#!/usr/bin/env python2
#
# 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/>.


# Note: The deserialization code originally comes from ABE.


from bitcoin import *
from util import print_error
import time
import struct

#
# Workalike python implementation of Bitcoin's CDataStream class.
#
import struct
import StringIO
import mmap

class SerializationError(Exception):
    """ Thrown when there's a problem deserializing or serializing """

class BCDataStream(object):
    def __init__(self):
        self.input = None
        self.read_cursor = 0

    def clear(self):
        self.input = None
        self.read_cursor = 0

    def write(self, bytes):  # Initialize with string of bytes
        if self.input is None:
            self.input = bytes
        else:
            self.input += bytes

    def map_file(self, file, start):  # Initialize with bytes from file
        self.input = mmap.mmap(file.fileno(), 0, access=mmap.ACCESS_READ)
        self.read_cursor = start

    def seek_file(self, position):
        self.read_cursor = position
        
    def close_file(self):
        self.input.close()

    def read_string(self):
        # Strings are encoded depending on length:
        # 0 to 252 :  1-byte-length followed by bytes (if any)
        # 253 to 65,535 : byte'253' 2-byte-length followed by bytes
        # 65,536 to 4,294,967,295 : byte '254' 4-byte-length followed by bytes
        # ... and the Bitcoin client is coded to understand:
        # greater than 4,294,967,295 : byte '255' 8-byte-length followed by bytes of string
        # ... but I don't think it actually handles any strings that big.
        if self.input is None:
            raise SerializationError("call write(bytes) before trying to deserialize")

        try:
            length = self.read_compact_size()
        except IndexError:
            raise SerializationError("attempt to read past end of buffer")

        return self.read_bytes(length)

    def write_string(self, string):
        # Length-encoded as with read-string
        self.write_compact_size(len(string))
        self.write(string)

    def read_bytes(self, length):
        try:
            result = self.input[self.read_cursor:self.read_cursor+length]
            self.read_cursor += length
            return result
        except IndexError:
            raise SerializationError("attempt to read past end of buffer")

        return ''

    def read_boolean(self): return self.read_bytes(1)[0] != chr(0)
    def read_int16(self): return self._read_num('<h')
    def read_uint16(self): return self._read_num('<H')
    def read_int32(self): return self._read_num('<i')
    def read_uint32(self): return self._read_num('<I')
    def read_int64(self): return self._read_num('<q')
    def read_uint64(self): return self._read_num('<Q')

    def write_boolean(self, val): return self.write(chr(1) if val else chr(0))
    def write_int16(self, val): return self._write_num('<h', val)
    def write_uint16(self, val): return self._write_num('<H', val)
    def write_int32(self, val): return self._write_num('<i', val)
    def write_uint32(self, val): return self._write_num('<I', val)
    def write_int64(self, val): return self._write_num('<q', val)
    def write_uint64(self, val): return self._write_num('<Q', val)

    def read_compact_size(self):
        size = ord(self.input[self.read_cursor])
        self.read_cursor += 1
        if size == 253:
            size = self._read_num('<H')
        elif size == 254:
            size = self._read_num('<I')
        elif size == 255:
            size = self._read_num('<Q')
        return size

    def write_compact_size(self, size):
        if size < 0:
            raise SerializationError("attempt to write size < 0")
        elif size < 253:
            self.write(chr(size))
        elif size < 2**16:
            self.write('\xfd')
            self._write_num('<H', size)
        elif size < 2**32:
            self.write('\xfe')
            self._write_num('<I', size)
        elif size < 2**64:
            self.write('\xff')
            self._write_num('<Q', size)

    def _read_num(self, format):
        (i,) = struct.unpack_from(format, self.input, self.read_cursor)
        self.read_cursor += struct.calcsize(format)
        return i

    def _write_num(self, format, num):
        s = struct.pack(format, num)
        self.write(s)

#
# enum-like type
# From the Python Cookbook, downloaded from http://code.activestate.com/recipes/67107/
#
import types, string, exceptions

class EnumException(exceptions.Exception):
    pass

class Enumeration:
    def __init__(self, name, enumList):
        self.__doc__ = name
        lookup = { }
        reverseLookup = { }
        i = 0
        uniqueNames = [ ]
        uniqueValues = [ ]
        for x in enumList:
            if type(x) == types.TupleType:
                x, i = x
            if type(x) != types.StringType:
                raise EnumException, "enum name is not a string: " + x
            if type(i) != types.IntType:
                raise EnumException, "enum value is not an integer: " + i
            if x in uniqueNames:
                raise EnumException, "enum name is not unique: " + x
            if i in uniqueValues:
                raise EnumException, "enum value is not unique for " + x
            uniqueNames.append(x)
            uniqueValues.append(i)
            lookup[x] = i
            reverseLookup[i] = x
            i = i + 1
        self.lookup = lookup
        self.reverseLookup = reverseLookup
    def __getattr__(self, attr):
        if not self.lookup.has_key(attr):
            raise AttributeError
        return self.lookup[attr]
    def whatis(self, value):
        return self.reverseLookup[value]


# This function comes from bitcointools, bct-LICENSE.txt.
def long_hex(bytes):
    return bytes.encode('hex_codec')

# This function comes from bitcointools, bct-LICENSE.txt.
def short_hex(bytes):
    t = bytes.encode('hex_codec')
    if len(t) < 11:
        return t
    return t[0:4]+"..."+t[-4:]




def parse_redeemScript(bytes):
    dec = [ x for x in script_GetOp(bytes.decode('hex')) ]

    # 2 of 2
    match = [ opcodes.OP_2, opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4, opcodes.OP_2, opcodes.OP_CHECKMULTISIG ]
    if match_decoded(dec, match):
        pubkeys = [ dec[1][1].encode('hex'), dec[2][1].encode('hex') ]
        return 2, pubkeys

    # 2 of 3
    match = [ opcodes.OP_2, opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4, opcodes.OP_3, opcodes.OP_CHECKMULTISIG ]
    if match_decoded(dec, match):
        pubkeys = [ dec[1][1].encode('hex'), dec[2][1].encode('hex'), dec[3][1].encode('hex') ]
        return 2, pubkeys



opcodes = Enumeration("Opcodes", [
    ("OP_0", 0), ("OP_PUSHDATA1",76), "OP_PUSHDATA2", "OP_PUSHDATA4", "OP_1NEGATE", "OP_RESERVED",
    "OP_1", "OP_2", "OP_3", "OP_4", "OP_5", "OP_6", "OP_7",
    "OP_8", "OP_9", "OP_10", "OP_11", "OP_12", "OP_13", "OP_14", "OP_15", "OP_16",
    "OP_NOP", "OP_VER", "OP_IF", "OP_NOTIF", "OP_VERIF", "OP_VERNOTIF", "OP_ELSE", "OP_ENDIF", "OP_VERIFY",
    "OP_RETURN", "OP_TOALTSTACK", "OP_FROMALTSTACK", "OP_2DROP", "OP_2DUP", "OP_3DUP", "OP_2OVER", "OP_2ROT", "OP_2SWAP",
    "OP_IFDUP", "OP_DEPTH", "OP_DROP", "OP_DUP", "OP_NIP", "OP_OVER", "OP_PICK", "OP_ROLL", "OP_ROT",
    "OP_SWAP", "OP_TUCK", "OP_CAT", "OP_SUBSTR", "OP_LEFT", "OP_RIGHT", "OP_SIZE", "OP_INVERT", "OP_AND",
    "OP_OR", "OP_XOR", "OP_EQUAL", "OP_EQUALVERIFY", "OP_RESERVED1", "OP_RESERVED2", "OP_1ADD", "OP_1SUB", "OP_2MUL",
    "OP_2DIV", "OP_NEGATE", "OP_ABS", "OP_NOT", "OP_0NOTEQUAL", "OP_ADD", "OP_SUB", "OP_MUL", "OP_DIV",
    "OP_MOD", "OP_LSHIFT", "OP_RSHIFT", "OP_BOOLAND", "OP_BOOLOR",
    "OP_NUMEQUAL", "OP_NUMEQUALVERIFY", "OP_NUMNOTEQUAL", "OP_LESSTHAN",
    "OP_GREATERTHAN", "OP_LESSTHANOREQUAL", "OP_GREATERTHANOREQUAL", "OP_MIN", "OP_MAX",
    "OP_WITHIN", "OP_RIPEMD160", "OP_SHA1", "OP_SHA256", "OP_HASH160",
    "OP_HASH256", "OP_CODESEPARATOR", "OP_CHECKSIG", "OP_CHECKSIGVERIFY", "OP_CHECKMULTISIG",
    "OP_CHECKMULTISIGVERIFY",
    ("OP_SINGLEBYTE_END", 0xF0),
    ("OP_DOUBLEBYTE_BEGIN", 0xF000),
    "OP_PUBKEY", "OP_PUBKEYHASH",
    ("OP_INVALIDOPCODE", 0xFFFF),
])


def script_GetOp(bytes):
    i = 0
    while i < len(bytes):
        vch = None
        opcode = ord(bytes[i])
        i += 1
        if opcode >= opcodes.OP_SINGLEBYTE_END:
            opcode <<= 8
            opcode |= ord(bytes[i])
            i += 1

        if opcode <= opcodes.OP_PUSHDATA4:
            nSize = opcode
            if opcode == opcodes.OP_PUSHDATA1:
                nSize = ord(bytes[i])
                i += 1
            elif opcode == opcodes.OP_PUSHDATA2:
                (nSize,) = struct.unpack_from('<H', bytes, i)
                i += 2
            elif opcode == opcodes.OP_PUSHDATA4:
                (nSize,) = struct.unpack_from('<I', bytes, i)
                i += 4
            vch = bytes[i:i+nSize]
            i += nSize

        yield (opcode, vch, i)


def script_GetOpName(opcode):
    return (opcodes.whatis(opcode)).replace("OP_", "")


def decode_script(bytes):
    result = ''
    for (opcode, vch, i) in script_GetOp(bytes):
        if len(result) > 0: result += " "
        if opcode <= opcodes.OP_PUSHDATA4:
            result += "%d:"%(opcode,)
            result += short_hex(vch)
        else:
            result += script_GetOpName(opcode)
    return result


def match_decoded(decoded, to_match):
    if len(decoded) != len(to_match):
        return False;
    for i in range(len(decoded)):
        if to_match[i] == opcodes.OP_PUSHDATA4 and decoded[i][0] <= opcodes.OP_PUSHDATA4 and decoded[i][0]>0:
            continue  # Opcodes below OP_PUSHDATA4 all just push data onto stack, and are equivalent.
        if to_match[i] != decoded[i][0]:
            return False
    return True

def get_address_from_input_script(bytes):
    try:
        decoded = [ x for x in script_GetOp(bytes) ]
    except Exception:
        # coinbase transactions raise an exception
        print_error("cannot find address in input script", bytes.encode('hex'))
        return [], {}, "(None)"

    # payto_pubkey
    match = [ opcodes.OP_PUSHDATA4 ]
    if match_decoded(decoded, match):
        return None, {}, "(pubkey)"

    # non-generated TxIn transactions push a signature
    # (seventy-something bytes) and then their public key
    # (65 bytes) onto the stack:
    match = [ opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4 ]
    if match_decoded(decoded, match):
        sig = decoded[0][1].encode('hex')
        pubkey = decoded[1][1].encode('hex')
        if sig[-2:] == '01':
            sig = sig[:-2]
            return [pubkey], {pubkey:sig}, public_key_to_bc_address(pubkey.decode('hex'))
        else:
            print_error("cannot find address in input script", bytes.encode('hex'))
            return [], {}, "(None)"


    # p2sh transaction, 2 of n
    match = [ opcodes.OP_0 ]
    while len(match) < len(decoded):
        match.append(opcodes.OP_PUSHDATA4)

    if match_decoded(decoded, match):

        redeemScript = decoded[-1][1]
        num = len(match) - 2
        signatures = map(lambda x:x[1][:-1].encode('hex'), decoded[1:-1])

        dec2 = [ x for x in script_GetOp(redeemScript) ]

        # 2 of 2
        match2 = [ opcodes.OP_2, opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4, opcodes.OP_2, opcodes.OP_CHECKMULTISIG ]
        if match_decoded(dec2, match2):
            pubkeys = [ dec2[1][1].encode('hex'), dec2[2][1].encode('hex') ]
            return pubkeys, signatures, hash_160_to_bc_address(hash_160(redeemScript), 5)
 
        # 2 of 3
        match2 = [ opcodes.OP_2, opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4, opcodes.OP_3, opcodes.OP_CHECKMULTISIG ]
        if match_decoded(dec2, match2):
            pubkeys = [ dec2[1][1].encode('hex'), dec2[2][1].encode('hex'), dec2[3][1].encode('hex') ]
            return pubkeys, signatures, hash_160_to_bc_address(hash_160(redeemScript), 5)

    print_error("cannot find address in input script", bytes.encode('hex'))
    return [], {}, "(None)"



def get_address_from_output_script(bytes):
    decoded = [ x for x in script_GetOp(bytes) ]

    # The Genesis Block, self-payments, and pay-by-IP-address payments look like:
    # 65 BYTES:... CHECKSIG
    match = [ opcodes.OP_PUSHDATA4, opcodes.OP_CHECKSIG ]
    if match_decoded(decoded, match):
        return True, public_key_to_bc_address(decoded[0][1])

    # Pay-by-Bitcoin-address TxOuts look like:
    # DUP HASH160 20 BYTES:... EQUALVERIFY CHECKSIG
    match = [ opcodes.OP_DUP, opcodes.OP_HASH160, opcodes.OP_PUSHDATA4, opcodes.OP_EQUALVERIFY, opcodes.OP_CHECKSIG ]
    if match_decoded(decoded, match):
        return False, hash_160_to_bc_address(decoded[2][1])

    # p2sh
    match = [ opcodes.OP_HASH160, opcodes.OP_PUSHDATA4, opcodes.OP_EQUAL ]
    if match_decoded(decoded, match):
        return False, hash_160_to_bc_address(decoded[1][1],5)

    return False, "(None)"


class Transaction:
    
    def __init__(self, raw):
        self.raw = raw
        self.deserialize()
        self.inputs = self.d['inputs']
        self.outputs = self.d['outputs']
        self.outputs = map(lambda x: (x['address'],x['value']), self.outputs)
        self.locktime = self.d['lockTime']

    def __str__(self):
        return self.raw

    @classmethod
    def from_io(klass, inputs, outputs):
        raw = klass.serialize(inputs, outputs, for_sig = None) # for_sig=-1 means do not sign
        self = klass(raw)
        self.inputs = inputs
        self.outputs = outputs
        return self

    @classmethod 
    def sweep(klass, privkeys, network, to_address, fee):
        inputs = []
        for privkey in privkeys:
            pubkey = public_key_from_private_key(privkey)
            address = address_from_private_key(privkey)
            u = network.synchronous_get([ ('blockchain.address.listunspent',[address])])[0]
            pay_script = klass.pay_script(address)
            for item in u:
                item['scriptPubKey'] = pay_script
                item['redeemPubkey'] = pubkey
                item['address'] = address
                item['prevout_hash'] = item['tx_hash']
                item['prevout_n'] = item['tx_pos']
            inputs += u

        if not inputs:
            return

        total = sum( map(lambda x:int(x.get('value')), inputs) ) - fee
        outputs = [(to_address, total)]
        self = klass.from_io(inputs, outputs)
        self.sign({ pubkey:privkey })
        return self

    @classmethod
    def multisig_script(klass, public_keys, num=None):
        n = len(public_keys)
        if num is None: num = n
        # supports only "2 of 2", and "2 of 3" transactions
        assert num <= n and n in [2,3]
    
        if num==2:
            s = '52'
        elif num == 3:
            s = '53'
        else:
            raise
    
        for k in public_keys:
            s += var_int(len(k)/2)
            s += k
        if n==2:
            s += '52'
        elif n==3:
            s += '53'
        else:
            raise
        s += 'ae'

        return s


    @classmethod
    def pay_script(self, addr):
        addrtype, hash_160 = bc_address_to_hash_160(addr)
        if addrtype == 48:
            script = '76a9'                                      # op_dup, op_hash_160
            script += '14'                                       # push 0x14 bytes
            script += hash_160.encode('hex')
            script += '88ac'                                     # op_equalverify, op_checksig
        elif addrtype == 5:
            script = 'a9'                                        # op_hash_160
            script += '14'                                       # push 0x14 bytes
            script += hash_160.encode('hex')
            script += '87'                                       # op_equal
        else:
            raise
        return script


    @classmethod
    def serialize( klass, inputs, outputs, for_sig = None ):

        push_script = lambda x: op_push(len(x)/2) + x
        s  = int_to_hex(1,4)                                         # version
        s += var_int( len(inputs) )                                  # number of inputs
        for i in range(len(inputs)):
            txin = inputs[i]
            s += txin['prevout_hash'].decode('hex')[::-1].encode('hex')   # prev hash
            s += int_to_hex(txin['prevout_n'],4)                          # prev index

            signatures = txin.get('signatures', {})
            if for_sig is None and not signatures:
                script = ''

            elif for_sig is None:
                pubkeys = txin['pubkeys']
                sig_list = ''
                for pubkey in pubkeys:
                    sig = signatures.get(pubkey)
                    if not sig: 
                        continue
                    sig = sig + '01'
                    sig_list += push_script(sig)

                if not txin.get('redeemScript'):
                    script = sig_list
                    script += push_script(pubkeys[0])
                else:
                    script = '00'                                    # op_0
                    script += sig_list
                    redeem_script = klass.multisig_script(pubkeys,2)
                    assert redeem_script == txin.get('redeemScript')
                    script += push_script(redeem_script)

            elif for_sig==i:
                if txin.get('redeemScript'):
                    script = txin['redeemScript']                    # p2sh uses the inner script
                else:
                    script = txin['scriptPubKey']                    # scriptsig
            else:
                script = ''
            s += var_int( len(script)/2 )                            # script length
            s += script
            s += "ffffffff"                                          # sequence

        s += var_int( len(outputs) )                                 # number of outputs
        for output in outputs:
            addr, amount = output
            s += int_to_hex( amount, 8)                              # amount
            script = klass.pay_script(addr)
            s += var_int( len(script)/2 )                           #  script length
            s += script                                             #  script
        s += int_to_hex(0,4)                                        #  lock time
        if for_sig is not None and for_sig != -1:
            s += int_to_hex(1, 4)                                   #  hash type
        return s


    def tx_for_sig(self,i):
        return self.serialize(self.inputs, self.outputs, for_sig = i)


    def hash(self):
        return Hash(self.raw.decode('hex') )[::-1].encode('hex')

    def add_signature(self, i, pubkey, sig):
        txin = self.inputs[i]
        signatures = txin.get("signatures",{})
        signatures[pubkey] = sig
        txin["signatures"] = signatures
        self.inputs[i] = txin
        print_error("adding signature for", pubkey)
        self.raw = self.serialize( self.inputs, self.outputs )


    def is_complete(self):
        for i, txin in enumerate(self.inputs):
            redeem_script = txin.get('redeemScript')
            num, redeem_pubkeys = parse_redeemScript(redeem_script) if redeem_script else (1, [txin.get('redeemPubkey')])
            signatures = txin.get("signatures",{})
            if len(signatures) == num:
                continue
            else:
                return False
        return True



    def sign(self, keypairs):
        print_error("tx.sign(), keypairs:", keypairs)

        for i, txin in enumerate(self.inputs):

            # if the input is multisig, parse redeem script
            redeem_script = txin.get('redeemScript')
            num, redeem_pubkeys = parse_redeemScript(redeem_script) if redeem_script else (1, [txin.get('redeemPubkey')])

            # add pubkeys
            txin["pubkeys"] = redeem_pubkeys
            # get list of already existing signatures
            signatures = txin.get("signatures",{})
            # continue if this txin is complete
            if len(signatures) == num:
                continue

            for_sig = Hash(self.tx_for_sig(i).decode('hex'))
            for pubkey in redeem_pubkeys:
                if pubkey in keypairs.keys():
                    # add signature
                    sec = keypairs[pubkey]
                    pkey = regenerate_key(sec)
                    secexp = pkey.secret
                    private_key = ecdsa.SigningKey.from_secret_exponent( secexp, curve = SECP256k1 )
                    public_key = private_key.get_verifying_key()
                    sig = private_key.sign_digest_deterministic( for_sig, hashfunc=hashlib.sha256, sigencode = ecdsa.util.sigencode_der )
                    assert public_key.verify_digest( sig, for_sig, sigdecode = ecdsa.util.sigdecode_der)
                    self.add_signature(i, pubkey, sig.encode('hex'))


        print_error("is_complete", self.is_complete())
        self.raw = self.serialize( self.inputs, self.outputs )



    def deserialize(self):
        vds = BCDataStream()
        vds.write(self.raw.decode('hex'))
        d = {}
        start = vds.read_cursor
        d['version'] = vds.read_int32()
        n_vin = vds.read_compact_size()
        d['inputs'] = []
        for i in xrange(n_vin):
            d['inputs'].append(self.parse_input(vds))
        n_vout = vds.read_compact_size()
        d['outputs'] = []
        for i in xrange(n_vout):
            d['outputs'].append(self.parse_output(vds, i))
        d['lockTime'] = vds.read_uint32()
        self.d = d
        return self.d
    

    def parse_input(self, vds):
        d = {}
        prevout_hash = hash_encode(vds.read_bytes(32))
        prevout_n = vds.read_uint32()
        scriptSig = vds.read_bytes(vds.read_compact_size())
        sequence = vds.read_uint32()

        if prevout_hash == '00'*32:
            d['is_coinbase'] = True
        else:
            d['is_coinbase'] = False
            d['prevout_hash'] = prevout_hash
            d['prevout_n'] = prevout_n
            d['sequence'] = sequence
            if scriptSig:
                pubkeys, signatures, address = get_address_from_input_script(scriptSig)
            else:
                pubkeys = []
                signatures = {}
                address = None
            d['address'] = address
            d['pubkeys'] = pubkeys
            d['signatures'] = signatures
        return d


    def parse_output(self, vds, i):
        d = {}
        d['value'] = vds.read_int64()
        scriptPubKey = vds.read_bytes(vds.read_compact_size())
        is_pubkey, address = get_address_from_output_script(scriptPubKey)
        d['is_pubkey'] = is_pubkey
        d['address'] = address
        d['scriptPubKey'] = scriptPubKey.encode('hex')
        d['prevout_n'] = i
        return d


    def add_extra_addresses(self, txlist):
        for i in self.inputs:
            if i.get("address") == "(pubkey)":
                prev_tx = txlist.get(i.get('prevout_hash'))
                if prev_tx:
                    address, value = prev_tx.outputs[i.get('prevout_n')]
                    print_error("found pay-to-pubkey address:", address)
                    i["address"] = address


    def has_address(self, addr):
        found = False
        for txin in self.inputs:
            if addr == txin.get('address'): 
                found = True
                break
        for txout in self.outputs:
            if addr == txout[0]:
                found = True
                break
        return found


    def get_value(self, addresses, prevout_values):
        # return the balance for that tx
        is_relevant = False
        is_send = False
        is_pruned = False
        is_partial = False
        v_in = v_out = v_out_mine = 0

        for item in self.inputs:
            addr = item.get('address')
            if addr in addresses:
                is_send = True
                is_relevant = True
                key = item['prevout_hash']  + ':%d'%item['prevout_n']
                value = prevout_values.get( key )
                if value is None:
                    is_pruned = True
                else:
                    v_in += value
            else:
                is_partial = True

        if not is_send: is_partial = False
                    
        for item in self.outputs:
            addr, value = item
            v_out += value
            if addr in addresses:
                v_out_mine += value
                is_relevant = True

        if is_pruned:
            # some inputs are mine:
            fee = None
            if is_send:
                v = v_out_mine - v_out
            else:
                # no input is mine
                v = v_out_mine

        else:
            v = v_out_mine - v_in

            if is_partial:
                # some inputs are mine, but not all
                fee = None
                is_send = v < 0
            else:
                # all inputs are mine
                fee = v_out - v_in

        return is_relevant, is_send, v, fee


    def get_input_info(self):
        keys = ['prevout_hash', 'prevout_n', 'address', 'KeyID', 'scriptPubKey', 'redeemScript', 'redeemPubkey', 'pubkeys', 'signatures', 'is_coinbase']
        info = []
        for i in self.inputs:
            item = {}
            for k in keys:
                v = i.get(k)
                if v is not None:
                    item[k] = v
            info.append(item)
        return info


    def as_dict(self):
        import json
        out = {
            "hex":self.raw,
            "complete":self.is_complete()
            }

        if not self.is_complete():
            input_info = self.get_input_info()
            out['input_info'] = json.dumps(input_info).replace(' ','')

        return out


    def required_fee(self, verifier):
        # see https://en.bitcoin.it/wiki/Transaction_fees
        threshold = 57600000*4
        size = len(self.raw)/2

        fee = 0
        for o in self.outputs:
            value = o[1]
            if value < DUST_SOFT_LIMIT:
                fee += MIN_RELAY_TX_FEE
        sum = 0
        for i in self.inputs:
            age = verifier.get_confirmations(i["prevout_hash"])[0]
            sum += i["value"] * age
        priority = sum / size
        print_error(priority, threshold)
        if size < 5000 and fee == 0 and priority > threshold:
            return 0
        fee += (1 + size / 1000) * MIN_RELAY_TX_FEE
        print_error(fee)
        return fee



    def add_input_info(self, input_info):
        for i, txin in enumerate(self.inputs):
            item = input_info[i]
            txin['scriptPubKey'] = item['scriptPubKey']
            txin['redeemScript'] = item.get('redeemScript')
            txin['redeemPubkey'] = item.get('redeemPubkey')
            txin['KeyID'] = item.get('KeyID')
            txin['signatures'] = item.get('signatures',{})
