# Path: pycoind/util/base58.py
# def decode_check(payload):
#     'Returns the base58 decoded value, verifying the checksum.'
#     payload = b58decode(payload, None)
#     if payload and sha256d(payload[:-4])[:4] == payload[-4:]:
#         return payload[:-4]
#     return None
# 
# def encode_check(payload):
#     'Returns the base58 encoding with a 4-byte checksum.'
# 
#     checksum = sha256d(payload)[:4]
#     return b58encode(payload + checksum)
# 
# Path: pycoind/util/hash.py
# def sha256d(data):
#     return sha256(sha256(data))
# 
# Path: pycoind/util/key.py
# def privkey_from_wif(privkey, prefix = chr(0x80)):
#     key = base58.decode_check(privkey)
#     if prefix != key[0]:
#         raise ValueError('wif private key has does not match prefix')
#     if len(key) == 33:
#         if privkey[0] != '5':
#             raise ValueError('uncompressed wif private key does not begin with 5')
#         return key[1:]
#     elif len(key) == 34:
#         if key[-1] != chr(0x01):
#             raise ValueError('compressed wif private key missing compression bit')
#         if privkey[0] not in ('L', 'K'):
#             raise ValueError('uncompressed wif private key does not begin with 5')
#         return key[1:-1]
#     raise ValueError('invalid wif private key')
# 
# def privkey_to_wif(privkey, prefix = chr(0x80)):
#     return base58.encode_check(prefix + privkey)
# 
# def publickey_to_address(publickey, version = chr(0)):
#     return pubkeyhash_to_address(hash160(publickey), version)


import base64
from .base58 import decode_check, encode_check
from .hash import sha256d
from .ecdsa import SECP256k1 as curve
from .ecdsa import ellipticcurve
from .ecdsa.util import randrange, string_to_number, number_to_string
from .key import privkey_from_wif, privkey_to_wif, publickey_to_address

__all__ = ['get_address', 'combine_private_keys']


def get_address(public_key, private_key, version = chr(0)):
    'Returns the address generated by combiningn a public key and private key.'

    # valid public key?
    if len(public_key) != 65 or public_key[0] != chr(0x04):
        raise ValueError('public key must be decompressed')

    # the public key's elliptic curve point
    x = string_to_number(public_key[1:1 + curve.baselen])
    y = string_to_number(public_key[1 + curve.baselen:])
    public_point = ellipticcurve.Point(curve.curve, x, y, curve.order)

    # the private key's public key's elliptic curve point
    private_key = privkey_from_wif(private_key)
    secexp = string_to_number(private_key)
    private_point = curve.generator * secexp

    # add them together
    combined = public_point + private_point

    # compute the new public key
    x = number_to_string(combined.x(), curve.order)
    y = number_to_string(combined.y(), curve.order)
    key_combined = chr(0x04) + x + y

    # return the public key's address

# Path: pycoind/util/base58.py
# def decode_check(payload):
#     'Returns the base58 decoded value, verifying the checksum.'
#     payload = b58decode(payload, None)
#     if payload and sha256d(payload[:-4])[:4] == payload[-4:]:
#         return payload[:-4]
#     return None
# 
# def encode_check(payload):
#     'Returns the base58 encoding with a 4-byte checksum.'
# 
#     checksum = sha256d(payload)[:4]
#     return b58encode(payload + checksum)
# 
# Path: pycoind/util/hash.py
# def sha256d(data):
#     return sha256(sha256(data))
# 
# Path: pycoind/util/key.py
# def privkey_from_wif(privkey, prefix = chr(0x80)):
#     key = base58.decode_check(privkey)
#     if prefix != key[0]:
#         raise ValueError('wif private key has does not match prefix')
#     if len(key) == 33:
#         if privkey[0] != '5':
#             raise ValueError('uncompressed wif private key does not begin with 5')
#         return key[1:]
#     elif len(key) == 34:
#         if key[-1] != chr(0x01):
#             raise ValueError('compressed wif private key missing compression bit')
#         if privkey[0] not in ('L', 'K'):
#             raise ValueError('uncompressed wif private key does not begin with 5')
#         return key[1:-1]
#     raise ValueError('invalid wif private key')
# 
# def privkey_to_wif(privkey, prefix = chr(0x80)):
#     return base58.encode_check(prefix + privkey)
# 
# def publickey_to_address(publickey, version = chr(0)):
#     return pubkeyhash_to_address(hash160(publickey), version)


# Path: pycoind/util/piecewise.py
import base64
from .base58 import decode_check, encode_check
from .hash import sha256d
from .ecdsa import SECP256k1 as curve
from .ecdsa import ellipticcurve
from .ecdsa.util import randrange, string_to_number, number_to_string
from .key import privkey_from_wif, privkey_to_wif, publickey_to_address


__all__ = ['get_address', 'combine_private_keys']


def get_address(public_key, private_key, version = chr(0)):
    'Returns the address generated by combiningn a public key and private key.'

    # valid public key?
    if len(public_key) != 65 or public_key[0] != chr(0x04):
        raise ValueError('public key must be decompressed')

    # the public key's elliptic curve point
    x = string_to_number(public_key[1:1 + curve.baselen])
    y = string_to_number(public_key[1 + curve.baselen:])
    public_point = ellipticcurve.Point(curve.curve, x, y, curve.order)

    # the private key's public key's elliptic curve point
    private_key = privkey_from_wif(private_key)
    secexp = string_to_number(private_key)
    private_point = curve.generator * secexp

    # add them together
    combined = public_point + private_point

    # compute the new public key
    x = number_to_string(combined.x(), curve.order)
    y = number_to_string(combined.y(), curve.order)
    key_combined = chr(0x04) + x + y

    # return the public key's address

    return publickey_to_address(key_combined, version = version)