import paramiko
import shutil
import hashlib
import os

class Server:
	def __init__(self, hostname='', port=0, username='', password=''):
		self.hostname = hostname
		self.port = port
		self.username = username
		self.password = password
		self.connection = self.connect()

	def __enter__(self,  hostname='', port=0, username='', password=''):
		return self

	def __exit__(self,  hostname='', port=0, username='', password=''):
		self.disconnect()

	def connect(self):
	    s = paramiko.SSHClient()
	    s.set_missing_host_key_policy(paramiko.AutoAddPolicy())
	    s.connect(self.hostname, self.port, self.username, self.password)
	    print "connection open"
	    return s

	def disconnect(self):
		self.connection.close()
		print "connection closed"

	def ExecuteCommand(self, bashCommand):
		stdin, stdout, stderr = self.connection.exec_command(bashCommand)
		#print stdout
		return stdout.read()

	"""returns nothing (but should) copy a file"""
	def DownloadFile(self, serverFileLocation, localFileLocation, filePrefix, filePostfix=''):
	    transport = paramiko.Transport((self.hostname, self.port))
	    transport.connect(username = self.username, password = self.password)
	    newFileName = self.CheckFileName('%s\\%s%s%s' % (localFileLocation, filePrefix, os.path.basename(serverFileLocation), filePostfix))

	    sftp = paramiko.SFTPClient.from_transport(transport)
	    sftp.get(serverFileLocation, newFileName)

	    print "Server Hash: %s" % self.HashRemoteFile(serverFileLocation)
	    print "Local Hash:  %s" % self.HashLocalFile(newFileName)
	    print ('HOST: %s \nREMOTE FILE: %s \nLOCAL FILE: %s' % (self.hostname, serverFileLocation, newFileName))

	    sftp.close()
	    transport.close()

	"""returns nothing (but should) copy a file"""
	def UploadFile(self, serverFileLocation, localFileLocation, filePrefix, filePostfix):
	    transport = paramiko.Transport((self.hostname, self.port))
	    transport.connect(username = self.username, password = self.password)
	    newFileName = self.CheckFileName('%s\\%s%s%s' % (localFileLocation, filePrefix, os.path.basename(serverFileLocation), filePostfix))

	    sftp = paramiko.SFTPClient.from_transport(transport)
	    sftp.get(serverFileLocation, newFileName)

	    print "Server Hash: %s" % self.HashRemoteFile(serverFileLocation)
	    print "Local Hash:  %s" % self.HashLocalFile(newFileName)
	    print ('HOST: %s \nREMOTE FILE: %s \nLOCAL FILE: %s' % (self.hostname, serverFileLocation, newFileName))

	    sftp.close()
	    transport.close()

	def CheckFileName(self, fileName):
	    fileCopyNumber = ''
	    i = 0
	    while os.path.isfile('%s\\%s' % (os.path.dirname(fileName), fileCopyNumber + os.path.basename(fileName))):
	        print 'File already found, choosing another name...'
	        i=i+1
	        fileCopyNumber = str(i) + '_'
	    return '%s\\%s' % (os.path.dirname(fileName), fileCopyNumber + os.path.basename(fileName))

	def HashRemoteFile(self, remoteFileLocation):
	    #this is slack, add more error checking etc to this
	    return self.ExecuteCommand("sha1sum %s" % (remoteFileLocation)).split('  ')[0]

	def HashLocalFile(self, file):
	    f = open(file, 'rb')
	    h = hashlib.sha1()
	    h.update(f.read())
	    hash = h.hexdigest()
	    f.close()
	    return hash