// -
//   ========================LICENSE_START=================================
//   O-RAN-SC
//   %%
//   Copyright (C) 2021: Nordix Foundation
//   %%
//   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.
//   ========================LICENSE_END===================================
//

package main

import (
	"crypto/tls"
	"fmt"
	"net/http"
	"time"

	"github.com/hashicorp/go-retryablehttp"
	log "github.com/sirupsen/logrus"
	"oransc.org/nonrtric/dmaapmediatorproducer/internal/config"
	"oransc.org/nonrtric/dmaapmediatorproducer/internal/jobs"
	"oransc.org/nonrtric/dmaapmediatorproducer/internal/restclient"
	"oransc.org/nonrtric/dmaapmediatorproducer/internal/server"
)

var configuration *config.Config

func init() {
	configuration = config.New()
}

func main() {
	log.SetLevel(configuration.LogLevel)
	log.Debug("Initializing DMaaP Mediator Producer")
	if err := validateConfiguration(configuration); err != nil {
		log.Fatalf("Stopping producer due to error: %v", err)
	}
	callbackAddress := fmt.Sprintf("%v:%v", configuration.InfoProducerHost, configuration.InfoProducerPort)

	var retryClient restclient.HTTPClient
	if cert, err := createClientCertificate(); err == nil {
		retryClient = createRetryClient(cert)
	} else {
		log.Fatalf("Stopping producer due to error: %v", err)
	}

	jobHandler := jobs.NewJobHandlerImpl("configs/type_config.json", retryClient, &http.Client{
		Timeout: time.Second * 5,
	})
	if err := registerTypesAndProducer(jobHandler, configuration.InfoCoordinatorAddress, callbackAddress, retryClient); err != nil {
		log.Fatalf("Stopping producer due to: %v", err)
	}

	log.Debug("Starting DMaaP Mediator Producer")
	go func() {
		log.Debugf("Starting callback server at port %v", configuration.InfoProducerPort)
		r := server.NewRouter(jobHandler)
		log.Fatalf("Server stopped: %v", http.ListenAndServeTLS(fmt.Sprintf(":%v", configuration.InfoProducerPort), configuration.ProducerCertPath, configuration.ProducerKeyPath, r))
	}()

	go jobHandler.RunJobs(configuration.DMaaPMRAddress)

	keepProducerAlive()
}

func validateConfiguration(configuration *config.Config) error {
	if configuration.InfoProducerHost == "" {
		return fmt.Errorf("missing INFO_PRODUCER_HOST")
	}
	if configuration.ProducerCertPath == "" || configuration.ProducerKeyPath == "" {
		return fmt.Errorf("missing PRODUCER_CERT and/or PRODUCER_KEY")
	}
	return nil
}

func createClientCertificate() (*tls.Certificate, error) {
	if cert, err := tls.LoadX509KeyPair(configuration.ProducerCertPath, configuration.ProducerKeyPath); err == nil {
		return &cert, nil
	} else {
		return nil, fmt.Errorf("cannot create x509 keypair from cert file %s and key file %s due to: %v", configuration.ProducerCertPath, configuration.ProducerKeyPath, err)
	}
}

func createRetryClient(cert *tls.Certificate) *http.Client {
	rawRetryClient := retryablehttp.NewClient()
	rawRetryClient.RetryWaitMax = time.Minute
	rawRetryClient.RetryMax = int(^uint(0) >> 1)
	rawRetryClient.HTTPClient.Transport = &http.Transport{
		TLSClientConfig: &tls.Config{
			Certificates: []tls.Certificate{
				*cert,
			},
			InsecureSkipVerify: true,
		},
	}

	return rawRetryClient.StandardClient()
}

func registerTypesAndProducer(jobHandler jobs.JobTypeHandler, infoCoordinatorAddress string, callbackAddress string, client restclient.HTTPClient) error {
	registrator := config.NewRegistratorImpl(infoCoordinatorAddress, client)
	if types, err := jobHandler.GetTypes(); err == nil {
		if regErr := registrator.RegisterTypes(types); regErr != nil {
			return fmt.Errorf("unable to register all types due to: %v", regErr)
		}
	} else {
		return fmt.Errorf("unable to get types to register due to: %v", err)
	}
	producer := config.ProducerRegistrationInfo{
		InfoProducerSupervisionCallbackUrl: callbackAddress + server.StatusPath,
		SupportedInfoTypes:                 jobHandler.GetSupportedTypes(),
		InfoJobCallbackUrl:                 callbackAddress + server.AddJobPath,
	}
	if err := registrator.RegisterProducer("DMaaP_Mediator_Producer", &producer); err != nil {
		return fmt.Errorf("unable to register producer due to: %v", err)
	}
	return nil
}

func keepProducerAlive() {
	forever := make(chan int)
	<-forever
}