Redesign roll calculator with auto first entry and chained add legs.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_hub_calculator_lib.py

@@ -1,6 +1,10 @@
 """hub_calculator_lib 测算逻辑。"""
 
-from hub_calculator_lib import calc_roll_calculator, calc_trend_calculator
+from hub_calculator_lib import (
+    calc_initial_roll_qty,
+    calc_roll_calculator,
+    calc_trend_calculator,
+)
 
 
 def test_trend_calculator_long_basic():
@@ -21,8 +25,6 @@ def test_trend_calculator_long_basic():
     assert data["risk_budget_u"] == 50.0
     assert len(data["rows"]) >= 2
     assert data["rows"][0]["label"] == "首仓"
-    assert data["first_profit_u"] is not None
-    assert data["first_profit_u"] > 0
 
 
 def test_trend_calculator_short_rejects_bad_bounds():
@@ -41,20 +43,69 @@ def test_trend_calculator_short_rejects_bad_bounds():
     assert err is not None
 
 
-def test_roll_calculator_long():
+def test_roll_calculator_first_leg_auto():
     data, err = calc_roll_calculator(
         direction="long",
         capital_usdt=1000,
         risk_percent=5,
-        qty_existing=10,
-        entry_existing=100,
+        entry_price=100,
+        stop_loss=95,
         take_profit=120,
-        add_price=105,
-        new_stop_loss=98,
+        add_legs=[],
         legs_done=0,
     )
     assert err is None
     assert data is not None
-    assert data["add_contracts"] > 0
-    assert data["qty_after"] > 10
-    assert data["profit_at_tp_u"] is not None
+    assert data["first_contracts"] == 10.0
+    assert len(data["rows"]) == 1
+    assert data["rows"][0]["loss_at_sl_u"] == 50.0
+    assert data["rows"][0]["profit_at_tp_u"] == 200.0
+
+
+def test_roll_calculator_chain_two_legs():
+    data, err = calc_roll_calculator(
+        direction="long",
+        capital_usdt=1000,
+        risk_percent=5,
+        entry_price=100,
+        stop_loss=95,
+        take_profit=120,
+        add_legs=[
+            {"add_price": 105, "new_stop_loss": 98},
+            {"add_price": 108, "new_stop_loss": 101},
+        ],
+        legs_done=0,
+    )
+    assert err is None
+    assert data is not None
+    assert len(data["rows"]) == 3
+    assert data["rows"][0]["label"] == "首仓"
+    assert data["rows"][1]["label"] == "滚仓1"
+    assert data["rows"][2]["label"] == "滚仓2"
+    assert float(data["final_contracts"]) > float(data["first_contracts"])
+
+
+def test_roll_calculator_rejects_too_many_legs():
+    data, err = calc_roll_calculator(
+        direction="long",
+        capital_usdt=1000,
+        risk_percent=5,
+        entry_price=100,
+        stop_loss=95,
+        take_profit=120,
+        add_legs=[
+            {"add_price": 105, "new_stop_loss": 98},
+            {"add_price": 108, "new_stop_loss": 101},
+            {"add_price": 110, "new_stop_loss": 103},
+            {"add_price": 112, "new_stop_loss": 105},
+        ],
+        legs_done=0,
+    )
+    assert data is None
+    assert err is not None
+
+
+def test_initial_roll_qty():
+    qty, err = calc_initial_roll_qty("long", 100, 95, 50)
+    assert err is None
+    assert qty == 10.0