package main

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

	"git.ryuvia.com/niklas/terdut-server/internal/api"
	"git.ryuvia.com/niklas/terdut-server/internal/config"
	"git.ryuvia.com/niklas/terdut-server/internal/db"
	"git.ryuvia.com/niklas/terdut-server/internal/notify"
)

var version = "dev"

func main() {
	cfg := config.Load()
	if err := cfg.Validate(); err != nil {
		log.Fatalf("config: %v", err)
	}

	database, err := db.Open(cfg.DSN)
	if err != nil {
		log.Fatalf("open db: %v", err)
	}
	defer database.Close()

	if err := db.Migrate(database); err != nil {
		log.Fatalf("migrate: %v", err)
	}

	notifyCfg := api.NotifyConfig{
		Providers:   notifyProviders(cfg),
		Fallback:    notifyFallback(cfg),
		PublicURL:   cfg.PublicURL,
		RepeatEvery: cfg.NotifyRepeat,
	}

	// The behaviour knobs move into the database on first start, after which an
	// administrator owns them and a redeploy leaves them alone.
	if err := api.SeedSettings(context.Background(), database, cfg); err != nil {
		log.Fatalf("seed settings: %v", err)
	}

	if err := api.SeedOperatorKey(context.Background(), database, cfg.OperatorKey); err != nil {
		log.Fatalf("%v", err)
	}

	router := api.NewRouter(database, notifyCfg, cfg, version)

	srv := &http.Server{
		Addr:         cfg.Addr,
		Handler:      router,
		ReadTimeout:  15 * time.Second,
		WriteTimeout: 15 * time.Second,
		IdleTimeout:  60 * time.Second,
	}

	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()

	go api.StartArchiver(ctx, database, cfg.ArchiveAfter, cfg.StaleAfter, notifyCfg)
	go api.StartNotifier(ctx, database, notifyCfg)

	go func() {
		log.Printf("terdut-server %s listening on %s", version, cfg.Addr)
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("listen: %v", err)
		}
	}()

	<-ctx.Done()
	log.Println("shutting down")
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := srv.Shutdown(shutdownCtx); err != nil {
		log.Printf("shutdown: %v", err)
	}
}

// notifyProviders registers the notification providers this install has
// configuration for. A provider with no configuration is simply absent, which is
// what keeps it out of the web UI's list of channel types.
func notifyProviders(cfg config.Config) *notify.Registry {
	var providers []notify.Provider
	if cfg.NtfyURL != "" {
		providers = append(providers, notify.NewNtfy(cfg.NtfyURL, cfg.NtfyToken))
	}
	return notify.NewRegistry(providers...)
}

// notifyFallback is where an incident goes when nobody on call can be reached.
// Only ntfy has a fallback setting today; a second provider adds its own.
func notifyFallback(cfg config.Config) notify.Target {
	if cfg.NtfyURL != "" && cfg.NtfyFallbackTopic != "" {
		return notify.Target{Type: notify.TypeNtfy, Address: cfg.NtfyFallbackTopic}
	}
	return notify.Target{}
}