Only the fee invoice amount is added to the ListPeers RPC paid fee

[YusukeShimizu]

Only the fee invoice at the time of swapout is recorded in the paid fee displayed in ListPeers.

• https://github.com/ElementsProject/peerswap/blob/master/peerswaprpc/peerswaprpc.proto#L12

Related: https://discord.com/channels/905126649224388629/905127419466350613/1191356265549533284.

Example Situation

Swap in and swap out once each from initiator node.

• initiator_node_id: 03926095277db2522ed467ab2e7a108cd771a994e39ef3945175fe1a24d4aba5a2
• responder_node_id:031872bccffbff6203d68bcaac7d2a088bc13e35026b31fdabe32a6d272397fe1a

peerswap1 listswaps
{
  "swaps": [
    {
      "id": "b963683c9ea47dbf23b74e35c131f262d6673d62739946b367eda0c8fbf6bf1c",
      "created_at": "1704244509",
      "asset": "btc",
      "type": "swap-out",
      "role": "sender",
      "state": "State_ClaimedPreimage",
      "initiator_node_id": "03926095277db2522ed467ab2e7a108cd771a994e39ef3945175fe1a24d4aba5a2",
      "peer_node_id": "031872bccffbff6203d68bcaac7d2a088bc13e35026b31fdabe32a6d272397fe1a",
      "amount": "10000000",
      "channel_id": "110:1:1",
      "opening_tx_id": "10912f55649640f8f829ddf029a0ad9462eb2c65ef335c2945c64d5c16887af0",
      "claim_tx_id": "f4965e25d53f509464153f088594db67c23d080949ba38732a165a10b1b06dbf",
      "cancel_message": "",
      "lnd_chan_id": "120946279120897"
    },
    {
      "id": "25ec85b3e22af44c1eeb862ae664949a11bb0ee49919ef0058352cceb75898cf",
      "created_at": "1704244534",
      "asset": "btc",
      "type": "swap-in",
      "role": "sender",
      "state": "State_ClaimedPreimage",
      "initiator_node_id": "03926095277db2522ed467ab2e7a108cd771a994e39ef3945175fe1a24d4aba5a2",
      "peer_node_id": "031872bccffbff6203d68bcaac7d2a088bc13e35026b31fdabe32a6d272397fe1a",
      "amount": "1000000",
      "channel_id": "110:1:1",
      "opening_tx_id": "8a7bbaed84cf0250f5051df15161e34ef14fcf2732ea00982628cddbf46ac1bf",
      "claim_tx_id": "",
      "cancel_message": "",
      "lnd_chan_id": "120946279120897"
    }
  ]
}

Initiator

The paid fee is the amount of the fee invoice.

./bin/pscli peerswap1 listpeers
{
  "peers": [
    {
      "node_id": "031872bccffbff6203d68bcaac7d2a088bc13e35026b31fdabe32a6d272397fe1a",
      "swaps_allowed": true,
      "supported_assets": [
        "btc",
        "lbtc"
      ],
      "channels": [
        {
          "channel_id": "120946279120897",
          "local_balance": "90979030",
          "remote_balance": "9017500",
          "active": true
        }
      ],
      "as_sender": {
        "swaps_out": "1",
        "swaps_in": "1",
        "sats_out": "10000000",
        "sats_in": "1000000"
      },
      "as_receiver": {
        "swaps_out": "0",
        "swaps_in": "0",
        "sats_out": "0",
        "sats_in": "0"
      },
      "paid_fee": "17500"
    }
  ]
}

Responder

The paid fee is 0.

peerswap2 listpeers
{
  "peers": [
    {
      "node_id": "03926095277db2522ed467ab2e7a108cd771a994e39ef3945175fe1a24d4aba5a2",
      "swaps_allowed": true,
      "supported_assets": [
        "btc",
        "lbtc"
      ],
      "channels": [
        {
          "channel_id": "120946279120897",
          "local_balance": "9017500",
          "remote_balance": "90979030",
          "active": true
        }
      ],
      "as_sender": {
        "swaps_out": "0",
        "swaps_in": "0",
        "sats_out": "0",
        "sats_in": "0"
      },
      "as_receiver": {
        "swaps_out": "1",
        "swaps_in": "1",
        "sats_out": "10000000",
        "sats_in": "1000000"
      },
      "paid_fee": "0"
    }
  ]
}

Idea for improvement

It would be good if the cost of onchain(opening tx/claim tx) incurred is additionally accounted for.