Add Polaris FastAPI backend: models/schemas, pricing+scoring+order router, importer, Celery tasks, API routers, seed script

2026-08-25 20:37:58 -07:00
parent 8573554bf9
commit 96b4fcaac9
32 changed files with 2211 additions and 0 deletions
--- a/backend/app/engines/order_router.py
+++ b/backend/app/engines/order_router.py
@@ -0,0 +1,122 @@
+"""Order router — select highest-scoring supplier and record profit.
+
+select_supplier: eligible = active supplier, linked supplier_product, stock >= qty.
+route_order: assigns supplier, computes supplier_cost / shipping_cost / fees,
+records net profit = retail_total - supplier_cost - shipping_cost - fees.
+"""
+from decimal import ROUND_HALF_UP, Decimal
+
+from app.engines import scoring
+from app.models import AuditLog, Product, Supplier, SupplierProduct
+
+CENT = Decimal("0.01")
+FEE_RATE = Decimal("0.05")  # payment processing estimate
+FEE_FLAT = Decimal("0.30")
+
+
+def _f(value) -> float:
+    try:
+        return float(value or 0)
+    except (TypeError, ValueError):
+        return 0.0
+
+
+def select_supplier(db, product_id, qty):
+    """Return (result_dict, error_str). result = {supplier, supplier_product, score}."""
+    product = db.query(Product).filter(Product.id == product_id).first()
+    if product is None:
+        return None, "product not found"
+
+    rows = (
+        db.query(SupplierProduct, Supplier)
+        .join(Supplier, SupplierProduct.supplier_id == Supplier.id)
+        .filter(
+            SupplierProduct.product_id == product_id,
+            Supplier.status == "active",
+            SupplierProduct.supplier_inventory >= qty,
+        )
+        .all()
+    )
+    if not rows:
+        return None, "no eligible supplier"
+
+    pool = {"avg_cost": sum(_f(sp.supplier_cost) for sp, _ in rows) / len(rows)}
+    scored = [
+        (scoring.score_supplier(db, supplier, sp, qty, pool), sp, supplier)
+        for sp, supplier in rows
+    ]
+    best_score, best_sp, best_supplier = max(scored, key=lambda t: t[0])
+    return {
+        "supplier": best_supplier,
+        "supplier_product": best_sp,
+        "score": best_score,
+    }, None
+
+
+def route_order(db, order):
+    """Route a newly created order to the best supplier(s) and record profit."""
+    supplier_id = None
+    supplier_cost = Decimal("0")
+    shipping_cost = Decimal("0")
+    routing_detail = []
+
+    for item in order.items or []:
+        result, err = select_supplier(db, item["product_id"], int(item["qty"]))
+        if err:
+            routing_detail.append({"product_id": item["product_id"], "error": err})
+            continue
+        sp = result["supplier_product"]
+        if supplier_id is None:
+            supplier_id = sp.supplier_id
+        supplier_cost += Decimal(str(sp.supplier_cost or 0)) * int(item["qty"])
+        shipping_cost += Decimal(str(sp.shipping_cost or 0))
+        routing_detail.append(
+            {
+                "product_id": item["product_id"],
+                "supplier": result["supplier"].name,
+                "supplier_score": result["score"],
+            }
+        )
+
+    order.supplier_id = supplier_id
+    order.supplier_cost = supplier_cost.quantize(CENT, rounding=ROUND_HALF_UP)
+    order.shipping_cost = shipping_cost.quantize(CENT, rounding=ROUND_HALF_UP)
+    order.fees = (Decimal(str(order.retail_total or 0)) * FEE_RATE + FEE_FLAT).quantize(
+        CENT, rounding=ROUND_HALF_UP
+    )
+    order.profit = (
+        Decimal(str(order.retail_total or 0))
+        - order.supplier_cost
+        - order.shipping_cost
+        - order.fees
+    ).quantize(CENT, rounding=ROUND_HALF_UP)
+
+    db.add(
+        AuditLog(
+            actor="order_router",
+            action="order_routed",
+            entity="order",
+            entity_id=order.order_number,
+            detail={
+                "supplier_id": str(supplier_id) if supplier_id else None,
+                "profit": float(order.profit),
+                "routing": routing_detail,
+            },
+        )
+    )
+
+    if supplier_id is None:
+        order.status = "new"  # stays unfulfilled; no eligible supplier
+        db.commit()
+        return {"routed": False, "reason": "no eligible supplier for any item"}
+
+    order.status = "confirmed"
+    db.commit()
+    return {
+        "routed": True,
+        "supplier_id": str(supplier_id),
+        "profit": float(order.profit),
+        "supplier_cost": float(order.supplier_cost),
+        "shipping_cost": float(order.shipping_cost),
+        "fees": float(order.fees),
+    }