package main

import (
	"flag"
	"log"
	"os"
	"path/filepath"
	"strings"

	"vppn/peer"

	"git.crumpington.com/lib/go/flock"
)

func main() {
	log.SetFlags(0)

	name := flag.String("name", "", "network name (required)")
	hub := flag.String("hub", "", "hub base URL (required)")
	flag.Parse()

	if *name == "" || *hub == "" {
		flag.Usage()
		os.Exit(1)
	}

	apiKey, err := loadAPIKey(*name)
	if err != nil {
		log.Fatalf("api key: %v", err)
	}

	// Directory existence is guaranteed by the apikey file read above.
	lockFile, err := flock.TryLock(vppnPath(*name, "lock"))
	if err != nil {
		log.Fatalf("lock: %v", err)
	}
	if lockFile == nil {
		log.Fatalf("already running for network %q", *name)
	}
	defer flock.Unlock(lockFile)

	state, err := peer.LoadOrInit(vppnPath(*name, "state.json"), *hub, apiKey)
	if err != nil {
		log.Fatalf("init: %v", err)
	}

	ifaceName := strings.TrimSuffix(state.LocalDomain, ".local")
	app, err := peer.New(state, *hub, apiKey, ifaceName, state.LocalDomain, vppnPath(*name, "network.json"))
	if err != nil {
		log.Fatalf("start: %v", err)
	}

	if err := app.Run(); err != nil {
		log.Fatalf("run: %v", err)
	}
}

func loadAPIKey(name string) (string, error) {
	data, err := os.ReadFile(vppnPath(name, "apikey"))
	if err != nil {
		return "", err
	}
	return strings.TrimSpace(string(data)), nil
}

func vppnPath(name, file string) string {
	home, err := os.UserHomeDir()
	if err != nil {
		return filepath.Join(".vppn", name, file)
	}
	return filepath.Join(home, ".vppn", name, file)
}