from db import *
from sqlalchemy import or_
import pwd
import subprocess
import os
import signal

def search_user(string, session):
	string = string.lower()
	exact_match = session.query(User).filter(or_(User.name==string, User.card==string)).first()
	if exact_match:
		return exact_match
	user_list = session.query(User).filter(or_(User.name.ilike('%'+string+'%'),
						   User.card.ilike('%'+string+'%'))).all()
	return user_list

def search_product(string, session):
	exact_match = session.query(Product)\
		      .filter(or_(Product.bar_code==string,
				  Product.name==string)).first()
	if exact_match:
		return exact_match
	product_list = session.query(Product)\
		       .filter(or_(Product.bar_code.ilike('%'+string+'%'),
				   Product.name.ilike('%'+string+'%'))).all()
	return product_list


def system_user_exists(username):
	try:
		pwd.getpwnam(username)
	except KeyError:
		return False
	except UnicodeEncodeError:
		return False
	else:
		return True

def guess_data_type(string):
	if string.startswith('ntnu') and string[4:].isdigit():
		return 'card'
	if string.isdigit() and len(string) in [8,13]:
		return 'bar_code'
# 	if string.isdigit() and len(string) > 5:
# 		return 'card'
	if string.isalpha() and string.islower() and system_user_exists(string):
		return 'username'
	return None


# def retrieve_user(string, session):
# #	first = session.query(User).filter(or_(User.name==string, User.card==string)).first()
# 	search = search_user(string,session)
# 	if isinstance(search,User):
# 		print "Found user "+search.name
# 		return search
# 	else:
# 		if len(search) == 0:
# 			print "No users found matching your search"
# 			return None
# 		if len(search) == 1:
# 			print "Found one user: "+list[0].name
# 			if confirm():
# 				return list[0]
# 			else:
# 				return None
# 		else:
# 			print "Found "+str(len(search))+" users:"
# 			return select_from_list(search)
			

# def confirm(prompt='Confirm? (y/n) '):
# 	while True:
# 		input = raw_input(prompt)
# 		if input in ["y","yes"]:
# 			return True
# 		elif input in ["n","no"]:
# 			return False
# 		else:
# 			print "Nonsense!"

# def select_from_list(list):
# 	while True:
# 		for i in range(len(list)):
# 			print i+1, " ) ", list[i].name
# 		choice = raw_input("Select user :\n")
# 		if choice in [str(x+1) for x in range(len(list))]:
# 			return list[int(choice)-1]
# 		else:
# 			return None

def argmax(d, all=False, value=None):
	maxarg = None
	maxargs = []
	if value != None:
		dd = d
		d = {}
		for key in dd.keys():
			d[key] = value(dd[key])
	for key in d.keys():
		if maxarg == None or d[key] > d[maxarg]:
			maxarg = key
	if all:
		return filter(lambda k: d[k] == d[maxarg], d.keys())
	return maxarg

def safe_str(obj):
	'''
	Ugly hack to avoid Python complaining about encodings.

	Call this on any object to turn it into a string which is
	(hopefully) safe for printing.
	'''
	if isinstance(obj, str):
		return obj
	if isinstance(obj, unicode):
		return obj.encode('utf8')
	else:
		return safe_str(unicode(obj))

def less(string):
	'''
	Run less with string as input; wait until it finishes.
	'''
	# If we don't ignore SIGINT while running the `less` process,
	# it will become a zombie when someone presses C-c.
	int_handler = signal.signal(signal.SIGINT, signal.SIG_IGN)
	env = dict(os.environ)
	env['LESSSECURE'] = '1'
	proc = subprocess.Popen('less', env=env, stdin=subprocess.PIPE)
	proc.communicate(safe_str(string))
	signal.signal(signal.SIGINT, int_handler)