05/31 Phase 3

app/services/goal_service.py

@@ -0,0 +1,89 @@
+"""
+Goal Service — projected completion, emergency fund calc.
+"""
+
+from datetime import date
+from dateutil.relativedelta import relativedelta
+from app.extensions import db
+from app.models.goal import Goal
+from app.models.transaction import Transaction
+from sqlalchemy import func
+
+
+def get_projected_completion(goal):
+    """
+    Estimate completion date based on average monthly contribution.
+    Returns date or None if can't be calculated.
+    """
+    if goal.is_completed:
+        return goal.completed_at
+
+    remaining = float(goal.target_amount) - float(goal.current_amount)
+    if remaining <= 0:
+        return date.today()
+
+    contributions = goal.contributions.all()
+    if len(contributions) < 2:
+        return None
+
+    # Average monthly contribution from history
+    contribs_sorted = sorted(contributions, key=lambda c: c.date)
+    first = contribs_sorted[0].date
+    last = contribs_sorted[-1].date
+    total_contrib = sum(float(c.amount) for c in contribs_sorted)
+
+    months_elapsed = (
+        (last.year - first.year) * 12 + (last.month - first.month)
+    ) or 1
+
+    avg_monthly = total_contrib / months_elapsed
+    if avg_monthly <= 0:
+        return None
+
+    months_needed = remaining / avg_monthly
+    projected = date.today() + relativedelta(months=int(months_needed) + 1)
+    return projected
+
+
+def get_emergency_fund_status():
+    """
+    Calculate emergency fund status:
+    - 3-month and 6-month expense targets
+    - Current liquid assets (checking + savings + cash)
+    """
+    from app.models.account import Account
+
+    # Average monthly expense (last 3 months)
+    today = date.today()
+    three_months_ago = today - relativedelta(months=3)
+
+    total_expenses = db.session.query(
+        func.coalesce(func.sum(Transaction.amount), 0)
+    ).filter(
+        Transaction.transaction_type == 'expense',
+        Transaction.date >= three_months_ago,
+        Transaction.date <= today,
+    ).scalar()
+
+    avg_monthly = float(total_expenses) / 3
+
+    # Liquid assets
+    liquid = db.session.query(
+        func.coalesce(func.sum(Account.balance), 0)
+    ).filter(
+        Account.is_active == True,
+        Account.account_type.in_(['checking', 'savings', 'cash']),
+    ).scalar()
+    liquid = float(liquid)
+
+    months_covered = (liquid / avg_monthly) if avg_monthly > 0 else 0
+
+    return {
+        'avg_monthly_expense': avg_monthly,
+        'liquid_assets': liquid,
+        'target_3mo': avg_monthly * 3,
+        'target_6mo': avg_monthly * 6,
+        'months_covered': round(months_covered, 1),
+        'pct_3mo': min(round((liquid / (avg_monthly * 3)) * 100, 1), 100) if avg_monthly > 0 else 0,
+        'pct_6mo': min(round((liquid / (avg_monthly * 6)) * 100, 1), 100) if avg_monthly > 0 else 0,
+    }