Only require -b <brokername> for filtering

Instead of requiring any `-b` try to import all built-in broker backend
python modules by default and only load those detected from the input symbol
list's fqsn values. In other words the `piker chart` cmd can be run sin
`-b` now and that flag is only required if you only want to load
a subset of the built-ins or are trying to load a specific
not-yet-builtin backend.

piker/cli/__init__.py

@@ -36,7 +36,6 @@
 
 
 log = get_logger('cli')
-DEFAULT_BROKER = 'questrade'
 
 
 @click.command()
@@ -118,7 +117,7 @@ async def main():
 @click.group(context_settings=config._context_defaults)
 @click.option(
     '--brokers', '-b',
-    default=[DEFAULT_BROKER],
+    default=None,
     multiple=True,
     help='Broker backend to use'
 )
@@ -144,10 +143,13 @@ def cli(
 
     ctx.ensure_object(dict)
 
-    if len(brokers) == 1:
-        brokermods = [get_brokermod(brokers[0])]
-    else:
-        brokermods = [get_brokermod(broker) for broker in brokers]
+    if not brokers:
+        # (try to) load all (supposedly) supported data/broker backends
+        from piker.brokers import __brokers__
+        brokers = __brokers__
+
+    brokermods = [get_brokermod(broker) for broker in brokers]
+    assert brokermods
 
     reg_addr: None | tuple[str, int] = None
     if host or port:

piker/ui/_app.py

@@ -19,15 +19,16 @@
 
 '''
 from functools import partial
+from types import ModuleType
 
 from PyQt5.QtCore import QEvent
 import trio
 
 from .._daemon import maybe_spawn_brokerd
-from ..brokers import get_brokermod
 from . import _event
 from ._exec import run_qtractor
 from ..data.feed import install_brokerd_search
+from ..data._source import unpack_fqsn
 from . import _search
 from ._chart import GodWidget
 from ..log import get_logger
@@ -36,27 +37,26 @@
 
 
 async def load_provider_search(
-
-    broker: str,
+    brokermod: str,
     loglevel: str,
 
 ) -> None:
 
-    log.info(f'loading brokerd for {broker}..')
+    name = brokermod.name
+    log.info(f'loading brokerd for {name}..')
 
     async with (
 
         maybe_spawn_brokerd(
-            broker,
+            name,
             loglevel=loglevel
         ) as portal,
 
         install_brokerd_search(
             portal,
-            get_brokermod(broker),
+            brokermod,
         ),
     ):
-
         # keep search engine stream up until cancelled
         await trio.sleep_forever()
 
@@ -67,7 +67,7 @@ async def _async_main(
     main_widget: GodWidget,
 
     syms: list[str],
-    brokernames: str,
+    brokers: dict[str, ModuleType],
     loglevel: str,
 
 ) -> None:
@@ -99,6 +99,11 @@ async def _async_main(
     sbar = godwidget.window.status_bar
     starting_done = sbar.open_status('starting ze sexy chartz')
 
+    needed_brokermods: dict[str, ModuleType] = {}
+    for fqsn in syms:
+        brokername, *_ = unpack_fqsn(fqsn)
+        needed_brokermods[brokername] = brokers[brokername]
+
     async with (
         trio.open_nursery() as root_n,
     ):
@@ -140,8 +145,12 @@ async def _async_main(
         ):
             # load other providers into search **after**
             # the chart's select cache
-            for broker in brokernames:
-                root_n.start_soon(load_provider_search, broker, loglevel)
+            for brokername, mod in needed_brokermods.items():
+                root_n.start_soon(
+                    load_provider_search,
+                    mod,
+                    loglevel,
+                )
 
             await order_mode_ready.wait()
 
@@ -171,7 +180,7 @@ async def _async_main(
 
 def _main(
     syms: list[str],
-    brokernames: [str],
+    brokermods: list[ModuleType],
     piker_loglevel: str,
     tractor_kwargs,
 ) -> None:
@@ -182,7 +191,11 @@ def _main(
     '''
     run_qtractor(
         func=_async_main,
-        args=(syms, brokernames, piker_loglevel),
+        args=(
+            syms,
+            {mod.name: mod for mod in brokermods},
+            piker_loglevel,
+        ),
         main_widget_type=GodWidget,
         tractor_kwargs=tractor_kwargs,
     )

piker/ui/cli.py

@@ -166,16 +166,16 @@ def chart(
             ))
             return
 
-
     # global opts
     brokernames = config['brokers']
+    brokermods = config['brokermods']
+    assert brokermods
     tractorloglevel = config['tractorloglevel']
     pikerloglevel = config['loglevel']
 
-
     _main(
         syms=symbols,
-        brokernames=brokernames,
+        brokermods=brokermods,
         piker_loglevel=pikerloglevel,
         tractor_kwargs={
             'debug_mode': pdb,