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from .errors import MiniscriptError
from .base import DescriptorBase
from .miniscript import Miniscript
from ..hashes import tagged_hash
from ..script import Script
class TapLeaf(DescriptorBase):
def __init__(self, miniscript=None, version=0xC0):
self.miniscript = miniscript
self.version = version
def __str__(self):
return str(self.miniscript)
@classmethod
def read_from(cls, s):
ms = Miniscript.read_from(s, taproot=True)
return cls(ms)
def serialize(self):
if self.miniscript is None:
return b""
return bytes([self.version]) + Script(self.miniscript.compile()).serialize()
@property
def keys(self):
return self.miniscript.keys
def derive(self, *args, **kwargs):
if self.miniscript is None:
return type(self)(None, version=self.version)
return type(self)(
self.miniscript.derive(*args, **kwargs),
self.version,
)
def branch(self, *args, **kwargs):
if self.miniscript is None:
return type(self)(None, version=self.version)
return type(self)(
self.miniscript.branch(*args, **kwargs),
self.version,
)
def to_public(self, *args, **kwargs):
if self.miniscript is None:
return type(self)(None, version=self.version)
return type(self)(
self.miniscript.to_public(*args, **kwargs),
self.version,
)
def _tweak_helper(tree):
# https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki#constructing-and-spending-taproot-outputs
if isinstance(tree, TapTree):
tree = tree.tree
if isinstance(tree, TapLeaf):
# one leaf on this branch
h = tagged_hash("TapLeaf", tree.serialize())
return ([(tree, b"")], h)
left, left_h = _tweak_helper(tree[0])
right, right_h = _tweak_helper(tree[1])
ret = [(leaf, c + right_h) for leaf, c in left] + [
(leaf, c + left_h) for leaf, c in right
]
if right_h < left_h:
left_h, right_h = right_h, left_h
return (ret, tagged_hash("TapBranch", left_h + right_h))
class TapTree(DescriptorBase):
def __init__(self, tree=None):
"""tree can be None, TapLeaf or a tuple (taptree, taptree)"""
self.tree = tree
# make sure all keys are taproot
for k in self.keys:
k.taproot = True
def __bool__(self):
return bool(self.tree)
def tweak(self):
if self.tree is None:
return b""
_, h = _tweak_helper(self.tree)
return h
@property
def keys(self):
if self.tree is None:
return []
if isinstance(self.tree, TapLeaf):
return self.tree.keys
left, right = self.tree
return left.keys + right.keys
@classmethod
def read_from(cls, s):
c = s.read(1)
if len(c) == 0:
return cls()
if c == b"{": # more than one miniscript
left = cls.read_from(s)
c = s.read(1)
if c == b"}":
return left
if c != b",":
raise MiniscriptError("Invalid taptree syntax: expected ','")
right = cls.read_from(s)
if s.read(1) != b"}":
raise MiniscriptError("Invalid taptree syntax: expected '}'")
return cls((left, right))
s.seek(-1, 1)
ms = TapLeaf.read_from(s)
return cls(ms)
def derive(self, *args, **kwargs):
if self.tree is None:
return type(self)(None)
if isinstance(self.tree, TapLeaf):
return type(self)(self.tree.derive(*args, **kwargs))
left, right = self.tree
return type(self)((left.derive(*args, **kwargs), right.derive(*args, **kwargs)))
def branch(self, *args, **kwargs):
if self.tree is None:
return type(self)(None)
if isinstance(self.tree, TapLeaf):
return type(self)(self.tree.branch(*args, **kwargs))
left, right = self.tree
return type(self)((left.branch(*args, **kwargs), right.branch(*args, **kwargs)))
def to_public(self, *args, **kwargs):
if self.tree is None:
return type(self)(None)
if isinstance(self.tree, TapLeaf):
return type(self)(self.tree.to_public(*args, **kwargs))
left, right = self.tree
return type(self)(
(left.to_public(*args, **kwargs), right.to_public(*args, **kwargs))
)
def __str__(self):
if self.tree is None:
return ""
if isinstance(self.tree, TapLeaf):
return str(self.tree)
(left, right) = self.tree
return "{%s,%s}" % (left, right)
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