/*
   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)
}