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

backend/app/engines/suppliers/csv_adapter.py

@@ -0,0 +1,78 @@
+"""CSV feed adapter.
+
+Reads a supplier CSV with columns:
+    sku,title,cost,inventory,shipping_cost,shipping_time,category,image_url
+    (optional: description, brand)
+`data_or_url` is either raw CSV text or an http(s) URL to fetch.
+"""
+import csv
+import io
+import urllib.request
+
+from app.engines.suppliers.base import SupplierAdapter, register_adapter
+
+
+@register_adapter
+class CSVAdapter(SupplierAdapter):
+    adapter_type = "csv"
+
+    def __init__(self, supplier, data_or_url=""):
+        super().__init__(supplier, data_or_url=data_or_url)
+        self._rows = None
+
+    def _load(self):
+        if self._rows is not None:
+            return
+        src = (self.data_or_url or "").strip()
+        if src.startswith(("http://", "https://")):
+            with urllib.request.urlopen(src, timeout=30) as resp:
+                src = resp.read().decode("utf-8", "replace")
+        self._rows = list(csv.DictReader(io.StringIO(src)))
+
+    def get_products(self):
+        self._load()
+        products = []
+        for row in self._rows:
+            sku = (row.get("sku") or "").strip()
+            title = (row.get("title") or "").strip()
+            if not sku or not title:
+                continue
+            products.append(
+                {
+                    "sku": sku,
+                    "title": title,
+                    "description": (row.get("description") or "").strip() or None,
+                    "category": (row.get("category") or "").strip() or None,
+                    "brand": (row.get("brand") or "").strip() or None,
+                    "cost": float(row.get("cost") or 0),
+                    "inventory": int(float(row.get("inventory") or 0)),
+                    "shipping_cost": float(row.get("shipping_cost") or 0),
+                    "shipping_time": (row.get("shipping_time") or "").strip() or "3-5 days",
+                    "image_url": (row.get("image_url") or "").strip() or None,
+                }
+            )
+        return products
+
+    def get_inventory(self):
+        return [
+            {"supplier_sku": p["sku"], "inventory": p["inventory"]}
+            for p in self.get_products()
+        ]
+
+    def get_price(self, sku):
+        for p in self.get_products():
+            if p["sku"] == sku:
+                return p["cost"]
+        return None
+
+    def create_order(self, items):
+        return {"adapter": "csv", "ref": f"csv:{len(items)}:items", "items": items}
+
+    def get_order_status(self, ref):
+        return "confirmed"
+
+    def get_tracking(self, ref):
+        return None
+
+    def cancel_order(self, ref):
+        return {"ref": ref, "status": "cancelled"}