package wechat

import (
	"crypto/sha1"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"github.com/pkg/errors"
	"io"
	"net/http"
)

type WechatService struct {
	AppId     string
	AppSecret string
	client    *http.Client
}

func NewWechatService(appId, appSecret string) *WechatService {
	return &WechatService{appId, appSecret, nil}
}

func (ws *WechatService) GetOpenID(code string) (string, error) {
	url := fmt.Sprintf(
		"https://api.weixin.qq.com/sns/oauth2/access_token?appid=%s&secret=%s&code=%s&grant_type=authorization_code",
		ws.AppId,
		ws.AppSecret,
		code,
	)
	resp, err := http.Get(url)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	var res struct {
		AccessToken  string `json:"access_token"`
		ExpiresIn    int    `json:"expires_in"`
		RefreshToken string `json:"refresh_token"`
		OpenID       string `json:"openid"`
		Scope        string `json:"scope"`
		ErrCode      int    `json:"errcode"`
		ErrMsg       string `json:"errmsg"`
	}

	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
		return "", errors.New("Failed to decode response")
	}
	fmt.Printf("%+v\n", res)
	if res.ErrCode != 0 {
		return "", errors.New(fmt.Sprintf("WeChat error: %s", res.ErrMsg))
	}

	// 🎯 获取到 openid
	return res.OpenID, nil
}

func (ws *WechatService) GetAccessToken() (string, error) {
	url := fmt.Sprintf("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=%s&secret=%s", ws.AppId, ws.AppSecret)
	resp, err := http.Get(url)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	var result map[string]interface{}
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return "", err
	}

	// 获取 access_token
	accessToken, ok := result["access_token"].(string)
	if !ok {
		return "", errors.New("获取 access_token 失败")
	}

	return accessToken, nil
}

func (ws *WechatService) GetJsapiTicket(accessToken string) (string, error) {
	url := fmt.Sprintf("https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=%s&type=jsapi", accessToken)

	resp, err := http.Get(url)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	var result map[string]interface{}
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return "", err
	}

	// 获取 jsapi_ticket
	jsapiTicket, ok := result["ticket"].(string)
	if !ok {
		return "", errors.New("获取 jsapi_ticket 失败")
	}

	return jsapiTicket, nil
}

func (ws *WechatService) SignWxConfig(signStr string) (string, error) {
	h := sha1.New()
	_, err := io.WriteString(h, signStr)
	if err != nil {
		return "", err
	}
	signature := hex.EncodeToString(h.Sum(nil))
	return signature, nil
}