package proxy

import (
	"bytes"
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"strings"

	log "app.yhyue.com/moapp/jylog"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/net/ghttp"
	"github.com/gogf/gf/v2/net/gtrace"
	"github.com/gogf/gf/v2/os/gctx"
	"github.com/gogf/gf/v2/os/gtime"
	"github.com/gogf/gf/v2/util/gconv"
	"jygit.jydev.jianyu360.cn/dataservice/tripartite_gateway/common/db"
	. "jygit.jydev.jianyu360.cn/dataservice/tripartite_gateway/common/gatecode"
	"jygit.jydev.jianyu360.cn/dataservice/tripartite_gateway/core/proxy/middleware"
	"jygit.jydev.jianyu360.cn/dataservice/tripartite_gateway/core/proxy/proxyClient"
	"jygit.jydev.jianyu360.cn/dataservice/tripartite_gateway/core/router"
)

const errTryTime = 10 //错误尝试

// InitGateWayServer 初始化网关服务
func InitGateWayServer(initCtx gctx.Ctx) *ghttp.Server {
	initCtx, span := gtrace.NewSpan(initCtx, "InitGateWayServer")
	defer span.End()
	//初始化可访问路由
	routerManager, err := router.InitRouterManager()
	if err != nil {
		log.WithContext(initCtx).Fatalln(err)
	}
	gateWayServer := g.Server()
	//关闭系统自带请求日志
	gateWayServer.SetLogger(g.Log())
	gateWayServer.SetErrorLogEnabled(false)
	//注册中间件
	//错误拦截
	gateWayServer.Use(func(r *ghttp.Request) {
		middleware.ErrorHandler(r, routerManager)
	})
	//context注入全局信息
	gateWayServer.Use(func(r *ghttp.Request) {
		r.SetError(routerManager.InfusionContext(r))
		r.Middleware.Next()
	})
	//前置过滤
	gateWayServer.Use(middleware.FilterHandler)
	//注册代理
	gateWayServer.BindHandler("POST:/*", proxyHandler) //接口代理
	gateWayServer.BindHandler("GET:/*", proxyHandler)  //页面代理
	return gateWayServer
}

// proxyHandler 网关代理Handler处理
// 完成所有前置校验后，请求代理服务逻辑
var proxyHandler = func(r *ghttp.Request) {
	_, span := gtrace.NewSpan(r.Context(), "proxyHandler")
	defer span.End()
	if r.GetError() != nil {
		return
	}
	gCtx := router.GetGContext(r.GetCtx())
	if gCtx.RouterRule.ReqLimit.Limit() {
		r.SetError(NewErrorWithCode(GLOBAL_ERR_OFTEN))
		return
	}
	defer gCtx.RouterRule.ReqLimit.UnLimit()
	reqBody, _ := ioutil.ReadAll(r.Body)
	r.Body = ioutil.NopCloser(bytes.NewReader(reqBody))
	// 获取请求上下文内容
	var hasErr bool
	errHandel := func(hw http.ResponseWriter, hr *http.Request, err error) {
		if strings.HasPrefix(err.Error(), "RespError_") {
			r.SetError(NewErrorWithCode(ErrCode(gconv.Int(strings.TrimPrefix(err.Error(), "RespError_")))))
			return
		}
		hasErr = true
		if err.Error() == "context canceled" {
			return
		}
		log.WithContext(r.Context()).Error("ErrorHandler ", err)
	}
	//计费
	change := func(resp *http.Response) error {
		if resp.StatusCode != 200 {
			return errors.New(fmt.Sprintf("RespError_%d", GLOBAL_ERR_SERVICE))
		} else if gCtx.RouterRule.Price <= 0 { //免费接口不处理
			return nil
		}
		status := 0
		isCharging := false //是否扣费
		result := ""
		if contentType := resp.Header.Get("content-type"); contentType == "application/json" {
			b, e := ioutil.ReadAll(resp.Body)
			jn := make(map[string]interface{})
			if e != nil {
				log.WithContext(r.Context()).Error("ChangeError", e)
			} else {
				if err := json.Unmarshal(b, &jn); err != nil {
					log.WithContext(r.Context()).Error("ChangeError", err)
				} else if _, ok := jn["error_code"]; !ok {
					log.WithContext(r.Context()).Error("ChangeError：缺少error_code", string(b))
				} else if gconv.Int64(jn["error_code"]) == gconv.Int64(GLOBAL_SUCCESS) {
					if error_msg, _ := jn["error_msg"].(string); error_msg == "" {
						jn["error_msg"] = "请求成功"
						b, _ = json.Marshal(jn)
						resp.Header.Set("content-length", fmt.Sprint(len(b)))
					}
					result = string(b)
					isCharging = true
				} else {
					status = 1
				}
				resp.Body = ioutil.NopCloser(bytes.NewReader(b))
			}
		} else if strings.Contains(resp.Header.Get("Content-Disposition"), "attachment") && resp.ContentLength > 0 { //下载文件
			isCharging = true
			result = fmt.Sprint(resp.ContentLength)
		}
		if isCharging {
			if db.GateWatMySql.ExecTx("计费处理", func(tx *sql.Tx) bool {
				appid := r.GetQuery("appid").String()
				updateRes := db.GateWatMySql.UpdateOrDeleteBySqlByTx(tx, `update user set amount=amount-? where appid=?`, gCtx.RouterRule.Price, appid)
				if updateRes <= 0 {
					log.WithContext(r.Context()).Error(appid, "更新计费失败")
					return false
				}
				datas := db.GateWatMySql.SelectBySqlByTx(tx, `select amount from user where appid=?`, appid)
				if datas == nil || len(*datas) == 0 {
					log.WithContext(r.Context()).Error(appid, "没有找到该账户信息")
					return false
				}
				//余额不足
				amount := gconv.Int64((*datas)[0]["amount"])
				if amount < 0 {
					status = -1
					log.WithContext(r.Context()).Error(appid, "余额不足")
					return false
				}
				logRes1, logRes2 := db.GateWatMySql.InsertBatchByTx(tx, "log", []string{"appid", "url", "param", "result", "price", "surplus", "ip", "create_time"}, []interface{}{appid, gCtx.RouterRule.ReqUrl, string(reqBody), result, gCtx.RouterRule.Price, amount, r.GetClientIp(), gtime.Now().String()})
				if logRes1 <= 0 || logRes2 <= 0 {
					return false
				}
				return true
			}) {
				status = 1
			}
		}
		if status == 0 {
			return errors.New(fmt.Sprintf("RespError_%d", GLOBAL_ERR_SERVICE))
		} else if status == -1 {
			return errors.New(fmt.Sprintf("RespError_%d", GLOBAL_ERR_NOBALANCE))
		}
		return nil
	}
	serverUrl, _ := url.Parse(gCtx.RouterRule.Server)
	// 请求重试，防止某个服务中断不可用，导致接口不可用。
	for i := 0; i < errTryTime; i++ {
		// 代理请求
		proxyClient.CreateCustomProxyClient(serverUrl, errHandel, change).ServeHTTP(r.Response.ResponseWriter, r.Request)
		// 未捕获到请求，标识请求成功
		if !hasErr {
			break
		} else if i == (errTryTime - 1) {
			r.SetError(NewErrorWithCode(GLOBAL_ERR_SERVICE, fmt.Sprintf("远端服务异常：%s", serverUrl.String())))
		}
	}
}