[MM-56073] MMCTL delete post command (#27539)

Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

server/channels/app/file.go

@@ -1594,3 +1594,65 @@ func getFileExtFromMimeType(mimeType string) string {
 	}
 	return "jpg"
 }
+
+func (a *App) PermanentDeleteFilesByPost(rctx request.CTX, postID string) *model.AppError {
+	fileInfos, err := a.Srv().Store().FileInfo().GetForPost(postID, false, true, true)
+	if err != nil {
+		return model.NewAppError("PermanentDeleteFilesByPost", "app.file_info.get_by_post_id.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+	}
+	if len(fileInfos) == 0 {
+		rctx.Logger().Debug("No files found for post", mlog.String("post_id", postID))
+		return nil
+	}
+
+	a.RemoveFilesFromFileStore(rctx, fileInfos)
+
+	err = a.Srv().Store().FileInfo().PermanentDeleteForPost(rctx, postID)
+	if err != nil {
+		return model.NewAppError("PermanentDeleteFilesByPost", "app.file_info.permanent_delete_for_post.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+	}
+
+	a.Srv().Store().FileInfo().InvalidateFileInfosForPostCache(postID, true)
+	a.Srv().Store().FileInfo().InvalidateFileInfosForPostCache(postID, false)
+
+	return nil
+}
+
+func (a *App) RemoveFilesFromFileStore(rctx request.CTX, fileInfos []*model.FileInfo) {
+	for _, info := range fileInfos {
+		a.RemoveFileFromFileStore(rctx, info.Path)
+		if info.PreviewPath != "" {
+			a.RemoveFileFromFileStore(rctx, info.PreviewPath)
+		}
+		if info.ThumbnailPath != "" {
+			a.RemoveFileFromFileStore(rctx, info.ThumbnailPath)
+		}
+	}
+}
+
+func (a *App) RemoveFileFromFileStore(rctx request.CTX, path string) {
+	res, appErr := a.FileExists(path)
+	if appErr != nil {
+		rctx.Logger().Warn(
+			"Error checking existence of file",
+			mlog.String("path", path),
+			mlog.Err(appErr),
+		)
+		return
+	}
+
+	if !res {
+		rctx.Logger().Warn("File not found", mlog.String("path", path))
+		return
+	}
+
+	appErr = a.RemoveFile(path)
+	if appErr != nil {
+		rctx.Logger().Warn(
+			"Unable to remove file",
+			mlog.String("path", path),
+			mlog.Err(appErr),
+		)
+		return
+	}
+}