feat: create oauth broker service

internal/service/oauth_broker_service.go

@@ -0,0 +1,76 @@
+package service
+
+import (
+	"errors"
+	"tinyauth/internal/config"
+
+	"github.com/rs/zerolog/log"
+)
+
+type OAuthService interface {
+	Init() error
+	GenerateState() string
+	GetAuthURL(state string) string
+	VerifyCode(code string) error
+	Userinfo() (config.Claims, error)
+}
+
+type OAuthBrokerService struct {
+	Services map[string]OAuthService
+	Configs  map[string]config.OAuthServiceConfig
+}
+
+func NewOAuthBrokerService(configs map[string]config.OAuthServiceConfig) *OAuthBrokerService {
+	return &OAuthBrokerService{
+		Services: make(map[string]OAuthService),
+		Configs:  configs,
+	}
+}
+
+func (broker *OAuthBrokerService) Init() error {
+	for name, cfg := range broker.Configs {
+		switch name {
+		case "github":
+			service := NewGithubOAuthService(cfg)
+			broker.Services[name] = service
+		case "google":
+			service := NewGoogleOAuthService(cfg)
+			broker.Services[name] = service
+		default:
+			service := NewGenericOAuthService(cfg)
+			broker.Services[name] = service
+		}
+	}
+
+	for name, service := range broker.Services {
+		err := service.Init()
+		if err != nil {
+			log.Error().Err(err).Msgf("Failed to initialize OAuth service: %s", name)
+			return err
+		}
+		log.Info().Msgf("Initialized OAuth service: %s", name)
+	}
+
+	return nil
+}
+
+func (broker *OAuthBrokerService) GetConfiguredServices() []string {
+	services := make([]string, 0, len(broker.Services))
+	for name := range broker.Services {
+		services = append(services, name)
+	}
+	return services
+}
+
+func (broker *OAuthBrokerService) GetService(name string) (OAuthService, bool) {
+	service, exists := broker.Services[name]
+	return service, exists
+}
+
+func (broker *OAuthBrokerService) GetUser(service string) (config.Claims, error) {
+	oauthService, exists := broker.Services[service]
+	if !exists {
+		return config.Claims{}, errors.New("oauth service not found")
+	}
+	return oauthService.Userinfo()
+}