Cast to `float` as needed from order-mode and ems

Since we're not quite yet using automatic typed msging from
`tractor`/`msgspec` (i.e. still manually decoding order ctl msgs from
built-in types..`dict`s still not `msgspec.Struct`) this adds the
appropriate typecasting ops to ensure the required precision is attained
prior to processing and/or submission to a brokerd backend service.

For the `.clearing._ems`,
- flip all `trigger_price` previously presumed to be `float` to just
  the field-identical `price: Decimal` and ensure we cast to `float`
  for any `trigger_price` usage, like before passing to `mk_check()`.

For `.ui.order_mode.OrderMode`,
- add a new `.curr_mkt: MktPair` convenience property to get the
  chart-active value.
- ensure we always use the `.curr_mkt.quantize() -> Decimal` before
  setting any IPC-msg's `.price` field!
- always cast `float(Order.price)` before use in setting line-levels.
- don't bother setting `Order.symbol` to a (now fully removed) `Symbol`
  instance since it's not really required-for-use anywhere; leaving it
  a `str` (per the type-annot) is fine for now?

piker/clearing/_ems.py

@@ -76,7 +76,6 @@ if TYPE_CHECKING:
 
 # TODO: numba all of this
 def mk_check(
-
     trigger_price: float,
     known_last: float,
     action: str,
@@ -1297,7 +1296,7 @@ async def process_client_order_cmds(
             case {
                 'oid': oid,
                 'symbol': fqme,
-                'price': trigger_price,
+                'price': price,
                 'size': size,
                 'action': ('buy' | 'sell') as action,
                 'exec_mode': ('live' | 'paper'),
@@ -1329,7 +1328,7 @@ async def process_client_order_cmds(
 
                     symbol=sym,
                     action=action,
-                    price=trigger_price,
+                    price=price,
                     size=size,
                     account=req.account,
                 )
@@ -1371,7 +1370,7 @@ async def process_client_order_cmds(
             case {
                 'oid': oid,
                 'symbol': fqme,
-                'price': trigger_price,
+                'price': price,
                 'size': size,
                 'exec_mode': exec_mode,
                 'action': action,
@@ -1399,7 +1398,12 @@ async def process_client_order_cmds(
                 if isnan(last):
                     last = flume.rt_shm.array[-1]['close']
 
-                pred = mk_check(trigger_price, last, action)
+                trigger_price: float = float(price)
+                pred = mk_check(
+                    trigger_price,
+                    last,
+                    action,
+                )
 
                 # NOTE: for dark orders currently we submit
                 # the triggered live order at a price 5 ticks

piker/ui/order_mode.py

@@ -21,6 +21,7 @@ Chart trading, the only way to scalp.
 from __future__ import annotations
 from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
+from decimal import Decimal
 from functools import partial
 from pprint import pformat
 import time
@@ -41,7 +42,6 @@ from piker.accounting import (
     Position,
     mk_allocator,
     MktPair,
-    Symbol,
 )
 from piker.clearing import (
     open_ems,
@@ -143,6 +143,15 @@ class OrderMode:
     }
     _staged_order: Order | None = None
 
+    @property
+    def curr_mkt(self) -> MktPair:
+        '''
+        Deliver the currently selected `MktPair` according
+        chart state.
+
+        '''
+        return self.chart.linked.mkt
+
     def on_level_change_update_next_order_info(
         self,
         level: float,
@@ -172,7 +181,12 @@ class OrderMode:
         line.update_labels(order_info)
 
         # update bound-in staged order
-        order.price = level
+        # order.price = level
+        mkt: MktPair = self.curr_mkt
+        order.price: Decimal = mkt.quantize(
+            size=level,
+            quantity_type='price',
+        )
         order.size = order_info['size']
 
         # when an order is changed we flip the settings side-pane to
@@ -187,7 +201,9 @@ class OrderMode:
 
     ) -> LevelLine:
 
-        level = order.price
+        # TODO, if we instead just always decimalize at the ems layer
+        # we can avoid this back-n-forth casting?
+        level = float(order.price)
 
         line = order_line(
             chart or self.chart,
@@ -224,7 +240,12 @@ class OrderMode:
             # the order mode allocator but we still need to update the
             # "staged" order message we'll send to the ems
             def update_order_price(y: float) -> None:
-                order.price = y
+                mkt: MktPair = self.curr_mkt
+                order.price: Decimal = mkt.quantize(
+                    size=y,
+                    quantity_type='price',
+                )
+                # order.price = y
 
             line._on_level_change = update_order_price
 
@@ -275,34 +296,31 @@ class OrderMode:
         chart = cursor.linked.chart
         if (
             not chart
-            and cursor
+            and
-            and cursor.active_plot
+            cursor
+            and
+            cursor.active_plot
         ):
             return
 
         chart = cursor.active_plot
-        price = cursor._datum_xy[1]
+        price: float = cursor._datum_xy[1]
         if not price:
             # zero prices are not supported by any means
             # since that's illogical / a no-op.
             return
 
-        mkt: MktPair = self.chart.linked.mkt
-
-        # NOTE : we could also use instead,
-        # mkt.quantize(price, quantity_type='price')
-        # but it returns a Decimal and it's probably gonna
-        # be slower?
         # TODO: should we be enforcing this precision
-        # at a different layer in the stack? right now
+        # at a different layer in the stack?
-        # any precision error will literally be relayed
+        # |_ might require `MktPair` tracking in the EMS?
-        # all the way back from the backend.
+        # |_ right now any precision error will be relayed
-
+        #    all the way back from the backend and vice-versa..
-        price = round(
+        #
-            price,
+        mkt: MktPair = self.curr_mkt
-            ndigits=mkt.price_tick_digits,
+        price: Decimal = mkt.quantize(
+            size=price,
+            quantity_type='price',
         )
-
         order = self._staged_order = Order(
             action=action,
             price=price,
@@ -515,14 +533,15 @@ class OrderMode:
             # if an order msg is provided update the line
             # **from** that msg.
             if order:
-                if order.price <= 0:
+                price: float = float(order.price)
+                if price <= 0:
                     log.error(f'Order has 0 price, cancelling..\n{order}')
                     self.cancel_orders([order.oid])
                     return None
 
-                line.set_level(order.price)
+                line.set_level(price)
                 self.on_level_change_update_next_order_info(
-                    level=order.price,
+                    level=price,
                     line=line,
                     order=order,
                     # use the corresponding position tracker for the
@@ -681,9 +700,9 @@ class OrderMode:
     ) -> Dialog | None:
         # NOTE: the `.order` attr **must** be set with the
         # equivalent order msg in order to be loaded.
-        order = msg.req
+        order: Order = msg.req
         oid = str(msg.oid)
-        symbol = order.symbol
+        symbol: str = order.symbol
 
         # TODO: MEGA UGGG ZONEEEE!
         src = msg.src
@@ -702,13 +721,22 @@ class OrderMode:
         order.oid = str(order.oid)
         order.brokers = [brokername]
 
-        # TODO: change this over to `MktPair`, but it's
+        # ?TODO? change this over to `MktPair`, but it's gonna be
-        # gonna be tough since we don't have any such data
+        # tough since we don't have any such data really in our
-        # really in our clearing msg schema..
+        # clearing msg schema..
-        order.symbol = Symbol.from_fqme(
+        # BUT WAIT! WHY do we even want/need this!?
-            fqsn=fqme,
+        #
-            info={},
+        # order.symbol = self.curr_mkt
-        )
+        #
+        # XXX, the old approach.. which i don't quire member why..
+        # -[ ] verify we for sure don't require this any more!
+        #  |_https://github.com/pikers/piker/issues/517
+        #
+        # order.symbol = Symbol.from_fqme(
+        #     fqsn=fqme,
+        #     info={},
+        # )
+
         maybe_dialog: Dialog | None = self.submit_order(
             send_msg=False,
             order=order,
@@ -1101,7 +1129,7 @@ async def process_trade_msg(
                         )
                     )
                 ):
-                    msg.req = order
+                    msg.req: Order = order
                     dialog: (
                         Dialog
                         # NOTE: on an invalid order submission (eg.