feat(fusion_accounting_assets): salvage_value service

Made-with: Cursor

fusion_accounting_assets/services/__init__.py

@@ -1,2 +1,3 @@
 from . import depreciation_methods
 from . import prorate
+from . import salvage_value

fusion_accounting_assets/services/salvage_value.py

@@ -0,0 +1,38 @@
+"""Salvage value (scrap value) calculation helpers.
+
+Most clients use straight % of cost; some use fixed dollar amounts.
+"""
+
+from dataclasses import dataclass
+from typing import Literal
+
+
+SalvageMethod = Literal['percentage', 'fixed', 'zero']
+
+
+@dataclass
+class SalvageConfig:
+    method: SalvageMethod
+    value: float = 0.0
+
+
+def compute_salvage_value(*, cost: float, config: SalvageConfig) -> float:
+    """Compute end-of-life salvage value."""
+    if config.method == 'zero':
+        return 0.0
+    if config.method == 'percentage':
+        return round(cost * config.value / 100, 2)
+    if config.method == 'fixed':
+        return round(config.value, 2)
+    raise ValueError(f"Unknown salvage method: {config.method}")
+
+
+def remaining_useful_life_value(*, current_book: float, salvage: float,
+                                periods_used: int, total_periods: int) -> float:
+    """Estimate remaining value if asset is sold/scrapped now."""
+    if total_periods <= 0:
+        return current_book
+    if periods_used >= total_periods:
+        return salvage
+    remaining_pct = (total_periods - periods_used) / total_periods
+    return round(salvage + (current_book - salvage) * remaining_pct, 2)