refactor(backend): switch to DDD

backend/internal/domain/entity.go

@@ -52,7 +52,6 @@ type (
 		Creator   User            `json:"creator"`
 		Notes     pgtype.Text     `json:"notes"`
 		Metadata  json.RawMessage `json:"metadata"`
-		Tags      []TagCore       `json:"tags"`
 		Viewed    int             `json:"viewed"`
 	}
 )

backend/internal/domain/errors.go

@@ -0,0 +1,46 @@
+package domain
+
+type ErrorCode string
+
+const (
+	// File errors
+	ErrFileNotFound     ErrorCode = "FILE_NOT_FOUND"
+	ErrMIMENotSupported ErrorCode = "MIME_NOT_SUPPORTEDF"
+
+	// Tag errors
+	ErrTagNotFound ErrorCode = "TAG_NOT_FOUND"
+
+	// General errors
+	ErrValidation ErrorCode = "VALIDATION_ERROR"
+	ErrInternal   ErrorCode = "INTERNAL_SERVER_ERROR"
+)
+
+type DomainError struct {
+	Err     error     `json:"-"`
+	Code    ErrorCode `json:"code"`
+	Message string    `json:"message"`
+	Details []any     `json:"-"`
+}
+
+func (e *DomainError) Error() string {
+	if e.Err != nil {
+		return e.Message + ": " + e.Err.Error()
+	}
+	return e.Message
+}
+
+func NewDomainError(err error, code ErrorCode, details ...any) *DomainError {
+	return &DomainError{
+		Err:     err,
+		Code:    code,
+		Details: details,
+	}
+}
+
+func NewUnexpectedError(err error) *DomainError {
+	return &DomainError{
+		Err:     err,
+		Code:    ErrInternal,
+		Message: "An unexpected error occured",
+	}
+}

backend/internal/domain/repositories.go

@@ -0,0 +1,16 @@
+package domain
+
+import (
+	"context"
+	"encoding/json"
+	"time"
+)
+
+type FileRepository interface {
+	GetAccess(ctx context.Context, user_id int, file_id string) (canView, canEdit bool, domainErr *DomainError)
+	GetSlice(ctx context.Context, user_id int, filter, sort string, limit, offset int) (files Slice[FileItem], domainErr *DomainError)
+	Get(ctx context.Context, user_id int, file_id string) (file FileFull, domainErr *DomainError)
+	Add(ctx context.Context, user_id int, name, mime string, datetime time.Time, notes string, metadata json.RawMessage) (file FileCore, domainErr *DomainError)
+	Update(ctx context.Context, user_id int, file_id string, updates map[string]interface{}) (domainErr *DomainError)
+	Delete(ctx context.Context, user_id int, file_id string) (domainErr *DomainError)
+}