// vim:ts=4:sts=4:sw=4:noet:tw=72

package ircd

import (
	"bufio"
	"fmt"
	"io"
	"net"
	"strings"
	"time"

	"code.dnix.de/an/irc"
	"code.dnix.de/an/xlog"
)

type Client interface {
	Name() string
	Send(*irc.Message)
	Receive(*irc.Message)
	Register() chan bool
	Destroy()
}

type RemoteClient struct {
	server *Server

	name     string
	password string
	modes    string

	isSSL        bool
	isRegistered bool
	isAuthed     bool
	isClosed     bool

	receive  chan *irc.Message
	register chan bool

	conn   net.Conn
	writeq chan string
}

func NewRemoteClient(srv *Server, conn net.Conn) *RemoteClient {
	cl := new(RemoteClient)
	cl.server = srv

	cl.name = ""
	cl.password = ""
	cl.modes = ""

	cl.receive = make(chan *irc.Message)
	cl.register = make(chan bool)

	cl.isRegistered = false
	cl.isAuthed = false
	cl.isClosed = false
	cl.conn = conn
	cl.writeq = make(chan string, 256)

	go cl.connReader()
	go cl.connWriter()
	go cl.dispatch()

	xlog.Info("RemoteClient connected")

	return cl
}

func (cl *RemoteClient) Name() string {
	return cl.name
}

func (cl *RemoteClient) Send(msg *irc.Message) {
	msg.Pre = cl.name
	cl.server.Dispatch <- msg
}

func (cl *RemoteClient) Receive(msg *irc.Message) {
	cl.receive <- msg
}

func (cl *RemoteClient) Register() chan bool {
	return cl.register
}

func (cl *RemoteClient) AddMode(mode string) {
	cl.modes = cl.modes + mode
}

func (cl *RemoteClient) DelMode(mode string) {
	cl.modes = strings.Replace(cl.modes, mode, "", -1)
}

func (cl *RemoteClient) HasMode(mode string) bool {
	return strings.IndexRune(cl.modes, rune(mode[0])) != -1
}

func (cl *RemoteClient) Destroy() {
	if cl.isClosed {
		return
	}
	cl.isClosed = true
	close(cl.writeq)
	cl.conn.Write([]byte("ERROR :Closing link"))
	cl.conn.Close()
	if cl.name != "" {
		xlog.Info("RemoteClient '%s' disconnected", cl.name)
	} else {
		xlog.Info("RemoteClient disconnected")
	}
}

func (cl *RemoteClient) dispatch() {
	for {
		time.Sleep(1 * time.Millisecond)
		if cl.isClosed {
			return
		}
		select {
		case msg := <-cl.receive:
			cl.writeMsg(msg)
		default:
			continue
		}
	}
}

func (cl *RemoteClient) connReader() {
	input := bufio.NewReader(cl.conn)
	for {
		if cl.isClosed {
			xlog.Debug("connReader: exiting")
			return
		}
		s, err := input.ReadString('\n')
		if err == io.EOF {
			xlog.Info("connReader: Connection closed by peer")
			cl.server.DelClient <- cl
			return
		}
		if err != nil {
			xlog.Error("connReader: %s", err.Error())
			cl.server.DelClient <- cl
			return
		}
		s = strings.Trim(s, "\r\n")
		cl.handleLine(s)
	}
}

func (cl *RemoteClient) connWriter() {
	for line := range cl.writeq {
		written := 0
		bytes := []byte(line + "\r\n")
		for written < len(line) {
			n, err := cl.conn.Write(bytes[written:])
			if err == io.EOF {
				xlog.Info("connWriter: Connection closed by peer")
				cl.server.DelClient <- cl
				return
			} else if err != nil {
				xlog.Error("connWriter: %s", err.Error())
				cl.server.DelClient <- cl
				return
			}
			written += n
		}
	}
	xlog.Debug("connWriter: exiting")
}

func (cl *RemoteClient) writeMsg(msg *irc.Message) {
	cl.writeLine(msg.String())
}

func (cl *RemoteClient) writeLine(format string, a ...interface{}) {
	cl.writeq <- fmt.Sprintf(format, a...)
}

var lineFuncs = map[string]func(*RemoteClient, *irc.Message) bool{
	"PASS": handleLinePass,
	"NICK": handleLineNick,
	"USER": handleLineUser,
}

func (cl *RemoteClient) handleLine(s string) {
	xlog.Debug("handleLine: [%s] '%s'", cl.name, s)
	msg := irc.Parse(s)
	hook, exists := lineFuncs[msg.Cmd]
	forward := true
	if exists {
		forward = hook(cl, msg)
	}
	if forward {
		cl.Send(msg)
	}
}

func checkAuth(cl *RemoteClient) {
	if cl.name == "" || cl.password == "" {
		return
	}
}

func handleLinePass(cl *RemoteClient, msg *irc.Message) bool {
	cl.password = msg.Args[0]
	return false
}

func handleLineNick(cl *RemoteClient, msg *irc.Message) bool {
	if cl.name != "" {
		return false
	}
	if len(msg.Args) < 1 {
		xlog.Warning("Nicksalat!")
		return false
	}
	cl.name = msg.Args[0]
	cl.server.AddClient <- cl
	if registered := <-cl.register; registered {
		cl.isRegistered = true
		xlog.Info("User '%s' registered", msg.Args[0])
	} else {
		xlog.Error("User '%s' already connected", msg.Args[0])
		cl.server.DelClient <- cl
	}
	return false
}

func handleLineUser(cl *RemoteClient, msg *irc.Message) bool {
	return false
}