#!/usr/bin/env python3
# Copyright (c) 2016-present The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test NULLDUMMY softfork.

Connect to a single node.
Generate 2 blocks (save the coinbases for later).
Generate COINBASE_MATURITY (CB) more blocks to ensure the coinbases are mature.
[Policy/Consensus] Check that NULLDUMMY compliant transactions are accepted in block CB + 3.
[Policy] Check that non-NULLDUMMY transactions are rejected before activation.
[Consensus] Check that the new NULLDUMMY rules are not enforced on block CB + 4.
[Policy/Consensus] Check that the new NULLDUMMY rules are enforced on block CB + 5.
"""
import time

from test_framework.address import address_to_scriptpubkey
from test_framework.blocktools import (
    COINBASE_MATURITY,
    NORMAL_GBT_REQUEST_PARAMS,
    add_witness_commitment,
    create_block,
)
from test_framework.messages import (
    CTransaction,
    tx_from_hex,
)
from test_framework.script import (
    OP_0,
    OP_TRUE,
)
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import (
    assert_equal,
    assert_raises_rpc_error,
)
from test_framework.wallet import getnewdestination
from test_framework.wallet_util import generate_keypair

NULLDUMMY_TX_ERROR = "mempool-script-verify-flag-failed (Dummy CHECKMULTISIG argument must be zero)"
NULLDUMMY_BLK_ERROR = "block-script-verify-flag-failed (Dummy CHECKMULTISIG argument must be zero)"

def invalidate_nulldummy_tx(tx):
    """Transform a NULLDUMMY compliant tx (i.e. scriptSig starts with OP_0)
    to be non-NULLDUMMY compliant by replacing the dummy with OP_TRUE"""
    assert_equal(tx.vin[0].scriptSig[0], OP_0)
    tx.vin[0].scriptSig = bytes([OP_TRUE]) + tx.vin[0].scriptSig[1:]


class NULLDUMMYTest(BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 1
        self.setup_clean_chain = True
        # This script tests NULLDUMMY activation, which is part of the 'segwit' deployment, so we go through
        # normal segwit activation here (and don't use the default always-on behaviour).
        self.extra_args = [[
            f'-testactivationheight=segwit@{COINBASE_MATURITY + 5}',
            '-addresstype=legacy',
        ]]

    def create_transaction(self, *, txid, input_details=None, addr, amount, privkey):
        input = {"txid": txid, "vout": 0}
        output = {addr: amount}
        rawtx = self.nodes[0].createrawtransaction([input], output)
        # Details only needed for scripthash or witness spends
        input = None if not input_details else [{**input, **input_details}]
        signedtx = self.nodes[0].signrawtransactionwithkey(rawtx, [privkey], input)
        return tx_from_hex(signedtx["hex"])

    def run_test(self):
        self.privkey, self.pubkey = generate_keypair(wif=True)
        cms = self.nodes[0].createmultisig(1, [self.pubkey.hex()])
        wms = self.nodes[0].createmultisig(1, [self.pubkey.hex()], 'p2sh-segwit')
        self.ms_address = cms["address"]
        ms_unlock_details = {"scriptPubKey": address_to_scriptpubkey(self.ms_address).hex(),
                             "redeemScript": cms["redeemScript"]}
        self.wit_ms_address = wms['address']

        self.coinbase_blocks = self.generate(self.nodes[0], 2)  # block height = 2
        coinbase_txid = []
        for i in self.coinbase_blocks:
            coinbase_txid.append(self.nodes[0].getblock(i)['tx'][0])
        self.generate(self.nodes[0], COINBASE_MATURITY)  # block height = COINBASE_MATURITY + 2
        self.lastblockhash = self.nodes[0].getbestblockhash()
        self.lastblockheight = COINBASE_MATURITY + 2
        self.lastblocktime = int(time.time()) + self.lastblockheight

        self.log.info(f"Test 1: NULLDUMMY compliant base transactions should be accepted to mempool and mined before activation [{COINBASE_MATURITY + 3}]")
        test1txs = [self.create_transaction(txid=coinbase_txid[0], addr=self.ms_address, amount=49,
                                            privkey=self.nodes[0].get_deterministic_priv_key().key)]
        txid1 = self.nodes[0].sendrawtransaction(test1txs[0].serialize_with_witness().hex(), 0)
        test1txs.append(self.create_transaction(txid=txid1, input_details=ms_unlock_details,
                                                addr=self.ms_address, amount=48,
                                                privkey=self.privkey))
        txid2 = self.nodes[0].sendrawtransaction(test1txs[1].serialize_with_witness().hex(), 0)
        test1txs.append(self.create_transaction(txid=coinbase_txid[1],
                                                addr=self.wit_ms_address, amount=49,
                                                privkey=self.nodes[0].get_deterministic_priv_key().key))
        txid3 = self.nodes[0].sendrawtransaction(test1txs[2].serialize_with_witness().hex(), 0)
        self.block_submit(self.nodes[0], test1txs, accept=True)

        self.log.info("Test 2: Non-NULLDUMMY base multisig transaction should not be accepted to mempool before activation")
        test2tx = self.create_transaction(txid=txid2, input_details=ms_unlock_details,
                                          addr=self.ms_address, amount=47,
                                          privkey=self.privkey)
        invalidate_nulldummy_tx(test2tx)
        assert_raises_rpc_error(-26, NULLDUMMY_TX_ERROR, self.nodes[0].sendrawtransaction, test2tx.serialize_with_witness().hex(), 0)

        self.log.info(f"Test 3: Non-NULLDUMMY base transactions should be accepted in a block before activation [{COINBASE_MATURITY + 4}]")
        self.block_submit(self.nodes[0], [test2tx], accept=True)

        self.log.info("Test 4: Non-NULLDUMMY base multisig transaction is invalid after activation")
        test4tx = self.create_transaction(txid=test2tx.txid_hex, input_details=ms_unlock_details,
                                          addr=getnewdestination()[2], amount=46,
                                          privkey=self.privkey)
        test6txs = [CTransaction(test4tx)]
        invalidate_nulldummy_tx(test4tx)
        assert_raises_rpc_error(-26, NULLDUMMY_TX_ERROR, self.nodes[0].sendrawtransaction, test4tx.serialize_with_witness().hex(), 0)
        self.block_submit(self.nodes[0], [test4tx], accept=False)

        self.log.info("Test 5: Non-NULLDUMMY P2WSH multisig transaction invalid after activation")
        test5tx = self.create_transaction(txid=txid3, input_details={"scriptPubKey": test1txs[2].vout[0].scriptPubKey.hex(),
                                          "amount": 49, "witnessScript": wms["redeemScript"]},
                                          addr=getnewdestination(address_type='p2sh-segwit')[2], amount=48,
                                          privkey=self.privkey)
        test6txs.append(CTransaction(test5tx))
        test5tx.wit.vtxinwit[0].scriptWitness.stack[0] = b'\x01'
        assert_raises_rpc_error(-26, NULLDUMMY_TX_ERROR, self.nodes[0].sendrawtransaction, test5tx.serialize_with_witness().hex(), 0)
        self.block_submit(self.nodes[0], [test5tx], with_witness=True, accept=False)

        self.log.info(f"Test 6: NULLDUMMY compliant base/witness transactions should be accepted to mempool and in block after activation [{COINBASE_MATURITY + 5}]")
        for i in test6txs:
            self.nodes[0].sendrawtransaction(i.serialize_with_witness().hex(), 0)
        self.block_submit(self.nodes[0], test6txs, with_witness=True, accept=True)

    def block_submit(self, node, txs, *, with_witness=False, accept):
        tmpl = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)
        assert_equal(tmpl['previousblockhash'], self.lastblockhash)
        assert_equal(tmpl['height'], self.lastblockheight + 1)
        block = create_block(tmpl=tmpl, ntime=self.lastblocktime + 1, txlist=txs)
        if with_witness:
            add_witness_commitment(block)
        block.solve()
        assert_equal(None if accept else NULLDUMMY_BLK_ERROR, node.submitblock(block.serialize().hex()))
        if accept:
            assert_equal(node.getbestblockhash(), block.hash_hex)
            self.lastblockhash = block.hash_hex
            self.lastblocktime += 1
            self.lastblockheight += 1
        else:
            assert_equal(node.getbestblockhash(), self.lastblockhash)


if __name__ == '__main__':
    NULLDUMMYTest(__file__).main()
