#!/usr/bin/env python
#
# Electrum - lightweight Bitcoin client
# Copyright (C) 2011 thomasv@gitorious
#
# This program 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.
#
# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.

import sys
import os
import hashlib
import ast
import threading
import random
import time
import math

from util import print_msg, print_error

from bitcoin import *
from account import *
from version import *

from transaction import Transaction
from plugins import run_hook
import bitcoin
from synchronizer import WalletSynchronizer

COINBASE_MATURITY = 500
DUST_THRESHOLD = 1000

# internal ID for imported account
IMPORTED_ACCOUNT = '/x'


class WalletStorage(object):

    def __init__(self, config):
        self.lock = threading.RLock()
        self.config = config
        self.data = {}
        self.file_exists = False
        self.path = self.init_path(config)
        print_error( "wallet path", self.path )
        if self.path:
            self.read(self.path)

    def init_path(self, config):
        """Set the path of the wallet."""

        # command line -w option
        path = config.get('wallet_path')
        if path:
            return path

        # path in config file
        path = config.get('default_wallet_path')
        if path:
            return path

        # default path
        dirpath = os.path.join(config.path, "wallets")
        if not os.path.exists(dirpath):
            os.mkdir(dirpath)

        new_path = os.path.join(config.path, "wallets", "default_wallet")

        # default path in pre 1.9 versions
        old_path = os.path.join(config.path, "electrum-nvc.dat")
        if os.path.exists(old_path) and not os.path.exists(new_path):
            os.rename(old_path, new_path)

        return new_path

    def read(self, path):
        """Read the contents of the wallet file."""
        try:
            with open(self.path, "r") as f:
                data = f.read()
        except IOError:
            return
        try:
            d = ast.literal_eval( data )  #parse raw data from reading wallet file
        except Exception:
            raise IOError("Cannot read wallet file.")

        self.data = d
        self.file_exists = True

    def get(self, key, default=None):

        with self.lock:
            v = self.data.get(key)
            if v is None:
                v = default
            return v

    def put(self, key, value, save = True):

        with self.lock:
            if value is not None:
                self.data[key] = value
            elif key in self.data:
                self.data.pop(key)
            if save:
                self.write()

    def write(self):
        s = repr(self.data)
        f = open(self.path,"w")
        f.write( s )
        f.close()
        if 'ANDROID_DATA' not in os.environ:
            import stat
            os.chmod(self.path,stat.S_IREAD | stat.S_IWRITE)


class Abstract_Wallet(object):
    """
    Wallet classes are created to handle various address generation methods.
    Completion states (watching-only, single account, no seed, etc) are handled inside classes.
    """
    def __init__(self, storage):
        self.storage = storage
        self.electrum_version = ELECTRUM_VERSION
        self.gap_limit_for_change = 3 # constant
        # saved fields
        self.seed_version          = storage.get('seed_version', NEW_SEED_VERSION)
        self.gap_limit             = storage.get('gap_limit', 5)
        self.use_change            = storage.get('use_change',True)
        self.use_encryption        = storage.get('use_encryption', False)
        self.seed                  = storage.get('seed', '')               # encrypted
        self.labels                = storage.get('labels', {})
        self.frozen_addresses      = storage.get('frozen_addresses',[])
        self.addressbook           = storage.get('contacts', [])

        self.history               = storage.get('addr_history',{})        # address -> list(txid, height)

        self.fee                   = int(storage.get('fee_per_kb', 1000))

        self.next_addresses = storage.get('next_addresses',{})

        # This attribute is set when wallet.start_threads is called.
        self.synchronizer = None

        # imported_keys is deprecated. The GUI should call convert_imported_keys
        self.imported_keys = self.storage.get('imported_keys',{})

        self.load_accounts()

        self.load_transactions()

        # not saved
        self.prevout_values = {}     # my own transaction outputs
        self.spent_outputs = []
        # spv
        self.verifier = None
        # there is a difference between wallet.up_to_date and interface.is_up_to_date()
        # interface.is_up_to_date() returns true when all requests have been answered and processed
        # wallet.up_to_date is true when the wallet is synchronized (stronger requirement)
        self.up_to_date = False
        self.lock = threading.Lock()
        self.transaction_lock = threading.Lock()
        self.tx_event = threading.Event()
        for tx_hash, tx in self.transactions.items():
            self.update_tx_outputs(tx_hash)

    def load_transactions(self):
        self.transactions = {}
        tx_list = self.storage.get('transactions',{})
        for k, raw in tx_list.items():
            try:
                tx = Transaction.deserialize(raw)
            except Exception, e:
                print_msg("Warning: Cannot deserialize transactions. skipping")
                continue
            self.add_pubkey_addresses(tx)
            self.transactions[k] = tx
        for h,tx in self.transactions.items():
            if not self.check_new_tx(h, tx):
                print_error("removing unreferenced tx", h)
                self.transactions.pop(h)

    def add_pubkey_addresses(self, tx):
        # find the address corresponding to pay-to-pubkey inputs
        h = tx.hash()

        # inputs
        tx.add_pubkey_addresses(self.transactions)

        # outputs of tx: inputs of tx2 
        for type, x, v in tx.outputs:
            if type == 'pubkey':
                for tx2 in self.transactions.values():
                    tx2.add_pubkey_addresses({h:tx})

    def get_action(self):
        pass

    def convert_imported_keys(self, password):
        for k, v in self.imported_keys.items():
            sec = pw_decode(v, password)
            pubkey = public_key_from_private_key(sec)
            address = public_key_to_bc_address(pubkey.decode('hex'))
            assert address == k
            self.import_key(sec, password)
            self.imported_keys.pop(k)
        self.storage.put('imported_keys', self.imported_keys)

    def load_accounts(self):
        self.accounts = {}

        d = self.storage.get('accounts', {})
        for k, v in d.items():
            if k == 0:
                v['mpk'] = self.storage.get('master_public_key')
                self.accounts[k] = OldAccount(v)
            elif v.get('imported'):
                self.accounts[k] = ImportedAccount(v)
            elif v.get('xpub3'):
                self.accounts[k] = BIP32_Account_2of3(v)
            elif v.get('xpub2'):
                self.accounts[k] = BIP32_Account_2of2(v)
            elif v.get('xpub'):
                self.accounts[k] = BIP32_Account(v)
            elif v.get('pending'):
                self.accounts[k] = PendingAccount(v)
            else:
                print_error("cannot load account", v)

    def synchronize(self):
        pass

    def can_create_accounts(self):
        return False

    def set_up_to_date(self,b):
        with self.lock: self.up_to_date = b

    def is_up_to_date(self):
        with self.lock: return self.up_to_date

    def update(self):
        self.up_to_date = False
        while not self.is_up_to_date():
            time.sleep(0.1)

    def is_imported(self, addr):
        account = self.accounts.get(IMPORTED_ACCOUNT)
        if account:
            return addr in account.get_addresses(0)
        else:
            return False

    def has_imported_keys(self):
        account = self.accounts.get(IMPORTED_ACCOUNT)
        return account is not None

    def import_key(self, sec, password):
        try:
            pubkey = public_key_from_private_key(sec)
            address = public_key_to_bc_address(pubkey.decode('hex'))
        except Exception:
            raise Exception('Invalid private key')

        if self.is_mine(address):
            raise Exception('Address already in wallet')

        if self.accounts.get(IMPORTED_ACCOUNT) is None:
            self.accounts[IMPORTED_ACCOUNT] = ImportedAccount({'imported':{}})
        self.accounts[IMPORTED_ACCOUNT].add(address, pubkey, sec, password)
        self.save_accounts()

        if self.synchronizer:
            self.synchronizer.subscribe_to_addresses([address])
        return address

    def delete_imported_key(self, addr):
        account = self.accounts[IMPORTED_ACCOUNT]
        account.remove(addr)
        if not account.get_addresses(0):
            self.accounts.pop(IMPORTED_ACCOUNT)
        self.save_accounts()

    def set_label(self, name, text = None):
        changed = False
        old_text = self.labels.get(name)
        if text:
            if old_text != text:
                self.labels[name] = text
                changed = True
        else:
            if old_text:
                self.labels.pop(name)
                changed = True

        if changed:
            self.storage.put('labels', self.labels, True)

        run_hook('set_label', name, text, changed)
        return changed

    def addresses(self, include_change = True, _next=True):
        o = []
        for a in self.accounts.keys():
            o += self.get_account_addresses(a, include_change)

        if _next:
            for addr in self.next_addresses.values():
                if addr not in o:
                    o += [addr]
        return o

    def is_mine(self, address):
        return address in self.addresses(True)

    def is_change(self, address):
        if not self.is_mine(address): return False
        acct, s = self.get_address_index(address)
        if s is None: return False
        return s[0] == 1

    def get_address_index(self, address):
        for account in self.accounts.keys():
            for for_change in [0,1]:
                addresses = self.accounts[account].get_addresses(for_change)
                for addr in addresses:
                    if address == addr:
                        return account, (for_change, addresses.index(addr))

        for k,v in self.next_addresses.items():
            if v == address:
                return k, (0,0)

        raise Exception("Address not found", address)

    def get_private_key(self, address, password):
        if self.is_watching_only():
            return []
        account_id, sequence = self.get_address_index(address)
        return self.accounts[account_id].get_private_key(sequence, self, password)

    def get_public_keys(self, address):
        account_id, sequence = self.get_address_index(address)
        return self.accounts[account_id].get_pubkeys(*sequence)

    def add_keypairs(self, tx, keypairs, password):
        # first check the provided password. This will raise if invalid.
        self.check_password(password)

        addr_list, xpub_list = tx.inputs_to_sign()
        for addr in addr_list:
            if self.is_mine(addr):
                private_keys = self.get_private_key(addr, password)
                for sec in private_keys:
                    pubkey = public_key_from_private_key(sec)
                    keypairs[ pubkey ] = sec

        for xpub, sequence in xpub_list:
            # look for account that can sign
            for k, account in self.accounts.items():
                if xpub in account.get_master_pubkeys():
                    break
            else:
                continue
            pk = account.get_private_key(sequence, self, password)
            for sec in pk:
                pubkey = public_key_from_private_key(sec)
                keypairs[pubkey] = sec

    def signrawtransaction(self, tx, private_keys, password):
        # check that the password is correct. This will raise if it's not.
        self.check_password(password)
        # build a list of public/private keys
        keypairs = {}
        # add private keys from parameter
        for sec in private_keys:
            pubkey = public_key_from_private_key(sec)
            keypairs[ pubkey ] = sec
        # add private_keys
        self.add_keypairs(tx, keypairs, password)
        # sign the transaction
        self.sign_transaction(tx, keypairs, password)

    def sign_message(self, address, message, password):
        keys = self.get_private_key(address, password)
        assert len(keys) == 1
        sec = keys[0]
        key = regenerate_key(sec)
        compressed = is_compressed(sec)
        return key.sign_message(message, compressed, address)

    def decrypt_message(self, pubkey, message, password):
        address = public_key_to_bc_address(pubkey.decode('hex'))
        keys = self.get_private_key(address, password)
        secret = keys[0]
        ec = regenerate_key(secret)
        decrypted = ec.decrypt_message(message)
        return decrypted

    def is_found(self):
        return self.history.values() != [[]] * len(self.history)

    def add_contact(self, address, label=None):
        self.addressbook.append(address)
        self.storage.put('contacts', self.addressbook, True)
        if label:
            self.set_label(address, label)

    def delete_contact(self, addr):
        if addr in self.addressbook:
            self.addressbook.remove(addr)
            self.storage.put('addressbook', self.addressbook, True)

    def fill_addressbook(self):
        for tx_hash, tx in self.transactions.items():
            is_relevant, is_send, _, _ = self.get_tx_value(tx)
            if is_send:
                for addr in tx.get_output_addresses():
                    if not self.is_mine(addr) and addr not in self.addressbook:
                        self.addressbook.append(addr)
        # redo labels
        # self.update_tx_labels()

    def get_num_tx(self, address):
        n = 0
        for tx in self.transactions.values():
            if address in tx.get_output_addresses(): n += 1
        return n

    def get_tx_value(self, tx, account=None):
        domain = self.get_account_addresses(account)
        return tx.get_value(domain, self.prevout_values)

    def update_tx_outputs(self, tx_hash):
        tx = self.transactions.get(tx_hash)

        for i, (type, addr, value) in enumerate(tx.get_outputs()):
            key = tx_hash+ ':%d'%i
            self.prevout_values[key] = value

        for item in tx.inputs:
            if self.is_mine(item.get('address')):
                key = item['prevout_hash'] + ':%d'%item['prevout_n']
                self.spent_outputs.append(key)

    def get_addr_balance(self, address):
        #assert self.is_mine(address)
        h = self.history.get(address,[])
        if h == ['*']: return 0,0
        c = u = 0
        received_coins = []   # list of coins received at address

        for tx_hash, tx_height in h:
            tx = self.transactions.get(tx_hash)
            if not tx: continue

            for i, (type, addr, value) in enumerate(tx.get_outputs()):
                if addr == address:
                    key = tx_hash + ':%d'%i
                    received_coins.append(key)

        for tx_hash, tx_height in h:
            tx = self.transactions.get(tx_hash)
            if not tx: continue
            v = 0

            for item in tx.inputs:
                addr = item.get('address')
                if addr == address:
                    key = item['prevout_hash']  + ':%d'%item['prevout_n']
                    value = self.prevout_values.get( key )
                    if key in received_coins:
                        v -= value

            for i, (type, addr, value) in enumerate(tx.get_outputs()):
                key = tx_hash + ':%d'%i
                if addr == address:
                    v += value

            if tx_height:
                c += v
            else:
                u += v
        return c, u

    def get_account_name(self, k):
        return self.labels.get(k, self.accounts[k].get_name(k))

    def get_account_names(self):
        account_names = {}
        for k in self.accounts.keys():
            account_names[k] = self.get_account_name(k)
        return account_names

    def get_account_addresses(self, a, include_change=True):
        if a is None:
            o = self.addresses(include_change)
        elif a in self.accounts:
            ac = self.accounts[a]
            o = ac.get_addresses(0)
            if include_change: o += ac.get_addresses(1)
        return o

    def get_account_balance(self, account):
        return self.get_balance(self.get_account_addresses(account))

    def get_frozen_balance(self):
        return self.get_balance(self.frozen_addresses)

    def get_balance(self, domain=None):
        if domain is None: domain = self.addresses(True)
        cc = uu = 0
        for addr in domain:
            c, u = self.get_addr_balance(addr)
            cc += c
            uu += u
        return cc, uu

    def get_unspent_coins(self, domain=None):
        coins = []
        if domain is None: domain = self.addresses(True)
        for addr in domain:
            h = self.history.get(addr, [])
            if h == ['*']: continue
            for tx_hash, tx_height in h:
                tx = self.transactions.get(tx_hash)
                if tx is None: raise Exception("Wallet not synchronized")
                outputs = tx.get_outputs()

                is_coinbase = tx.inputs[0].get('prevout_hash') == '0'*64
                is_coinstake = outputs[0][2] == 0

                #print is_coinstake

                for i, (type, address, value) in enumerate(outputs):
                    output = {'address':address, 'value':value, 'prevout_n':i}
                    if address != addr: continue
                    key = tx_hash + ":%d"%i
                    if key in self.spent_outputs: continue
                    output['prevout_hash'] = tx_hash
                    output['height'] = tx_height
                    output['coinbase'] = is_coinbase
                    output['coinstake'] = is_coinstake
                    output["type"] = type
                    coins.append((tx_height, output))

        # sort by age
        if coins:
            coins = sorted(coins)
            if coins[-1][0] != 0:
                while coins[0][0] == 0:
                    coins = coins[1:] + [ coins[0] ]
        return [x[1] for x in coins]

    def choose_tx_inputs( self, amount, fixed_fee, num_outputs, domain = None, coins = None ):
        """ todo: minimize tx size """
        total = 0
        fee = self.fee if fixed_fee is None else fixed_fee

        if not coins:
            if domain is None:
                domain = self.addresses(True)
            for i in self.frozen_addresses:
                if i in domain: domain.remove(i)
            coins = self.get_unspent_coins(domain)

        inputs = []

        for item in coins:
            if (item.get('coinbase') or item.get('coinstake')) and item.get('height') + COINBASE_MATURITY > self.network.get_local_height():
                continue
            v = item.get('value')
            total += v
            inputs.append(item)
            fee = self.estimated_fee(inputs, num_outputs) if fixed_fee is None else fixed_fee
            if total >= amount + fee: break
        else:
            inputs = []

        return inputs, total, fee

    def set_fee(self, fee):
        if self.fee != fee:
            self.fee = fee
            self.storage.put('fee_per_kb', self.fee, True)

    def estimated_fee(self, inputs, num_outputs):
        estimated_size =  len(inputs) * 180 + num_outputs * 34    # this assumes non-compressed keys
        fee = self.fee * int(math.ceil(estimated_size/1000.))
        return fee

    def add_tx_change( self, inputs, outputs, amount, fee, total, change_addr=None):
        "add change to a transaction"
        change_amount = total - ( amount + fee )
        if change_amount > DUST_THRESHOLD:
            if not change_addr:

                # send change to one of the accounts involved in the tx
                address = inputs[0].get('address')
                account, _ = self.get_address_index(address)

                if not self.use_change or account == IMPORTED_ACCOUNT:
                    change_addr = inputs[-1]['address']
                else:
                    change_addr = self.accounts[account].get_addresses(1)[-self.gap_limit_for_change]

            # Insert the change output at a random position in the outputs
            posn = random.randint(0, len(outputs))
            outputs[posn:posn] = [( 'address', change_addr,  change_amount)]
        return outputs

    def get_history(self, address):
        with self.lock:
            return self.history.get(address)

    def get_status(self, h):
        if not h: return None
        if h == ['*']: return '*'
        status = ''
        for tx_hash, height in h:
            status += tx_hash + ':%d:' % height
        return hashlib.sha256( status ).digest().encode('hex')

    def receive_tx_callback(self, tx_hash, tx, tx_height):

        with self.transaction_lock:
            self.add_pubkey_addresses(tx)
            if not self.check_new_tx(tx_hash, tx):
                # may happen due to pruning
                print_error("received transaction that is no longer referenced in history", tx_hash)
                return
            self.transactions[tx_hash] = tx
            self.network.pending_transactions_for_notifications.append(tx)
            self.save_transactions()
            if self.verifier and tx_height>0:
                self.verifier.add(tx_hash, tx_height)
            self.update_tx_outputs(tx_hash)

    def save_transactions(self):
        tx = {}
        for k,v in self.transactions.items():
            tx[k] = str(v)
        self.storage.put('transactions', tx, True)

    def receive_history_callback(self, addr, hist):

        if not self.check_new_history(addr, hist):
            raise Exception("error: received history for %s is not consistent with known transactions"%addr)

        with self.lock:
            self.history[addr] = hist
            self.storage.put('addr_history', self.history, True)

        if hist != ['*']:
            for tx_hash, tx_height in hist:
                if tx_height>0:
                    # add it in case it was previously unconfirmed
                    if self.verifier: self.verifier.add(tx_hash, tx_height)

    def get_tx_history(self, account=None):
        if not self.verifier:
            return []

        with self.transaction_lock:
            history = self.transactions.items()
            history.sort(key = lambda x: self.verifier.get_txpos(x[0]))
            result = []

            balance = 0
            for tx_hash, tx in history:
                is_relevant, is_mine, v, fee = self.get_tx_value(tx, account)
                if v is not None: balance += v

            c, u = self.get_account_balance(account)

            if balance != c+u:
                result.append( ('', 1000, 0, c+u-balance, None, c+u-balance, None ) )

            balance = c + u - balance
            for tx_hash, tx in history:
                is_relevant, is_mine, value, fee = self.get_tx_value(tx, account)
                if not is_relevant:
                    continue
                if value is not None:
                    balance += value

                conf, timestamp = self.verifier.get_confirmations(tx_hash) if self.verifier else (None, None)
                result.append( (tx_hash, conf, is_mine, value, fee, balance, timestamp) )

        return result

    def get_label(self, tx_hash):
        label = self.labels.get(tx_hash)
        is_default = (label == '') or (label is None)
        if is_default: label = self.get_default_label(tx_hash)
        return label, is_default

    def get_default_label(self, tx_hash):
        tx = self.transactions.get(tx_hash)
        default_label = ''
        if tx:
            is_relevant, is_mine, _, _ = self.get_tx_value(tx)
            if is_mine:
                for o_addr in tx.get_output_addresses():
                    if not self.is_mine(o_addr):
                        try:
                            default_label = self.labels[o_addr]
                        except KeyError:
                            default_label = '>' + o_addr
                        break
                else:
                    default_label = '(internal)'
            else:
                for o_addr in tx.get_output_addresses():
                    if self.is_mine(o_addr) and not self.is_change(o_addr):
                        break
                else:
                    for o_addr in tx.get_output_addresses():
                        if self.is_mine(o_addr):
                            break
                    else:
                        o_addr = None

                if o_addr:
                    try:
                        default_label = self.labels[o_addr]
                    except KeyError:
                        default_label = '<' + o_addr

        return default_label

    def make_unsigned_transaction(self, outputs, fee=None, change_addr=None, domain=None, coins=None ):
        for type, address, x in outputs:
            if type == 'op_return':
                continue
            if type == 'address':
                assert is_address(address), "Address " + address + " is invalid!"
        amount = sum( map(lambda x:x[2], outputs) )
        inputs, total, fee = self.choose_tx_inputs( amount, fee, len(outputs), domain, coins )
        if not inputs:
            raise ValueError("Not enough funds")
        for txin in inputs:
            self.add_input_info(txin)
        outputs = self.add_tx_change(inputs, outputs, amount, fee, total, change_addr)
        return Transaction(int(time.time()), inputs, outputs)

    def mktx(self, outputs, password, fee=None, change_addr=None, domain= None, coins = None ):
        tx = self.make_unsigned_transaction(outputs, fee, change_addr, domain, coins)
        keypairs = {}
        self.add_keypairs(tx, keypairs, password)
        if keypairs:
            self.sign_transaction(tx, keypairs, password)
        return tx

    def add_input_info(self, txin):
        address = txin['address']
        account_id, sequence = self.get_address_index(address)
        account = self.accounts[account_id]
        redeemScript = account.redeem_script(*sequence)
        pubkeys = account.get_pubkeys(*sequence)
        x_pubkeys = account.get_xpubkeys(*sequence)
        # sort pubkeys and x_pubkeys, using the order of pubkeys
        pubkeys, x_pubkeys = zip( *sorted(zip(pubkeys, x_pubkeys)))
        txin['pubkeys'] = list(pubkeys)
        txin['x_pubkeys'] = list(x_pubkeys)
        txin['signatures'] = [None] * len(pubkeys)

        if redeemScript:
            txin['redeemScript'] = redeemScript
            txin['num_sig'] = 2
        else:
            txin['redeemPubkey'] = account.get_pubkey(*sequence)
            txin['num_sig'] = 1

    def sign_transaction(self, tx, keypairs, password):
        tx.sign(keypairs)
        run_hook('sign_transaction', tx, password)

    def sendtx(self, tx):
        # synchronous
        h = self.send_tx(tx)
        self.tx_event.wait()
        return self.receive_tx(h, tx)

    def send_tx(self, tx):
        # asynchronous
        self.tx_event.clear()
        self.network.send([('blockchain.transaction.broadcast', [str(tx)])], self.on_broadcast)
        return tx.hash()

    def on_broadcast(self, i, r):
        self.tx_result = r.get('result')
        self.tx_event.set()

    def receive_tx(self, tx_hash, tx):
        out = self.tx_result
        if out != tx_hash:
            return False, "error: " + out
        run_hook('receive_tx', tx, self)
        return True, out

    def update_password(self, old_password, new_password):
        if new_password == '':
            new_password = None

        if self.has_seed():
            decoded = self.get_seed(old_password)
            self.seed = pw_encode( decoded, new_password)
            self.storage.put('seed', self.seed, True)

        imported_account = self.accounts.get(IMPORTED_ACCOUNT)
        if imported_account:
            imported_account.update_password(old_password, new_password)
            self.save_accounts()

        if hasattr(self, 'master_private_keys'):
            for k, v in self.master_private_keys.items():
                b = pw_decode(v, old_password)
                c = pw_encode(b, new_password)
                self.master_private_keys[k] = c
            self.storage.put('master_private_keys', self.master_private_keys, True)

        self.use_encryption = (new_password != None)
        self.storage.put('use_encryption', self.use_encryption,True)

    def freeze(self,addr):
        if self.is_mine(addr) and addr not in self.frozen_addresses:
            self.frozen_addresses.append(addr)
            self.storage.put('frozen_addresses', self.frozen_addresses, True)
            return True
        else:
            return False

    def unfreeze(self,addr):
        if self.is_mine(addr) and addr in self.frozen_addresses:
            self.frozen_addresses.remove(addr)
            self.storage.put('frozen_addresses', self.frozen_addresses, True)
            return True
        else:
            return False

    def set_verifier(self, verifier):
        self.verifier = verifier

        # review transactions that are in the history
        for addr, hist in self.history.items():
            if hist == ['*']: continue
            for tx_hash, tx_height in hist:
                if tx_height>0:
                    # add it in case it was previously unconfirmed
                    self.verifier.add(tx_hash, tx_height)

        # if we are on a pruning server, remove unverified transactions
        vr = self.verifier.transactions.keys() + self.verifier.verified_tx.keys()
        for tx_hash in self.transactions.keys():
            if tx_hash not in vr:
                self.transactions.pop(tx_hash)

    def check_new_history(self, addr, hist):
        # check that all tx in hist are relevant
        if hist != ['*']:
            for tx_hash, height in hist:
                tx = self.transactions.get(tx_hash)
                if not tx: continue
                if not tx.has_address(addr):
                    return False

        # check that we are not "orphaning" a transaction
        old_hist = self.history.get(addr,[])
        if old_hist == ['*']: return True

        for tx_hash, height in old_hist:
            if tx_hash in map(lambda x:x[0], hist): continue
            found = False
            for _addr, _hist in self.history.items():
                if _addr == addr: continue
                if _hist == ['*']: continue
                _tx_hist = map(lambda x:x[0], _hist)
                if tx_hash in _tx_hist:
                    found = True
                    break

            if not found:
                tx = self.transactions.get(tx_hash)
                # tx might not be there
                if not tx: continue

                # already verified?
                if self.verifier.get_height(tx_hash):
                    continue
                # unconfirmed tx
                print_error("new history is orphaning transaction:", tx_hash)
                # check that all outputs are not mine, request histories
                ext_requests = []
                for _addr in tx.get_output_addresses():
                    # assert not self.is_mine(_addr)
                    ext_requests.append( ('blockchain.address.get_history', [_addr]) )

                ext_h = self.network.synchronous_get(ext_requests)
                print_error("sync:", ext_requests, ext_h)
                height = None
                for h in ext_h:
                    if h == ['*']: continue
                    for item in h:
                        if item.get('tx_hash') == tx_hash:
                            height = item.get('height')
                if height:
                    print_error("found height for", tx_hash, height)
                    self.verifier.add(tx_hash, height)
                else:
                    print_error("removing orphaned tx from history", tx_hash)
                    self.transactions.pop(tx_hash)

        return True

    def check_new_tx(self, tx_hash, tx):
        # 1 check that tx is referenced in addr_history.
        addresses = []
        for addr, hist in self.history.items():
            if hist == ['*']:continue
            for txh, height in hist:
                if txh == tx_hash:
                    addresses.append(addr)

        if not addresses:
            return False

        # 2 check that referencing addresses are in the tx
        for addr in addresses:
            if not tx.has_address(addr):
                return False

        return True

    def start_threads(self, network):
        from verifier import TxVerifier
        self.network = network
        if self.network is not None:
            self.verifier = TxVerifier(self.network, self.storage)
            self.verifier.start()
            self.set_verifier(self.verifier)
            self.synchronizer = WalletSynchronizer(self, network)
            self.synchronizer.start()
        else:
            self.verifier = None
            self.synchronizer =None

    def stop_threads(self):
        if self.network:
            self.verifier.stop()
            self.synchronizer.stop()

    def restore(self, cb):
        pass

    def get_accounts(self):
        return self.accounts

    def save_accounts(self):
        d = {}
        for k, v in self.accounts.items():
            d[k] = v.dump()
        self.storage.put('accounts', d, True)

    def can_import(self):
        return not self.is_watching_only()

    def is_used(self, address):
        h = self.history.get(address,[])
        c, u = self.get_addr_balance(address)
        return len(h), len(h) > 0 and c == -u

    def address_is_old(self, address, age_limit=2):
        age = -1
        h = self.history.get(address, [])
        if h == ['*']:
            return True
        for tx_hash, tx_height in h:
            if tx_height == 0:
                tx_age = 0
            else:
                tx_age = self.network.get_local_height() - tx_height + 1
            if tx_age > age:
                age = tx_age
        return age > age_limit


class Imported_Wallet(Abstract_Wallet):

    def __init__(self, storage):
        Abstract_Wallet.__init__(self, storage)
        a = self.accounts.get(IMPORTED_ACCOUNT)
        if not a:
            self.accounts[IMPORTED_ACCOUNT] = ImportedAccount({'imported':{}})
        self.storage.put('wallet_type', 'imported', True)

    def is_watching_only(self):
        acc = self.accounts[IMPORTED_ACCOUNT]
        n = acc.keypairs.values()
        return n == [(None, None)] * len(n)

    def has_seed(self):
        return False

    def is_deterministic(self):
        return False

    def check_password(self, password):
        self.accounts[IMPORTED_ACCOUNT].get_private_key((0,0), self, password)

    def is_used(self, address):
        h = self.history.get(address,[])
        return len(h), False

    def get_master_public_keys(self):
        return {}

    def is_beyond_limit(self, address, account, is_change):
        return False


class Deterministic_Wallet(Abstract_Wallet):

    def __init__(self, storage):
        Abstract_Wallet.__init__(self, storage)

    def has_seed(self):
        return self.seed != ''

    def is_deterministic(self):
        return True

    def is_watching_only(self):
        return not self.has_seed()

    def add_seed(self, seed, password):
        if self.seed:
            raise Exception("a seed exists")

        self.seed_version, self.seed = self.prepare_seed(seed)
        if password:
            self.seed = pw_encode( self.seed, password)
            self.use_encryption = True
        else:
            self.use_encryption = False

        self.storage.put('seed', self.seed, True)
        self.storage.put('seed_version', self.seed_version, True)
        self.storage.put('use_encryption', self.use_encryption,True)
        self.create_master_keys(password)

    def get_seed(self, password):
        return pw_decode(self.seed, password)

    def get_mnemonic(self, password):
        return self.get_seed(password)

    def change_gap_limit(self, value):
        if value >= self.gap_limit:
            self.gap_limit = value
            self.storage.put('gap_limit', self.gap_limit, True)
            #self.interface.poke('synchronizer')
            return True

        elif value >= self.min_acceptable_gap():
            for key, account in self.accounts.items():
                addresses = account[0]
                k = self.num_unused_trailing_addresses(addresses)
                n = len(addresses) - k + value
                addresses = addresses[0:n]
                self.accounts[key][0] = addresses

            self.gap_limit = value
            self.storage.put('gap_limit', self.gap_limit, True)
            self.save_accounts()
            return True
        else:
            return False

    def num_unused_trailing_addresses(self, addresses):
        k = 0
        for a in addresses[::-1]:
            if self.history.get(a):break
            k = k + 1
        return k

    def min_acceptable_gap(self):
        # fixme: this assumes wallet is synchronized
        n = 0
        nmax = 0

        for account in self.accounts.values():
            addresses = account.get_addresses(0)
            k = self.num_unused_trailing_addresses(addresses)
            for a in addresses[0:-k]:
                if self.history.get(a):
                    n = 0
                else:
                    n += 1
                    if n > nmax: nmax = n
        return nmax + 1

    def create_new_address(self, account=None, for_change=0):
        if account is None:
            account = self.default_account()
        address = account.create_new_address(for_change)
        self.history[address] = []
        if self.synchronizer:
            self.synchronizer.add(address)
        self.save_accounts()
        return address

    def synchronize_sequence(self, account, for_change):
        limit = self.gap_limit_for_change if for_change else self.gap_limit
        while True:
            addresses = account.get_addresses(for_change)
            if len(addresses) < limit:
                self.create_new_address(account, for_change)
                continue
            if map( lambda a: self.address_is_old(a), addresses[-limit:] ) == limit*[False]:
                break
            else:
                self.create_new_address(account, for_change)

    def check_pending_accounts(self):
        for account_id, addr in self.next_addresses.items():
            if self.address_is_old(addr):
                print_error( "creating account", account_id )
                xpub = self.master_public_keys[account_id]
                account = BIP32_Account({'xpub':xpub})
                self.add_account(account_id, account)
                self.next_addresses.pop(account_id)

    def synchronize_account(self, account):
        self.synchronize_sequence(account, 0)
        self.synchronize_sequence(account, 1)

    def synchronize(self):
        self.check_pending_accounts()
        for account in self.accounts.values():
            if type(account) in [ImportedAccount, PendingAccount]:
                continue
            self.synchronize_account(account)

    def restore(self, callback):
        from i18n import _
        def wait_for_wallet():
            self.set_up_to_date(False)
            while not self.is_up_to_date():
                msg = "%s\n%s %d\n%s %.1f"%(
                    _("Please wait..."),
                    _("Addresses generated:"),
                    len(self.addresses(True)),
                    _("Kilobytes received:"),
                    self.network.interface.bytes_received/1024.)

                apply(callback, (msg,))
                time.sleep(0.1)

        def wait_for_network():
            while not self.network.is_connected():
                msg = "%s \n" % (_("Connecting..."))
                apply(callback, (msg,))
                time.sleep(0.1)

        # wait until we are connected, because the user might have selected another server
        if self.network:
            wait_for_network()
            wait_for_wallet()
        else:
            self.synchronize()
        self.fill_addressbook()

    def create_account(self, name, password):
        i = self.num_accounts()
        account_id = self.account_id(i)
        account = self.make_account(account_id, password)
        self.add_account(account_id, account)
        if name:
            self.set_label(account_id, name)

        # add address of the next account
        _, _ = self.next_account_address(password)


    def add_account(self, account_id, account):
        self.accounts[account_id] = account
        self.save_accounts()

    def account_is_pending(self, k):
        return type(self.accounts.get(k)) == PendingAccount

    def delete_pending_account(self, k):
        assert self.account_is_pending(k)
        self.accounts.pop(k)
        self.save_accounts()

    def create_pending_account(self, name, password):
        account_id, addr = self.next_account_address(password)
        self.set_label(account_id, name)
        self.accounts[account_id] = PendingAccount({'pending':addr})
        self.save_accounts()

    def is_beyond_limit(self, address, account, is_change):
        if type(account) == ImportedAccount:
            return False
        addr_list = account.get_addresses(is_change)
        i = addr_list.index(address)
        prev_addresses = addr_list[:max(0, i)]
        limit = self.gap_limit_for_change if is_change else self.gap_limit
        if len(prev_addresses) < limit:
            return False
        prev_addresses = prev_addresses[max(0, i - limit):]
        for addr in prev_addresses:
            if self.history.get(addr):
                return False
        return True

    def get_action(self):
        if not self.get_master_public_key():
            return 'create_seed'
        if not self.accounts:
            return 'create_accounts'


class NewWallet(Deterministic_Wallet):

    def __init__(self, storage):
        Deterministic_Wallet.__init__(self, storage)
        self.master_public_keys  = storage.get('master_public_keys', {})
        self.master_private_keys = storage.get('master_private_keys', {})

    def default_account(self):
        return self.accounts["m/0'"]

    def is_watching_only(self):
        return not bool(self.master_private_keys)

    def can_create_accounts(self):
        return 'm/' in self.master_private_keys.keys()

    def get_master_public_key(self):
        """xpub of the main account"""
        return self.master_public_keys.get("m/0'")

    def get_master_public_keys(self):
        out = {}
        for k, account in self.accounts.items():
            name = self.get_account_name(k)
            mpk_text = '\n\n'.join( account.get_master_pubkeys() )
            out[name] = mpk_text
        return out

    def get_master_private_key(self, account, password):
        k = self.master_private_keys.get(account)
        if not k: return
        xpriv = pw_decode( k, password)
        return xpriv

    def check_password(self, password):
        xpriv = self.get_master_private_key( "m/", password )
        xpub = self.master_public_keys["m/"]
        assert deserialize_xkey(xpriv)[3] == deserialize_xkey(xpub)[3]

    def create_xprv_wallet(self, xprv, password):
        xpub = bitcoin.xpub_from_xprv(xprv)
        account = BIP32_Account({'xpub':xpub})
        account_id = 'm/' + bitcoin.get_xkey_name(xpub)
        self.storage.put('seed_version', self.seed_version, True)
        self.add_master_private_key(account_id, xprv, password)
        self.add_master_public_key(account_id, xpub)
        self.add_account(account_id, account)

    def create_watching_only_wallet(self, xpub):
        account = BIP32_Account({'xpub':xpub})
        account_id = 'm/' + bitcoin.get_xkey_name(xpub)
        self.storage.put('seed_version', self.seed_version, True)
        self.add_master_public_key(account_id, xpub)
        self.add_account(account_id, account)

    def create_accounts(self, password):
        # First check the password is valid (this raises if it isn't).
        if not self.is_watching_only():
            self.check_password(password)
        self.create_account('Main account', password)

    def add_master_public_key(self, name, xpub):
        self.master_public_keys[name] = xpub
        self.storage.put('master_public_keys', self.master_public_keys, True)

    def add_master_private_key(self, name, xpriv, password):
        self.master_private_keys[name] = pw_encode(xpriv, password)
        self.storage.put('master_private_keys', self.master_private_keys, True)

    def add_master_keys(self, root, account_id, password):
        x = self.master_private_keys.get(root)
        if x:
            master_xpriv = pw_decode(x, password )
            xpriv, xpub = bip32_private_derivation(master_xpriv, root, account_id)
            self.add_master_public_key(account_id, xpub)
            self.add_master_private_key(account_id, xpriv, password)
        else:
            master_xpub = self.master_public_keys[root]
            xpub = bip32_public_derivation(master_xpub, root, account_id)
            self.add_master_public_key(account_id, xpub)
        return xpub

    def create_master_keys(self, password):
        xpriv, xpub = bip32_root(mnemonic_to_seed(self.get_seed(password),'').encode('hex'))
        self.add_master_public_key("m/", xpub)
        self.add_master_private_key("m/", xpriv, password)

    def can_sign(self, tx):
        if self.is_watching_only():
            return False
        if tx.is_complete():
            return False
        addr_list, xpub_list = tx.inputs_to_sign()
        for addr in addr_list:
            if self.is_mine(addr):
                return True
        mpk = [ self.master_public_keys[k] for k in self.master_private_keys.keys() ]
        for xpub, sequence in xpub_list:
            if xpub in mpk:
                return True
        return False

    def num_accounts(self):
        keys = []
        for k, v in self.accounts.items():
            if type(v) != BIP32_Account:
                continue
            keys.append(k)

        i = 0
        while True:
            account_id = self.account_id(i)
            if account_id not in keys: break
            i += 1
        return i

    def next_account_address(self, password):
        i = self.num_accounts()
        account_id = self.account_id(i)

        addr = self.next_addresses.get(account_id)
        if not addr:
            account = self.make_account(account_id, password)
            addr = account.first_address()
            self.next_addresses[account_id] = addr
            self.storage.put('next_addresses', self.next_addresses)

        return account_id, addr

    def account_id(self, i):
        return "m/%d'"%i

    def make_account(self, account_id, password):
        """Creates and saves the master keys, but does not save the account"""
        xpub = self.add_master_keys("m/", account_id, password)
        account = BIP32_Account({'xpub':xpub})
        return account

    def make_seed(self):
        import mnemonic, ecdsa
        entropy = ecdsa.util.randrange( pow(2,160) )
        nonce = 0
        while True:
            ss = "%040x"%(entropy+nonce)
            s = hashlib.sha256(ss.decode('hex')).digest().encode('hex')
            # we keep only 13 words, that's approximately 139 bits of entropy
            words = mnemonic.mn_encode(s)[0:13]
            seed = ' '.join(words)
            if is_new_seed(seed):
                break  # this will remove 8 bits of entropy
            nonce += 1
        return seed

    def prepare_seed(self, seed):
        import unicodedata
        return NEW_SEED_VERSION, unicodedata.normalize('NFC', unicode(seed.strip()))


class Wallet_2of2(NewWallet):
    """ This class is used for multisignature addresses"""

    def __init__(self, storage):
        NewWallet.__init__(self, storage)
        self.storage.put('wallet_type', '2of2', True)

    def default_account(self):
        return self.accounts['m/']

    def can_create_accounts(self):
        return False

    def can_import(self):
        return False

    def create_account(self, name, password):
        xpub1 = self.master_public_keys.get("m/")
        xpub2 = self.master_public_keys.get("cold/")
        account = BIP32_Account_2of2({'xpub':xpub1, 'xpub2':xpub2})
        self.add_account('m/', account)

    def get_master_public_keys(self):
        xpub1 = self.master_public_keys.get("m/")
        xpub2 = self.master_public_keys.get("cold/")
        return {'hot':xpub1, 'cold':xpub2}

    def get_action(self):
        xpub1 = self.master_public_keys.get("m/")
        xpub2 = self.master_public_keys.get("cold/")
        if xpub1 is None:
            return 'create_seed'
        if xpub2 is None:
            return 'add_cosigner'
        if not self.accounts:
            return 'create_accounts'


class Wallet_2of3(Wallet_2of2):
    """ This class is used for multisignature addresses"""

    def __init__(self, storage):
        Wallet_2of2.__init__(self, storage)
        self.storage.put('wallet_type', '2of3', True)

    def create_account(self, name, password):
        xpub1 = self.master_public_keys.get("m/")
        xpub2 = self.master_public_keys.get("cold/")
        xpub3 = self.master_public_keys.get("remote/")
        account = BIP32_Account_2of3({'xpub':xpub1, 'xpub2':xpub2, 'xpub3':xpub3})
        self.add_account('m/', account)

    def get_master_public_keys(self):
        xpub1 = self.master_public_keys.get("m/")
        xpub2 = self.master_public_keys.get("cold/")
        xpub3 = self.master_public_keys.get("remote/")
        return {'hot':xpub1, 'cold':xpub2, 'remote':xpub3}

    def get_action(self):
        xpub1 = self.master_public_keys.get("m/")
        xpub2 = self.master_public_keys.get("cold/")
        xpub3 = self.master_public_keys.get("remote/")
        if xpub1 is None:
            return 'create_seed'
        if xpub2 is None or xpub3 is None:
            return 'add_two_cosigners'
        if not self.accounts:
            return 'create_accounts'


class OldWallet(Deterministic_Wallet):

    def default_account(self):
        return self.accounts[0]

    def make_seed(self):
        import mnemonic
        seed = random_seed(128)
        return ' '.join(mnemonic.mn_encode(seed))

    def prepare_seed(self, seed):
        import mnemonic
        # see if seed was entered as hex
        seed = seed.strip()
        try:
            assert seed
            seed.decode('hex')
            return OLD_SEED_VERSION, str(seed)
        except Exception:
            pass

        words = seed.split()
        seed = mnemonic.mn_decode(words)
        if not seed:
            raise Exception("Invalid seed")

        return OLD_SEED_VERSION, seed

    def create_master_keys(self, password):
        seed = self.get_seed(password)
        mpk = OldAccount.mpk_from_seed(seed)
        self.storage.put('master_public_key', mpk, True)

    def get_master_public_key(self):
        return self.storage.get("master_public_key")

    def get_master_public_keys(self):
        return {'Main Account':self.get_master_public_key()}

    def create_accounts(self, password):
        mpk = self.storage.get("master_public_key")
        self.create_account(mpk)

    def create_account(self, mpk):
        self.accounts[0] = OldAccount({'mpk':mpk, 0:[], 1:[]})
        self.save_accounts()

    def create_watching_only_wallet(self, mpk):
        self.seed_version = OLD_SEED_VERSION
        self.storage.put('seed_version', self.seed_version, True)
        self.storage.put('master_public_key', mpk, True)
        self.create_account(mpk)

    def get_seed(self, password):
        seed = pw_decode(self.seed, password).encode('utf8')
        return seed

    def check_password(self, password):
        seed = self.get_seed(password)
        self.accounts[0].check_seed(seed)

    def get_mnemonic(self, password):
        import mnemonic
        s = self.get_seed(password)
        return ' '.join(mnemonic.mn_encode(s))

    def check_pending_accounts(self):
        pass

    def can_sign(self, tx):
        if self.is_watching_only():
            return False
        if tx.is_complete():
            return False
        addr_list, xpub_list = tx.inputs_to_sign()
        for addr in addr_list:
            if self.is_mine(addr):
                return True
        for xpub, sequence in xpub_list:
            if xpub == self.master_public_key:
                return True
        return False

# former WalletFactory
class Wallet(object):
    """The main wallet "entry point".
    This class is actually a factory that will return a wallet of the correct
    type when passed a WalletStorage instance."""

    def __new__(self, storage):
        config = storage.config

        self.wallet_types = [ 
            ('standard', ("Standard wallet"),          NewWallet if config.get('bip32') else OldWallet),
            ('imported', ("Imported wallet"),          Imported_Wallet),
            ('2of2',     ("Multisig wallet (2 of 2)"), Wallet_2of2),
            ('2of3',     ("Multisig wallet (2 of 3)"), Wallet_2of3)
        ]
        run_hook('add_wallet_types', self.wallet_types)

        for t, l, WalletClass in self.wallet_types:
            if t == storage.get('wallet_type'):
                return WalletClass(storage)

        if not storage.file_exists:
            seed_version = NEW_SEED_VERSION if config.get('bip32') is True else OLD_SEED_VERSION
        else:
            seed_version = storage.get('seed_version')
            if not seed_version:
                seed_version = OLD_SEED_VERSION if len(storage.get('master_public_key')) == 128 else NEW_SEED_VERSION

        if seed_version == OLD_SEED_VERSION:
            return OldWallet(storage)
        elif seed_version == NEW_SEED_VERSION:
            return NewWallet(storage)
        else:
            msg = "This wallet seed is not supported."
            if seed_version in [5]:
                msg += "\nTo open this wallet, try 'git checkout seed_v%d'"%seed_version
            print msg
            sys.exit(1)

    @classmethod
    def is_seed(self, seed):
        if not seed:
            return False
        elif is_old_seed(seed):
            return True
        elif is_new_seed(seed):
            return True
        else:
            return False

    @classmethod
    def is_old_mpk(self, mpk):
        try:
            int(mpk, 16)
            assert len(mpk) == 128
            return True
        except:
            return False

    @classmethod
    def is_xpub(self, text):
        try:
            assert text[0:4] == 'xpub'
            deserialize_xkey(text)
            return True
        except:
            return False

    @classmethod
    def is_xprv(self, text):
        try:
            assert text[0:4] == 'xprv'
            deserialize_xkey(text)
            return True
        except:
            return False

    @classmethod
    def is_address(self, text):
        if not text:
            return False
        for x in text.split():
            if not bitcoin.is_address(x):
                return False
        return True

    @classmethod
    def is_private_key(self, text):
        if not text:
            return False
        for x in text.split():
            if not bitcoin.is_private_key(x):
                return False
        return True

    @classmethod
    def from_seed(self, seed, storage):
        if is_old_seed(seed):
            klass = OldWallet
        elif is_new_seed(seed):
            klass = NewWallet
        w = klass(storage)
        return w

    @classmethod
    def from_address(self, text, storage):
        w = Imported_Wallet(storage)
        for x in text.split():
            w.accounts[IMPORTED_ACCOUNT].add(x, None, None, None)
        w.save_accounts()
        return w

    @classmethod
    def from_private_key(self, text, storage):
        w = Imported_Wallet(storage)
        for x in text.split():
            w.import_key(x, None)
        return w

    @classmethod
    def from_old_mpk(self, mpk, storage):
        w = OldWallet(storage)
        w.seed = ''
        w.create_watching_only_wallet(mpk)
        return w

    @classmethod
    def from_xpub(self, xpub, storage):
        w = NewWallet(storage)
        w.create_watching_only_wallet(xpub)
        return w

    @classmethod
    def from_xprv(self, xprv, password, storage):
        w = NewWallet(storage)
        w.create_xprv_wallet(xprv, password)
        return w