// Package server provides functionality to easily set up an HTTTP server.
//
// Clients:
//		Database
package server

import (
	"context"
	"fmt"
	"net/http"
	"os"
	"os/signal"
	"syscall"

	"github.com/gorilla/mux"
	"github.com/kevinmidboe/planetposen-mail/client/sendgrid"
	"github.com/kevinmidboe/planetposen-mail/config"
	log "github.com/sirupsen/logrus"
)

// Server holds the HTTP server, router, config and all clients.
type Server struct {
	Config   *config.Config
	HTTP     *http.Server
	Router   *mux.Router
	SendGrid *sendgrid.Client
}

// Create sets up the HTTP server, router and all clients.
// Returns an error if an error occurs.
func (s *Server) Create(ctx context.Context, config *config.Config) error {
	// metrics.RegisterPrometheusCollectors()

	s.Config = config
	s.Router = mux.NewRouter()
	s.HTTP = &http.Server{
		Addr:    fmt.Sprintf(":%s", s.Config.Port),
		Handler: s.Router,
	}

	var sendGridClient sendgrid.Client
	if err := sendGridClient.Init(config); err != nil {
		return fmt.Errorf("error initializing sendgrid client: %w", err)
	}

	s.SendGrid = &sendGridClient

	s.setupRoutes()

	return nil
}

// Serve tells the server to start listening and serve HTTP requests.
// It also makes sure that the server gracefully shuts down on exit.
// Returns an error if an error occurs.
func (s *Server) Serve(ctx context.Context) error {
	// closer, err := trace.InitGlobalTracer(s.Config)

	// if err != nil {
	// 	return err
	// }

	// defer closer.Close()

	go func(ctx context.Context, s *Server) {
		stop := make(chan os.Signal, 1)
		signal.Notify(stop, os.Interrupt, syscall.SIGTERM)

		<-stop

		log.Info("Shutdown signal received")

		if err := s.HTTP.Shutdown(ctx); err != nil {
			log.Error(err.Error())
		}
	}(ctx, s)

	log.Infof("Ready at: %s", s.Config.Port)

	if err := s.HTTP.ListenAndServe(); err != http.ErrServerClosed {
		log.Fatalf(err.Error())
	}

	return nil
}