package oauth

import (
	"context"
	"encoding/json"
	"errors"
	"log"
	"recipe-manager/config"
	"recipe-manager/helpers"
	"recipe-manager/models"

	"golang.org/x/oauth2"
)

type OAuthService interface {
	AuthURL(state string, stateMap map[string]string) string
	GetState(state string) (map[string]string, bool)
	RemoveState(state string)
	Exchange(ctx context.Context, code string) (*oauth2.Token, error)
	GetUserInfo(ctx context.Context, token *oauth2.Token) (*models.User, error)
	RefreshToken(ctx context.Context, token *oauth2.Token) (*oauth2.Token, error)
}

type oauthService struct {
	cfg     *config.ServerConfig
	gConfig *oauth2.Config
	nonce   map[string]map[string]string
}

func NewOAuthService(cfg *config.ServerConfig) OAuthService {

	clientSecret, err := helpers.GetClientSecret("client_secret.json")

	if err != nil {
		log.Fatalf("Unable to get client secret: %v", err)
	}

	clientSecret.RedirectURL = cfg.ServerDomain + "/auth/google/callback"

	return &oauthService{
		cfg:     cfg,
		gConfig: clientSecret,
		nonce:   make(map[string]map[string]string),
	}
}

func (o *oauthService) AuthURL(state string, stateMap map[string]string) string {

	if stateMap != nil {
		o.nonce[state] = stateMap
	} else {
		o.nonce[state] = make(map[string]string)
	}

	authCodeOptions := []oauth2.AuthCodeOption{
		// oauth2.SetAuthURLParam("hd", "forth.co.th"),
		oauth2.SetAuthURLParam("include_granted_scopes", "true"),
		oauth2.AccessTypeOffline,
	}

	return o.gConfig.AuthCodeURL(state, authCodeOptions...)
}

func (o *oauthService) GetState(state string) (map[string]string, bool) {
	val, ok := o.nonce[state]
	return val, ok
}

func (o *oauthService) RemoveState(state string) {
	delete(o.nonce, state)
}

func (o *oauthService) Exchange(ctx context.Context, code string) (*oauth2.Token, error) {

	return o.gConfig.Exchange(ctx, code)
}

func (o *oauthService) GetUserInfo(ctx context.Context, token *oauth2.Token) (*models.User, error) {
	client := o.gConfig.Client(ctx, token)
	resp, err := client.Get("https://www.googleapis.com/oauth2/v3/userinfo")
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

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

	if userInfo["error"] != nil {
		return nil, errors.New("error getting user info")
	}

	return &models.User{
		Name:    userInfo["name"].(string),
		Email:   userInfo["email"].(string),
		Picture: userInfo["picture"].(string),
	}, nil
}

func (o *oauthService) RefreshToken(ctx context.Context, token *oauth2.Token) (*oauth2.Token, error) {
	return o.gConfig.TokenSource(ctx, token).Token()
}