[#55] Over calc candlesticks on prepend

Author: MerlinR

CHANGELOG.md

@@ -6,6 +6,14 @@ The project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html
 
 ---
 
+## 3.0.1
+
+*Release Date: -*
+
+- CandlestickType now re-calculates after prepending to ensure prev transformed are still correct
+
+---
+
 ## 3.0.0
 
 *Release Date: 2025-04-08*

hexital/core/candle.py

@@ -24,7 +24,7 @@ class Candle:
     timeframe: Optional[timedelta]
     aggregation_factor: int
     tag: Optional[str] = None
-    refs: Dict[str, Any]
+    refs: Dict[str, Sequence | None]
     _start_timestamp: Optional[datetime] = None
     _end_timestamp: Optional[datetime] = None
 

hexital/core/candlestick_type.py

@@ -4,6 +4,7 @@
 from typing import List, Optional
 
 from hexital.core.candle import Candle
+from hexital.utils.indexing import valid_index
 from hexital.utils.weakreflist import WeakList
 
 
@@ -57,27 +58,37 @@ def transform(self, mode: CalcMode = CalcMode.INSERT, index: Optional[int] = Non
         for index in range(start_index, len(self.candles)):
             candle = self.candles[index]
 
-            if mode == CalcMode.PREPEND and self.acronym in candle.refs:
-                break
-
             trans_cdl = self.transform_candle(candle)
 
             # None Candles never added to derived
             if not trans_cdl:
                 candle.refs[self.acronym] = None
                 continue
 
-            for cdl in trans_cdl if isinstance(trans_cdl, Sequence) else [trans_cdl]:
-                cdl.tag = self.acronym
-
-                if mode != CalcMode.PREPEND:
-                    self.derived_candles.append(cdl)
-                else:
-                    self.derived_candles.insert(self._derived_idx, cdl)
-
-                self._derived_idx += 1
+            if candles := self._insert_derived_candles(mode, trans_cdl):
+                candle.refs[self.acronym] = candles
+            else:
+                break
 
-            candle.refs[self.acronym] = trans_cdl
+    def _insert_derived_candles(
+        self, mode: CalcMode, candles: Candle | Sequence[Candle]
+    ) -> Sequence:
+        candle_ = candles if isinstance(candles, Sequence) else [candles]
+
+        for cdl in candle_:
+            cdl.tag = self.acronym
+
+            if mode == CalcMode.PREPEND:
+                if (
+                    valid_index(self._derived_idx, len(self.derived_candles))
+                    and cdl == self.derived_candles[self._derived_idx]
+                ):
+                    return []
+                self.derived_candles.insert(self._derived_idx, cdl)
+            else:
+                self.derived_candles.append(cdl)
+            self._derived_idx += 1
+        return candle_
 
     def _find_transform_index(self) -> int:
         """Optimisation method, to find where to start calculating the indicator from

hexital/utils/weakreflist.py

@@ -33,7 +33,7 @@ def reset(self):
     def __getitem__(self, idx: slice | SupportsIndex) -> T | List[T]:
         if self._dirty:
             self.flush()
-        if isinstance(idx, int):
+        if isinstance(idx, SupportsIndex):
             return self._refs[idx]()
         else:
             return [v() for v in self._refs[idx]]