package SwagMock

import (
	"bytes"
	"encoding/json"
	"github.com/gin-gonic/gin"
	"github.com/pkg/errors"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strings"
)

type Options struct {
	Host string
	Port int
}

var generator *StubGenerator

//Swagger Mock 服务初始化【没有使用Middleware Handler 机制】
func Init(r *gin.Engine) {

	generator, _= NewStubGenerator("docs/swagger.json", StubGeneratorOptions{
		Overlay:  "",
		BasePath: "",
	})

	for path,pathItem :=  range generator.spec.Paths.Paths{
		if pathItem.Get !=nil{
			r.GET("/mock" + path, func(c *gin.Context) {
				ValidJsonIn(c.Writer,c.Request)

				MockJsonOut(c.Writer,c.Request)
			})
		}
		if pathItem.Post !=nil{
			r.POST("/mock" + path, func(c *gin.Context) {
				ValidJsonIn(c.Writer,c.Request)

				MockJsonOut(c.Writer,c.Request)
			})
		}
	}
}

//返回Mock Json数据【根据 Swagger Spec】
func MockJsonOut(res http.ResponseWriter, req *http.Request) {
		//获取json文件，如果成功，直接返回json文件内容
		strJson,err:= ioutil.ReadFile("docs" + req.URL.Path + ".json")

		if err ==nil{
			res.Header().Set("Content-Type", "application/json")

			//err = json.NewEncoder(res).Encode(strJson)

			res.Write(strJson)

			return
		}
		//根据Swagger Spec解析，生成随机json内容
		response, err := generator.StubResponse(req.URL.Path[5:], req.Method)

		if err != nil {
			log.Println(errors.Wrap(err, "unable to stub response"))

			http.Error(res, "stub server error - check the logs", http.StatusInternalServerError)

			return
		}
		//使用随机内容，创建json文件，路径为：docs/root_path/api_name.json
		var buf bytes.Buffer

		json.NewEncoder(&buf).Encode(response)

		os.MkdirAll("docs" + req.URL.Path[0:strings.LastIndex(req.URL.Path,"/")],0666)

		err = ioutil.WriteFile("docs" + req.URL.Path + ".json",buf.Bytes(),0666)

		if err != nil {
			log.Println(errors.Wrap(err, "Mock Error: creating json temp file"))
		}

		//返回随机生成的json内容
		res.Header().Set("Content-Type", "application/json")

		err = json.NewEncoder(res).Encode(response)

		if err != nil {
			log.Println(errors.Wrap(err, "unable to serialize generated response stub"))

			http.Error(res, "stub server error - check the logs", http.StatusInternalServerError)

			return
		}
	}

//验证 调用参数是否合法【根据 Swagger Spec】
func ValidJsonIn(res http.ResponseWriter, req *http.Request) {
		switch req.Method {
		case "POST", "GET":
			operation, err := generator.FindOperation(req.URL.Path[5:], req.Method)

			if err != nil {
				log.Println(errors.Wrap(err, "finding operation schema for path and method"))
				break
			}

			err = ValidateConsumes(*operation, *req)
			if err != nil {
				log.Println(errors.Wrap(err, "validating content type header"))
			}

			err = ValidateParameters(*operation, *req)
			if err != nil {
				log.Println(errors.Wrap(err, "validating parameters"))
			}
		}
	}