Previously for incoming transports, the diagnostic_name (for log messages)
was just "responder" -- not sufficient to distinguish peers.
We now use the pubkey instead.
For outgoing transports it is f"{host}:{port}" (unchanged).
We could just use the pubkey for both uniformly; but it is quite long, and
it is hard to distinguish them at a glance.
(related to prev commit, but really another bug)
If we had two peers with the same pubkey (peer A in the process of teardown, peer B ~freshly connected),
peer A might remove peer B from lnworker.peers via close_and_cleanup().
rm `close_and_cleanup()` call from reestablish_channel - it was added
as a workaround for this bug (in 8b95b2127d)
before we understood the cause.
If a remote node tries to establish a transport with us but we already
have an open transport with such a node id, there are two sane ways to go, either:
- keep existing transport open, reject new transport
- close existing transport, establish new transport
We could do either; I chose to do the second option here, as that is what
lnd and eclair seem to be doing.
Previously we would get into an inconsistent state: both transports open,
but only one of them stored in lnworker.peers.
Previously the min() was passed lightning amounts and on-chain amounts mixed;
which is conceptually a type error. It is now only passed on-chain amounts.
Due to the bug, we did not allow a swap to fully exhaust out "LN receive" capacity.
Now the max amt can be slighly larger.
- document SwapManager._get_recv_amount and SwapManager._get_send_amount
- change calculations so that they match the boltz-backend
- note that in the reverse swap case, the server does not care about the on-chain claim tx the client
needs to pay for. This introduced some implicit hacks and inconsistencies in the code in the past,
it is still a bit ugly but at least this is now explicit.
- SwapManager._get_recv_amount and SwapManager._get_send_amount are now proper inverses of each other
-----
Here are some code snippets to play around with in Qt console.
For the forward swap case:
```
from electrum import ecc; lnworker = wallet.lnworker; sm = lnworker.swap_manager
invoice = network.run_from_another_thread(lnworker.create_invoice(amount_msat=3000000*1000, message="swap", expiry=86400))[1]; request_data = {"type": "submarine", "pairId": "BTC/BTC", "orderSide": "sell", "invoice": invoice, "refundPublicKey": ecc.GENERATOR.get_public_key_bytes().hex()}
network.send_http_on_proxy('post', sm.api_url + '/createswap', json=request_data, timeout=30)
sm.get_send_amount(3000000, is_reverse=False)
sm.get_recv_amount(3026730, is_reverse=False)
```
For the reverse swap case:
```
from electrum import ecc; import os; lnworker = wallet.lnworker; sm = lnworker.swap_manager
request_data = {"type": "reversesubmarine", "pairId": "BTC/BTC", "orderSide": "buy", "invoiceAmount": 3000000, "preimageHash": os.urandom(32).hex(), "claimPublicKey": ecc.GENERATOR.get_public_key_bytes().hex()}
network.send_http_on_proxy('post', sm.api_url + '/createswap', json=request_data, timeout=30)
sm.get_recv_amount(3000000, is_reverse=True)
sm.get_send_amount(2974443, is_reverse=True)
```
It is not realistic to expect Electrum to be used as a watchtower
in GUI mode, and possibly counter-productive (may set wrong
expectations).
A proper watchtower should be configured as a daemon. The
documentation will be updated to reflect this change.
Note that this will not fix the value for already existing channels
that have been created with onchain backup; one would need a wallet_db
upgrade in order to fix them (probably not worth the effort).
