snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/channels/app/imports/import_types.go

@@ -0,0 +1,293 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package imports
+
+import (
+	"archive/zip"
+	"encoding/json"
+
+	"github.com/mattermost/mattermost/server/public/model"
+)
+
+// Import Data Models
+
+type LineImportData struct {
+	Type          string                   `json:"type"`
+	Role          *RoleImportData          `json:"role,omitempty"`
+	Scheme        *SchemeImportData        `json:"scheme,omitempty"`
+	Team          *TeamImportData          `json:"team,omitempty"`
+	Channel       *ChannelImportData       `json:"channel,omitempty"`
+	User          *UserImportData          `json:"user,omitempty"`
+	Bot           *BotImportData           `json:"bot,omitempty"`
+	Post          *PostImportData          `json:"post,omitempty"`
+	DirectChannel *DirectChannelImportData `json:"direct_channel,omitempty"`
+	DirectPost    *DirectPostImportData    `json:"direct_post,omitempty"`
+	Emoji         *EmojiImportData         `json:"emoji,omitempty"`
+	Version       *int                     `json:"version,omitempty"`
+	Info          *VersionInfoImportData   `json:"info,omitempty"`
+}
+
+type VersionInfoImportData struct {
+	Generator  string          `json:"generator"`
+	Version    string          `json:"version"`
+	Created    string          `json:"created"`
+	Additional json.RawMessage `json:"additional,omitempty"`
+}
+
+type TeamImportData struct {
+	Name            *string `json:"name"`
+	DisplayName     *string `json:"display_name"`
+	Type            *string `json:"type"`
+	Description     *string `json:"description,omitempty"`
+	AllowOpenInvite *bool   `json:"allow_open_invite,omitempty"`
+	Scheme          *string `json:"scheme,omitempty"`
+}
+
+type ChannelImportData struct {
+	Team        *string            `json:"team"`
+	Name        *string            `json:"name"`
+	DisplayName *string            `json:"display_name"`
+	Type        *model.ChannelType `json:"type"`
+	Header      *string            `json:"header,omitempty"`
+	Purpose     *string            `json:"purpose,omitempty"`
+	Scheme      *string            `json:"scheme,omitempty"`
+	DeletedAt   *int64             `json:"deleted_at,omitempty"`
+}
+
+type Avatar struct {
+	ProfileImage     *string   `json:"profile_image,omitempty"`
+	ProfileImageData *zip.File `json:"-"`
+}
+
+type UserImportData struct {
+	Avatar
+	Username           *string `json:"username"`
+	Email              *string `json:"email"`
+	AuthService        *string `json:"auth_service"`
+	AuthData           *string `json:"auth_data,omitempty"`
+	Password           *string `json:"password,omitempty"`
+	Nickname           *string `json:"nickname"`
+	FirstName          *string `json:"first_name"`
+	LastName           *string `json:"last_name"`
+	Position           *string `json:"position"`
+	Roles              *string `json:"roles"`
+	Locale             *string `json:"locale"`
+	UseMarkdownPreview *string `json:"feature_enabled_markdown_preview,omitempty"`
+	UseFormatting      *string `json:"formatting,omitempty"`
+	ShowUnreadSection  *string `json:"show_unread_section,omitempty"`
+	DeleteAt           *int64  `json:"delete_at,omitempty"`
+
+	SendOnCtrlEnter          *string `json:"send_on_ctrl_enter,omitempty"`
+	CodeBlockCtrlEnter       *string `json:"code_block_ctrl_enter,omitempty"`
+	ShowJoinLeave            *string `json:"show_join_leave,omitempty"`
+	ShowUnreadScrollPosition *string `json:"show_unread_scroll_position,omitempty"`
+	SyncDrafts               *string `json:"sync_drafts,omitempty"`
+	LimitVisibleDmsGms       *string `json:"limit_visible_dms_gms,omitempty"`
+	NameFormat               *string `json:"name_format,omitempty"`
+
+	Teams *[]UserTeamImportData `json:"teams,omitempty"`
+
+	Theme               *string `json:"theme,omitempty"`
+	UseMilitaryTime     *string `json:"military_time,omitempty"`
+	CollapsePreviews    *string `json:"link_previews,omitempty"`
+	MessageDisplay      *string `json:"message_display,omitempty"`
+	CollapseConsecutive *string `json:"collapse_consecutive_messages,omitempty"`
+	ColorizeUsernames   *string `json:"colorize_usernames,omitempty"`
+	ChannelDisplayMode  *string `json:"channel_display_mode,omitempty"`
+	TutorialStep        *string `json:"tutorial_step,omitempty"`
+	EmailInterval       *string `json:"email_interval,omitempty"`
+
+	NotifyProps  *UserNotifyPropsImportData `json:"notify_props,omitempty"`
+	CustomStatus *model.CustomStatus        `json:"custom_status,omitempty"`
+}
+
+type BotImportData struct {
+	Avatar
+	Username    *string `json:"username"`
+	Owner       *string `json:"owner"`
+	DisplayName *string `json:"display_name"`
+	Description *string `json:"description,omitempty"`
+	DeleteAt    *int64  `json:"delete_at,omitempty"`
+}
+
+type UserNotifyPropsImportData struct {
+	Desktop      *string `json:"desktop"`
+	DesktopSound *string `json:"desktop_sound"`
+
+	Email *string `json:"email"`
+
+	Mobile           *string `json:"mobile"`
+	MobilePushStatus *string `json:"mobile_push_status"`
+
+	ChannelTrigger  *string `json:"channel"`
+	CommentsTrigger *string `json:"comments"`
+	MentionKeys     *string `json:"mention_keys"`
+}
+
+type UserTeamImportData struct {
+	Name     *string                  `json:"name"`
+	Roles    *string                  `json:"roles"`
+	Theme    *string                  `json:"theme,omitempty"`
+	Channels *[]UserChannelImportData `json:"channels,omitempty"`
+}
+
+type UserChannelImportData struct {
+	Name               *string                           `json:"name"`
+	Roles              *string                           `json:"roles"`
+	NotifyProps        *UserChannelNotifyPropsImportData `json:"notify_props,omitempty"`
+	Favorite           *bool                             `json:"favorite,omitempty"`
+	MentionCount       *int64                            `json:"mention_count,omitempty"`
+	MentionCountRoot   *int64                            `json:"mention_count_root,omitempty"`
+	UrgentMentionCount *int64                            `json:"urgend_mention_count,omitempty"`
+	MsgCount           *int64                            `json:"msg_count,omitempty"`
+	MsgCountRoot       *int64                            `json:"msg_count_root,omitempty"`
+	LastViewedAt       *int64                            `json:"last_viewed_at,omitempty"`
+}
+
+type DirectChannelMemberImportData struct {
+	Username           *string                           `json:"username"`
+	NotifyProps        *UserChannelNotifyPropsImportData `json:"notify_props,omitempty"`
+	SchemeUser         *bool                             `json:"scheme_user,omitempty"`
+	SchemeAdmin        *bool                             `json:"scheme_admin,omitempty"`
+	SchemeGuest        *bool                             `json:"scheme_guest,omitempty"`
+	MentionCount       *int64                            `json:"mention_count,omitempty"`
+	MentionCountRoot   *int64                            `json:"mention_count_root,omitempty"`
+	UrgentMentionCount *int64                            `json:"urgend_mention_count,omitempty"`
+	MsgCount           *int64                            `json:"msg_count,omitempty"`
+	MsgCountRoot       *int64                            `json:"msg_count_root,omitempty"`
+	LastViewedAt       *int64                            `json:"last_viewed_at,omitempty"`
+}
+
+type UserChannelNotifyPropsImportData struct {
+	Desktop                  *string `json:"desktop"`
+	Mobile                   *string `json:"mobile"`
+	MarkUnread               *string `json:"mark_unread"`
+	Email                    *string `json:"email,omitempty"`
+	IgnoreChannelMentions    *string `json:"ignore_channel_mentions,omitempty"`
+	ChannelAutoFollowThreads *string `json:"channel_auto_follow_threads,omitempty"`
+}
+
+type EmojiImportData struct {
+	Name  *string   `json:"name"`
+	Image *string   `json:"image"`
+	Data  *zip.File `json:"-"`
+}
+
+type ReactionImportData struct {
+	User      *string `json:"user"`
+	CreateAt  *int64  `json:"create_at"`
+	EmojiName *string `json:"emoji_name"`
+}
+
+type ReplyImportData struct {
+	User *string `json:"user"`
+
+	Type     *string                `json:"type"`
+	Message  *string                `json:"message"`
+	Props    *model.StringInterface `json:"props"`
+	CreateAt *int64                 `json:"create_at"`
+	EditAt   *int64                 `json:"edit_at"`
+
+	FlaggedBy   *[]string               `json:"flagged_by,omitempty"`
+	Reactions   *[]ReactionImportData   `json:"reactions,omitempty"`
+	Attachments *[]AttachmentImportData `json:"attachments,omitempty"`
+	IsPinned    *bool                   `json:"is_pinned,omitempty"`
+}
+
+type PostImportData struct {
+	Team    *string `json:"team"`
+	Channel *string `json:"channel"`
+	User    *string `json:"user"`
+
+	Type     *string                `json:"type"`
+	Message  *string                `json:"message"`
+	Props    *model.StringInterface `json:"props"`
+	CreateAt *int64                 `json:"create_at"`
+	EditAt   *int64                 `json:"edit_at"`
+
+	FlaggedBy   *[]string               `json:"flagged_by,omitempty"`
+	Reactions   *[]ReactionImportData   `json:"reactions,omitempty"`
+	Replies     *[]ReplyImportData      `json:"replies,omitempty"`
+	Attachments *[]AttachmentImportData `json:"attachments,omitempty"`
+	IsPinned    *bool                   `json:"is_pinned,omitempty"`
+
+	ThreadFollowers *[]ThreadFollowerImportData `json:"thread_followers,omitempty"`
+}
+
+type DirectChannelImportData struct {
+	Members      *[]string                        `json:"members,omitempty"`
+	Participants []*DirectChannelMemberImportData `json:"participants,omitempty"`
+	FavoritedBy  *[]string                        `json:"favorited_by,omitempty"`
+	ShownBy      *[]string                        `json:"shown_by,omitempty"`
+
+	Header *string `json:"header"`
+}
+
+type DirectPostImportData struct {
+	ChannelMembers *[]string `json:"channel_members"`
+	User           *string   `json:"user"`
+
+	Type     *string                `json:"type"`
+	Message  *string                `json:"message"`
+	Props    *model.StringInterface `json:"props"`
+	CreateAt *int64                 `json:"create_at"`
+	EditAt   *int64                 `json:"edit_at"`
+
+	FlaggedBy   *[]string               `json:"flagged_by,omitempty"`
+	Reactions   *[]ReactionImportData   `json:"reactions"`
+	Replies     *[]ReplyImportData      `json:"replies"`
+	Attachments *[]AttachmentImportData `json:"attachments"`
+	IsPinned    *bool                   `json:"is_pinned,omitempty"`
+
+	ThreadFollowers *[]ThreadFollowerImportData `json:"thread_followers,omitempty"`
+}
+
+type SchemeImportData struct {
+	Name                    *string         `json:"name"`
+	DisplayName             *string         `json:"display_name"`
+	Description             *string         `json:"description"`
+	Scope                   *string         `json:"scope"`
+	DefaultTeamAdminRole    *RoleImportData `json:"default_team_admin_role"`
+	DefaultTeamUserRole     *RoleImportData `json:"default_team_user_role"`
+	DefaultChannelAdminRole *RoleImportData `json:"default_channel_admin_role"`
+	DefaultChannelUserRole  *RoleImportData `json:"default_channel_user_role"`
+	DefaultTeamGuestRole    *RoleImportData `json:"default_team_guest_role"`
+	DefaultChannelGuestRole *RoleImportData `json:"default_channel_guest_role"`
+}
+
+type RoleImportData struct {
+	Name          *string   `json:"name"`
+	DisplayName   *string   `json:"display_name"`
+	Description   *string   `json:"description"`
+	Permissions   *[]string `json:"permissions"`
+	SchemeManaged *bool     `json:"scheme_managed"`
+}
+
+type LineImportWorkerData struct {
+	LineImportData
+	LineNumber int
+}
+
+type LineImportWorkerError struct {
+	Error      *model.AppError
+	LineNumber int
+}
+
+type AttachmentImportData struct {
+	Path *string   `json:"path"`
+	Data *zip.File `json:"-"`
+}
+
+type ComparablePreference struct {
+	Category string
+	Name     string
+}
+
+type ThreadFollowerImportData struct {
+	// User is the username of the follower. It's the general convention
+	// for import data types to name it as user for the username.
+	User           *string `json:"user"`
+	LastViewed     *int64  `json:"last_viewed,omitempty"`
+	UnreadMentions *int64  `json:"unread_mentions,omitempty"`
+}

server/channels/app/imports/import_validators.go

@@ -0,0 +1,884 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package imports
+
+import (
+	"encoding/json"
+	"net/http"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/mlog"
+)
+
+// IsRootJsonlFile reports whether the given zip entry name refers to a .jsonl
+// file at the root of the archive (no directory component). This is used to
+// locate the import manifest while ignoring .jsonl files that may exist as
+// exported attachments in subdirectories.
+func IsRootJsonlFile(name string) bool {
+	return filepath.Ext(name) == ".jsonl" && filepath.Dir(name) == "."
+}
+
+func ValidateSchemeImportData(data *SchemeImportData) *model.AppError {
+	if data.Scope == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_scheme_import_data.null_scope.error", nil, "", http.StatusBadRequest)
+	}
+
+	switch *data.Scope {
+	case model.SchemeScopeTeam:
+		if data.DefaultTeamAdminRole == nil || data.DefaultTeamUserRole == nil || data.DefaultChannelAdminRole == nil || data.DefaultChannelUserRole == nil {
+			return model.NewAppError("BulkImport", "app.import.validate_scheme_import_data.wrong_roles_for_scope.error", nil, "", http.StatusBadRequest)
+		}
+	case model.SchemeScopeChannel:
+		if data.DefaultTeamAdminRole != nil || data.DefaultTeamUserRole != nil || data.DefaultChannelAdminRole == nil || data.DefaultChannelUserRole == nil {
+			return model.NewAppError("BulkImport", "app.import.validate_scheme_import_data.wrong_roles_for_scope.error", nil, "", http.StatusBadRequest)
+		}
+	default:
+		return model.NewAppError("BulkImport", "app.import.validate_scheme_import_data.unknown_scheme.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Name == nil || !model.IsValidSchemeName(*data.Name) {
+		return model.NewAppError("BulkImport", "app.import.validate_scheme_import_data.name_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.DisplayName == nil || *data.DisplayName == "" || len(*data.DisplayName) > model.SchemeDisplayNameMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_scheme_import_data.display_name_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Description != nil && len(*data.Description) > model.SchemeDescriptionMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_scheme_import_data.description_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.DefaultTeamAdminRole != nil {
+		if err := ValidateRoleImportData(data.DefaultTeamAdminRole); err != nil {
+			return err
+		}
+	}
+
+	if data.DefaultTeamUserRole != nil {
+		if err := ValidateRoleImportData(data.DefaultTeamUserRole); err != nil {
+			return err
+		}
+	}
+
+	if data.DefaultTeamGuestRole != nil {
+		if err := ValidateRoleImportData(data.DefaultTeamGuestRole); err != nil {
+			return err
+		}
+	}
+
+	if data.DefaultChannelAdminRole != nil {
+		if err := ValidateRoleImportData(data.DefaultChannelAdminRole); err != nil {
+			return err
+		}
+	}
+
+	if data.DefaultChannelUserRole != nil {
+		if err := ValidateRoleImportData(data.DefaultChannelUserRole); err != nil {
+			return err
+		}
+	}
+
+	if data.DefaultChannelGuestRole != nil {
+		if err := ValidateRoleImportData(data.DefaultChannelGuestRole); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func ValidateRoleImportData(data *RoleImportData) *model.AppError {
+	if data.Name == nil || !model.IsValidRoleName(*data.Name) {
+		return model.NewAppError("BulkImport", "app.import.validate_role_import_data.name_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.DisplayName == nil || *data.DisplayName == "" || len(*data.DisplayName) > model.RoleDisplayNameMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_role_import_data.display_name_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Description != nil && len(*data.Description) > model.RoleDescriptionMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_role_import_data.description_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Permissions != nil {
+		for _, permission := range *data.Permissions {
+			permissionValidated := false
+			for _, p := range append(model.AllPermissions, model.DeprecatedPermissions...) {
+				if permission == p.Id {
+					permissionValidated = true
+					break
+				}
+			}
+
+			if !permissionValidated {
+				return model.NewAppError("BulkImport", "app.import.validate_role_import_data.invalid_permission.error", nil, "permission"+permission, http.StatusBadRequest)
+			}
+		}
+	}
+
+	return nil
+}
+
+func ValidateTeamImportData(data *TeamImportData) *model.AppError {
+	if data.Name == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.name_missing.error", nil, "", http.StatusBadRequest)
+	} else if len(*data.Name) > model.TeamNameMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.name_length.error", nil, "", http.StatusBadRequest)
+	} else if model.IsReservedTeamName(*data.Name) {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.name_reserved.error", nil, "", http.StatusBadRequest)
+	} else if !model.IsValidTeamName(strings.ToLower(*data.Name)) { // uppercase letters are not allowed in team names, but for import path we are more forgiving
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.name_characters.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.DisplayName == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.display_name_missing.error", nil, "", http.StatusBadRequest)
+	} else if utf8.RuneCountInString(*data.DisplayName) == 0 || utf8.RuneCountInString(*data.DisplayName) > model.TeamDisplayNameMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.display_name_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Type == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.type_missing.error", nil, "", http.StatusBadRequest)
+	} else if *data.Type != model.TeamOpen && *data.Type != model.TeamInvite {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.type_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Description != nil && len(*data.Description) > model.TeamDescriptionMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.description_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Scheme != nil && !model.IsValidSchemeName(*data.Scheme) {
+		return model.NewAppError("BulkImport", "app.import.validate_team_import_data.scheme_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+func ValidateChannelImportData(data *ChannelImportData) *model.AppError {
+	if data.Team == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.team_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Name == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.name_missing.error", nil, "", http.StatusBadRequest)
+	} else if len(*data.Name) > model.ChannelNameMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.name_length.error", nil, "", http.StatusBadRequest)
+	} else if !model.IsValidChannelIdentifier(strings.ToLower(*data.Name)) { // uppercase letters are not allowed in channel names, but for import path we are more forgiving
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.name_characters.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.DisplayName == nil || utf8.RuneCountInString(*data.DisplayName) == 0 {
+		data.DisplayName = data.Name // when displayName is missing we use name instead for displaying so we might as well convert it here.
+	} else if utf8.RuneCountInString(*data.DisplayName) > model.ChannelDisplayNameMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.display_name_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Type == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.type_missing.error", nil, "", http.StatusBadRequest)
+	} else if *data.Type != model.ChannelTypeOpen && *data.Type != model.ChannelTypePrivate {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.type_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Header != nil && utf8.RuneCountInString(*data.Header) > model.ChannelHeaderMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.header_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Purpose != nil && utf8.RuneCountInString(*data.Purpose) > model.ChannelPurposeMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.purpose_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Scheme != nil && !model.IsValidSchemeName(*data.Scheme) {
+		return model.NewAppError("BulkImport", "app.import.validate_channel_import_data.scheme_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+func ValidateUserImportData(data *UserImportData) *model.AppError {
+	if data.ProfileImage != nil && data.ProfileImageData == nil {
+		// Check if the resolved path is within the expected base path.
+		if _, valid := ValidateAttachmentPathForImport(*data.ProfileImage, model.ExportDataDir); !valid {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.invalid_image_path.error", map[string]any{"Path": *data.ProfileImage}, "", http.StatusBadRequest)
+		}
+		if _, err := os.Stat(*data.ProfileImage); os.IsNotExist(err) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.profile_image.error", nil, "", http.StatusNotFound).Wrap(err)
+		} else if err != nil {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.profile_image.error", nil, "", http.StatusBadRequest).Wrap(err)
+		}
+	}
+
+	if data.Username == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.username_missing.error", nil, "", http.StatusBadRequest)
+	} else if !model.IsValidUsername(model.NormalizeUsername(*data.Username)) { // we already lowercase the username while saving and querying so we are more forgiving here
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.username_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Email == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.email_missing.error", nil, "", http.StatusBadRequest)
+	} else if *data.Email == "" || len(*data.Email) > model.UserEmailMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.email_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.AuthData != nil && data.Password != nil {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.auth_data_and_password.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.AuthData != nil && len(*data.AuthData) > model.UserAuthDataMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.auth_data_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	blank := func(str *string) bool {
+		if str == nil {
+			return true
+		}
+		return *str == ""
+	}
+
+	if (!blank(data.AuthService) && blank(data.AuthData)) || (blank(data.AuthService) && !blank(data.AuthData)) {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.auth_data_and_service_dependency.error", nil, "", http.StatusBadRequest)
+	}
+
+	if appErr := validateAuthService(data.AuthService); appErr != nil {
+		return appErr
+	}
+
+	if data.Password != nil && *data.Password == "" {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.password_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Password != nil && len(*data.Password) > model.UserPasswordMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.password_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Nickname != nil && utf8.RuneCountInString(*data.Nickname) > model.UserNicknameMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.nickname_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.FirstName != nil && utf8.RuneCountInString(*data.FirstName) > model.UserFirstNameMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.first_name_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.LastName != nil && utf8.RuneCountInString(*data.LastName) > model.UserLastNameMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.last_name_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Position != nil && utf8.RuneCountInString(*data.Position) > model.UserPositionMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.position_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Roles != nil && !model.IsValidUserRoles(*data.Roles) {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.roles_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if err := validateGuestRoles(*data); err != nil {
+		return err
+	}
+
+	if data.NotifyProps != nil {
+		if data.NotifyProps.Desktop != nil && !isValidUserNotifyLevel(*data.NotifyProps.Desktop) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_desktop_invalid.error", nil, "", http.StatusBadRequest)
+		}
+
+		if data.NotifyProps.DesktopSound != nil && !isValidTrueOrFalseString(*data.NotifyProps.DesktopSound) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_desktop_sound_invalid.error", nil, "", http.StatusBadRequest)
+		}
+
+		if data.NotifyProps.Email != nil && !isValidTrueOrFalseString(*data.NotifyProps.Email) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_email_invalid.error", nil, "", http.StatusBadRequest)
+		}
+
+		if data.NotifyProps.Mobile != nil && !isValidUserNotifyLevel(*data.NotifyProps.Mobile) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_mobile_invalid.error", nil, "", http.StatusBadRequest)
+		}
+
+		if data.NotifyProps.MobilePushStatus != nil && !isValidPushStatusNotifyLevel(*data.NotifyProps.MobilePushStatus) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_mobile_push_status_invalid.error", nil, "", http.StatusBadRequest)
+		}
+
+		if data.NotifyProps.ChannelTrigger != nil && !isValidTrueOrFalseString(*data.NotifyProps.ChannelTrigger) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_channel_trigger_invalid.error", nil, "", http.StatusBadRequest)
+		}
+
+		if data.NotifyProps.CommentsTrigger != nil && !isValidCommentsNotifyLevel(*data.NotifyProps.CommentsTrigger) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_comments_trigger_invalid.error", nil, "", http.StatusBadRequest)
+		}
+
+		if data.NotifyProps.MentionKeys != nil && model.MentionKeysExceedLimits(*data.NotifyProps.MentionKeys) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.notify_props_mention_keys_invalid.error",
+				map[string]any{"MaxCount": model.MentionKeysMaxCount, "MaxLength": model.MentionKeysMaxLength}, "", http.StatusBadRequest)
+		}
+	}
+
+	if data.UseMarkdownPreview != nil && !isValidTrueOrFalseString(*data.UseMarkdownPreview) {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.advanced_props_feature_markdown_preview.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.UseFormatting != nil && !isValidTrueOrFalseString(*data.UseFormatting) {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.advanced_props_formatting.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.ShowUnreadSection != nil && !isValidTrueOrFalseString(*data.ShowUnreadSection) {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.advanced_props_show_unread_section.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.EmailInterval != nil && !isValidEmailBatchingInterval(*data.EmailInterval) {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.advanced_props_email_interval.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Teams != nil {
+		return ValidateUserTeamsImportData(data.Teams)
+	}
+
+	return nil
+}
+
+func ValidateBotImportData(data *BotImportData) *model.AppError {
+	if data.ProfileImage != nil && data.ProfileImageData == nil {
+		// Check if the resolved path is within the expected base path.
+		if _, valid := ValidateAttachmentPathForImport(*data.ProfileImage, model.ExportDataDir); !valid {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.invalid_image_path.error", map[string]any{"Path": *data.ProfileImage}, "", http.StatusBadRequest)
+		}
+
+		if _, err := os.Stat(*data.ProfileImage); os.IsNotExist(err) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.profile_image.error", nil, "", http.StatusNotFound).Wrap(err)
+		} else if err != nil {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.profile_image.error", nil, "", http.StatusBadRequest).Wrap(err)
+		}
+	}
+
+	if data.Username == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.username_missing.error", nil, "", http.StatusBadRequest)
+	} else if !model.IsValidUsername(model.NormalizeUsername(*data.Username)) { // we already lowercase the username while saving and querying so we are more forgiving here
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.username_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.DisplayName != nil && utf8.RuneCountInString(*data.DisplayName) > model.UserFirstNameMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.first_name_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Owner == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_bot_import_data.owner_missing.error", nil, "", http.StatusBadRequest)
+	} else if !model.IsValidUsername(*data.Owner) {
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.username_invalid.error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+var validAuthServices = []string{
+	"",
+	model.UserAuthServiceEmail,
+	model.UserAuthServiceGitlab,
+	model.UserAuthServiceSaml,
+	model.UserAuthServiceLdap,
+	model.ServiceGoogle,
+	model.ServiceOffice365,
+	model.ServiceOpenid,
+}
+
+func validateAuthService(authService *string) *model.AppError {
+	if authService == nil {
+		return nil
+	}
+	if slices.Contains(validAuthServices, *authService) {
+		return nil
+	}
+
+	return model.NewAppError("BulkImport", "app.import.validate_user_teams_import_data.invalid_auth_service.error", map[string]any{"AuthService": *authService}, "", http.StatusBadRequest)
+}
+
+func ValidateUserTeamsImportData(data *[]UserTeamImportData) *model.AppError {
+	if data == nil {
+		return nil
+	}
+
+	for _, tdata := range *data {
+		if tdata.Name == nil {
+			return model.NewAppError("BulkImport", "app.import.validate_user_teams_import_data.team_name_missing.error", nil, "", http.StatusBadRequest)
+		}
+
+		if tdata.Roles != nil && !model.IsValidUserRoles(*tdata.Roles) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_teams_import_data.invalid_roles.error", nil, "", http.StatusBadRequest)
+		}
+
+		if tdata.Channels != nil {
+			if err := ValidateUserChannelsImportData(tdata.Channels); err != nil {
+				return err
+			}
+		}
+
+		if tdata.Theme != nil && strings.Trim(*tdata.Theme, " \t\r") != "" {
+			var unused map[string]string
+			if err := json.NewDecoder(strings.NewReader(*tdata.Theme)).Decode(&unused); err != nil {
+				return model.NewAppError("BulkImport", "app.import.validate_user_teams_import_data.invalid_team_theme.error", nil, "", http.StatusBadRequest).Wrap(err)
+			}
+		}
+	}
+
+	return nil
+}
+
+func ValidateUserChannelsImportData(data *[]UserChannelImportData) *model.AppError {
+	if data == nil {
+		return nil
+	}
+
+	for _, cdata := range *data {
+		if cdata.Name == nil {
+			return model.NewAppError("BulkImport", "app.import.validate_user_channels_import_data.channel_name_missing.error", nil, "", http.StatusBadRequest)
+		}
+
+		if cdata.Roles != nil && !model.IsValidUserRoles(*cdata.Roles) {
+			return model.NewAppError("BulkImport", "app.import.validate_user_channels_import_data.invalid_roles.error", nil, "", http.StatusBadRequest)
+		}
+
+		if cdata.NotifyProps != nil {
+			if cdata.NotifyProps.Desktop != nil && !model.IsChannelNotifyLevelValid(*cdata.NotifyProps.Desktop) {
+				return model.NewAppError("BulkImport", "app.import.validate_user_channels_import_data.invalid_notify_props_desktop.error", nil, "", http.StatusBadRequest)
+			}
+
+			if cdata.NotifyProps.Mobile != nil && !model.IsChannelNotifyLevelValid(*cdata.NotifyProps.Mobile) {
+				return model.NewAppError("BulkImport", "app.import.validate_user_channels_import_data.invalid_notify_props_mobile.error", nil, "", http.StatusBadRequest)
+			}
+
+			if cdata.NotifyProps.MarkUnread != nil && !model.IsChannelMarkUnreadLevelValid(*cdata.NotifyProps.MarkUnread) {
+				return model.NewAppError("BulkImport", "app.import.validate_user_channels_import_data.invalid_notify_props_mark_unread.error", nil, "", http.StatusBadRequest)
+			}
+		}
+	}
+
+	return nil
+}
+
+func ValidateReactionImportData(data *ReactionImportData, parentCreateAt int64) *model.AppError {
+	if data.User == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_reaction_import_data.user_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.EmojiName == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_reaction_import_data.emoji_name_missing.error", nil, "", http.StatusBadRequest)
+	} else if utf8.RuneCountInString(*data.EmojiName) > model.EmojiNameMaxLength {
+		return model.NewAppError("BulkImport", "app.import.validate_reaction_import_data.emoji_name_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.CreateAt == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_reaction_import_data.create_at_missing.error", nil, "", http.StatusBadRequest)
+	} else if *data.CreateAt == 0 {
+		return model.NewAppError("BulkImport", "app.import.validate_reaction_import_data.create_at_zero.error", nil, "", http.StatusBadRequest)
+	} else if *data.CreateAt < parentCreateAt {
+		return model.NewAppError("BulkImport", "app.import.validate_reaction_import_data.create_at_before_parent.error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+func ValidateReplyImportData(data *ReplyImportData, parentCreateAt int64, maxPostSize int) *model.AppError {
+	if data.User == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_reply_import_data.user_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Message == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_reply_import_data.message_missing.error", nil, "", http.StatusBadRequest)
+	} else if utf8.RuneCountInString(*data.Message) > maxPostSize {
+		return model.NewAppError("BulkImport", "app.import.validate_reply_import_data.message_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.CreateAt == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_reply_import_data.create_at_missing.error", nil, "", http.StatusBadRequest)
+	} else if *data.CreateAt == 0 {
+		return model.NewAppError("BulkImport", "app.import.validate_reply_import_data.create_at_zero.error", nil, "", http.StatusBadRequest)
+	} else if *data.CreateAt < parentCreateAt {
+		mlog.Warn("Reply CreateAt is before parent post CreateAt", mlog.Int("reply_create_at", *data.CreateAt), mlog.Int("parent_create_at", parentCreateAt))
+	}
+
+	if data.Props != nil && utf8.RuneCountInString(model.StringInterfaceToJSON(*data.Props)) > model.PostPropsMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.props_too_large.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Reactions != nil {
+		for _, reaction := range *data.Reactions {
+			if err := ValidateReactionImportData(&reaction, *data.CreateAt); err != nil {
+				return err
+			}
+		}
+	}
+
+	if data.Attachments != nil {
+		for _, attachment := range *data.Attachments {
+			if err := ValidateAttachmentImportData(&attachment); err != nil {
+				return model.NewAppError("BulkImport", "app.import.validate_reply_import_data.attachment.error", nil, "", http.StatusNotFound).Wrap(err)
+			}
+		}
+	}
+
+	return nil
+}
+
+func ValidatePostImportData(data *PostImportData, maxPostSize int) *model.AppError {
+	if data.Team == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.team_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Channel == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.channel_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.User == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.user_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Message == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.message_missing.error", nil, "", http.StatusBadRequest)
+	} else if utf8.RuneCountInString(*data.Message) > maxPostSize {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.message_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.CreateAt == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.create_at_missing.error", nil, "", http.StatusBadRequest)
+	} else if *data.CreateAt == 0 {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.create_at_zero.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Reactions != nil {
+		for _, reaction := range *data.Reactions {
+			if err := ValidateReactionImportData(&reaction, *data.CreateAt); err != nil {
+				return err
+			}
+		}
+	}
+
+	if data.Replies != nil {
+		for _, reply := range *data.Replies {
+			if err := ValidateReplyImportData(&reply, *data.CreateAt, maxPostSize); err != nil {
+				return err
+			}
+		}
+	}
+
+	if data.Props != nil && utf8.RuneCountInString(model.StringInterfaceToJSON(*data.Props)) > model.PostPropsMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_post_import_data.props_too_large.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Attachments != nil {
+		for _, attachment := range *data.Attachments {
+			if err := ValidateAttachmentImportData(&attachment); err != nil {
+				return model.NewAppError("BulkImport", "app.import.validate_post_import_data.attachment.error", nil, "", http.StatusNotFound).Wrap(err)
+			}
+		}
+	}
+
+	if data.ThreadFollowers != nil {
+		for _, follower := range *data.ThreadFollowers {
+			if err := ValidateThreadFollowerImportData(&follower); err != nil {
+				return model.NewAppError("BulkImport", "app.import.validate_post_import_data.thread_follower.error", nil, "", http.StatusBadRequest).Wrap(err)
+			}
+		}
+	}
+
+	return nil
+}
+
+func ValidateDirectChannelImportData(data *DirectChannelImportData) *model.AppError {
+	if data.Participants == nil && data.Members == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_channel_import_data.members_required.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Participants != nil && len(data.Participants) != 2 {
+		if len(data.Participants) < model.ChannelGroupMinUsers {
+			return model.NewAppError("BulkImport", "app.import.validate_direct_channel_import_data.members_too_few.error", nil, "", http.StatusBadRequest)
+		} else if len(data.Participants) > model.ChannelGroupMaxUsers {
+			return model.NewAppError("BulkImport", "app.import.validate_direct_channel_import_data.members_too_many.error", nil, "", http.StatusBadRequest)
+		}
+	}
+
+	if data.Members != nil && len(*data.Members) != 2 {
+		if len(*data.Members) < model.ChannelGroupMinUsers {
+			return model.NewAppError("BulkImport", "app.import.validate_direct_channel_import_data.members_too_few.error", nil, "", http.StatusBadRequest)
+		} else if len(*data.Members) > model.ChannelGroupMaxUsers {
+			return model.NewAppError("BulkImport", "app.import.validate_direct_channel_import_data.members_too_many.error", nil, "", http.StatusBadRequest)
+		}
+	}
+
+	if data.Header != nil && utf8.RuneCountInString(*data.Header) > model.ChannelHeaderMaxRunes {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_channel_import_data.header_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.FavoritedBy != nil {
+		for _, favoriter := range *data.FavoritedBy {
+			found := false
+			for _, member := range data.Participants {
+				if favoriter == *member.Username {
+					found = true
+					break
+				}
+			}
+			if data.Members != nil {
+				if slices.Contains(*data.Members, favoriter) {
+					found = true
+				}
+			}
+			if !found {
+				return model.NewAppError("BulkImport", "app.import.validate_direct_channel_import_data.unknown_favoriter.error", map[string]any{"Username": favoriter}, "", http.StatusBadRequest)
+			}
+		}
+	}
+
+	return nil
+}
+
+func ValidateDirectPostImportData(data *DirectPostImportData, maxPostSize int) *model.AppError {
+	if data.ChannelMembers == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.channel_members_required.error", nil, "", http.StatusBadRequest)
+	}
+
+	if len(*data.ChannelMembers) != 2 {
+		if len(*data.ChannelMembers) < model.ChannelGroupMinUsers {
+			return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.channel_members_too_few.error", nil, "", http.StatusBadRequest)
+		} else if len(*data.ChannelMembers) > model.ChannelGroupMaxUsers {
+			return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.channel_members_too_many.error", nil, "", http.StatusBadRequest)
+		}
+	}
+
+	if data.User == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.user_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Message == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.message_missing.error", nil, "", http.StatusBadRequest)
+	} else if utf8.RuneCountInString(*data.Message) > maxPostSize {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.message_length.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.CreateAt == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.create_at_missing.error", nil, "", http.StatusBadRequest)
+	} else if *data.CreateAt == 0 {
+		return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.create_at_zero.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.FlaggedBy != nil {
+		for _, flagger := range *data.FlaggedBy {
+			found := slices.Contains(*data.ChannelMembers, flagger)
+			if !found {
+				return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.unknown_flagger.error", map[string]any{"Username": flagger}, "", http.StatusBadRequest)
+			}
+		}
+	}
+
+	if data.Reactions != nil {
+		for _, reaction := range *data.Reactions {
+			if err := ValidateReactionImportData(&reaction, *data.CreateAt); err != nil {
+				return err
+			}
+		}
+	}
+
+	if data.Replies != nil {
+		for _, reply := range *data.Replies {
+			if err := ValidateReplyImportData(&reply, *data.CreateAt, maxPostSize); err != nil {
+				return err
+			}
+		}
+	}
+
+	if data.Attachments != nil {
+		for _, attachment := range *data.Attachments {
+			if err := ValidateAttachmentImportData(&attachment); err != nil {
+				return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.attachment.error", nil, "", http.StatusNotFound).Wrap(err)
+			}
+		}
+	}
+
+	if data.ThreadFollowers != nil {
+		for _, follower := range *data.ThreadFollowers {
+			if err := ValidateThreadFollowerImportData(&follower); err != nil {
+				return model.NewAppError("BulkImport", "app.import.validate_direct_post_import_data.thread_follower.error", nil, "", http.StatusBadRequest).Wrap(err)
+			}
+		}
+	}
+
+	return nil
+}
+
+// ValidateEmojiImportData validates emoji data and returns if the import name
+// conflicts with a system emoji.
+func ValidateEmojiImportData(data *EmojiImportData) *model.AppError {
+	if data == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_emoji_import_data.empty.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Name == nil || *data.Name == "" {
+		return model.NewAppError("BulkImport", "app.import.validate_emoji_import_data.name_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.Image == nil || *data.Image == "" {
+		return model.NewAppError("BulkImport", "app.import.validate_emoji_import_data.image_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	// Check if the resolved path is within the expected base path.
+	if _, valid := ValidateAttachmentPathForImport(*data.Image, model.ExportDataDir); !valid {
+		return model.NewAppError("BulkImport", "app.import.validate_emoji_import_data.invalid_image_path.error", map[string]any{"Path": *data.Image}, "", http.StatusBadRequest)
+	}
+
+	if err := model.IsValidEmojiName(*data.Name); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func ValidateThreadFollowerImportData(data *ThreadFollowerImportData) *model.AppError {
+	if data == nil {
+		return model.NewAppError("BulkImport", "app.import.validate_thread_follower_data.empty.error", nil, "", http.StatusBadRequest)
+	}
+
+	if data.User == nil || *data.User == "" {
+		return model.NewAppError("BulkImport", "app.import.validate_thread_follower_data.user_missing.error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+func isValidTrueOrFalseString(value string) bool {
+	return value == "true" || value == "false"
+}
+
+func isValidUserNotifyLevel(notifyLevel string) bool {
+	return notifyLevel == model.ChannelNotifyAll ||
+		notifyLevel == model.ChannelNotifyMention ||
+		notifyLevel == model.ChannelNotifyNone
+}
+
+func isValidPushStatusNotifyLevel(notifyLevel string) bool {
+	return notifyLevel == model.StatusOnline ||
+		notifyLevel == model.StatusAway ||
+		notifyLevel == model.StatusOffline
+}
+
+func isValidCommentsNotifyLevel(notifyLevel string) bool {
+	return notifyLevel == model.CommentsNotifyAny ||
+		notifyLevel == model.CommentsNotifyRoot ||
+		notifyLevel == model.CommentsNotifyNever
+}
+
+func isValidEmailBatchingInterval(emailInterval string) bool {
+	return emailInterval == model.PreferenceEmailIntervalImmediately ||
+		emailInterval == model.PreferenceEmailIntervalFifteen ||
+		emailInterval == model.PreferenceEmailIntervalHour
+}
+
+// validateGuestRoles checks if the user has guest roles consistently across system, team, and channel levels.
+// At this point, we assume that the user has a valid role scheme.
+func validateGuestRoles(data UserImportData) *model.AppError {
+	if data.Roles == nil {
+		return nil
+	}
+	isSystemGuest := model.IsInRole(*data.Roles, model.SystemGuestRoleId)
+
+	// If user has no teams, they can still be a system guest without issue
+	if data.Teams == nil || len(*data.Teams) == 0 {
+		return nil
+	}
+
+	var isTeamGuest, isChannelGuest bool
+	var hasChannels bool // hasChannels indicates if the user has any channels within their teams
+
+	var teamGuestCount, channelGuestCount int
+	var totalTeams, totalChannels int
+
+	totalTeams = len(*data.Teams)
+	for _, team := range *data.Teams {
+		if team.Roles != nil && model.IsInRole(*team.Roles, model.TeamGuestRoleId) {
+			teamGuestCount++
+		}
+
+		if len(model.SafeDereference(team.Channels)) > 0 {
+			hasChannels = true
+			totalChannels += len(*team.Channels)
+
+			for _, channel := range *team.Channels {
+				if channel.Roles != nil && model.IsInRole(*channel.Roles, model.ChannelGuestRoleId) {
+					channelGuestCount++
+				}
+			}
+		}
+	}
+
+	// Set flags based on whether all available teams/channels have guest roles
+	if totalTeams > 0 && teamGuestCount == totalTeams {
+		isTeamGuest = true
+	}
+
+	if hasChannels && channelGuestCount == totalChannels {
+		isChannelGuest = true
+	}
+
+	// If the user is a system guest, they must have consistent guest roles in any teams/channels they belong to
+	if isSystemGuest {
+		// If they have teams, they must be a team guest in all teams
+		if totalTeams > 0 && !isTeamGuest {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.system_guest_missing_team_guest_roles.error", map[string]any{"TeamGuestCount": teamGuestCount, "TotalTeams": totalTeams}, "", http.StatusBadRequest)
+		}
+
+		// If they have channels, they must be a channel guest in all channels
+		if hasChannels && !isChannelGuest {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.system_guest_missing_channel_guest_roles.error", map[string]any{"ChannelGuestCount": channelGuestCount, "TotalChannels": totalChannels}, "", http.StatusBadRequest)
+		}
+
+		return nil
+	}
+
+	// If not a system guest, ensure consistency in the other direction
+	// If they're a team or channel guest, they must be a system guest
+	if (isTeamGuest || isChannelGuest) && !isSystemGuest {
+		if isTeamGuest {
+			return model.NewAppError("BulkImport", "app.import.validate_user_import_data.team_guest_missing_system_guest_role.error", nil, "", http.StatusBadRequest)
+		}
+		return model.NewAppError("BulkImport", "app.import.validate_user_import_data.channel_guest_missing_system_guest_role.error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+// ValidateAttachmentPathForImport joins 'path' to 'basePath' (defaulting to "." if empty) and ensures
+// the result does not escape the base directory. Returns the cleaned joined path (and true),
+// or an empty string (and false) if the result escapes the base.
+func ValidateAttachmentPathForImport(path, basePath string) (string, bool) {
+	if basePath == "" {
+		basePath = "."
+	}
+
+	joined := filepath.Join(basePath, path)
+
+	// Check if the resolved joined path is within basePath
+	rel, err := filepath.Rel(basePath, joined)
+	if err != nil {
+		return "", false
+	}
+	if strings.HasPrefix(rel, ".."+string(filepath.Separator)) || rel == ".." {
+		return "", false
+	}
+
+	return joined, true
+}
+
+func ValidateAttachmentImportData(data *AttachmentImportData) *model.AppError {
+	if data == nil {
+		return nil
+	}
+
+	if data.Path == nil || *data.Path == "" {
+		return nil
+	}
+
+	// Check if the resolved path is within the expected base path.
+	if _, valid := ValidateAttachmentPathForImport(*data.Path, model.ExportDataDir); !valid {
+		return model.NewAppError("BulkImport", "app.import.validate_attachment_import_data.invalid_path.error", map[string]any{"Path": *data.Path}, "", http.StatusBadRequest)
+	}
+
+	return nil
+}