channel watcher class

lib/lnwatcher.py

@@ -0,0 +1,39 @@
+from .util import PrintError
+from .lnbase import Outpoint, funding_output_script
+from .bitcoin import redeem_script_to_address
+
+class LNWatcher(PrintError):
+
+    def __init__(self, network, channel_state):
+        self.network = network
+        self.channel_state = channel_state
+        self.channels ={}
+
+    def parse_response(self, response):
+        if response.get('error'):
+            self.print_error("response error:", response)
+            return None, None
+        return response['params'], response['result']
+
+    def watch_channel(self, chan):
+        script = funding_output_script(chan.local_config, chan.remote_config)
+        funding_address = redeem_script_to_address('p2wsh', script)
+        self.channels[funding_address] = chan
+        self.network.subscribe_to_addresses([funding_address], self.on_address_status)
+
+    def on_address_status(self, response):
+        params, result = self.parse_response(response)
+        if not params:
+            return
+        addr = params[0]
+        self.network.request_address_utxos(addr, self.on_utxos)
+
+    def on_utxos(self, response):
+        params, result = self.parse_response(response)
+        if not params:
+            return
+        addr = params[0]
+        chan = self.channels[addr]
+        outpoints = [Outpoint(x["tx_hash"], x["tx_pos"]) for x in result]
+        if chan.funding_outpoint not in outpoints:
+            self.channel_state[chan.channel_id] = "CLOSED"