Tasa Cero: exclude anchors from budget/analytics aggregates

The anchor stays visible in listings but only its cuotas count toward
actuals — future cuotas intentionally show up in future months as
committed spend.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/app/api/v1/endpoints/analytics.py

@@ -9,7 +9,7 @@ from sqlmodel import Session, func, select
 from app.auth import get_current_user
 from app.db import get_session
 from app.models.models import Category, Transaction, TransactionType
-from app.services.budget_projection import get_cycle_range
+from app.services.budget_projection import NOT_INSTALLMENT_ANCHOR, get_cycle_range
 from app.services.exchange_rate import get_converted_amount_expr
 
 router = APIRouter(prefix="/analytics", tags=["analytics"])
@@ -53,7 +53,10 @@ def spending_by_category(
             func.sum(amount_crc).label("total"),
             func.count().label("count"),
         )
-        .where(Transaction.transaction_type == TransactionType.COMPRA)
+        .where(
+            Transaction.transaction_type == TransactionType.COMPRA,
+            NOT_INSTALLMENT_ANCHOR,
+        )
         .group_by(Transaction.category_id)
     )
 
@@ -126,6 +129,7 @@ def monthly_trend(
                 Transaction.transaction_type == TransactionType.COMPRA,
                 Transaction.date >= start,
                 Transaction.date < end,
+                NOT_INSTALLMENT_ANCHOR,
             )
         ).first()
 
@@ -171,7 +175,10 @@ def daily_spending(
             func.sum(amount_crc).label("total"),
             func.count().label("count"),
         )
-        .where(Transaction.transaction_type == TransactionType.COMPRA)
+        .where(
+            Transaction.transaction_type == TransactionType.COMPRA,
+            NOT_INSTALLMENT_ANCHOR,
+        )
         .group_by(func.date(Transaction.date))
         .order_by(func.date(Transaction.date))
     )

backend/app/services/budget_projection.py

@@ -23,6 +23,11 @@ FRESH_START_MONTH = 3
 # Income-like transaction types that should never be counted as expenses
 INCOME_TYPES = (TransactionType.DEPOSITO, TransactionType.SALARY)
 
+# Tasa Cero: the original purchase ("anchor") is excluded from all budget
+# aggregates — its generated cuota transactions are counted instead.
+# See app/services/installments.py.
+NOT_INSTALLMENT_ANCHOR = Transaction.is_installment_anchor == False  # noqa: E712
+
 
 def get_effective_amount(item: RecurringItem, month: int, year: int) -> float | None:
     """Return the effective amount for a recurring item in a given month, or None if inactive."""
@@ -133,7 +138,7 @@ def compute_actuals_by_source(
                 func.coalesce(func.sum(amount_crc), 0),
                 func.count(),
             )
-            .where(*where)
+            .where(NOT_INSTALLMENT_ANCHOR, *where)
             .group_by(Transaction.source, Transaction.transaction_type)
         ).all()
         return {(s, t): (float(total), cnt) for s, t, total, cnt in rows}
@@ -225,6 +230,7 @@ def compute_actuals_by_category(
                 Transaction.source == TransactionSource.CREDIT_CARD,
                 Transaction.category_id.is_not(None),  # type: ignore[union-attr]
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
                 Transaction.deferred_to_next_cycle == False,  # noqa: E712
             )
             .group_by(Transaction.category_id, Transaction.transaction_type)
@@ -245,6 +251,7 @@ def compute_actuals_by_category(
                 Transaction.source == TransactionSource.CREDIT_CARD,
                 Transaction.category_id.is_not(None),  # type: ignore[union-attr]
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
                 Transaction.deferred_to_next_cycle == True,  # noqa: E712
             )
             .group_by(Transaction.category_id, Transaction.transaction_type)
@@ -265,6 +272,7 @@ def compute_actuals_by_category(
                 Transaction.source != TransactionSource.CREDIT_CARD,
                 Transaction.category_id.is_not(None),  # type: ignore[union-attr]
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
             )
             .group_by(Transaction.category_id, Transaction.transaction_type)
         ).all()
@@ -306,6 +314,7 @@ def compute_cc_by_category(
                 Transaction.date < cc_end,
                 Transaction.source == TransactionSource.CREDIT_CARD,
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
                 Transaction.deferred_to_next_cycle == False,  # noqa: E712
             )
             .group_by(Transaction.category_id, Transaction.transaction_type)
@@ -324,6 +333,7 @@ def compute_cc_by_category(
                 Transaction.date < prev_end,
                 Transaction.source == TransactionSource.CREDIT_CARD,
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
                 Transaction.deferred_to_next_cycle == True,  # noqa: E712
             )
             .group_by(Transaction.category_id, Transaction.transaction_type)
@@ -440,6 +450,7 @@ def compute_monthly_projection(
                 Transaction.source == TransactionSource.CREDIT_CARD,
                 Transaction.category_id.is_(None),  # type: ignore[union-attr]
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
                 Transaction.deferred_to_next_cycle == False,  # noqa: E712
             )
             .group_by(Transaction.transaction_type)
@@ -455,6 +466,7 @@ def compute_monthly_projection(
                 Transaction.source == TransactionSource.CREDIT_CARD,
                 Transaction.category_id.is_(None),  # type: ignore[union-attr]
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
                 Transaction.deferred_to_next_cycle == True,  # noqa: E712
             )
             .group_by(Transaction.transaction_type)
@@ -470,6 +482,7 @@ def compute_monthly_projection(
                 Transaction.source != TransactionSource.CREDIT_CARD,
                 Transaction.category_id.is_(None),  # type: ignore[union-attr]
                 col(Transaction.transaction_type).notin_(INCOME_TYPES),
+                NOT_INSTALLMENT_ANCHOR,
             )
             .group_by(Transaction.transaction_type)
         ).all()