package main

import (
	"context"
	"errors"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"

	"github.com/prometheus/client_golang/prometheus/promhttp"

	"ocspcrl/internal/metrics"
)

func startServer(server *http.Server, label string) <-chan struct{} {
	closed := make(chan struct{})
	go func() {
		log.Printf("starting %s server on %+q", label, server.Addr)
		if listenError := server.ListenAndServe(); !errors.Is(listenError, http.ErrServerClosed) {
			log.Printf("%s server error: %v", label, listenError)
		}
		close(closed)
	}()
	return closed
}

func main() {
	log.SetFlags(log.Lshortfile)
	config := parseConfiguration(os.Args[1:])

	cas, discoverError := discoverCas(config.casDirectory)
	if discoverError != nil {
		log.Fatalf("failed to load cas: %v", discoverError)
	}

	applicationRouter := buildApplicationRouter(cas)

	terminationChan := make(chan os.Signal, 1)
	signal.Notify(terminationChan, syscall.SIGINT, syscall.SIGTERM)

	hupChan := make(chan os.Signal, 1)
	signal.Notify(hupChan, syscall.SIGHUP)
	go runReloadWorker(hupChan, cas)

	applicationServer := &http.Server{Addr: config.applicationListenAddress, Handler: metrics.Middleware(applicationRouter)}
	metricsServer := &http.Server{Addr: config.metricsListenAddress, Handler: promhttp.Handler()}

	applicationServerClosed := startServer(applicationServer, "application")
	metricsServerClosed := startServer(metricsServer, "metrics")

	<-terminationChan
	close(hupChan)
	applicationServer.Shutdown(context.TODO())
	metricsServer.Shutdown(context.TODO())
	<-applicationServerClosed
	<-metricsServerClosed
}