// FTP Client for Google Go language.
// Author: smallfish <smallfish.xy@gmail.com>

package ftp

import (
"fmt"
"os"
"net"
"strconv"
"strings"
)

type FTP struct {
host string
port int
user string
passwd string
pasv int
cmd string
Code int
Message string
Debug bool
stream []byte
conn net.Conn
Error os.Error
}

func (ftp *FTP) debugInfo(s string) {
if ftp.Debug {
fmt.Println(s)
}
}

func (ftp *FTP) Connect(host string, port int) {
addr := fmt.Sprintf("%s:%d", host, port)
ftp.conn, ftp.Error = net.Dial("tcp", addr)
ftp.Response()
ftp.host = host
ftp.port = port
}

func (ftp *FTP) Login(user, passwd string) {
ftp.Request("USER " + user)
ftp.Request("PASS " + passwd)
ftp.user = user
ftp.passwd = passwd
}

func (ftp *FTP) Response() (code int, message string) {
ret := make([]byte, 1024)
n, _ := ftp.conn.Read(ret)
msg := string(ret[:n])
code, _ = strconv.Atoi(msg[:3])
message = msg[4 : len(msg)-2]
ftp.debugInfo("<*cmd*> " + ftp.cmd)
ftp.debugInfo(fmt.Sprintf("<*code*> %d", code))
ftp.debugInfo("<*message*> " + message)
return
}

func (ftp *FTP) Request(cmd string) {
ftp.conn.Write([]byte(cmd + "\r\n"))
ftp.cmd = cmd
ftp.Code, ftp.Message = ftp.Response()
if cmd == "PASV" {
start, end := strings.Index(ftp.Message, "("), strings.Index(ftp.Message, ")")
s := strings.Split(ftp.Message[start:end], ",", -1)
l1, _ := strconv.Atoi(s[len(s)-2])
l2, _ := strconv.Atoi(s[len(s)-1])
ftp.pasv = l1*256 + l2
}
if (cmd != "PASV") && (ftp.pasv > 0) {
ftp.Message = newRequest(ftp.host, ftp.pasv, ftp.stream)
ftp.debugInfo("<*response*> " + ftp.Message)
ftp.pasv = 0
ftp.stream = nil
ftp.Code, _ = ftp.Response()
}
}

func (ftp *FTP) Pasv() {
ftp.Request("PASV")
}

func (ftp *FTP) Pwd() {
ftp.Request("PWD")
}

func (ftp *FTP) Cwd(path string) {
ftp.Request("CWD " + path)
}

func (ftp *FTP) Mkd(path string) {
ftp.Request("MKD " + path)
}

func (ftp *FTP) Size(path string) (size int) {
ftp.Request("SIZE " + path)
size, _ = strconv.Atoi(ftp.Message)
return
}

func (ftp *FTP) List() {
ftp.Pasv()
ftp.Request("LIST")
}

func (ftp *FTP) Stor(file string, data []byte) {
ftp.Pasv()
if data != nil {
ftp.stream = data
}
ftp.Request("STOR " + file)
}

func (ftp *FTP) Quit() {
ftp.Request("QUIT")
ftp.conn.Close()
}

// new connect to FTP pasv port, return data
func newRequest(host string, port int, b []byte) string {
conn, _ := net.Dial("tcp", fmt.Sprintf("%s:%d", host, port))
defer conn.Close()
if b != nil {
conn.Write(b)
return "OK"
}
ret := make([]byte, 4096)
n, _ := conn.Read(ret)
return string(ret[:n])
}


//go/8663