// Hammerhead is the control plane: web UI + API that tells blacktip and bamboo what to do.
package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"net"
	"net/http"
	"os"
	"strconv"
	"time"

	"git.veillax.com/Veillax/hammerhead"
	"git.veillax.com/Veillax/hammerhead/internal/secretbox"
	"git.veillax.com/Veillax/reef/dotenv"
	"git.veillax.com/Veillax/reef/selfupdate"
)

// version is set at build time (deploy/build.sh).
var version = "dev"

// localAddr turns a listen address into one this machine can dial: ":8080" and "0.0.0.0:8080"
// become "127.0.0.1:8080".
func localAddr(listen string) string {
	host, port, err := net.SplitHostPort(listen)
	if err != nil {
		return listen
	}
	if host == "" || host == "0.0.0.0" || host == "::" {
		host = "127.0.0.1"
	}
	return net.JoinHostPort(host, port)
}

func env(k, def string) string {
	if v := os.Getenv(k); v != "" {
		return v
	}
	return def
}

func main() {
	// secrets come from a .env file (or the real environment), read before flags so flags can default to them
	envFile := dotenv.ArgPath(os.Args[1:], ".env")
	if used, err := dotenv.Load(envFile); err != nil {
		log.Fatalf("read %s: %v", envFile, err)
	} else if used != "" {
		log.Printf("loaded settings from %s", used)
	}

	listen := flag.String("listen", env("HAMMERHEAD_LISTEN", ":8080"), "address for the web UI and API")
	data := flag.String("data", env("HAMMERHEAD_DATA", "./hammerhead-data"), "directory for the database")
	url := flag.String("url", env("HAMMERHEAD_URL", ""), "public URL people reach hammerhead at (used for login redirects and SSO); can also be set in Settings")
	flag.String("env", ".env", "file to read secrets and settings from")
	genkey := flag.Bool("genkey", false, "print a new random HAMMERHEAD_MASTER_KEY and exit")
	autoUpdate := flag.Bool("auto-update", os.Getenv("HAMMERHEAD_AUTO_UPDATE") == "1", "check for new releases every few hours and update and restart by itself (Linux and macOS)")
	showVersion := flag.Bool("version", false, "print the version and exit")
	flag.Parse()
	if *showVersion {
		os.Stdout.WriteString("hammerhead " + version + "\n")
		return
	}
	if *genkey {
		fmt.Println(secretbox.GenerateKey())
		return
	}

	days, _ := strconv.Atoi(os.Getenv("HAMMERHEAD_LOG_DAYS"))
	srv, err := hammerhead.New(*data, hammerhead.Options{
		AdminEmail:       os.Getenv("HAMMERHEAD_ADMIN_EMAIL"),
		AdminPassword:    os.Getenv("HAMMERHEAD_ADMIN_PASSWORD"),
		DashboardURL:     *url,
		MasterKey:        os.Getenv("HAMMERHEAD_MASTER_KEY"),
		MetricsToken:     os.Getenv("HAMMERHEAD_METRICS_TOKEN"),
		LogRetentionDays: days,
		SelfDomain:       os.Getenv("HAMMERHEAD_SELF_DOMAIN"),
		SelfTarget:       localAddr(*listen),
		SelfTunnel:       os.Getenv("HAMMERHEAD_SELF_TUNNEL"),
		Version:          version,
		AutoUpdate:       *autoUpdate,
	})
	if err != nil {
		log.Fatal(err)
	}
	defer srv.Close()
	if *autoUpdate {
		go selfupdate.Run(context.Background(), selfupdate.Config{Server: "https://git.veillax.com", Repo: "Veillax/hammerhead", App: "hammerhead", Current: version, Logf: log.Printf, Restart: func(exe string) error { srv.Close(); return selfupdate.Restart(exe) }})
	}
	log.Printf("hammerhead %s listening on %s (open it in a browser to finish setup)", version, *listen)
	hs := &http.Server{Addr: *listen, Handler: srv.Handler(), ReadHeaderTimeout: 10 * time.Second}
	log.Fatal(hs.ListenAndServe())
}