package miniProgram

import (
 "errors"
 "fmt"
 "gitee.com/yizhisamoye/GoWeChat/utils"
 "net/http"
 "strings"
 "time"
)

const BaseUrl = "https://api.weixin.qq.com"

type WxMiniProgram struct {
 appId string
 appSecret string
 accessToken string
 expireIn int64
 expireTime *time.Time
 Options map[string]string
}

func NewWxMiniProgram(appId, appSecret string, options ...map[string]string) (*WxMiniProgram, error) {
 if strings.TrimSpace(appId) == "" || strings.TrimSpace(appSecret) == "" {
 return nil, errors.New("")
 }
 mp := new(WxMiniProgram)
 mp.appId = appId
 mp.appSecret = appSecret
 err := mp.FetchAccessToken()
 if len(options) > 0 {
 mp.Options = options[0]
 } else {
 mp.Options = make(map[string]string)
 }
 return mp, err
}

func (mp WxMiniProgram)FetchAccessToken()error{
 url:=fmt.Sprintf(BaseUrl+"/cgi-bin/token?grant_type=client_credential&appid=%s&secret=%s",mp.appId,mp.appSecret)
 resp, err := http.Get(url)
 if err != nil {
 return err
 }
 result, err := utils.CheckWxResp(resp)
 if err != nil {
 return err
 }
 if accessToken, exist := result["access_token"]; exist {
 mp.accessToken = accessToken.(string)
 mp.expireIn = int64(result["expires_in"].(float64))
 expireTime := time.Now()
 expireTime = expireTime.Add(time.Second * time.Duration(mp.expireIn))
 mp.expireTime = &expireTime
 }
 return nil
}

//验证access_token是否有效
func (c WxMiniProgram) IsAccessTokenValid() bool {
 if len(c.accessToken) == 0 {
 return false
 }
 if c.expireTime == nil {
 return false
 }
 if c.expireTime.Before(time.Now()) {
 fmt.Println(c.expireTime)
 return false
 }
 return true
}

//取出access_token,这里专门做成一个返回值的函数,忽略了拉去token的err,主要是为了方便直接使用
func(c *WxMiniProgram) GetAccessToken()string{
 if c.IsAccessTokenValid(){
 return c.accessToken
 }
 err:=c.FetchAccessToken()
 if err!=nil{
 return""
 }
 return c.accessToken
}

func(c *WxMiniProgram)GetAppId()string{
 return c.appId
}