import os
import os.path
import subprocess
import uuid
import socket
import xattr
import shutil
class GlusterManager:
	'''
	This class manage cluster filesystem by Glusterfs
	'''
	def __init__(self):
		self.varpath = '/var/lib/glusterd/'
		self.peerspath = self.varpath + 'peers'
		self.volspath = self.varpath + 'vols'
		self.mount_lock = '/run/n4d-glusterfs.lock'
		self.mount_boot_path = '/var/lib/n4d-glusterfs/volumes'
	#def __init__
	
	def startup(self,options):
		pass
	#def startup
	
	def test(self):
		pass
	#def test

	def backup(self):
		pass
	#def backup

	def path_is_clean(self,path):
		if not os.path.exists(path):
			return {'status':False,'msg':'This path not exists.'}

		# check not have .glusterfs folder
		if ( os.path.exists(path + "/.glusterfs" )):
			return {'status':False,'msg':'.glusterfs folder exists. You may clean this directory'}

		# check directory is void
		if ( len(os.listdir(path)) > 0 ):
			return {'status':False,'msg':'This folder not is void.'}

		# check not have xattr 
		list_xattr = [x.encode('utf-8') for x in xattr.listxattr(path)]
		if ("trusted.glusterfs.volume-id" in list_xattr or "trusted.gfid" in list_xattr):
			return {'status':False,'msg':'There are extended atributes. You may clean'}

		return {'status':True,'msg':'This path is ok'}
	#def path_is_clean

	def clean_path(self,path):
		if ( os.path.exists(path + "/.glusterfs")):
			shutil.rmtree(path + "/.glusterfs")
		list_xattr = [x.encode('utf-8') for x in xattr.listxattr(path)]
		if ('trusted.glusterfs.volume-id' in list_xattr):
			xattr.removexattr(path,'trusted.glusterfs.volume-id')
		if ( 'trusted.gfid' in list_xattr):
			xattr.removexattr(path,'trusted.gfid')
		return {'status': True, 'msg':'This folder is ok to add into cluster'}
	#def clean_path

	def create_vol(self, vol_name, my_name, brick, transport='tcp'):
		'''
		p = 0 
		- Creation of volume $vol_name has been successful. Please start the volume to access data.
		erro 255 
		- Brick: $my_name:/$brick already in use
		- Volume $vol_name already exists
		- Host $my_name not a friend
		'''
		if not self.__gluster_is_started__():
			return {'status':False,'msg':'Glusterfs is down.'}
		action = ['gluster','volume','create',vol_name,'transport',transport,my_name+":/"+brick]
		p = subprocess.Popen(action,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
		stdout, stderr = p.communicate()
		return_code = p.poll()
		if return_code == 0 :
			return {'status': True, 'msg':'Volume ' + vol_name + ' is created. Now you must start it'}
		else:
			if "or a prefix of it is already part of a volume" in stderr :
				return {'status': False, 'msg' : stderr.strip() + ". You must launch clean_path n4d method for /"+brick +", because this directory has been used in the past and may be dirty" }
			return {'status': False, 'msg' : stderr.strip() }
	#def create_vol

	def add_brick(self,vol_name,server_name,brick):
		if not self.__gluster_is_started__():
			return {'status':False,'msg':'Glusterfs is down.'}
		if not os.path.exists(self.volspath +'/'+vol_name):
			return {'status':False,'msg':'This volume not exists.'}
		try:
			info_vol = open(self.volspath +'/'+vol_name+'/info','r').readlines()
		except:
			return {'status':False,'msg':'There is error in internal configuration for this volume.'}
		list_bricks = []
		for x in info_vol:
			try:
				key,value = x.split('=')
			except:
				continue
			if key == 'replica_count':
				replica = str(int(value) + 1)
				continue
			if key.startswith('brick-'):
				list_bricks.append(value.strip())
		if server_name+":-"+brick.replace('/','-') in list_bricks:
			return {'status':True,'msg':'This brick has been added in the past.'}

		action = ['gluster','volume','add-brick',vol_name,'replica',replica,server_name+":/"+brick]
		p = subprocess.Popen(action,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
		out,err = p.communicate()
		return_code = p.poll()
		if return_code != 0:
			return {'status': False, 'msg':err}
		action = ['gluster','volume','heal',vol_name,'full']
		p = subprocess.call(action)
		return {'status': True, 'msg':'Brick ' + server_name +':/' + brick +' is join to '+ vol_name}
	#def add_brick

	def remove_brick(self,vol_name,server_name,brick):
		if not self.__gluster_is_started__():
			return {'status':False,'msg':'Glusterfs is down.'}
		if not os.path.exists(self.volspath +'/'+vol_name):
			return {'status':False,'msg':'This volume not exists.'}
		try:
			info_vol = open(self.volspath +'/'+vol_name+'/info','r').readlines()
		except:
			return {'status':False,'msg':'There is error in internal configuration for this volume.'}
		list_bricks = []
		for x in info_vol:
			try:
				key,value = x.split('=')
			except:
				continue
			if key == 'replica_count':
				replica = str(int(value) - 1)
				continue
			if key.startswith('brick-'):
				list_bricks.append(value.strip())
		if not server_name+":-"+brick.replace('/','-') in list_bricks:
			return {'status':True,'msg':'This brick has been removed in the past or never exists.'}

		action = ['gluster','volume','remove-brick',vol_name,'replica',replica,server_name+":/"+brick]
		p = subprocess.Popen(action,stdout=subprocess.PIPE,stderr=subprocess.PIPE,stdin=subprocess.PIPE)
		out,err = p.communicate(input='y\n')
		return_code = p.poll()
		if return_code != 0:
			return {'status': False, 'msg':err}
		return {'status': True, 'msg':'Brick ' + server_name +':/' + brick +' is removed from '+ vol_name}
	#def remove_brick

	def delete_vol(self,vol_name):
		if not self.__gluster_is_started__():
			return {'status':False,'msg':'Glusterfs is down.'}
		if not os.path.exists(self.volspath +'/'+vol_name):
			return {'status':False,'msg':'This volume not exists.'}
		action = ['gluster','volume','delete',vol_name]
		p = subprocess.Popen(action,stdout=subprocess.PIPE,stderr=subprocess.PIPE,stdin=subprocess.PIPE)
		out,err = p.communicate(input='y\n')
		return_code = p.poll()
		if return_code != 0:
			return {'status': False, 'msg':err}
		return {'status': True, 'msg':'Volume ' + vol_name +' is deleted'}
	#def delete_vol

	def start_vol(self,vol_name):
		if not self.__gluster_is_started__():
			return {'status':False,'msg':'Glusterfs is down.'}
		if vol_name not in os.listdir(self.volspath):
			return {'status':False,'msg':'Not exists this volume.'}
		action = ['gluster','volume','start',vol_name]
		p = subprocess.Popen(action,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
		stdout, stderr = p.communicate()
		return_code = p.poll()
		if return_code == 0:
			return {'status': True, 'msg':'volume ' + vol_name + ' has been started'}
		else:
			if "already started" in stderr:
				return {'status': True, 'msg':'volume ' + vol_name + ' has been started in the past'}
			return {'status': False, 'msg': stderr.strip()}
	#def start_vol

	def stop_vol(self,vol_name):
		if not self.__gluster_is_started__():
			
			return {'status':False,'msg':'Glusterfs is down.'}
		if vol_name not in os.listdir(self.volspath):
			return {'status':False,'msg':'Not exists this volume.'}
		action = ['gluster','volume','stop',vol_name]
		p = subprocess.Popen(action,stdout=subprocess.PIPE,stderr=subprocess.PIPE,stdin=subprocess.PIPE)
		stdout, stderr = p.communicate(input='y\n')
		return_code = p.poll()
		if return_code == 0:
			return {'status': True, 'msg':'volume ' + vol_name + ' has been stoped'}
		else:
			if "is not in the started state" in stderr:
				return {'status': True, 'msg':stderr.strip()}
			return {'status': False, 'msg': stderr.strip()}
	#def stop_vol
	
	def add_peer(self,peer):
		if self.__i_am_he__(peer):
			return {'status':'True','msg':'I am this peer'}
		if self.__gluster_is_started__():
			p = subprocess.call(['gluster','peer','probe',peer])
			if ( p != 0 ) :
				return {'status':False,'msg':'peer '+ peer + ' is unknown'}
			else:
				return {'status':True,'msg':'Peer is added'}
		else:
			try:
				socket.gethostbyname(peer)
			except:
				return {'status':False,'msg':'peer '+ peer + ' is unknown'}
			id = self.__peer_added__(peer)
			if id != None:
				return {'status':True,'msg':'Peer has been added in the past. Glusterfs service is down. You may start'}
			id = str(uuid.uuid4())
			f = open(self.peerspath+'/'+id,'w')
			f.write('uuid='+id+'\n')
			f.write('state=3\n')
			f.write('hostname1='+peer+'\n')
			f.close()
			return {'status':True,'msg':'Peer is added, but Glusterfs service is down. You may start'}
	#def add_peer

	def del_peer(self,peer,force=False):
		if self.__i_am_he__(peer):
			return {'status':'False','msg':'I am this peer'}
		if self.__gluster_is_started__():
			action = ['gluster','peer','detach']
			if force:
				action.append('force')
			action.append(peer)
			p = subprocess.call(action)
			if ( p != 0 and p != 1) :
				return {'status':False,'msg':'peer '+ peer + ' is unknown'}
			elif (p != 0):
				return {'status': True, 'msg': "This peer isn't cluster"}
			else:
				return {'status':True,'msg':'Peer is detached'}
		else:
			id = self.__peer_added__(peer)
			if id == None:
				return {'status':True,'msg':"This peer isn't cluster"}
			os.remove(self.peerspath+'/'+id)
			return {'status':True,'msg':'Peer is removed, but Glusterfs service is down. You may start'}

	#def del_peer
	
	def mount_on_boot(self,tag,source,dest,options=""):
		if os.path.exists(self.mount_lock):
			return {'status':False,'msg':'mount_on_boot method is locked because other request is being processing at the moment '}
		f = open(self.mount_lock,'w')
		f.close()
		f = open(self.mount_boot_path,'a')
		f.write(source + " " + dest + " " + options + "#TAG "+ tag+"-"+ dest + "\n")
		f.close()
		os.remove(self.mount_lock)
		return {'status':True,'msg':'Added correctly'}
	#def mount_on_boot
	
	def mount_now(self):
		os.remove('/run/n4d-glusterfs.lock')
		os.system("service mounting-glusterfs restart")
		return {'status':True,'msg':'Mounting'}
	#def mount_now


	def clean_mount_on_boot(self):
		os.remove(self.mount_boot_path)
	#def clean_mount_on_boot
	
	
	
	'''
		Internal Methods
	'''
	
	def __gluster_is_started__(self):
		if os.path.exists('/run/glusterd.pid'):
			return True
		else:
			return False
	#def __gluster_is_started__

	def __i_am_he__(self,peer):
		fqdn = socket.getfqdn()
		if peer == fqdn :
			return True
		else:
			return False
	#def __i_am_he__

	def __peer_added__(self,peer):
		needle = "hostname1="+str(peer)
		for p in os.listdir(self.peerspath):
			# x are all fields striped from file in list
			listfield = [field.strip() for field in open(self.peerspath+"/"+p).readlines()]
			if needle in listfield:
				return p
		return None