[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/client/apps/appcreate.go

@@ -0,0 +1,126 @@
+/*
+   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 apps
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/oauth"
+)
+
+// these consts are used to ensure users can't spam huge entries into our database
+const (
+	formFieldLen    = 1024
+	formRedirectLen = 2056
+)
+
+// AppsPOSTHandler swagger:operation POST /api/v1/apps appCreate
+//
+// Register a new application on this instance.
+//
+// The registered application can be used to obtain an application token.
+// This can then be used to register a new account, or (through user auth) obtain an access token.
+//
+// The parameters can also be given in the body of the request, as JSON, if the content-type is set to 'application/json'.
+// The parameters can also be given in the body of the request, as XML, if the content-type is set to 'application/xml'.
+//
+//	---
+//	tags:
+//	- apps
+//
+//	consumes:
+//	- application/json
+//	- application/xml
+//	- application/x-www-form-urlencoded
+//
+//	produces:
+//	- application/json
+//
+//	responses:
+//		'200':
+//			description: "The newly-created application."
+//			schema:
+//				"$ref": "#/definitions/application"
+//		'400':
+//			description: bad request
+//		'401':
+//			description: unauthorized
+//		'403':
+//			description: forbidden
+//		'404':
+//			description: not found
+//		'406':
+//			description: not acceptable
+//		'500':
+//			description: internal server error
+func (m *Module) AppsPOSTHandler(c *gin.Context) {
+	authed, err := oauth.Authed(c, false, false, false, false)
+	if err != nil {
+		apiutil.ErrorHandler(c, gtserror.NewErrorUnauthorized(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	if _, err := apiutil.NegotiateAccept(c, apiutil.JSONAcceptHeaders...); err != nil {
+		apiutil.ErrorHandler(c, gtserror.NewErrorNotAcceptable(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	form := &apimodel.ApplicationCreateRequest{}
+	if err := c.ShouldBind(form); err != nil {
+		apiutil.ErrorHandler(c, gtserror.NewErrorBadRequest(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	if len([]rune(form.ClientName)) > formFieldLen {
+		err := fmt.Errorf("client_name must be less than %d characters", formFieldLen)
+		apiutil.ErrorHandler(c, gtserror.NewErrorBadRequest(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	if len([]rune(form.RedirectURIs)) > formRedirectLen {
+		err := fmt.Errorf("redirect_uris must be less than %d characters", formRedirectLen)
+		apiutil.ErrorHandler(c, gtserror.NewErrorBadRequest(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	if len([]rune(form.Scopes)) > formFieldLen {
+		err := fmt.Errorf("scopes must be less than %d characters", formFieldLen)
+		apiutil.ErrorHandler(c, gtserror.NewErrorBadRequest(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	if len([]rune(form.Website)) > formFieldLen {
+		err := fmt.Errorf("website must be less than %d characters", formFieldLen)
+		apiutil.ErrorHandler(c, gtserror.NewErrorBadRequest(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	apiApp, errWithCode := m.processor.AppCreate(c.Request.Context(), authed, form)
+	if errWithCode != nil {
+		apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGet)
+		return
+	}
+
+	c.JSON(http.StatusOK, apiApp)
+}