#!/usr/bin/env python

import os, sys, md5, shelve
from Crypto.Cipher import Blowfish
from optparse import OptionParser
from getpass import getpass


try:
    database = shelve.open("%s/.zpass/zpass.dbm" % os.environ["HOME"])

except:
    print "Cant create file database, check permissions"
    sys.exit(1)

def show_record(record):
    if database.has_key(record):
        record = database[record]
        print "Your username is: \n%s " % _decode_data(record[0])
        print "Your password is: \n%s" % _decode_data(record[1])
        print "Additional information: \n%s" % _decode_data(record[2])
    else:
        print "No such record. Execute '%s -l' to list all records avialable" % sys.argv[0]

def add_record(record):
    if database.has_key(record):
        print "This record already exists"
    else:
        username = raw_input("Please enter an username:\n")
        password = raw_input("Please enter an password:\n")
        comment = raw_input("Please enter additional information:\n")
        database[record] = map(_encode_data, (username, password, comment))
        database.close()

def list_records():
    for key in database.keys():
        if key != '__passphrase':
            print key

def modify_record(record):
    if not database.has_key(record):
        print "No such record in database"
    else:
        username = raw_input("Please enter an username: (leave blank to retain old username)\n")
        password = raw_input("Please enter an password: (leave blank to retain old password)\n")
        comment = raw_input("Please enter an comment: (leave blank to retain old comment)\n")
        if not username:
            username = _decode_data(database[record][0])
        if not password:
            password = _decode_data(database[record][1])
        if not comment:
            comment = _decode_data(database[record][2])
        database[record] = map(_encode_data, (username, password, comment))
        database.close()

def delete_record(record):
    if not database.has_key(record):
        print "No such record in database"
    else:
        yesno = raw_input("Are you sure you want to delete %s? (y/n): " % record)
        if yesno == 'y':
            del database[record]
            print "Record %s successfully deleted" % record
        else:
            print "The only allowed variants is 'y' for yes, and 'n' for no"
        database.close()


def controller():
    parser = OptionParser(description="Python password reminder", prog="zpass", version="0.1", usage="%prog [-a|s|m|d|l|h|v] [arg1]")
    parser.add_option('--add', '-a', metavar="record", help="Add new record to database")
    parser.add_option('--show', '-s', metavar="record", help="Show record data")
    parser.add_option('--modify', '-m', metavar="record", help="Modify record data in database")
    parser.add_option('--delete', '-d', metavar="record", help="Delete record data from database")
    parser.add_option('--list', '-l', action="store_true", help="List all record names in database")
    options, arguments = parser.parse_args()
    if len(arguments) != 0:
        parser.error("You should use option and one record name")
    elif options.add and options.show:
        parser.error("options -a and -s are mutually exclusive")
    elif options.add:
        add_record(options.add)
    elif options.show:
        show_record(options.show)
    elif options.list:
        list_records()
    elif options.modify:
        modify_record(options.modify)
    elif options.delete:
        delete_record(options.delete)

def check_passphrase():
    global user_passphrase
    user_passphrase = getpass("Please enter an passphrase\n")
    if database.has_key('__passphrase'):
        if not md5.new(user_passphrase).hexdigest() == database['__passphrase']:
            print "Wrong passphrase"
            sys.exit(1)
    else:
        database['__passphrase'] = md5.new(user_passphrase).hexdigest()

    return controller()

def _encode_data(value):
    return Blowfish.new(user_passphrase, Blowfish.MODE_CFB).encrypt(value)

def _decode_data(value):
    return Blowfish.new(user_passphrase, Blowfish.MODE_CFB).decrypt(value)

check_passphrase()