// Package rpc ...
//
// Description : rpc ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 2022-06-29 15:21
package rpc

import (
	"bytes"
	"compress/gzip"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"path/filepath"
	"strings"
	"sync"
	"time"

	"github.com/tidwall/gjson"

	"git.zhangdeman.cn/zhangdeman/util"

	"github.com/ddliu/go-httpclient"
	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

var (
	// Request 请求实例
	Request *request
)

// InitRPC 初始化RPC服务
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 15:23 2022/6/29
func InitRPC(serviceTable map[string]*Service, loggerInstance *zap.Logger) error {
	if nil == serviceTable {
		serviceTable = make(map[string]*Service)
	}
	for _, item := range serviceTable {
		if item.ApiTable == nil {
			item.ApiTable = make(map[string]*Api)
		}
	}
	Request = &request{
		logger:       loggerInstance,
		serviceTable: serviceTable,
		lock:         &sync.RWMutex{},
	}
	return nil
}

// InitRPCFromCfgDir 使用RPC配置文件路径初始化RPC
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 17:41 2022/7/1
func InitRPCFromCfgDir(cfgDir string, logger *zap.Logger) error {
	serviceTable := make(map[string]*Service)
	filepathNames, _ := filepath.Glob(filepath.Join(cfgDir, "*"))
	for i := range filepathNames {
		var (
			serviceInfo Service
			err         error
		)

		if err = util.File.ReadAnyFileContent(filepathNames[i], &serviceInfo); nil != err {
			return err
		}
		serviceTable[serviceInfo.Flag] = &serviceInfo
	}
	return InitRPC(serviceTable, logger)
}

// InitRPCFromCfgFile 从配置文件初始化RPC服务
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 17:42 2022/7/1
func InitRPCFromCfgFile(cfgFile string, logger *zap.Logger) error {
	var (
		serviceTable map[string]*Service
		err          error
	)
	if err = util.File.ReadAnyFileContent(cfgFile, &serviceTable); nil != err {
		return err
	}
	return InitRPC(serviceTable, logger)
}

type request struct {
	logger       *zap.Logger
	serviceTable map[string]*Service
	lock         *sync.RWMutex
}

// AddService 新增一个服务
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 17:13 2022/6/29
func (r *request) AddService(serviceInfo *Service) error {
	if nil == serviceInfo {
		return errors.New("service info is nil")
	}
	if nil == serviceInfo.SuccessCodeList {
		serviceInfo.SuccessCodeList = []string{"0"}
	}
	if nil == serviceInfo.SuccessHttpCodeList {
		serviceInfo.SuccessHttpCodeList = []int{http.StatusOK}
	}
	if len(serviceInfo.CodeField) == 0 {
		serviceInfo.CodeField = DefaultCodeField
	}
	if len(serviceInfo.DataField) == 0 {
		serviceInfo.DataField = DefaultDataField
	}
	if len(serviceInfo.MessageField) == 0 {
		serviceInfo.MessageField = DefaultMessageField
	}
	r.lock.Lock()
	defer r.lock.Unlock()
	if _, exist := r.serviceTable[serviceInfo.Flag]; exist {
		return errors.New(serviceInfo.Flag + " already exist")
	}
	r.serviceTable[serviceInfo.Flag] = serviceInfo
	return nil
}

// GetServiceInfo ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 11:32 2022/6/30
func (r *request) GetServiceInfo(serviceFlag string) (*Service, error) {
	var (
		serviceInfo *Service
		exist       bool
	)

	r.lock.RLock()
	defer r.lock.RUnlock()
	if serviceInfo, exist = r.serviceTable[serviceFlag]; !exist {
		return nil, errors.New(serviceFlag + " -> 服务不存在")
	}
	return serviceInfo, nil
}

// RemoveService 删除一个service
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 11:46 2022/6/30
func (r *request) RemoveService(serviceFlag string) {
	r.lock.Lock()
	defer r.lock.Unlock()
	delete(r.serviceTable, serviceFlag)
}

// AddServiceApi 向一个service中增加Api
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 11:26 2022/6/30
func (r *request) AddServiceApi(serviceFlag string, apiConfig *Api) error {
	var (
		serviceInfo *Service
		err         error
	)

	if serviceInfo, err = r.GetServiceInfo(serviceFlag); nil != err {
		return err
	}
	if len(apiConfig.SuccessCodeList) == 0 {
		apiConfig.SuccessCodeList = serviceInfo.SuccessCodeList
	}
	if len(apiConfig.SuccessHttpCodeList) == 0 {
		apiConfig.SuccessHttpCodeList = serviceInfo.SuccessHttpCodeList
	}
	if len(apiConfig.CodeField) == 0 {
		apiConfig.CodeField = serviceInfo.CodeField
	}
	if len(apiConfig.DataField) == 0 {
		apiConfig.DataField = serviceInfo.DataField
	}
	if len(apiConfig.MessageField) == 0 {
		apiConfig.MessageField = serviceInfo.MessageField
	}
	r.lock.Lock()
	defer r.lock.Unlock()
	if nil == serviceInfo.ApiTable {
		serviceInfo.ApiTable = make(map[string]*Api)
	}
	serviceInfo.ApiTable[apiConfig.Flag] = apiConfig
	return nil
}

// GetServiceApi 获取服务api配置
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 11:53 2022/6/30
func (r *request) GetServiceApi(serviceFlag string, apiFlag string) (*Service, *Api, error) {
	var (
		serviceInfo *Service
		err         error
		exist       bool
		apiInfo     *Api
	)
	if serviceInfo, err = r.GetServiceInfo(serviceFlag); nil != err {
		return nil, nil, err
	}
	r.lock.RLock()
	defer r.lock.RUnlock()
	if apiInfo, exist = serviceInfo.ApiTable[apiFlag]; !exist {
		return nil, nil, errors.New(serviceFlag + " : " + apiFlag + " -> api")
	}
	return serviceInfo, apiInfo, nil
}

// RemoveServiceApi 删除服务下的一个api
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 12:02 2022/6/30
func (r *request) RemoveServiceApi(serviceFlag string, apiFlag string) {
	var (
		serviceInfo *Service
		err         error
	)
	if serviceInfo, _, err = r.GetServiceApi(serviceFlag, apiFlag); nil != err {
		// 不存在无需处理
		return
	}
	r.lock.Lock()
	defer r.lock.Unlock()
	delete(serviceInfo.ApiTable, apiFlag)
}

// Get ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 14:25 2022/6/30
func (r *request) Get() error {
	return nil
}

// Send 统一的发送请求方法
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 14:24 2022/6/30
func (r *request) Send(ctx *gin.Context, serviceFlag string, apiFlag string, parameter map[string]interface{}, header map[string]string, receiver interface{}) error {
	var (
		serviceConfig       *Service
		apiConfig           *Api
		err                 error
		fullURL             string
		client              *httpclient.HttpClient
		body                []byte
		response            *httpclient.Response
		responseBody        []byte
		code, message, data string
	)

	// 日志数据
	logDataList := []zap.Field{
		zap.String("service_flag", serviceFlag),
		zap.String("service_api_flag", apiFlag),
		zap.Any("input_param", parameter),
	}
	defer func() {
		// 记录请求日志
		r.loggerRequest(ctx, logDataList...)
	}()
	if serviceConfig, apiConfig, err = r.GetServiceApi(serviceFlag, apiFlag); nil != err {
		logDataList = append(logDataList, zap.Any("read_api_config_fail", err.Error()))
		return err
	}
	logDataList = append(logDataList, zap.Any("api_config", apiConfig))

	// 完整的请求地址
	fullURL, body = r.getFullURLAndBody(serviceConfig, apiConfig, parameter)

	logDataList = append(logDataList, zap.String("full_utl", fullURL))
	fullHeader := make(map[string]string)
	for k, v := range apiConfig.Header {
		fullHeader[k] = v
	}
	for k, v := range header {
		fullHeader[k] = v
	}
	// 获取客户端
	client = r.GetHttpClient(fullHeader, apiConfig.Timeout)
	var bodyReader io.Reader
	if nil != body {
		logDataList = append(logDataList, zap.String("request_body", string(body)))
		bodyReader = bytes.NewReader(body)
	}

	requestStartTime := time.Now().UnixNano() / 1e6
	requestFinishTime := int64(0)

	logDataList = append(logDataList, zap.Int64("start_time", requestStartTime))
	if response, err = client.Do(apiConfig.Method, fullURL, apiConfig.Header, bodyReader); nil != err {
		requestFinishTime = time.Now().UnixNano() / 1e6
		logDataList = append(logDataList, zap.Int64("finish_time", requestFinishTime))
		logDataList = append(logDataList, zap.Int64("used_time", requestFinishTime-requestStartTime))
		logDataList = append(logDataList, zap.String("request_fail_reason", err.Error()))
		return err
	}

	requestFinishTime = time.Now().UnixNano() / 1e6
	logDataList = append(logDataList, zap.Int64("finish_time", requestFinishTime))
	logDataList = append(logDataList, zap.Int64("used_time", requestFinishTime-requestStartTime))
	logDataList = append(logDataList, zap.Any("response_header", response.Header))
	logDataList = append(logDataList, zap.Any("response_http_code", response.StatusCode))

	if responseBody, err = r.getResponseBody(response); nil != err {
		logDataList = append(logDataList, zap.String("read_body_fail_reason", err.Error()))
		return err
	}

	logDataList = append(logDataList, zap.Any("response_body", string(responseBody)))

	responseFieldCfg := r.getCodeAndMessageAndDataField(serviceConfig, apiConfig)
	successHttpCodeList, successBusinessCodeList := r.getSuccessHttpCodeAndSuccessBusinessCode(serviceConfig, apiConfig)
	if !r.httpCodeIsSuccess(response.StatusCode, successHttpCodeList) {
		return fmt.Errorf("HTTP状态码异常 : %v -> %v", response.StatusCode, response.Status)
	}

	// 解析响应的业务数据
	code, message, data = r.getCodeAndMessageAndData(responseBody, responseFieldCfg)
	if !r.codeIsSuccess(code, successBusinessCodeList) {
		return fmt.Errorf("业务状态码异常 : %v -> %v", code, message)
	}

	if nil == receiver {
		// 数据接收指针为 nil , 则认为状态码为成功既是成功
		return nil
	}
	if err = parseResponseBody(response.Header.Get("Content-Type"), []byte(data), receiver); nil != err {
		logDataList = append(logDataList, zap.Any("response_body_parse_fail_reason", err.Error()))
	}
	return err
}

// getResponseBody 获取响应体
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 3:10 2022/10/4
func (r *request) getResponseBody(response *httpclient.Response) ([]byte, error) {
	var (
		responseBody []byte
		err          error
		gzipInstance *gzip.Reader
		buf          bytes.Buffer
	)
	if responseBody, err = io.ReadAll(response.Body); nil != err {
		return nil, err
	}
	// 判断返回值是否经过gzip压缩
	responseGzip := response.Header.Get("content-encoding")
	if strings.ToLower(responseGzip) == "gzip" {
		// 压缩过的数据，在处理response body
		if gzipInstance, err = gzip.NewReader(bytes.NewReader(responseBody)); nil != err {
			return nil, err
		}
		defer func() {
			_ = gzipInstance.Close()
		}()
		if _, err = io.Copy(&buf, gzipInstance); nil != err {
			return nil, err
		}
		responseBody = buf.Bytes()
	}
	// 判断是否为gbk编码,若是,转为utf8
	isGBK := strings.Contains(strings.ToLower(response.Header.Get("content-type")), "gbk")
	if isGBK {
		return []byte(util.String.Convert(string(responseBody), "gbk", "utf-8")), nil
	}
	// 判断是否为gb2312,若是,转为utf8
	isGB2312 := strings.Contains(strings.ToLower(response.Header.Get("content-type")), "gb2312")
	if isGB2312 {
		return []byte(util.String.Convert(string(responseBody), "gb2312", "utf-8")), nil
	}
	return responseBody, nil
}

// GetHttpClient 获取client实例
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 17:00 2022/6/30
func (r *request) GetHttpClient(header map[string]string, timeout ApiTimeout) *httpclient.HttpClient {
	client := httpclient.NewHttpClient()
	if timeout.Connect <= 0 {
		timeout.Connect = DefaultConnectTimeout
	}

	if timeout.Read <= 0 {
		timeout.Read = DefaultReadTimeout
	}
	client.WithHeaders(header)
	client.WithOption(httpclient.OPT_CONNECTTIMEOUT_MS, timeout.Connect)
	client.WithOption(httpclient.OPT_TIMEOUT_MS, timeout.Read)
	return client
}

// getFullURL ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 17:23 2022/6/30
func (r *request) getFullURLAndBody(serviceConfig *Service, apiConfig *Api, parameter map[string]interface{}) (string, []byte) {
	fullURL := strings.TrimRight(serviceConfig.Domain, "/") + "/" + strings.TrimLeft(apiConfig.URI, "/")
	for name, val := range parameter {
		paramTpl := "{{" + name + "}}"
		if !strings.Contains(fullURL, paramTpl) {
			continue
		}
		fullURL = strings.ReplaceAll(fullURL, paramTpl, fmt.Sprintf("%v", val))
		// 替换到URL的参数, 从body删除
		delete(parameter, name)
	}
	parameterPair := make([]string, 0)
	var body []byte
	switch strings.ToUpper(apiConfig.Method) {
	case http.MethodGet:
		fallthrough
	case http.MethodHead:
		fallthrough
	case http.MethodOptions:
		fallthrough
	case http.MethodConnect:
		fallthrough
	case http.MethodPatch:
		fallthrough
	case http.MethodTrace:
		for name, val := range parameter {
			var valStr string
			_ = util.ConvertAssign(&valStr, val)
			parameterPair = append(parameterPair, fmt.Sprintf("%v=%v", name, valStr))
		}
	case http.MethodPost:
		fallthrough
	case http.MethodPut:
		fallthrough
	case http.MethodDelete:
		body, _ = json.Marshal(parameter)
	}
	query := strings.Join(parameterPair, "&")
	if len(query) == 0 {
		return fullURL, body
	}
	return fullURL + "?" + query, body
}

// validateResponseHttpCode 验证http状态码
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 18:18 2022/6/30
func (r *request) validateResponseHttpCode(apiConfig *Api, response *httpclient.Response) error {
	// 判断状态码
	isHttpSuccess := false
	for _, successCode := range apiConfig.SuccessHttpCodeList {
		if successCode == response.StatusCode {
			isHttpSuccess = true
			break
		}
	}
	if !isHttpSuccess {
		return fmt.Errorf("http响应状态码异常 -> %v", response.StatusCode)
	}
	return nil
}

// getCodeAndMessageAndData 读取业务状态码 + 文案 + 数据
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 18:20 2022/6/30
func (r *request) getCodeAndMessageAndData(responseBody []byte, responseFieldCfg responseDaFieldConfig) (string, string, string) {
	var (
		code    = SpecialFiledVal
		message = SpecialFiledVal
		data    string
	)
	if responseFieldCfg.Code != SpecialFiledVal {
		code = gjson.Get(string(responseBody), responseFieldCfg.Code).String()
	}
	if responseFieldCfg.Message != SpecialFiledVal {
		message = gjson.Get(string(responseBody), responseFieldCfg.Message).String()
	}
	if responseFieldCfg.Data == SpecialFiledVal {
		data = string(responseBody)
	} else {
		data = gjson.Get(string(responseBody), responseFieldCfg.Data).String()
	}
	return code, message, data
}

// codeIsSuccess 判断业务状态码是否为成功
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 18:27 2022/6/30
func (r *request) codeIsSuccess(input string, successCodeList []string) bool {
	if input == SpecialFiledVal {
		// 不需要验证状态码,直接返回成功
		return true
	}
	for _, item := range successCodeList {
		if item == input {
			return true
		}
	}
	return false
}

// httpCodeIsSuccess http状态码是否为成功
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 18:31 2022/6/30
func (r *request) httpCodeIsSuccess(input int, successCodeList []int) bool {
	for _, item := range successCodeList {
		if item == input {
			return true
		}
	}
	return false
}

// getSuccessHttpCodeAndSuccessBusinessCode 获取成功的http 和 业务状态码列表
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 16:48 2022/7/1
func (r *request) getSuccessHttpCodeAndSuccessBusinessCode(serviceInfo *Service, apiInfo *Api) ([]int, []string) {
	var (
		successHttpCodeList     = apiInfo.SuccessHttpCodeList
		successBusinessCodeList = apiInfo.SuccessCodeList
	)

	if len(apiInfo.SuccessHttpCodeList) == 0 {
		successHttpCodeList = serviceInfo.SuccessHttpCodeList
	}

	if len(apiInfo.SuccessHttpCodeList) == 0 {
		successBusinessCodeList = serviceInfo.SuccessCodeList
	}

	if len(successHttpCodeList) == 0 {
		successHttpCodeList = []int{http.StatusOK}
	}

	if len(successBusinessCodeList) == 0 {
		successBusinessCodeList = []string{"0"}
	}
	return successHttpCodeList, successBusinessCodeList
}

// getCodeAndMessageAndDataField 获取三个字段信息
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 16:54 2022/7/1
func (r *request) getCodeAndMessageAndDataField(serviceInfo *Service, apiInfo *Api) responseDaFieldConfig {
	cfg := responseDaFieldConfig{
		Code:    apiInfo.CodeField,
		Message: apiInfo.MessageField,
		Data:    apiInfo.DataField,
	}
	if len(cfg.Code) == 0 {
		cfg.Code = serviceInfo.CodeField
	}

	if len(cfg.Message) == 0 {
		cfg.Message = serviceInfo.MessageField
	}

	if len(cfg.Data) == 0 {
		cfg.Data = serviceInfo.DataField
	}

	return cfg
}

// loggerRequest 记录请求日志
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 17:54 2022/7/1
func (r *request) loggerRequest(ctx *gin.Context, dataList ...zap.Field) {
	if nil == r.logger {
		// 未设置日志实例
		return
	}
	r.logger.Info("API接口请求日志记录", dataList...)
}