first steps towards sql connections to supabase

backend/src/payments/payment_handler.py

@@ -4,9 +4,11 @@ from typing import Literal
 from datetime import datetime, timedelta
 
 import requests
-from pydantic import BaseModel, Field, field_validator
+from pydantic import BaseModel, Field, field_validator, model_post_init
 from fastapi.responses import RedirectResponse
 
+from ..supabase.supabase import SupabaseClient
+from ..structs.shop import Item, BasketItem
 from ..configuration.environment import Environment
 from ..cache import CreditCache, make_credit_cache_key
 
@@ -19,54 +21,6 @@ BASE_URL_PROD = 'https://api-m.paypal.com'
 BASE_URL_SANDBOX = 'https://api-m.sandbox.paypal.com'
 
 
-class BasketItem(BaseModel):
-    """
-    Represents a single item in the user's basket.
-
-    Attributes:
-        id (str): The unique identifier for the item.
-        quantity (int): The number of units of the item.
-    """
-    id: str
-    quantity: int
-
-
-class Item(BaseModel):
-    """
-    Represents an item available in the shop.
-
-    Attributes:
-        id (str): The unique identifier for the item.
-        name (str): The name of the item.
-        description (str): The description of the item.
-        unit_price (float): The unit price of the item.
-    """
-    id: str
-    name: str
-    description: str
-    unit_price: float
-    unit_credits: int
-
-
-def item_from_sql(item_id: str):
-    """
-    Fetches an item from the database by its ID.
-
-    Args:
-        item_id (str): The unique identifier for the item.
-
-    Returns:
-        Item: The item object retrieved from the database.
-    """
-    # TODO: Replace with actual SQL fetch logic
-    return Item(
-        id = '12345678',
-        name = 'test_item',
-        description = 'lorem ipsum',
-        unit_price = 0.1,
-        unit_credits = 5
-    )
-
 
 class OrderRequest(BaseModel):
     """
@@ -89,6 +43,8 @@ class OrderRequest(BaseModel):
     items: list[Item] = Field(default_factory=list)
     total_price: float = None
     total_credits: int = None
+    supabase_client: SupabaseClient
+
 
     @field_validator('basket')
     def validate_basket(cls, v):
@@ -103,10 +59,16 @@ class OrderRequest(BaseModel):
         Returns:
             list: The validated basket.
         """
-        if not v or not all(isinstance(i, BasketItem) for i in v):
-            raise ValueError('Basket must contain BasketItem objects')
-        return
-    
+        if not v:
+            raise ValueError("Basket cannot be empty")
+
+        # Pydantic already converts dict -> BasketItem, so isinstance works
+        if not all(isinstance(i, BasketItem) for i in v):
+            raise ValueError("Basket must contain BasketItem objects")
+
+        return v
+
+
     def load_items_and_price(self):
         # This should be automatic upon initialization of the class
         """
@@ -116,12 +78,17 @@ class OrderRequest(BaseModel):
         self.total_price = 0
         self.total_credits = 0
         for basket_item in self.basket:
-            item = item_from_sql(basket_item.id)
+            item = self.supabase_client.get_item(basket_item.id, self.currency)
             self.items.append(item)
             self.total_price += item.unit_price * basket_item.quantity      # increment price
             self.total_credits += item.unit_credits * basket_item.quantity  # increment credit balance
 
 
+    @model_post_init
+    def auto_load_items(self, _):
+        self.load_items_and_price()
+
+
     def to_paypal_items(self): 
         """
         Converts items to the PayPal API item format.
@@ -187,8 +154,6 @@ class PaypalClient:
             self.key = Environment.paypal_key_prod
             self.base_url = BASE_URL_PROD
 
-
-
     def _get_access_token(self) -> str | None:
         """
         Gets (and caches) a PayPal access token.

backend/src/payments/payment_router.py

@@ -44,7 +44,8 @@ def create_order(
     order = OrderRequest(
         user_id = user_id,
         basket=basket,
-        currency=currency
+        currency=currency,
+        supabase_client=supabase
     )
 
     # Process the order and return the details

backend/src/structs/shop.py

@@ -0,0 +1,32 @@
+"""Module to handle classes related to online shop"""
+from pydantic import BaseModel
+
+
+class BasketItem(BaseModel):
+    """
+    Represents a single item in the user's basket.
+
+    Attributes:
+        item_id (str): The unique identifier for the item.
+        quantity (int): The number of units of the item.
+    """
+    item_id: str
+    quantity: int
+
+
+class Item(BaseModel):
+    """
+    Represents an item available in the shop.
+
+    Attributes:
+        item_id (str): The unique identifier for the item.
+        name (str): The name of the item.
+        description (str): The description of the item.
+        unit_price (float): The unit price of the item.
+    """
+    item_id: str
+    name: str
+    description: str
+    unit_price: float
+    unit_credits: int
+    currency: str

backend/src/supabase/supabase.py

@@ -4,6 +4,7 @@ import yaml
 from fastapi import HTTPException, status
 from supabase import create_client, Client, ClientOptions
 
+from ..structs.shop import Item, BasketItem
 from ..constants import PARAMETERS_DIR
 from ..configuration.environment import Environment
 
@@ -166,3 +167,90 @@ class SupabaseClient:
             return True
         else:
             raise Exception("Error incrementing credit balance.")
+
+
+    def get_item(self, item_id: int, currency: str) -> Item | None:
+        """
+        Fetch full item info (name, description) and price/credits for a given currency.
+        Returns an Item pydantic model.
+        """
+        # First, validate the currency
+        try:
+            ok = self.validate_currency(currency=currency)
+        except Exception as e:
+            self.logger.error(e)
+            raise Exception from e
+
+        # Fetch from items table
+        item_res = (
+            self.supabase
+            .table("items")
+            .select("*")
+            .eq("id", item_id)
+            .single()
+            .execute()
+        )
+
+        if item_res.data is None:
+            raise ValueError(f"Item {item_id} does not exist.")
+
+        base_item = item_res.data
+
+        # Fetch price for this currency and item_id
+        price_res = (
+            self.supabase
+            .table("item_prices")
+            .select("*")
+            .eq("item_id", item_id)
+            .eq("currency", currency.upper())
+            .single()
+            .execute()
+        )
+
+        if price_res.data is None:
+            raise ValueError(f"Price for item {item_id} in {currency} does not exist.")
+
+        price = price_res.data
+
+        # Return Item model
+        return Item(
+            id=base_item["id"],
+            name=base_item["name"],
+            description=base_item["description"],
+            unit_price=price["unit_price"],
+            unit_credits=price["unit_credits"],
+            currency=price["currency"]
+        )
+
+
+    def validate_currency(self, currency: str) -> dict:
+        """
+        Validates that a currency exists in the available_currencies table
+        and is active.
+
+        Args:
+            currency (str): Currency code (e.g. 'EUR', 'USD', 'CHF').
+
+        Returns:
+            dict: The currency row.
+
+        Raises:
+            ValueError: If currency does not exist or is inactive.
+        """
+
+        result = (
+            self.supabase
+            .table("available_currencies")
+            .select("*")
+            .eq("currency", currency.upper())
+            .single()
+            .execute()
+        )
+
+        if result.data is None:
+            raise ValueError(f"Currency '{currency}' is not supported yet.")
+
+        if result.data.get("active") is not True:
+            raise ValueError(f"Currency '{currency}' is currently not supported.")
+
+        return True