Implement Google OAuth2 with Swagger UI integration

fastapi_ecom/app.py

@@ -1,5 +1,6 @@
 import uvicorn
 from fastapi import FastAPI
+from starlette.middleware.sessions import SessionMiddleware
 
 from fastapi_ecom.config import config
 from fastapi_ecom.router import business, customer, order, product
@@ -18,8 +19,14 @@
         description="E-Commerce API for businesses and end users using FastAPI.",
         version="0.1.0",
         openapi_tags=tags_metadata,
+        swagger_ui_init_oauth={
+            "clientId": config.GOOGLE_CLIENT_ID,
+            "clientSecret": config.GOOGLE_CLIENT_SECRET,
+        }
     )
 
+app.add_middleware(SessionMiddleware, secret_key=config.GOOGLE_CLIENT_SECRET)
+
 PREFIX = "/api/v1"
 
 @app.get("/")

fastapi_ecom/config/config.py.example

@@ -16,6 +16,9 @@ dtbsbport = "5432"
 # The driver used to access the database
 dtbsdriver = "postgresql+asyncpg"
 
+# Set the echo for logging of all SQL statements
+confecho = True
+
 # The location of serving the application service
 servhost = "127.0.0.1"
 
@@ -25,5 +28,8 @@ servport = 8080
 # Automatically reload if the code is changed
 cgreload = True
 
-# Set the echo for logging of all SQL statements
-confecho = True
+# Google client id
+GOOGLE_CLIENT_ID = "example.apps.googleusercontent.com"
+
+# Google Client secret
+GOOGLE_CLIENT_SECRET = "example"

fastapi_ecom/database/models/business.py

@@ -23,19 +23,27 @@ class Business(baseobjc, UUIDCreatableMixin, DateCreatableMixin, DateUpdateableM
     :cvar city: City where the business is located.
     :cvar state: State where the business is located.
     :cvar is_verified: Flag indicating if the business account is verified.
+    :cvar oauth_provider: OAuth provider name.
+    :cvar oauth_id: OAuth provider's user ID
+    :cvar oauth_email: Email address from OAuth.
+    :cvar created_via_oauth: Flag indicating if the business account is created using OAuth.
     :cvar products: Relationship to the `Product` model, representing the products offered by the
                     business.
     """
     __tablename__ = "businesses"
 
     id = Column("id", Integer, primary_key=True, index=True, autoincrement=True)
     email = Column("email_address", String(100), unique=True, index=True, nullable=False)
-    password = Column("password", Text, nullable=False)
+    password = Column("password", Text, nullable=True)
     name = Column("business_name", String(100), nullable=False)
-    addr_line_1 = Column("address_line_1", Text, nullable=False)
+    addr_line_1 = Column("address_line_1", Text, nullable=True)
     addr_line_2 = Column("address_line_2", Text, nullable=True)
-    city = Column("city", Text, nullable=False)
-    state = Column("state", Text, nullable=False)
+    city = Column("city", Text, nullable=True)
+    state = Column("state", Text, nullable=True)
     is_verified = Column("is_verified", Boolean, default=False)
+    oauth_provider = Column("oauth_provider", String(50), nullable=True)
+    oauth_id = Column("oauth_id", String(100), nullable=True)
+    oauth_email = Column("oauth_email", String(100), nullable=True)
+    created_via_oauth = Column("created_via_oauth", Boolean, default=False)
 
     products = relationship("Product", back_populates="businesses")

fastapi_ecom/database/models/customer.py

@@ -23,18 +23,26 @@ class Customer(baseobjc, UUIDCreatableMixin, DateCreatableMixin, DateUpdateableM
     :cvar city: City where the customer resides.
     :cvar state: State where the customer resides.
     :cvar is_verified: Flag indicating if the customer account is verified.
+    :cvar oauth_provider: OAuth provider name.
+    :cvar oauth_id: OAuth provider's user ID
+    :cvar oauth_email: Email address from OAuth.
+    :cvar created_via_oauth: Flag indicating if the customer account is created using OAuth.
     :cvar orders: Relationship to the `Order` model, representing orders placed by the customer.
     """
     __tablename__ = "customers"
 
     id = Column("id", Integer, primary_key=True, index=True, autoincrement=True)
     email = Column("email_address", String(100), unique=True, index=True, nullable=False)
-    password = Column("password", Text, nullable=False)
+    password = Column("password", Text, nullable=True)
     name = Column("full_name", String(100), nullable=False)
-    addr_line_1 = Column("address_line_1", Text, nullable=False)
+    addr_line_1 = Column("address_line_1", Text, nullable=True)
     addr_line_2 = Column("address_line_2", Text, nullable=True)
-    city = Column("city", Text, nullable=False)
-    state = Column("state", Text, nullable=False)
+    city = Column("city", Text, nullable=True)
+    state = Column("state", Text, nullable=True)
     is_verified = Column("is_verified", Boolean, default=False)
+    oauth_provider = Column("oauth_provider", String(50), nullable=True)
+    oauth_id = Column("oauth_id", String(100), nullable=True)
+    oauth_email = Column("oauth_email", String(100), nullable=True)
+    created_via_oauth = Column("created_via_oauth", Boolean, default=False)
 
     orders = relationship("Order", back_populates="customers")

fastapi_ecom/database/pydantic_schemas/business.py

@@ -35,10 +35,10 @@ class BusinessView(BusinessBase):
     """
     email: EmailStr
     name: str
-    addr_line_1: str
-    addr_line_2: str
-    city: str
-    state: str
+    addr_line_1: Optional[str]
+    addr_line_2: Optional[str]
+    city: Optional[str]
+    state: Optional[str]
 
 
 class BusinessCreate(BusinessView):

fastapi_ecom/migrations/versions/02d907ef8e5b_add_oauth_related_fields.py

@@ -0,0 +1,92 @@
+"""add oauth related fields
+
+Revision ID: 02d907ef8e5b
+Revises: 60c8ccec25ac
+Create Date: 2025-07-27 19:45:21.800069
+
+"""
+from collections.abc import Sequence
+from typing import Union
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = '02d907ef8e5b'
+down_revision: Union[str, None] = '60c8ccec25ac'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('businesses', sa.Column('oauth_provider', sa.String(length=50), nullable=True))
+    op.add_column('businesses', sa.Column('oauth_id', sa.String(length=100), nullable=True))
+    op.add_column('businesses', sa.Column('oauth_email', sa.String(length=100), nullable=True))
+    op.add_column('businesses', sa.Column('created_via_oauth', sa.Boolean(), nullable=True))
+    op.alter_column('businesses', 'password',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    op.alter_column('businesses', 'address_line_1',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    op.alter_column('businesses', 'city',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    op.alter_column('businesses', 'state',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    op.add_column('customers', sa.Column('oauth_provider', sa.String(length=50), nullable=True))
+    op.add_column('customers', sa.Column('oauth_id', sa.String(length=100), nullable=True))
+    op.add_column('customers', sa.Column('oauth_email', sa.String(length=100), nullable=True))
+    op.add_column('customers', sa.Column('created_via_oauth', sa.Boolean(), nullable=True))
+    op.alter_column('customers', 'password',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    op.alter_column('customers', 'address_line_1',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    op.alter_column('customers', 'city',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    op.alter_column('customers', 'state',
+               existing_type=sa.TEXT(),
+               nullable=True)
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('customers', 'state',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.alter_column('customers', 'city',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.alter_column('customers', 'address_line_1',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.alter_column('customers', 'password',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.drop_column('customers', 'created_via_oauth')
+    op.drop_column('customers', 'oauth_email')
+    op.drop_column('customers', 'oauth_id')
+    op.drop_column('customers', 'oauth_provider')
+    op.alter_column('businesses', 'state',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.alter_column('businesses', 'city',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.alter_column('businesses', 'address_line_1',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.alter_column('businesses', 'password',
+               existing_type=sa.TEXT(),
+               nullable=False)
+    op.drop_column('businesses', 'created_via_oauth')
+    op.drop_column('businesses', 'oauth_email')
+    op.drop_column('businesses', 'oauth_id')
+    op.drop_column('businesses', 'oauth_provider')
+    # ### end Alembic commands ###

fastapi_ecom/utils/auth.py

@@ -1,64 +1,67 @@
-import bcrypt
+from typing import Optional
+
 from fastapi import Depends, HTTPException, status
-from fastapi.security import HTTPBasic, HTTPBasicCredentials
-from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy.future import select
-from sqlalchemy.orm import selectinload
 
-from fastapi_ecom.database.db_setup import get_db
 from fastapi_ecom.database.models.business import Business
 from fastapi_ecom.database.models.customer import Customer
+from fastapi_ecom.utils.basic_auth import verify_basic_business_cred, verify_basic_customer_cred
+from fastapi_ecom.utils.oauth import verify_oauth_business_cred, verify_oauth_customer_cred
 
-# Initialize HTTP Basic Authentication.
-# This will prompt users for a username and password when accessing secured endpoints.
-security = HTTPBasic()
 
-async def verify_cust_cred(credentials: HTTPBasicCredentials = Depends(security), db: AsyncSession = Depends(get_db)) -> Customer:
+async def verify_cust_cred(
+    basic_customer: Optional[Customer] = Depends(verify_basic_customer_cred),
+    oauth_customer: Optional[Customer] = Depends(verify_oauth_customer_cred)
+) -> Customer:
     """
-    Verify customer credentials using HTTP Basic Authentication.
-    This function retrieves the customer record from the database using the provided username
-    (email address) and verifies the provided password against the stored hashed password.
+    Verify customer credentials using either HTTP Basic Authentication or OAuth.
+
+    This function attempts to authenticate a customer using multiple authentication
+    methods. It first tries HTTP Basic Authentication, then falls back to OAuth
+    authentication if basic auth is not provided or fails.
 
-    :param credentials: HTTPBasicCredentials containing the username and password.
-    :param db: Database session to query customer data.
+    :param basic_customer: Customer object from HTTP Basic Authentication or None.
+    :param oauth_customer: Customer object from OAuth authentication or None.
 
-    :return: The customer object if authentication is successful.
+    :return: The authenticated customer object.
 
-    :raises HTTPException: If the username or password is incorrect.
+    :raises HTTPException: If neither authentication method succeeds.
     """
-    query = select(Customer).where(Customer.email == credentials.username).options(selectinload("*"))
-    result = await db.execute(query)
-    customer_by_email = result.scalar_one_or_none()
-    if not customer_by_email or not bcrypt.checkpw(credentials.password.encode('utf-8'), customer_by_email.password.encode('utf-8')):
-        raise HTTPException(
-            status_code = status.HTTP_401_UNAUTHORIZED,
-            detail = "Invalid authentication credentials",
-            headers = {"WWW-Authenticate": "Basic"},
-        )
-    else:
-        return customer_by_email
-
-async def verify_business_cred(credentials: HTTPBasicCredentials = Depends(security), db: AsyncSession = Depends(get_db)) -> Business:
+    if basic_customer:
+        return basic_customer
+
+    if oauth_customer:
+        return oauth_customer
+
+    raise HTTPException(
+        status_code = status.HTTP_401_UNAUTHORIZED,
+        detail = "Not Authenticated",
+    )
+
+async def verify_business_cred(
+    basic_business: Optional[Business] = Depends(verify_basic_business_cred),
+    oauth_business: Optional[Business] = Depends(verify_oauth_business_cred)
+) -> Business:
     """
-    Verify business credentials using HTTP Basic Authentication.
-    This function retrieves the business record from the database using the provided username
-    (email address) and verifies the provided password against the stored hashed password.
+    Verify business credentials using either HTTP Basic Authentication or OAuth.
+
+    This function attempts to authenticate a business using multiple authentication
+    methods. It first tries HTTP Basic Authentication, then falls back to OAuth
+    authentication if basic auth is not provided or fails.
 
-    :param credentials: HTTPBasicCredentials containing the username and password.
-    :param db: Database session to query business data.
+    :param basic_business: Business object from HTTP Basic Authentication or None.
+    :param oauth_business: Business object from OAuth authentication or None.
 
-    :return: The business object if authentication is successful.
+    :return: The authenticated business object.
 
-    :raises HTTPException: If the username or password is incorrect.
+    :raises HTTPException: If neither authentication method succeeds.
     """
-    query = select(Business).where(Business.email == credentials.username).options(selectinload("*"))
-    result = await db.execute(query)
-    business_by_email = result.scalar_one_or_none()
-    if not business_by_email or not bcrypt.checkpw(credentials.password.encode('utf-8'), business_by_email.password.encode('utf-8')):
-        raise HTTPException(
-            status_code = status.HTTP_401_UNAUTHORIZED,
-            detail = "Invalid authentication credentials",
-            headers = {"WWW-Authenticate": "Basic"},
-        )
-    else:
-        return business_by_email
+    if basic_business:
+        return basic_business
+
+    if oauth_business:
+        return oauth_business
+
+    raise HTTPException(
+        status_code = status.HTTP_401_UNAUTHORIZED,
+        detail = "Not Authenticated",
+    )

fastapi_ecom/utils/basic_auth.py

@@ -0,0 +1,66 @@
+import bcrypt
+from fastapi import Depends
+from fastapi.security import HTTPBasic, HTTPBasicCredentials
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.future import select
+from sqlalchemy.orm import selectinload
+
+from fastapi_ecom.database.db_setup import get_db
+from fastapi_ecom.database.models.business import Business
+from fastapi_ecom.database.models.customer import Customer
+
+# Initialize HTTP Basic Authentication.
+# This will prompt users for a username and password when accessing secured endpoints.
+security = HTTPBasic(auto_error=False)
+
+async def verify_basic_customer_cred(credentials: HTTPBasicCredentials | None = Depends(security), db: AsyncSession = Depends(get_db)) -> Customer:
+    """
+    Verify customer credentials using HTTP Basic Authentication.
+
+    This function retrieves the customer record from the database using the provided username
+    (email address) and verifies the provided password against the stored hashed password.
+
+    :param credentials: HTTPBasicCredentials containing the username and password.
+    :param db: Database session to query customer data.
+
+    :return: The customer object if authentication is successful else returns None.
+    """
+    if not credentials:  #pragma: no cover
+        return None
+
+    query = select(Customer).where(Customer.email == credentials.username).options(selectinload("*"))
+    result = await db.execute(query)
+    customer_by_email = result.scalar_one_or_none()
+
+    if not customer_by_email:
+        return None
+    elif not bcrypt.checkpw(credentials.password.encode('utf-8'), customer_by_email.password.encode('utf-8')):
+        return None
+    else:
+        return customer_by_email
+
+async def verify_basic_business_cred(credentials: HTTPBasicCredentials | None = Depends(security), db: AsyncSession = Depends(get_db)) -> Business:
+    """
+    Verify business credentials using HTTP Basic Authentication.
+
+    This function retrieves the business record from the database using the provided username
+    (email address) and verifies the provided password against the stored hashed password.
+
+    :param credentials: HTTPBasicCredentials containing the username and password.
+    :param db: Database session to query business data.
+
+    :return: The business object if authentication is successful else returns None.
+    """
+    if not credentials:  #pragma: no cover
+        return None
+
+    query = select(Business).where(Business.email == credentials.username).options(selectinload("*"))
+    result = await db.execute(query)
+    business_by_email = result.scalar_one_or_none()
+
+    if not business_by_email:
+        return None
+    elif not bcrypt.checkpw(credentials.password.encode('utf-8'), business_by_email.password.encode('utf-8')):
+        return None
+    else:
+        return business_by_email