[chore] The Big Middleware and API Refactor (tm) (#1250)

* interim commit: start refactoring middlewares into package under router

* another interim commit, this is becoming a big job

* another fucking massive interim commit

* refactor bookmarks to new style

* ambassador, wiz zeze commits you are spoiling uz

* she compiles, we're getting there

* we're just normal men; we're just innocent men

* apiutil

* whoopsie

* i'm glad noone reads commit msgs haha :blob_sweat:

* use that weirdo go-bytesize library for maxMultipartMemory

* fix media module paths

internal/api/fileserver.go

@@ -0,0 +1,55 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package api
+
+import (
+	"github.com/superseriousbusiness/gotosocial/internal/api/fileserver"
+	"github.com/superseriousbusiness/gotosocial/internal/middleware"
+	"github.com/superseriousbusiness/gotosocial/internal/processing"
+	"github.com/superseriousbusiness/gotosocial/internal/router"
+)
+
+type Fileserver struct {
+	fileserver *fileserver.Module
+}
+
+func (f *Fileserver) Route(r router.Router) {
+	fileserverGroup := r.AttachGroup("fileserver")
+
+	// attach middlewares appropriate for this group
+	fileserverGroup.Use(
+		middleware.RateLimit(),
+		// Since we'll never host different files at the same
+		// URL (bc the ULIDs are generated per piece of media),
+		// it's sensible and safe to use a long cache here, so
+		// that clients don't keep fetching files over + over again.
+		//
+		// Nevertheless, we should use 'private' to indicate
+		// that there might be media in there which are gated by ACLs.
+		middleware.CacheControl("private", "max-age=604800"),
+	)
+
+	f.fileserver.Route(fileserverGroup.Handle)
+}
+
+func NewFileserver(p processing.Processor) *Fileserver {
+	return &Fileserver{
+		fileserver: fileserver.New(p),
+	}
+}