#!/usr/bin/env python3
# Copyright (c) 2014-2016 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 spending coinbase transactions.

The coinbase transaction in block N can appear in block
N+100... so is valid in the mempool when the best block
height is N+99.
This test makes sure coinbase spends that will be mature
in the next block are accepted into the memory pool,
but less mature coinbase spends are NOT.
"""

from decimal import Decimal

from test_framework.test_framework import BitcoinTestFramework
from test_framework.blocktools import create_raw_transaction
from test_framework.util import assert_equal, assert_raises_rpc_error


class MempoolSpendCoinbaseTest(BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 1

    def skip_test_if_missing_module(self):
        self.skip_if_no_wallet()

    def run_test(self):
        chain_height = self.nodes[0].getblockcount()
        assert_equal(chain_height, 200)
        node0_address = self.nodes[0].getnewaddress()

        # Coinbase at height chain_height-100+1 ok in mempool, should
        # get mined. Coinbase at height chain_height-100+2 is
        # is too immature to spend.
        b = [ self.nodes[0].getblockhash(n) for n in range(101, 103) ]
        coinbase_txids = [ self.nodes[0].getblock(h)['tx'][0] for h in b ]
        spends_raw = [ create_raw_transaction(self.nodes[0], txid, node0_address, amount=500 - Decimal('0.00001')) for txid in coinbase_txids ]

        spend_101_id = self.nodes[0].sendrawtransaction(spends_raw[0])

        # coinbase at height 102 should be too immature to spend
        assert_raises_rpc_error(-26,"bad-txns-premature-spend-of-coinbase", self.nodes[0].sendrawtransaction, spends_raw[1])

        # mempool should have just spend_101:
        assert_equal(self.nodes[0].getrawmempool(), [ spend_101_id ])

        # mine a block, spend_101 should get confirmed
        self.nodes[0].generate(1)
        assert_equal(set(self.nodes[0].getrawmempool()), set())

        # ... and now height 102 can be spent:
        spend_102_id = self.nodes[0].sendrawtransaction(spends_raw[1])
        assert_equal(self.nodes[0].getrawmempool(), [ spend_102_id ])

if __name__ == '__main__':
    MempoolSpendCoinbaseTest().main()