"""/api/chain/address must keep mining rewards younger than COINBASE_MATURITY
out of the spendable balance and the spendable UTXO list, so wallets never
build a transaction the node rejects as a premature coinbase spend."""

import pytest

import web_app

TIP = 1000
ADDR = "moon1qmaturitytest"


class _Rpc:
    """scantxoutset: three coins. gettxout: which are coinbase."""

    def __init__(self, gettxout_fails=False):
        self.gettxout_calls = []
        self.gettxout_fails = gettxout_fails

    def scantxoutset(self, *_a):
        return {
            "success": True,
            "height": TIP,
            "unspents": [
                # old mining reward: mature, no gettxout needed
                {"txid": "aa" * 32, "vout": 0, "amount": 10, "height": TIP - 500},
                # fresh mining reward: still maturing
                {"txid": "bb" * 32, "vout": 0, "amount": 10, "height": TIP - 5},
                # fresh ordinary payment: spendable straight away
                {"txid": "cc" * 32, "vout": 1, "amount": 2.5, "height": TIP - 5},
            ],
        }

    def gettxout(self, txid, vout, _mempool):
        self.gettxout_calls.append(txid)
        if self.gettxout_fails:
            raise RuntimeError("rpc down")
        return {"coinbase": txid == "bb" * 32, "value": 10}


@pytest.fixture()
def rpc(monkeypatch):
    fake = _Rpc()
    monkeypatch.setattr(web_app, "_merchant_use_rpc", lambda: True)
    monkeypatch.setattr(web_app, "_valid_receiving_address", lambda a: True)
    monkeypatch.setattr(web_app, "_get_merchant_rpc", lambda: fake)
    monkeypatch.setattr(web_app, "_budgeted_scantxoutset", lambda r, a: r.scantxoutset())
    web_app._chain_addr_cache.clear()
    web_app.app.config["TESTING"] = True
    return fake


def test_maturing_reward_is_not_spendable(rpc):
    j = web_app.app.test_client().get(f"/api/chain/address/{ADDR}").get_json()
    assert j["balance_units"] == 1_250_000_000          # 10 + 2.5 spendable
    assert j["immature_units"] == 1_000_000_000         # the fresh reward
    assert j["total_units"] == 2_250_000_000
    assert {u["txid"] for u in j["utxos"]} == {"aa" * 32, "cc" * 32}
    assert [u["txid"] for u in j["immature_utxos"]] == ["bb" * 32]
    assert j["immature_utxos"][0]["matures_at_height"] == TIP - 5 + 99
    # only the two recent coins needed a coinbase lookup
    assert sorted(rpc.gettxout_calls) == ["bb" * 32, "cc" * 32]


def test_reward_becomes_spendable_at_maturity(rpc, monkeypatch):
    # coin at height h is spendable in block h+100, i.e. once the tip is h+99
    orig = rpc.scantxoutset

    def at_maturity(*_a):
        res = orig()
        res["height"] = (TIP - 5) + 99
        return res

    monkeypatch.setattr(rpc, "scantxoutset", at_maturity)
    j = web_app.app.test_client().get(f"/api/chain/address/{ADDR}").get_json()
    assert j["immature_units"] == 0
    assert j["balance_units"] == j["total_units"] == 2_250_000_000


def test_unknown_coinbase_status_is_treated_as_maturing(monkeypatch):
    fake = _Rpc(gettxout_fails=True)
    monkeypatch.setattr(web_app, "_merchant_use_rpc", lambda: True)
    monkeypatch.setattr(web_app, "_valid_receiving_address", lambda a: True)
    monkeypatch.setattr(web_app, "_get_merchant_rpc", lambda: fake)
    monkeypatch.setattr(web_app, "_budgeted_scantxoutset", lambda r, a: r.scantxoutset())
    web_app._chain_addr_cache.clear()
    j = web_app.app.test_client().get(f"/api/chain/address/{ADDR}").get_json()
    assert [u["txid"] for u in j["utxos"]] == ["aa" * 32]
    assert j["balance_units"] == 1_000_000_000