Initial commit: Open sourcing all of the Maple Open Technologies code.

cloud/maplefile-backend/internal/usecase/user/getbyid.go

@@ -0,0 +1,95 @@
+// codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/usecase/user/getbyid.go
+package user
+
+import (
+	"context"
+	"errors"
+
+	"go.uber.org/zap"
+
+	"github.com/gocql/gocql"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/config"
+	dom_user "codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/domain/user"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/httperror"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/validation"
+)
+
+type UserGetByIDUseCase interface {
+	Execute(ctx context.Context, id gocql.UUID) (*dom_user.User, error)
+}
+
+type userGetByIDUseCaseImpl struct {
+	config *config.Configuration
+	logger *zap.Logger
+	repo   dom_user.Repository
+}
+
+func NewUserGetByIDUseCase(config *config.Configuration, logger *zap.Logger, repo dom_user.Repository) UserGetByIDUseCase {
+	logger = logger.Named("UserGetByIDUseCase")
+
+	// Defensive check: ensure dependencies are not nil
+	if config == nil {
+		panic("config cannot be nil")
+	}
+	if logger == nil {
+		panic("logger cannot be nil")
+	}
+	if repo == nil {
+		panic("repository cannot be nil")
+	}
+
+	return &userGetByIDUseCaseImpl{
+		config: config,
+		logger: logger,
+		repo:   repo,
+	}
+}
+
+func (uc *userGetByIDUseCaseImpl) Execute(ctx context.Context, id gocql.UUID) (*dom_user.User, error) {
+	// Defensive check: ensure use case was properly initialized
+	if uc.repo == nil {
+		uc.logger.Error("repository is nil - use case was not properly initialized")
+		return nil, errors.New("internal error: repository not available")
+	}
+
+	//
+	// STEP 1: Validation.
+	//
+
+	e := make(map[string]string)
+	if id.String() == "" {
+		e["id"] = "missing value"
+	}
+	if len(e) != 0 {
+		uc.logger.Warn("Validation failed for get by ID",
+			zap.Any("error", e),
+			zap.String("id", id.String()))
+		return nil, httperror.NewForBadRequest(&e)
+	}
+
+	//
+	// STEP 2: Get from database.
+	//
+
+	uc.logger.Debug("Getting user by ID",
+		zap.String("user_id", id.String()))
+
+	user, err := uc.repo.GetByID(ctx, id)
+	if err != nil {
+		uc.logger.Error("Failed to get user from repository",
+			zap.String("user_id", id.String()),
+			zap.Any("error", err))
+		return nil, err
+	}
+
+	if user != nil {
+		uc.logger.Debug("Successfully retrieved user",
+			zap.String("user_id", id.String()),
+			zap.String("email", validation.MaskEmail(user.Email)))
+	} else {
+		uc.logger.Debug("User not found",
+			zap.String("user_id", id.String()))
+	}
+
+	return user, nil
+}