#!/usr/bin/python

#Author: Stephen Moon
#Date: 3/5/09
#Retrieves Perforce binaries or ASCII files from ftp.perforce.com
#
#Usage:
#   In Windows, remove She-bang line
#
import ftplib, re, os, sys

#holds each displayed line entry
class DirEntry(object): #inherits from class object
   def __init__(self,line): #only accept one argument line
	self.parts = line.split(None,8) #split into 8 parts for each line

   def isValid(self):
	return len(self.parts) >= 6 #if num of parts greater than 6 then it's valid

   def getType(self):
	return self.parts[0][0] #get the very first character on the line (i.e. 

   def getFilename(self):
	if self.getType() != 'l': #if it is not a link
	   return self.parts[-1] #return the last part
	else:
	   return self.parts[-1].split(' -> ', 1)[0] #if it is, return shortcut

   def getLinkDest(self): #looks for whether the link originates
	if self.getType() == 'l':
	   return self.parts[-1].split(' -> ', 1)[1]
	else:
	   raise RuntimeError, "getLinkDest() called on non-link item"

#creates a key (fname) and value (line for the filename)
class DirScanner(dict): #inherits from class list 
   def addline(self,line): #only accepts one arugment line
	obj = DirEntry(line)
	if obj.isValid(): #line object contains more than 6 parts
	   self[obj.getFilename()] = obj #creates a key/value pair, key = fname

#downloads a file
def downloadFile(ftpobj, filename):
   ftpobj.voidcmd("Type I")

   #based on the filename, it returns a tuple of the data connection and the expected
   #size of data
   datasock, estimatedSize = ftpobj.ntransfercmd("RETR %s" % filename)
   transbytes = 0
   
   fd = open(filename, 'wb')
   while True:
	buf = datasock.recv(2048)
	if not len(buf):
	   break;
	fd.write(buf)
	transbytes += len(buf)
	sys.stdout.write("%s: Received %d " % (filename, transbytes))
	if estimatedSize:
	   sys.stdout.write("of %d bytes (%.1f%%)\n" % (estimatedSize,
	   100.0 * float(transbytes) / float(estimatedSize)))
	else:
	   sys.stdout.write("bytes")
   fd.close()
   datasock.close()
   ftpobj.voidresp()
   sys.stdout.write("\n")

def displayFiles(ftp):

   data = {} 
   data = DirScanner() #create data object of class DirScanner
   ftp.dir(data.addline) #add lines to dict when dir is run

   keys = data.keys() #get the keys
   keys.sort() #sort it

   #print it to the sorted filenames
   for i,eachEntry in enumerate(keys):
      if data[eachEntry].getType() == '-': #DirEntry object using fileName key
         print '(',i,'):\t[FILE]\t',eachEntry
      elif data[eachEntry].getType() == 'd': #same as above but directory
         print '(',i,'):\t [DIR]\t',eachEntry
   print '\n[u]: go up one directory'
   print '[e]: exit\n'
   
   return data

#main start here
ftp = ftplib.FTP('ftp.perforce.com','ftp','ident')

data = displayFiles(ftp) 
choice = raw_input("Choose the directory from the above choices: ")

while True:
   if choice is 'u':
	ftp.cwd("..")
   elif choice is 'e':
	break;
   elif choice.isalpha():
	print "\n*** You have entered alpha character other than given choices ***\n"
   elif(int(choice) <= len(data) - 1): 

	keys = data.keys()
	keys.sort() # filenames sorted
	for i, fileName in enumerate(keys):
	   if i == int(choice):
	      if data[fileName].getType() == '-': #DirEntry object using fileName key
		   downloadFile(ftp,fileName)
	      elif data[fileName].getType() == 'd': #same as above but directory
		   ftp.cwd(fileName)
   else:
	print "\n*** You have made an invalid choice ***\n"

   data = displayFiles(ftp) 
   choice = raw_input("choose the directory from the above choices: ")

ftp.quit()