package server

import (
	//  "io"
	"net"
	//  "errors"
	"fmt"
	"math/rand"
	"os"
	"path/filepath"
	"runtime"
	"time"

	"github.com/beoran/woe/monolog"
	"github.com/beoran/woe/world"
)

var MSSP map[string]string

const STATUS_OK = 0
const STATUS_CANNOT_LISTEN = 1
const STATUS_RESTART = 0
const STATUS_SHUTDOWN = 4
const MAX_CLIENTS = 1000

func init() {
	MSSP = map[string]string{
		"NAME":             "Workers Of Eruta",
		"UPTIME":           string(time.Now().Unix()),
		"PLAYERS":          "0",
		"CRAWL DELAY":      "0",
		"CODEBASE":         "WOE",
		"CONTACT":          "beoran@gmail.com",
		"CREATED":          "2015",
		"ICON":             "None",
		"LANGUAGE":         "English",
		"LOCATION":         "USA",
		"MINIMUM AGE":      "18",
		"WEBSITE":          "beoran.net",
		"FAMILY":           "Custom",
		"GENRE":            "Science Fiction",
		"GAMEPLAY":         "Adventure",
		"STATUS":           "Alpha",
		"GAMESYSTEM":       "Custom",
		"INTERMUD":         "",
		"SUBGENRE":         "None",
		"AREAS":            "0",
		"HELPFILES":        "0",
		"MOBILES":          "0",
		"OBJECTS":          "0",
		"ROOMS":            "1",
		"CLASSES":          "0",
		"LEVELS":           "0",
		"RACES":            "3",
		"SKILLS":           "900",
		"ANSI":             "1",
		"MCCP":             "1",
		"MCP":              "0",
		"MSDP":             "0",
		"MSP":              "0",
		"MXP":              "0",
		"PUEBLO":           "0",
		"UTF-8":            "1",
		"VT100":            "1",
		"XTERM 255 COLORS": "1",
		"PAY TO PLAY":      "0",
		"PAY FOR PERKS":    "0",
		"HIRING BUILDERS":  "0",
		"HIRING CODERS":    "0"}
}

type Server struct {
	address    string
	listener   net.Listener
	clients    map[int]*Client
	tickers    map[string]*Ticker
	alive      bool
	World      *world.World
	exitstatus int
}

type Ticker struct {
	*time.Ticker
	Server       *Server
	Name         string
	Milliseconds int
	callback     func(me *Ticker, t time.Time) (stop bool)
}

const DEFAULT_MOTD_OK = `
###############################
#       Workers Of Eruta      # 
###############################

`

const DEFAULT_MOTD = `
Welcome!
`

func (me *Server) SetupWorld() (err error) {
	me.World, err = world.LoadWorld(me.DataPath(), "WOE")

	if err != nil {
		monolog.Error("Could not load world WOE: %s", err)
		return err
	}

	if me.World == nil {
		monolog.Info("Creating new default world...")
		me.World = world.NewWorld("WOE", DEFAULT_MOTD, me.DataPath())
		err := me.World.Save(me.DataPath())
		if err != nil {
			monolog.Error("Could not save world: %v", err)
			return err
		} else {
			monolog.Info("Saved default world.")
		}
	}
	return nil
}

func NewServer(address string) (server *Server, err error) {
	listener, err := net.Listen("tcp", address)
	if err != nil {
		return nil, err
	}

	monolog.Info("Server listening on %s.", address)

	clients := make(map[int]*Client)
	tickers := make(map[string]*Ticker)

	server = &Server{address, listener, clients, tickers, true, nil, STATUS_RESTART}
	err = server.SetupWorld()
	if err != nil {
		monolog.Error("Could not set up or load world!")
		return nil, err
	}

	monolog.Info("Server world set up.")
	server.AddDefaultTickers()
	monolog.Info("Tickers set up.")

	return server, err
}

func NewTicker(server *Server, name string, milliseconds int, callback func(me *Ticker, t time.Time) bool) *Ticker {
	ticker := time.NewTicker(time.Millisecond * time.Duration(milliseconds))
	return &Ticker{ticker, server, name, milliseconds, callback}
}

func (me *Ticker) Run() {
OUTER:
	for me.Server.alive {
		for tick := range me.C {
			if !me.callback(me, tick) {
				break OUTER
			}
		}
	}
}

func (me *Server) RemoveTicker(name string) {
	ticker, have := me.tickers[name]
	if !have {
		return
	}
	ticker.Stop()
	delete(me.tickers, name)
}

func (me *Server) StopTicker(name string) {
	ticker, have := me.tickers[name]
	if !have {
		return
	}
	ticker.Stop()
}

func (me *Server) AddTicker(name string, milliseconds int, callback func(me *Ticker, t time.Time) bool) *Ticker {
	_, have := me.tickers[name]

	if have {
		me.RemoveTicker(name)
	}

	ticker := NewTicker(me, name, milliseconds, callback)
	me.tickers[name] = ticker
	go ticker.Run()

	return ticker
}

func onWeatherTicker(me *Ticker, t time.Time) bool {
	me.Server.BroadcastToChannel("weather", "The weather is changing...\n")
	return true
}

func (me *Server) AddDefaultTickers() {
	me.AddTicker("weather", 30000, onWeatherTicker)
}

func (me *Server) handleDisconnectedClients() {
	for me.alive {
		time.Sleep(1)
		for id, client := range me.clients {
			if !client.IsAlive() {
				monolog.Info("Client %d has disconnected.", client.id)
				client.Close()
				delete(me.clients, id)
			}
		}
	}
}

func (me *Server) findFreeID() (id int, err error) {
	for id = 0; id < MAX_CLIENTS; id++ {
		client, have := me.clients[id]
		if (!have) || (client == nil) {
			return id, nil
		}
	}
	return -1, fmt.Errorf("Too many clients!")
}

func (me *Server) onConnect(conn net.Conn) (err error) {
	id, err := me.findFreeID()
	if err != nil {
		monolog.Info("Refusing connection for %s: too many clients. ", conn.RemoteAddr().String())
		conn.Close()
		return nil
	}
	monolog.Info("New client connected from %s, id %d. ", conn.RemoteAddr().String(), id)
	client := NewClient(me, id, conn)
	me.clients[id] = client
	return client.Serve()
}

func (me *Server) Shutdown() {
	monolog.Info("Server is going to shut down.")
	me.alive = false
	me.exitstatus = STATUS_SHUTDOWN
}

func (me *Server) Restart() {
	monolog.Info("Server is going to restart.")
	me.alive = false
	me.exitstatus = STATUS_RESTART
}

func (me *Server) Close() {
	monolog.Info("Closing server, shutting down tickers.")

	for name, _ := range me.tickers {
		me.RemoveTicker(name)
	}

	monolog.Info("Closing server, shutting down clients.")
	for _, client := range me.clients {
		if client.IsAlive() {
			client.Close()
		}
	}

	me.handleDisconnectedClients()
	monolog.Info("Closed server.")
}

func (me *Server) Serve() (status int, err error) {
	// Setup random seed here, or whatever
	rand.Seed(time.Now().UTC().UnixNano())

	go me.handleDisconnectedClients()

	for me.alive {
		if tcplistener, ok := me.listener.(*net.TCPListener); ok {
			tcplistener.SetDeadline(time.Now().Add(5 * time.Second))
		}
		conn, err := me.listener.Accept()
		if err != nil {
			if noe, ok := err.(*net.OpError); ok && noe.Timeout() {
				// it's a timeout. Do nothing, just listen again.
				// this to allow the alive flag to do it's work.
			} else {
				return STATUS_CANNOT_LISTEN, err
			}
		} else {
			go me.onConnect(conn)
		}
		runtime.Gosched()
	}
	return me.exitstatus, nil
}

func (me *Server) BroadcastString(message string) {
	for _, client := range me.clients {
		if client.IsAlive() {
			client.WriteString(message)
		}
	}
}

func (me *Server) Broadcast(format string, args ...interface{}) {
	msg := fmt.Sprintf(format, args...)
	me.BroadcastString(msg)
}

func (me *Server) BroadcastStringToChannel(channelname string, message string) {
	for _, client := range me.clients {
		if client.IsLoginFinished() && client.IsListeningToChannel(channelname) {
			client.WriteString(message)
		}
	}
}

func (me *Server) BroadcastToChannel(channelname string, format string, args ...interface{}) {
	msg := fmt.Sprintf(format, args...)
	me.BroadcastStringToChannel(channelname, msg)
}

// Returns the data path of the server
func (me *Server) DataPath() string {
	//
	cwd, err := os.Getwd()
	monolog.Debug("Current direcory: %s (%v).", cwd, err)

	if err != nil {
		cwd = "."
	}

	fp := filepath.Join(cwd, "data", "var")
	monolog.Debug("Data path: %s (%v). ", fp, err)

	return fp
}

// Returns the script path of the server
func (me *Server) ScriptPath() string {
	//
	cwd, err := os.Getwd()
	if err != nil {
		cwd = "."
	}

	return filepath.Join(cwd, "data", "script")
}