Stage 05.2 - interactive draft builder

app/src/trading/orders/models.py

@@ -9,4 +9,19 @@ class OrderDraft:
     side: str
     order_type: str
     quantity: str
+    price: str | None = None
     status: str = "draft"
+
+
+@dataclass(slots=True)
+class OrderEntryContext:
+    symbol: str
+    side: str
+    order_type: str
+    balance_currency: str
+    available_balance: float
+    reference_price: float
+    last_price: float
+    bid_price: float
+    ask_price: float
+    quantity_presets: list[str]

app/src/trading/orders/service.py

@@ -1,9 +1,10 @@
 from __future__ import annotations
 
 from src.core.config import load_settings
+from src.integrations.exchange.service import ExchangeService
 from src.storage.repositories.order_drafts import OrderDraftRepository
 from src.trading.journal.service import JournalService
-from src.trading.orders.models import OrderDraft
+from src.trading.orders.models import OrderDraft, OrderEntryContext
 
 
 class OrderDraftsService:
@@ -11,29 +12,39 @@ class OrderDraftsService:
         self.settings = load_settings()
         self.repository = OrderDraftRepository()
         self.journal = JournalService()
+        self.exchange = ExchangeService()
 
-    def create_default_draft(self) -> OrderDraft:
-        draft = OrderDraft(
+    def build_draft(
+        self,
+        *,
+        side: str,
+        order_type: str,
+        quantity: str,
+        price: str | None = None,
+    ) -> OrderDraft:
+        return OrderDraft(
             symbol=self.settings.default_symbol,
-            side="BUY",
-            order_type="MARKET",
-            quantity="0.001",
+            side=side.upper(),
+            order_type=order_type.upper(),
+            quantity=quantity,
+            price=price,
             status="draft",
         )
-        self._save_draft(draft)
-        return draft
 
-    def _save_draft(self, draft: OrderDraft) -> None:
+    def save_draft(self, draft: OrderDraft) -> None:
+        payload = {
+            "source": "trade_screen",
+            "mode": "draft_only",
+            "price": draft.price,
+        }
+
         self.repository.add_draft(
             symbol=draft.symbol,
             side=draft.side,
             order_type=draft.order_type,
             quantity=draft.quantity,
             status=draft.status,
-            payload={
-                "source": "trade_screen",
-                "mode": "draft_only",
-            },
+            payload=payload,
         )
 
         try:
@@ -45,6 +56,7 @@ class OrderDraftsService:
                     "side": draft.side,
                     "order_type": draft.order_type,
                     "quantity": draft.quantity,
+                    "price": draft.price,
                     "status": draft.status,
                 },
             )
@@ -53,3 +65,99 @@ class OrderDraftsService:
 
     def list_recent_drafts(self, limit: int = 5) -> list[dict[str, str]]:
         return self.repository.list_recent_drafts(limit=limit)
+
+    def get_entry_context(self, *, side: str, order_type: str) -> OrderEntryContext:
+        validation = self.exchange.validate_symbol(self.settings.default_symbol)
+        if not validation.is_valid or validation.symbol_info is None:
+            raise ValueError(validation.message)
+
+        balances = self.exchange.get_balance_summary()
+        market = self.exchange.get_market_snapshot(self.settings.default_symbol)
+
+        base_asset = validation.symbol_info.base_asset or "BASE"
+        quote_asset = validation.symbol_info.quote_asset or "QUOTE"
+
+        available_by_currency = {
+            item.currency.upper(): float(item.available)
+            for item in balances
+        }
+
+        side_upper = side.upper()
+        order_type_upper = order_type.upper()
+
+        if side_upper == "BUY":
+            balance_currency = quote_asset.upper()
+            available_balance = available_by_currency.get(balance_currency, 0.0)
+            reference_price = float(market["ask_price"])
+            max_qty = (available_balance / reference_price) if reference_price > 0 else 0.0
+        else:
+            balance_currency = base_asset.upper()
+            available_balance = available_by_currency.get(balance_currency, 0.0)
+            reference_price = float(market["bid_price"])
+            max_qty = available_balance
+
+        quantity_presets = [
+            self._format_number(max_qty * 0.25),
+            self._format_number(max_qty * 0.50),
+            self._format_number(max_qty * 0.75),
+            self._format_number(max_qty),
+        ]
+
+        return OrderEntryContext(
+            symbol=self.settings.default_symbol,
+            side=side_upper,
+            order_type=order_type_upper,
+            balance_currency=balance_currency,
+            available_balance=available_balance,
+            reference_price=reference_price,
+            last_price=float(market["last_price"]),
+            bid_price=float(market["bid_price"]),
+            ask_price=float(market["ask_price"]),
+            quantity_presets=quantity_presets,
+        )
+
+    @staticmethod
+    def normalize_side(raw: str) -> str | None:
+        value = (raw or "").strip().upper()
+        if value in {"BUY", "SELL"}:
+            return value
+        return None
+
+    @staticmethod
+    def normalize_order_type(raw: str) -> str | None:
+        value = (raw or "").strip().upper()
+        if value in {"MARKET", "LIMIT"}:
+            return value
+        return None
+
+    @staticmethod
+    def normalize_quantity(raw: str) -> str | None:
+        value = (raw or "").strip().replace(",", ".")
+        if not value:
+            return None
+        try:
+            quantity = float(value)
+        except ValueError:
+            return None
+        if quantity <= 0:
+            return None
+        return value
+
+    @staticmethod
+    def normalize_price(raw: str) -> str | None:
+        value = (raw or "").strip().replace(",", ".")
+        if not value:
+            return None
+        try:
+            price = float(value)
+        except ValueError:
+            return None
+        if price <= 0:
+            return None
+        return value
+
+    @staticmethod
+    def _format_number(value: float) -> str:
+        text = f"{value:.8f}"
+        text = text.rstrip("0").rstrip(".")
+        return text or "0"

app/src/trading/orders/states.py

@@ -0,0 +1,8 @@
+from aiogram.fsm.state import State, StatesGroup
+
+
+class NewOrderDraftStates(StatesGroup):
+    waiting_side = State()
+    waiting_type = State()
+    waiting_quantity = State()
+    waiting_price = State()