# -*- coding: utf-8 -*-
 
# Copyright (c) 2018  Michael Rasmussen <mir@datanom.net>
 
# This file is part of SecureMail.

# SecureMail is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# SecureMail is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with SecureMail.  If not, see <https://www.gnu.org/licenses/>.

import pickle
from db import DBInterface as DBI
from cryptonize import Cryptonize
from nacl.public import PublicKey

class NoSuchUser(Exception):
    pass

class User:
    """
    Class implementing the backend users
    """
    def __init__(self, key=None):
        if key is not None:
            self.load(key)
        else:
            self.pubkeys = {}

    def store(self, key):
        crypto = Cryptonize()
        cipher = crypto.symmetric_encrypt(key, pickle.dumps(self))
        DBI.store_user(crypto.generate_hash(key), cipher)

    def load(self, key):
        crypto = Cryptonize()
        cipher = DBI.load_user(crypto.generate_hash(key))
        if cipher is None:
            raise NoSuchUser('{0}: User not found'.format(key))
        plain = crypto.symmetric_decrypt(key, cipher)
        try:
            obj = pickle.loads(plain)
            self.__dict__.update(obj.__dict__)
        except pickle.UnpicklingError as e:
            raise e
    
    def add_pubkey(self, email, key):
        if email not in self.pubkeys:
            self.pubkeys[email] = key.encode()
        else:
            raise KeyError('{0}: Exists'.format(email))
    
    def update_pubkey(self, email, key):
        self.pubkeys[email] = key.encode()

    def delete_pubkey(self, email):
        if email in self.pubkeys:
            del self.pubkeys[email]

    def get_pubkey(self, email):
        if email in self.pubkeys:
            key = self.pubkeys[email]
            key = PublicKey(key)
        else:
            key = None
        
        return key

    @property
    def name(self):
        return self._name

    @name.setter
    def name(self, name):
        self._name = name

    @property
    def email(self):
        return self._email

    @email.setter
    def email(self, email):
        self._email = email

    @property
    def pubkeys(self):
        return self._pubkeys

    @pubkeys.setter
    def pubkeys(self, pubkeys):
        if type(pubkeys) is not type({}):
            raise ValueError('Not dictionary')
        self._pubkeys = pubkeys

if __name__ == '__main__':
    try:
        u = User('test')
        for attr, value in u.__dict__.items():
            print ('{0}: {1}'.format(attr, value))
        print ('{0} - {1} - {2}'.format(u.name, u.email, u.pubkeys))
        key = ''
        for i in range(40):
            key += '{0}'.format(i)
        u = User()
        u.name = 'testname1'
        u.email = 'testname1@securemail.icu'
        u.pubkeys = {'test': 'some test', 'test1': 'some test 1'}
        try:
            u.store(key)
        except:
            u = User(key)
            for attr, value in u.__dict__.items():
                print ('{0}: {1}'.format(attr, value))
            print ('{0} - {1} - {2}'.format(u.name, u.email, u.pubkeys))
        from nacl.public import Box
        c = Cryptonize()
        keypair1 = c.get_key_pair()
        keypair2 = c.get_key_pair()
        try:
            u.add_pubkey('test', keypair2[1])
        except KeyError:
            u.update_pubkey('test', keypair2[1])
        bob_box = Box(keypair1[0], u.get_pubkey('test'))
        message = "Kill all humans æøåÅØÆ"
        encrypted = bob_box.encrypt(message.encode())
        alice_box = Box(keypair2[0], keypair1[1])
        plaintext = alice_box.decrypt(encrypted)
        print (plaintext.decode())
#        c = Cryptonize()
#        key = 'æselØre' #c.get_random_key()
#        cipher = c.symmetric_encrypt(key, pickle.dumps(u))
#        obj = pickle.loads(c.symmetric_decrypt(key, cipher))
#        for attr, value in obj.__dict__.items():
#            print ('{0}: {1}'.format(attr, value))
    except NoSuchUser:
        u = User()
        u.name = 'testname'
        u.email = 'testname@securemail.icu'
        u.store('test')
    except Exception as e:
        print (e)