11from dataclasses import dataclass
22from enum import Enum
33from io import BytesIO
4- from typing import Callable
4+ from typing import Callable , Optional
55
6- from .argtypes import ArgType
6+ from .argtypes import ArgType , SignerType
77from .btctools import script , key
88from .btctools .auth_proxy import AuthServiceProxy
99from .btctools .messages import COutPoint , CTransaction , CTxIn , CTxInWitness
@@ -245,6 +245,36 @@ def __repr__(self):
245245 return f"{ self .__class__ .__name__ } { self .naked_internal_pubkey .hex ()}
246246
247247
248+ # Encapsulates a blind signer for one or more known keys.
249+ # Used byt the ContractManager to sign for the clause arguments of SignerType type.
250+ #
251+ # In the real world, we wouldn't blindly sign a hash, so the `sign` method
252+ # would include other info to help the signer decide (e.g.: the transaction)
253+ # There are no bad people here, though, so we keep it simple for now.
254+ class SchnorrSigner :
255+ def __init__ (self , keys : key .ExtendedKey | list [key .ExtendedKey ]):
256+ if not isinstance (keys , list ):
257+ keys = [keys ]
258+
259+ for key in keys :
260+ if not key .is_private :
261+ raise ValueError ("The SchnorrSigner needs the private keys" )
262+
263+ self .keys = keys
264+
265+ def sign (self , msg : bytes , pubkey : bytes ) -> bytes | None :
266+ if len (msg ) != 32 :
267+ raise ValueError ("msg should be 32 bytes long" )
268+ if len (pubkey ) != 32 :
269+ raise ValueError ("pubkey should be an x-only pubkey" )
270+
271+ for k in self .keys :
272+ if k .pubkey [1 :] == pubkey :
273+ return key .sign_schnorr (k .privkey , msg )
274+
275+ return None
276+
277+
248278class ContractInstanceStatus (Enum ):
249279 ABSTRACT = 0
250280 FUNDED = 1
@@ -258,6 +288,8 @@ def __init__(self, contract: StandardP2TR | StandardAugmentedP2TR):
258288
259289 self .data_expanded = None # TODO: figure out a good API for this
260290
291+ self .manager : ContractManager = None
292+
261293 self .last_height = 0
262294
263295 self .status = ContractInstanceStatus .ABSTRACT
@@ -303,6 +335,15 @@ def __repr__(self):
303335 value = self .funding_tx .vout [self .outpoint .n ].nValue
304336 return f"{ self .__class__ .__name__ } { self .contract } { self .data if self .data is None else self .data .hex ()} { value } { self .status } { self .outpoint }
305337
338+ def __call__ (self , clause_name : str , * , signer : Optional [SchnorrSigner ] = None , outputs : list [CTxOut ] = [], ** kwargs ) -> list ['ContractInstance' ]:
339+ if self .manager is None :
340+ raise ValueError ("Direct invocation is only allowed after adding the instance to a ContractManager" )
341+
342+ if self .status != ContractInstanceStatus .FUNDED :
343+ raise ValueError ("Only implemented for FUNDED instances" )
344+
345+ return self .manager .spend_instance (self , clause_name , kwargs , signer = signer , outputs = outputs )
346+
306347
307348class ContractManager :
308349 def __init__ (self , contract_instances : list [ContractInstance ], rpc : AuthServiceProxy , * , poll_interval : float = 1 , mine_automatically : bool = False ):
@@ -324,6 +365,10 @@ def _check_instance(self, instance: ContractInstance, exp_statuses: None | Contr
324365 raise ValueError ("Instance not in this manager" )
325366
326367 def add_instance (self , instance : ContractInstance ):
368+ if instance .manager is not None :
369+ raise ValueError ("The instance can only be added to one ContractManager" )
370+
371+ instance .manager = self
327372 self .instances .append (instance )
328373
329374 def wait_for_outpoint (self , instance : ContractInstance , txid : str | None = None ):
@@ -544,3 +589,54 @@ def wait_for_spend(self, instances: ContractInstance | list[ContractInstance]) -
544589 for instance in result :
545590 self .add_instance (instance )
546591 return result
592+
593+ def fund_instance (self , contract : StandardP2TR | StandardAugmentedP2TR , amount : int , data : Optional [bytes ] = None ) -> ContractInstance :
594+ """
595+ Convenience method to create an instance of a contract, add it to the ContractManager,
596+ and send a transaction to fund it with a certain amount.
597+ """
598+ instance = ContractInstance (contract )
599+
600+ if isinstance (contract , StandardP2TR ) and data is not None :
601+ raise ValueError ("The data must None for a contract with no embedded data" )
602+
603+ if isinstance (contract , StandardAugmentedP2TR ):
604+ if data is None :
605+ raise ValueError ("The data must be provided for an augmented P2TR contract instance" )
606+ instance .data = data
607+ self .add_instance (instance )
608+ txid = self .rpc .sendtoaddress (instance .get_address (), amount / 100_000_000 )
609+ self .wait_for_outpoint (instance , txid )
610+ return instance
611+
612+ def spend_instance (self , instance : ContractInstance , clause_name : str , args : dict , * , signer : Optional [SchnorrSigner ], outputs : Optional [list [CTxOut ]] = None ) -> list [ContractInstance ]:
613+ """
614+ Creates and broadcasts a transaction that spends a contract instance using a specified clause and arguments.
615+
616+ :param instance: The ContractInstance to spend from.
617+ :param clause_name: The name of the clause to be executed in the contract.
618+ :param args: A dictionary of arguments required for the clause.
619+ :param outputs: if not None, a list of CTxOut to add at the end of the list of
620+ outputs generated by the clause.
621+ :return: A list of ContractInstances resulting from the spend transaction.
622+ """
623+ spend_tx , sighashes = self .get_spend_tx ((instance , clause_name , args ))
624+
625+ assert len (sighashes ) == 1
626+
627+ sighash = sighashes [0 ]
628+
629+ if outputs is not None :
630+ spend_tx .vout .extend (outputs )
631+
632+ clause = instance .contract ._clauses_dict [clause_name ] # TODO: refactor, accessing private member
633+ for arg_name , arg_type in clause .arg_specs :
634+ if isinstance (arg_type , SignerType ):
635+ if signer is None :
636+ raise ValueError ("No signer was provided, but the witness requires signatures" )
637+ args [arg_name ] = signer .sign (sighash , arg_type .pubkey )
638+
639+ spend_tx .wit .vtxinwit = [self .get_spend_wit (instance , clause_name , args )]
640+ result = self .spend_and_wait (instance , spend_tx )
641+
642+ return result
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