/utils"
	"github.com/fatih/structs"
)

const (
	DefClientTimeout              = 10 * time.Second
	DefSleepSecondWhenExceedLimit = 3 * time.Second
	DefRandSlice                  = 10
	DefMaxRecoverableRetryCount   = 3
	DefMaxExceedLimitRetryCount   = 25
)

type APIRetryConfig struct {
	MaxExceedLimitRetryCount   int
	MaxRecoverableRetryCount   int
	SleepSecondWhenExceedLimit time.Duration
}

type APIConfig struct {
	APIRetryConfig
	ClientTimeout time.Duration
}

type AccessPlatformAPIWithRetryParam struct {
	APIRetryConfig
	Client  *http.Client
	Request *http.Request
}

var (
	DefAPIConfig = APIConfig{
		APIRetryConfig: APIRetryConfig{
			MaxExceedLimitRetryCount:   DefMaxExceedLimitRetryCount,
			MaxRecoverableRetryCount:   DefMaxRecoverableRetryCount,
			SleepSecondWhenExceedLimit: DefSleepSecondWhenExceedLimit,
		},
		ClientTimeout: DefClientTimeout,
	}
)

const (
	ErrLevelSuccess        = "JXC4_SUCCESS"
	ErrLevelExceedLimit    = "JXC4_EXCEED_LIMIT"
	ErrLevelRecoverableErr = "JXC4_RECOVERABLE"
	ErrLevelGeneralFail    = "JXC4_GENERAL_FAIL"
	ErrLevelCodeIsNotOK    = "JXC4_CODE_IS_NOT_OK"
)

const (
	maxDataSizeDontOutput = 200 * 1024
)

// common api access error
var (
	ErrAPIAccessFailed         = errors.New("access API failed")
	ErrHTTPCodeIsNot200        = errors.New("HTTP code is not 200")
	ErrResponseDataFormatWrong = errors.New("the data of response has wrong format")
)

// common callback response
var (
	ErrStrUnescapeError            = "can not unescape data:%v, error:%v"
	ErrStrUnmarshalError           = "can not unmarshal data:%v, error:%v"
	ErrStrCallbackSignatureIsWrong = "wrong signature"
)

func init() {
	structs.DefaultTagName = "json"
}

func getClonedData(r *bytes.Buffer) string {
	retVal := string(r.Bytes())
	if len(retVal) > maxDataSizeDontOutput {
		return "request data is too large"
	}
	return retVal
}

func AccessPlatformAPIWithRetry(client *http.Client, handleRequest func() *http.Request, config *APIConfig, handleResponse func(bodyMap map[string]interface{}) (string, error)) error {
	exceedLimitRetryCount := 0
	recoverableErrorRetryCount := 0
	for {
		savedBuf := new(bytes.Buffer)
		request := handleRequest()
		if request.Body != nil {
			request.Body = ioutil.NopCloser(io.TeeReader(request.Body, savedBuf))
		}
		beginTime := time.Now()
		// baseapi.SugarLogger.Debugf("begin AccessPlatformAPIWithRetry url:%v", request.URL)
		response, err := client.Do(request)
		// baseapi.SugarLogger.Debugf("end AccessPlatformAPIWithRetry url:%v, request:%s", request.URL, getClonedData(savedBuf))
		if err != nil {
			baseapi.SugarLogger.Debugf("AccessPlatformAPIWithRetry client.Get return err:%v", err)
			err, ok := err.(net.Error)
			if ok && err.Timeout() && recoverableErrorRetryCount <= config.MaxRecoverableRetryCount {
				recoverableErrorRetryCount++
				continue
			} else {
				baseapi.SugarLogger.Errorf("AccessPlatformAPIWithRetry access api url:%v, request:%v, error:%v", request.URL, getClonedData(savedBuf), err)
				return ErrAPIAccessFailed
			}
		}
		usedMilliSecond := time.Now().Sub(beginTime) / time.Millisecond
		if usedMilliSecond > 5000 {
			baseapi.SugarLogger.Infof("AccessPlatformAPIWithRetry access api too slow, url:%v, request:%v, usedMilliSecond:%d", request.URL, getClonedData(savedBuf), usedMilliSecond)
		}
		defer response.Body.Close()
		if response.StatusCode != 200 {
			if bodyData, err := ioutil.ReadAll(response.Body); err == nil {
				baseapi.SugarLogger.Errorf("AccessPlatformAPIWithRetry HTTP code is:%d, url:%v, request:%v, response:%s", response.StatusCode, request.URL, getClonedData(savedBuf), string(bodyData))
			} else {
				baseapi.SugarLogger.Errorf("AccessPlatformAPIWithRetry HTTP code is:%d, url:%v, request:%v", response.StatusCode, request.URL, getClonedData(savedBuf))
			}
			return ErrHTTPCodeIsNot200
		}
		var errLevel string
		bodyMap, err := utils.HTTPResponse2Json(response)
		if err != nil {
			errLevel = ErrLevelRecoverableErr
		} else {
			errLevel, err = handleResponse(bodyMap)
		}
		// baseapi.SugarLogger.Debugf("AccessPlatformAPIWithRetry url:%v, request:%v, response:%s", request.URL, getClonedData(savedBuf), utils.Format4Output(bodyMap, true))
		if err == nil {
			return nil
		} else if errLevel == ErrLevelExceedLimit {
			exceedLimitRetryCount++
			if exceedLimitRetryCount <= config.MaxExceedLimitRetryCount {
				time.Sleep(config.SleepSecondWhenExceedLimit)
				continue
			}
		} else if errLevel == ErrLevelRecoverableErr {
			recoverableErrorRetryCount++
			if recoverableErrorRetryCount <= config.MaxRecoverableRetryCount {
				continue
			}
		}
		baseapi.SugarLogger.Infof("AccessPlatformAPIWithRetry failed, url:%v, request:%v, response:%s, error:%v", request.URL, getClonedData(savedBuf), utils.Format4Output(bodyMap, true), err)
		return err
	}
}