Add authentication and metrics

internal/auth/auth.go

@@ -0,0 +1,87 @@
+package auth
+
+import (
+	"context"
+	"errors"
+	"github.com/Unkn0wnCat/calapi/internal/ghost"
+	"github.com/Unkn0wnCat/calapi/internal/logger"
+	"github.com/go-chi/chi/middleware"
+	"github.com/spf13/viper"
+	"go.uber.org/zap"
+)
+
+const (
+	AuthTypeGhost = "GHOST"
+	AuthTypeNone  = "NONE"
+)
+
+type User struct {
+	ID       string
+	Username string
+	Name     string
+}
+
+func Authenticate(ctx context.Context, username string, password string) (*User, error) {
+	switch viper.GetString("auth.type") {
+	case AuthTypeGhost:
+		return AuthenticateGhost(ctx, username, password)
+	case AuthTypeNone:
+		logger.Logger.Info("anonymously authenticated",
+			zap.String("requestId", middleware.GetReqID(ctx)),
+		)
+		return &User{
+			ID:       "ANON-NO-AUTH",
+			Username: "anonymous",
+			Name:     "Anonymous User",
+		}, nil
+	default:
+		return nil, errors.New("unknown authentication method")
+	}
+}
+
+func AuthenticateGhost(ctx context.Context, username string, password string) (*User, error) {
+	api := ghost.GhostAPI{
+		BaseURL: viper.GetString("auth.ghost.base_url"),
+		Jar:     nil,
+	}
+
+	_, err := api.Login(username, password)
+	if err != nil {
+		logger.Logger.Warn("invalid ghost credentials",
+			zap.String("requestId", middleware.GetReqID(ctx)),
+			zap.Error(err),
+		)
+		return nil, err
+	}
+
+	ghostUser, err := api.UserSelf()
+	if err != nil {
+		logger.Logger.Error("ghost error",
+			zap.String("requestId", middleware.GetReqID(ctx)),
+			zap.Error(err),
+		)
+		return nil, err
+	}
+
+	if len(ghostUser.Users) == 0 {
+		logger.Logger.Error("unexpected empty response from Ghost API",
+			zap.String("requestId", middleware.GetReqID(ctx)),
+		)
+		return nil, errors.New("unexpected empty response from Ghost API")
+	}
+
+	logger.Logger.Info("ghost authentication success",
+		zap.String("requestId", middleware.GetReqID(ctx)),
+		zap.String("userId", ghostUser.Users[0].ID),
+		zap.String("username", ghostUser.Users[0].Email),
+		zap.Error(err),
+	)
+
+	user := &User{
+		ID:       ghostUser.Users[0].ID,
+		Username: ghostUser.Users[0].Email,
+		Name:     ghostUser.Users[0].Name,
+	}
+
+	return user, nil
+}