swapserver: add commands for stats

Adds two command to the swapserver plugin to retrieve some stats so swap
providers can see more easily what is going on on their swapserver.

electrum/plugins/swapserver/__init__.py

@@ -1,5 +1,90 @@
+from typing import TYPE_CHECKING, List
+
 from electrum.simple_config import ConfigVar, SimpleConfig
+from electrum.commands import plugin_command
+
+if TYPE_CHECKING:
+    from electrum.commands import Commands
+    from electrum.wallet import Abstract_Wallet
+
+
+plugin_name = "swapserver"
+
 
 SimpleConfig.SWAPSERVER_PORT = ConfigVar('plugins.swapserver.port', default=None, type_=int, plugin=__name__)
 SimpleConfig.SWAPSERVER_FEE_MILLIONTHS = ConfigVar('plugins.swapserver.fee_millionths', default=5000, type_=int, plugin=__name__)
 SimpleConfig.SWAPSERVER_ANN_POW_NONCE = ConfigVar('plugins.swapserver.ann_pow_nonce', default=0, type_=int, plugin=__name__)
+
+
+@plugin_command('wl', plugin_name)
+async def get_history(self: 'Commands', wallet: 'Abstract_Wallet' = None, plugin = None) -> List[dict]:
+    """
+    Get a list of all swaps provided by this swapserver.
+    Single elements can potentially cover multiple swaps if transactions have been batched.
+
+    Example result:
+
+        [
+            {
+                "date": "2025-09-04",
+                "label": "Forward swap 0.2018 mBTC",
+                "timestamp": 1756982141,  # unix timestamp
+                "return_sat": -205  # value in satoshi that has been earned or lost with this swap
+            },
+            {
+                "date": "2025-09-04",
+                "label": "Reverse swap 0.30406 mBTC",
+                "timestamp": 1756983236,
+                "return_sat": 64
+            }
+        ]
+    """
+    assert wallet.lnworker, "lightning not available"
+    assert wallet.lnworker.swap_manager, "swap manager not available"
+
+    full_history = wallet.get_full_history()
+    swap_group_ids = set(
+        x['group_id'] for x in wallet.lnworker.swap_manager.get_groups_for_onchain_history().values()
+    )
+
+    swap_history_items = []
+    for swap_group_id in swap_group_ids:
+        if swap_history_item := full_history.get('group:' + swap_group_id):
+            swap_history_items.append(swap_history_item)
+
+    result = []
+    for swap in swap_history_items:
+        result.append({
+            'label': swap['label'],
+            'return_sat': int(swap['value'].value),
+            'date': swap['date'].strftime("%Y-%m-%d"),
+            'timestamp': swap['timestamp']
+        })
+    result = sorted(result, key=lambda x: x['timestamp'])
+    return result
+
+
+@plugin_command('wl', plugin_name)
+async def get_summary(self: 'Commands', wallet: 'Abstract_Wallet' = None, plugin = None) -> dict:
+    """Get a summary of all swaps provided by this swapserver.
+    Can become incorrect if closed lightning channels have been deleted in this wallet.
+
+    Example result:
+    {
+        "num_swaps": 160,
+        "overall_return_sat": 159052,  # value earned or lost in satoshi
+        "swaps_per_day": 0.78  # between first swap and last swap
+    }
+    """
+    swap_history = await get_history(self)
+    profit_loss_sum = sum(swap['return_sat'] for swap in swap_history) if swap_history else 0
+    first_swap = min(swap['timestamp'] for swap in swap_history) if swap_history else 0
+    last_swap = max(swap['timestamp'] for swap in swap_history) if swap_history else 0
+    days_in_operation = (last_swap - first_swap) // 86400
+    swaps_per_day = (len(swap_history) / days_in_operation) if days_in_operation > 0 else 0
+
+    return {
+        'num_swaps': len(swap_history),
+        'overall_return_sat': profit_loss_sum,
+        'swaps_per_day': round(swaps_per_day, 2),
+    }