package user

import (
	"context"
	"yunyan/pb"
	"yunyan/sys/ipinfo"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"

	"google.golang.org/api/oauth2/v2"
	"google.golang.org/api/option"
)

type (
	FacebookTokenDebugResponse struct {
		Data struct {
			AppID     string   `json:"app_id"`
			IsValid   bool     `json:"is_valid"`
			UserID    string   `json:"user_id"`
			ExpiresAt int64    `json:"expires_at"`
			Scopes    []string `json:"scopes"`
		} `json:"data"`
	}
	WeChatTokenResponse struct {
		AccessToken  string `json:"access_token"`
		ExpiresIn    int    `json:"expires_in"`
		RefreshToken string `json:"refresh_token"`
		OpenID       string `json:"openid"`
		Scope        string `json:"scope"`
	}

	WeChatUserInfoResponse struct {
		OpenID     string `json:"openid"`
		Nickname   string `json:"nickname"`
		HeadImgURL string `json:"headimgurl"`
	}
)

func verifyGoogleIDToken(idToken string) (*oauth2.Tokeninfo, error) {
	ctx := context.Background()

	// 创建 OAuth2 服务
	oauth2Service, err := oauth2.NewService(ctx, option.WithHTTPClient(http.DefaultClient))
	if err != nil {
		return nil, fmt.Errorf("failed to create OAuth2 service: %v", err)
	}

	// 调用 Google 的 Tokeninfo 接口验证 ID Token
	tokenInfo, err := oauth2Service.Tokeninfo().IdToken(idToken).Do()
	if err != nil {
		return nil, fmt.Errorf("invalid ID Token: %v", err)
	}

	// 检查 Token 是否有效
	if tokenInfo.VerifiedEmail != true {
		return nil, fmt.Errorf("email not verified")
	}

	return tokenInfo, nil
}

func verifyFacebookAccessToken(accessToken, facebookAppID, facebookAppSecret string) (string, error) {
	// 调用 Facebook 的 Debug Token 接口
	url := fmt.Sprintf(
		"https://graph.facebook.com/debug_token?input_token=%s&access_token=%s|%s",
		accessToken, facebookAppID, facebookAppSecret,
	)

	resp, err := http.Get(url)
	if err != nil {
		return "", fmt.Errorf("failed to call Facebook API: %v", err)
	}
	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return "", fmt.Errorf("failed to read response body: %v", err)
	}

	// 解析 Facebook 的响应
	var tokenResponse FacebookTokenDebugResponse
	if err := json.Unmarshal(body, &tokenResponse); err != nil {
		return "", fmt.Errorf("failed to parse Facebook response: %v", err)
	}

	// 检查 Token 是否有效
	if !tokenResponse.Data.IsValid {
		return "", fmt.Errorf("token is invalid")
	}

	// 检查 App ID 是否匹配
	if tokenResponse.Data.AppID != facebookAppID {
		return "", fmt.Errorf("invalid app ID")
	}

	// 返回用户 ID
	return tokenResponse.Data.UserID, nil
}

func getWeChatAccessToken(code, wechatAppID, wechatAppSecret string) (*WeChatTokenResponse, error) {
	// 调用微信 API 获取 Access Token
	url := fmt.Sprintf(
		"https://api.weixin.qq.com/sns/oauth2/access_token?appid=%s&secret=%s&code=%s&grant_type=authorization_code",
		wechatAppID, wechatAppSecret, code,
	)

	resp, err := http.Get(url)
	if err != nil {
		return nil, fmt.Errorf("failed to call WeChat API: %v", err)
	}
	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read response body: %v", err)
	}

	// 解析微信的响应
	var tokenResponse WeChatTokenResponse
	if err := json.Unmarshal(body, &tokenResponse); err != nil {
		return nil, fmt.Errorf("failed to parse WeChat response: %v", err)
	}

	return &tokenResponse, nil
}

func getWeChatUserInfo(accessToken, openID string) (*WeChatUserInfoResponse, error) {
	// 调用微信 API 获取用户信息
	url := fmt.Sprintf(
		"https://api.weixin.qq.com/sns/userinfo?access_token=%s&openid=%s",
		accessToken, openID,
	)

	resp, err := http.Get(url)
	if err != nil {
		return nil, fmt.Errorf("failed to call WeChat API: %v", err)
	}
	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read response body: %v", err)
	}

	// 解析微信的响应
	var userInfo WeChatUserInfoResponse
	if err := json.Unmarshal(body, &userInfo); err != nil {
		return nil, fmt.Errorf("failed to parse WeChat response: %v", err)
	}

	return &userInfo, nil
}

// ToRegion 将 IPData 转换为区域枚举
// 优先按特大国家匹配，再按洲级别归类
func ToRegion(d *ipinfo.IPData) pb.Region {
	if d == nil {
		return pb.Region_RegionUnknown
	}

	// 优先匹配特大国家
	switch d.CountryCode {
	case "CN", "HK", "MO":
		return pb.Region_RegionChina
	case "US":
		return pb.Region_RegionUSA
	case "RU":
		return pb.Region_RegionRussia
	case "BR":
		return pb.Region_RegionBrazil
	case "IN":
		return pb.Region_RegionIndia
	}

	// 亚洲内部细分
	if d.ContinentCode == "AS" {
		switch d.CountryCode {
		// 东亚（日韩蒙等）
		case "JP", "KR", "MN", "TW":
			return pb.Region_RegionEastAsia
		// 东南亚
		case "VN", "TH", "MY", "SG", "ID", "PH", "MM", "KH", "LA", "BN", "TL":
			return pb.Region_RegionSoutheastAsia
		// 南亚
		case "PK", "BD", "LK", "NP", "BT", "MV", "AF":
			return pb.Region_RegionSouthAsia
		// 西亚/中东
		case "SA", "AE", "IR", "IQ", "TR", "IL", "JO", "KW", "QA", "BH", "OM",
			"YE", "SY", "LB", "PS", "CY", "GE", "AM", "AZ", "UZ", "KZ", "TM", "TJ", "KG":
			return pb.Region_RegionMiddleEast
		default:
			return pb.Region_RegionEastAsia
		}
	}

	// 按洲归类
	switch d.ContinentCode {
	case "EU":
		return pb.Region_RegionEurope
	case "NA":
		return pb.Region_RegionNorthAmerica
	case "SA":
		return pb.Region_RegionSouthAmerica
	case "AF":
		return pb.Region_RegionAfrica
	case "OC":
		return pb.Region_RegionOceania
	}

	return pb.Region_RegionUnknown
}