refactor: move oauth providers into services (non-working)

internal/service/github_oauth_service.go

@@ -0,0 +1,144 @@
+package service
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"tinyauth/internal/config"
+
+	"golang.org/x/oauth2"
+)
+
+var GithubOAuthScopes = []string{"user:email", "read:user"}
+
+type GithubEmailResponse []struct {
+	Email   string `json:"email"`
+	Primary bool   `json:"primary"`
+}
+
+type GithubUserInfoResponse struct {
+	Login string `json:"login"`
+	Name  string `json:"name"`
+}
+
+type GithubOAuthService struct {
+	Config   oauth2.Config
+	Context  context.Context
+	Token    *oauth2.Token
+	Verifier string
+}
+
+func NewGithubOAuthService(config config.OAuthServiceConfig) *GithubOAuthService {
+	return &GithubOAuthService{
+		Config: oauth2.Config{
+			ClientID:     config.ClientID,
+			ClientSecret: config.ClientSecret,
+			RedirectURL:  config.RedirectURL,
+			Scopes:       GithubOAuthScopes,
+		},
+	}
+}
+
+func (github *GithubOAuthService) Init() error {
+	httpClient := &http.Client{}
+	ctx := context.Background()
+	ctx = context.WithValue(ctx, oauth2.HTTPClient, httpClient)
+	verifier := oauth2.GenerateVerifier()
+
+	github.Context = ctx
+	github.Verifier = verifier
+	return nil
+}
+
+func (github *GithubOAuthService) Name() string {
+	return "github"
+}
+
+func (github *GithubOAuthService) GenerateState() string {
+	b := make([]byte, 128)
+	rand.Read(b)
+	state := base64.URLEncoding.EncodeToString(b)
+	return state
+}
+
+func (github *GithubOAuthService) GetAuthURL(state string) string {
+	return github.Config.AuthCodeURL(state, oauth2.AccessTypeOffline, oauth2.S256ChallengeOption(github.Verifier))
+}
+
+func (github *GithubOAuthService) VerifyCode(code string) error {
+	token, err := github.Config.Exchange(github.Context, code, oauth2.VerifierOption(github.Verifier))
+
+	if err != nil {
+		return nil
+	}
+
+	github.Token = token
+	return nil
+}
+
+func (github *GithubOAuthService) Userinfo() (config.Claims, error) {
+	var user config.Claims
+
+	client := github.Config.Client(github.Context, github.Token)
+
+	res, err := client.Get("https://api.github.com/user")
+	if err != nil {
+		return user, err
+	}
+	defer res.Body.Close()
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return user, err
+	}
+
+	var userInfo GithubUserInfoResponse
+
+	err = json.Unmarshal(body, &userInfo)
+	if err != nil {
+		return user, err
+	}
+
+	res, err = client.Get("https://api.github.com/user/emails")
+	if err != nil {
+		return user, err
+	}
+	defer res.Body.Close()
+
+	body, err = io.ReadAll(res.Body)
+	if err != nil {
+		return user, err
+	}
+
+	var emails GithubEmailResponse
+
+	err = json.Unmarshal(body, &emails)
+	if err != nil {
+		return user, err
+	}
+
+	for _, email := range emails {
+		if email.Primary {
+			user.Email = email.Email
+			break
+		}
+	}
+
+	if len(emails) == 0 {
+		return user, errors.New("no emails found")
+	}
+
+	// Use first available email if no primary email was found
+	if user.Email == "" {
+		user.Email = emails[0].Email
+	}
+
+	user.PreferredUsername = userInfo.Login
+	user.Name = userInfo.Name
+
+	return user, nil
+}