kucoin: port to new `NoBsWs` api semantics

No longer need to implement connection timeout logic in the streaming
code, instead we just `async for` that bby B)

Further refining:
- better `KucoinTrade` msg parsing and handling with object cases.
- make `subscribe()` do sub request in a loop wand wair for acks.

piker/brokers/kucoin.py

@@ -1,4 +1,6 @@
-# Copyright (C) Jared Goldman (in stewardship for pikers)
+# Copyright (C) (in stewardship for pikers)
+# - Jared Goldman
+# - Tyler Goodlet
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
@@ -693,7 +695,6 @@ async def stream_quotes(
                 ),
             ) as ws,
             open_ping_task(ws, ping_interval, connect_id),
-            # subscribe(ws, connect_id, kucoin_sym),
             aclosing(stream_messages(ws, sym_str)) as msg_gen,
         ):
             typ, quote = await anext(msg_gen)
@@ -716,39 +717,44 @@ async def subscribe(
     connect_id,
     bs_mktid,
 
+    # subs are filled in with `bs_mktid` from avbove
+    topics: list[str] = [
+        '/market/ticker:{bs_mktid}',  # clearing events
+        '/spotMarket/level2Depth5:{bs_mktid}',  # level 2
+    ],
+
 ) -> AsyncGenerator[None, None]:
-    # level 2 sub
+
+    eps: list[str] = []
+    for topic in topics:
+        ep: str = topic.format(bs_mktid=bs_mktid)
+        eps.append(ep)
         await ws.send_msg(
             {
                 'id': connect_id,
                 'type': 'subscribe',
-            'topic': f'/spotMarket/level2Depth5:{bs_mktid}',
+                'topic': ep,
+                # 'topic': f'/spotMarket/level2Depth5:{bs_mktid}',
                 'privateChannel': False,
                 'response': True,
             }
         )
 
-    # watch trades
-    await ws.send_msg(
-        {
-            'id': connect_id,
-            'type': 'subscribe',
-            'topic': f'/market/ticker:{bs_mktid}',
-            'privateChannel': False,
-            'response': True,
-        }
-    )
+    for _ in topics:
+        ack_msg = await ws.recv_msg()
+        log.info(f'Sub ACK: {ack_msg}')
 
     yield
 
     # unsub
     if ws.connected():
         log.info(f'Unsubscribing to {bs_mktid} feed')
+        for ep in eps:
             await ws.send_msg(
                 {
                     'id': connect_id,
                     'type': 'unsubscribe',
-                'topic': f'/market/ticker:{bs_mktid}',
+                    'topic': ep,
                     'privateChannel': False,
                     'response': True,
                 }
@@ -760,24 +766,23 @@ async def stream_messages(
     sym: str,
 
 ) -> AsyncGenerator[tuple[str, dict], None]:
-    timeouts = 0
-    last_trade_ts = 0
+    '''
+    Core (live) feed msg handler: relay market events
+    to the piker-ized tick-stream format.
 
-    while True:
-        with trio.move_on_after(3) as cs:
-            msg = await ws.recv_msg()
-        if cs.cancelled_caught:
-            timeouts += 1
-            if timeouts > 2:
-                log.error(
-                    'kucoin feed is sh**ing the bed... rebooting...')
-                await ws._connect()
+    '''
+    last_trade_ts: float = 0
 
+    async for dict_msg in ws:
+        if 'subject' not in dict_msg:
+            log.warn(f'Unhandled message: {dict_msg}')
             continue
-        if msg.get('subject'):
-            msg = KucoinMsg(**msg)
-            match msg.subject:
-                case 'trade.ticker':
+
+        msg = KucoinMsg(**dict_msg)
+        match msg:
+            case KucoinMsg(
+                subject='trade.ticker',
+            ):
                 trade_data = KucoinTrade(**msg.data)
 
                 # XXX: Filter for duplicate messages as ws feed will
@@ -802,7 +807,9 @@ async def stream_messages(
                     ],
                 }
 
-                case 'level2':
+            case KucoinMsg(
+                subject='level2',
+            ):
                 l2_data = KucoinL2(**msg.data)
                 first_ask = l2_data.asks[0]
                 first_bid = l2_data.bids[0]