# This file is part of the TREZOR project.

#

# Copyright (C) 2012-2016 Marek Palatinus <slush@satoshilabs.com>

# Copyright (C) 2012-2016 Pavol Rusnak <stick@satoshilabs.com>

# Copyright (C) 2016 Jochen Hoenicke <hoenicke@gmail.com>

#

# This library is free software: you can redistribute it and/or modify

# it under the terms of the GNU Lesser General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This library 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 Lesser General Public License for more details.

#

# You should have received a copy of the GNU Lesser General Public License

# along with this library. If not, see <http://www.gnu.org/licenses/>.

import binascii

from decimal import Decimal

import requests

import json

from . import types_pb2 as proto_types

cache_dir = None

class TxApi(object):

def __init__(self, network, url):

self.network = network

self.url = url

def fetch_json(self, url, resource, resourceid):

global cache_dir

if cache_dir:

cache_file = '%s/%s_%s_%s.json' % (cache_dir, self.network, resource, resourceid)

try: # looking into cache first

j = json.load(open(cache_file))

return j

except:

pass

try:

r = requests.get('%s/%s/%s' % (self.url, resource, resourceid), headers={'User-agent': 'Mozilla/5.0'})

j = r.json()

except:

raise Exception('URL error: %s' % url)

if cache_file:

try: # saving into cache

json.dump(j, open(cachefile, 'w'))

except:

pass

return j

def get_tx(self, txhash):

raise NotImplementedError

class TxApiInsight(TxApi):

def __init__(self, network, url, zcash=None):

super(TxApiInsight, self).__init__(network, url)

self.zcash = zcash

def get_tx(self, txhash):

data = self.fetch_json(self.url, 'tx', txhash)

t = proto_types.TransactionType()

t.version = data['version']

t.lock_time = data['locktime']

for vin in data['vin']:

i = t.inputs.add()

if 'coinbase' in vin.keys():

i.prev_hash = b"\0"*32

i.prev_index = 0xffffffff # signed int -1

i.script_sig = binascii.unhexlify(vin['coinbase'])

i.sequence = vin['sequence']

else:

i.prev_hash = binascii.unhexlify(vin['txid'])

i.prev_index = vin['vout']

i.script_sig = binascii.unhexlify(vin['scriptSig']['hex'])

i.sequence = vin['sequence']

for vout in data['vout']:

o = t.bin_outputs.add()

o.amount = int(Decimal(str(vout['value'])) * 100000000)

o.script_pubkey = binascii.unhexlify(vout['scriptPubKey']['hex'])

if self.zcash:

if t.version == 2:

joinsplit_cnt = len(data['vjoinsplit'])

if joinsplit_cnt == 0:

t.extra_data =b'\x00'

else:

if joinsplit_cnt >= 253:

# we assume cnt < 253, so we can treat varIntLen(cnt) as 1

raise ValueError('Too many joinsplits')

extra_data_len = 1 + joinsplit_cnt * 1802 + 32 + 64

raw = self.fetch_json(self.url, 'rawtx', txhash)

raw = binascii.unhexlify(raw['rawtx'])

t.extra_data = raw[-extra_data_len:]

return t

def get_raw_tx(self, txhash):

data = self.fetch_json(self.url, 'rawtx', txhash)['rawtx']

return data

class TxApiSmartbit(TxApi):

def get_tx(self, txhash):

data = self.fetch_json(self.url, 'tx', txhash)

data = data['transaction']

t = proto_types.TransactionType()

t.version = int(data['version'])

t.lock_time = data['locktime']

for vin in data['inputs']:

i = t.inputs.add()

if 'coinbase' in vin.keys():

i.prev_hash = b"\0"*32

i.prev_index = 0xffffffff # signed int -1

i.script_sig = binascii.unhexlify(vin['coinbase'])

i.sequence = vin['sequence']

else:

i.prev_hash = binascii.unhexlify(vin['txid'])

i.prev_index = vin['vout']

i.script_sig = binascii.unhexlify(vin['script_sig']['hex'])

i.sequence = vin['sequence']

for vout in data['outputs']:

o = t.bin_outputs.add()

o.amount = int(Decimal(vout['value']) * 100000000)

o.script_pubkey = binascii.unhexlify(vout['script_pub_key']['hex'])

return t

TxApiBitcoin = TxApiInsight(network='insight_bitcoin', url='https://insight.bitpay.com/api/')

TxApiTestnet = TxApiInsight(network='insight_testnet', url='https://test-insight.bitpay.com/api/')

TxApiSegnet = TxApiSmartbit(network='smartbit_segnet', url='https://segnet-api.smartbit.com.au/v1/blockchain/')

TxApiZcashTestnet = TxApiInsight(network='insight_zcashtestnet', url='https://explorer.testnet.z.cash/api/', zcash=True)