// Copyright © 2019 Banzai Cloud
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package errorresponse

import (
	"net/http"

	"github.com/banzaicloud/telescopes/internal/platform/classifier"
	"github.com/banzaicloud/telescopes/internal/platform/problems"
	"github.com/gin-gonic/gin"
)

// Responder marks responders
type Responder interface {
	// Respond implements the responding logic / it's intended to be self-contained
	Respond(err error)
}

// errorResponder struct in charge for assembling classified error responses
type errorResponder struct {
	errClassifier classifier.Classifier
	gCtx          *gin.Context
}

// Respond assembles the error response corresponding to the passed in error
func (er *errorResponder) Respond(err error) {
	if responseData, e := er.errClassifier.Classify(err); e == nil {
		er.respond(responseData)
		return
	}

	er.gCtx.JSON(http.StatusInternalServerError, problems.NewUnknownProblem(err))
}

// respond sets the response in the gin context
func (er *errorResponder) respond(d interface{}) {
	if pb, ok := d.(*problems.ProblemWrapper); ok {
		er.gCtx.JSON(pb.Status, pb)
		return
	}

	er.gCtx.JSON(http.StatusInternalServerError, problems.NewUnknownProblem(d))
}

// NewErrorResponder configures a new error responder
func NewErrorResponder(ginCtx *gin.Context) Responder {
	return &errorResponder{
		errClassifier: classifier.NewErrorClassifier(),
		gCtx:          ginCtx,
	}
}
