#!/usr/bin/env python3
# Copyright (c) 2015 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 activation of the first version bits soft fork.

This soft fork will activate the following BIPS:
BIP 68  - nSequence relative lock times
BIP 112 - CHECKSEQUENCEVERIFY
BIP 113 - MedianTimePast semantics for nLockTime

regtest lock-in with 108/144 block signalling
activation after a further 144 blocks

mine 82 blocks whose coinbases will be used to generate inputs for our tests
mine 61 blocks to transition from DEFINED to STARTED
mine 144 blocks only 100 of which are signaling readiness in order to fail to change state this period
mine 144 blocks with 108 signaling and verify STARTED->LOCKED_IN
mine 140 blocks and seed block chain with the 82 inputs will use for our tests at height 572
mine 3 blocks and verify still at LOCKED_IN and test that enforcement has not triggered
mine 1 block and test that enforcement has triggered (which triggers ACTIVE)
Test BIP 113 is enforced
Mine 4 blocks so next height is 580 and test BIP 68 is enforced for time and height
Mine 1 block so next height is 581 and test BIP 68 now passes time but not height
Mine 1 block so next height is 582 and test BIP 68 now passes time and height
Test that BIP 112 is enforced

Various transactions will be used to test that the BIPs rules are not enforced before the soft fork activates
And that after the soft fork activates transactions pass and fail as they should according to the rules.
For each BIP, transactions of versions 1 and 2 will be tested.
----------------
BIP 113:
bip113tx - modify the nLocktime variable

BIP 68:
bip68txs - 16 txs with nSequence relative locktime of 10 with various bits set as per the relative_locktimes below

BIP 112:
bip112txs_vary_nSequence - 16 txs with nSequence relative_locktimes of 10 evaluated against 10 OP_CSV OP_DROP
bip112txs_vary_nSequence_9 - 16 txs with nSequence relative_locktimes of 9 evaluated against 10 OP_CSV OP_DROP
bip112txs_vary_OP_CSV - 16 txs with nSequence = 10 evaluated against varying {relative_locktimes of 10} OP_CSV OP_DROP
bip112txs_vary_OP_CSV_9 - 16 txs with nSequence = 9 evaluated against varying {relative_locktimes of 10} OP_CSV OP_DROP
bip112tx_special - test negative argument to OP_CSV
"""
from decimal import Decimal
from itertools import product
from io import BytesIO

from test_framework.blocktools import create_coinbase, create_block
from test_framework.mininode import ToHex, CTransaction
from test_framework.mininode import network_thread_start, P2PDataStore
from test_framework.script import (
    CScript,
    OP_CHECKSEQUENCEVERIFY,
    OP_DROP,
)
from test_framework.test_framework import (BitcoinTestFramework, GENESISTIME)
from test_framework.util import (
    assert_equal,
    get_bip9_status,
    hex_str_to_bytes,
)

BASE_RELATIVE_LOCKTIME = 10
SEQ_DISABLE_FLAG = 1 << 31
SEQ_RANDOM_HIGH_BIT = 1 << 25
SEQ_TYPE_FLAG = 1 << 22
SEQ_RANDOM_LOW_BIT = 1 << 18

def relative_locktime(sdf, srhb, stf, srlb):
    """Returns a locktime with certain bits set."""

    locktime = BASE_RELATIVE_LOCKTIME