package main

import (
	"flag"
	"fmt"
	"log"
	"net"
	"os"
	"os/signal"

	leveldb "github.com/jmhodges/levigo"
)

func main() {

	var port int
	var host string
	var cacheSize int

	flag.IntVar(&port, "port", 6379, "port to bind")
	flag.StringVar(&host, "host", "", "host to bind")
	flag.IntVar(&cacheSize, "cache", 32, "cache size in MB")
	flag.Parse()

	args := flag.Args()

	if len(args) < 1 {
		log.Fatal("Missing path to world")
	}

	cache := leveldb.NewLRUCache(cacheSize * 1024 * 1024)
	defer cache.Close()

	opts := leveldb.NewOptions()
	opts.SetCache(cache)
	opts.SetCreateIfMissing(true)

	var err error
	var db *leveldb.DB

	if db, err = leveldb.Open(args[0], opts); err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	var listener net.Listener

	listener, err = net.Listen("tcp", fmt.Sprintf("%s:%d", host, port))
	if err != nil {
		log.Fatal(err)
	}
	defer listener.Close()
	log.Printf("Server started at %s", listener.Addr())

	connChan := make(chan net.Conn)
	defer close(connChan)
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, os.Interrupt, os.Kill)

	go func() {
		for {
			conn, err := listener.Accept()
			if err != nil {
				log.Fatal(err)
			}
			log.Printf("Client accepted from: %s", conn.RemoteAddr())
			connChan <- conn
		}
	}()

	for {
		select {
		case conn := <-connChan:
			go NewConnection(conn, db).Run()
		case <-sigChan:
			log.Println("Shutting down")
			return
		}
	}
}