Implement Task Manager API with FastAPI and SQLite

- Setup project structure and FastAPI application
- Configure SQLite database with SQLAlchemy ORM
- Setup Alembic for database migrations
- Implement user authentication with JWT
- Create task models and CRUD operations
- Implement task assignment functionality
- Add detailed API documentation
- Create comprehensive README with usage instructions
- Lint code with Ruff

README.md

@@ -1,3 +1,167 @@
-# FastAPI Application
+# Task Manager API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A comprehensive task management API built with FastAPI and SQLite. This API provides a full-featured backend for task management applications, including user authentication, task CRUD operations, and task assignment functionality.
+
+## Features
+
+- **User Management**
+  - User registration and authentication
+  - JWT-based authentication
+  - User profile management
+  
+- **Task Management**
+  - Create, read, update, and delete tasks
+  - Task filtering and search
+  - Task status tracking (todo, in_progress, completed, cancelled)
+  - Task priority levels (low, medium, high, urgent)
+  
+- **Task Assignment**
+  - Assign tasks to multiple users
+  - View tasks assigned to you
+  - Task ownership and permission controls
+  
+- **API Documentation**
+  - Interactive API documentation with Swagger UI and ReDoc
+  - Detailed endpoint descriptions
+
+## Technical Stack
+
+- **Framework**: FastAPI
+- **Database**: SQLite with SQLAlchemy ORM
+- **Migration Tool**: Alembic
+- **Authentication**: JWT with OAuth2
+- **Password Hashing**: Bcrypt
+
+## Project Structure
+
+```
+taskmanagerapi/
+├── alembic.ini                 # Alembic configuration
+├── main.py                     # Application entry point
+├── migrations/                 # Database migrations
+│   ├── env.py
+│   ├── README
+│   ├── script.py.mako
+│   └── versions/               # Migration versions
+│       └── 001_initial_tables.py
+├── app/                        # Application package
+│   ├── api/                    # API endpoints
+│   │   └── v1/                 # API version 1
+│   │       ├── api.py          # API router
+│   │       └── endpoints/      # API endpoint modules
+│   │           ├── auth.py
+│   │           ├── health.py
+│   │           ├── task_assignments.py
+│   │           ├── tasks.py
+│   │           └── users.py
+│   ├── core/                   # Core modules
+│   │   ├── config.py           # Application configuration
+│   │   ├── deps.py             # Dependencies
+│   │   ├── docs.py             # API documentation
+│   │   └── security.py         # Security utilities
+│   ├── db/                     # Database
+│   │   ├── base.py             # Base models
+│   │   ├── base_class.py       # Base class for models
+│   │   ├── base_models.py      # Import all models
+│   │   └── session.py          # Database session
+│   ├── models/                 # SQLAlchemy models
+│   │   ├── task.py
+│   │   └── user.py
+│   ├── schemas/                # Pydantic schemas
+│   │   ├── task.py
+│   │   ├── token.py
+│   │   └── user.py
+│   ├── services/               # Business logic
+│   └── utils/                  # Utility functions
+└── requirements.txt            # Project dependencies
+```
+
+## Getting Started
+
+### Prerequisites
+
+- Python 3.8+
+- pip (Python package installer)
+
+### Installation
+
+1. Clone the repository:
+   ```bash
+   git clone <repository-url>
+   cd taskmanagerapi
+   ```
+
+2. Install dependencies:
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+3. Set environment variables:
+   ```bash
+   # For production use, set a secure secret key
+   export SECRET_KEY="your-secure-secret-key"
+   # Optional: Set the JWT token expiration time in minutes
+   export ACCESS_TOKEN_EXPIRE_MINUTES=30
+   ```
+
+4. Run database migrations:
+   ```bash
+   alembic upgrade head
+   ```
+
+5. Start the application:
+   ```bash
+   uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+   ```
+
+6. Access the API documentation:
+   - Swagger UI: http://localhost:8000/docs
+   - ReDoc: http://localhost:8000/redoc
+
+### Environment Variables
+
+| Variable | Description | Default |
+|----------|-------------|---------|
+| SECRET_KEY | JWT secret key | "your-super-secret-key-for-development-only" |
+| ACCESS_TOKEN_EXPIRE_MINUTES | JWT token expiration in minutes | 30 |
+
+## API Endpoints
+
+### Authentication
+
+- **POST /api/v1/auth/login** - Login and get access token
+
+### Users
+
+- **POST /api/v1/users** - Register a new user
+- **GET /api/v1/users/me** - Get current user info
+- **PUT /api/v1/users/me** - Update current user
+- **GET /api/v1/users/{user_id}** - Get user by ID (admin or self only)
+- **PUT /api/v1/users/{user_id}** - Update user by ID (admin only)
+
+### Tasks
+
+- **GET /api/v1/tasks** - List tasks (owned or assigned to current user)
+- **POST /api/v1/tasks** - Create a new task
+- **GET /api/v1/tasks/{task_id}** - Get task by ID
+- **PUT /api/v1/tasks/{task_id}** - Update task by ID
+- **DELETE /api/v1/tasks/{task_id}** - Delete task by ID (soft delete)
+
+### Task Assignments
+
+- **GET /api/v1/tasks/{task_id}/assignees** - Get task assignees
+- **POST /api/v1/tasks/{task_id}/assignees/{user_id}** - Assign user to task
+- **DELETE /api/v1/tasks/{task_id}/assignees/{user_id}** - Remove user from task
+
+### Health
+
+- **GET /api/v1/health** - API health check
+- **GET /health** - General health check
+
+## License
+
+This project is licensed under the MIT License - see the LICENSE file for details.
+
+## Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.

alembic.ini

@@ -0,0 +1,85 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat migrations/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite URL - using absolute path
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks=black
+# black.type=console_scripts
+# black.entrypoint=black
+# black.options=-l 79
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

app/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/api/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/api/v1/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/api/v1/api.py

@@ -0,0 +1,15 @@
+from fastapi import APIRouter
+
+from app.api.v1.endpoints import auth, health, task_assignments, tasks, users
+
+api_router = APIRouter()
+
+api_router.include_router(health.router, prefix="/health", tags=["Health"])
+api_router.include_router(auth.router, prefix="/auth", tags=["Authentication"])
+api_router.include_router(users.router, prefix="/users", tags=["Users"])
+api_router.include_router(tasks.router, prefix="/tasks", tags=["Tasks"])
+api_router.include_router(
+    task_assignments.router,
+    prefix="/tasks",
+    tags=["Task Assignments"]
+)

app/api/v1/endpoints/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/api/v1/endpoints/auth.py

@@ -0,0 +1,40 @@
+from datetime import timedelta
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordRequestForm
+from sqlalchemy.orm import Session
+
+from app.core.config import settings
+from app.core.deps import authenticate_user, get_db
+from app.core.security import create_access_token
+from app.schemas.token import Token
+
+router = APIRouter()
+
+
+@router.post("/login", response_model=Token)
+def login_access_token(
+    db: Session = Depends(get_db),
+    form_data: OAuth2PasswordRequestForm = Depends()
+) -> Any:
+    """
+    OAuth2 compatible token login, get an access token for future requests
+    """
+    user = authenticate_user(db, form_data.username, form_data.password)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect username or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    # Create access token
+    access_token_expires = timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+
+    return {
+        "access_token": create_access_token(
+            user.id, expires_delta=access_token_expires
+        ),
+        "token_type": "bearer",
+    }

app/api/v1/endpoints/health.py

@@ -0,0 +1,20 @@
+from fastapi import APIRouter
+from starlette.responses import JSONResponse
+
+from app.core.config import settings
+
+router = APIRouter()
+
+
+@router.get("/")
+async def health_check():
+    """
+    Check if the API service is running properly
+    """
+    return JSONResponse(
+        content={
+            "status": "healthy",
+            "version": settings.VERSION,
+            "project": settings.PROJECT_NAME,
+        }
+    )

app/api/v1/endpoints/task_assignments.py

@@ -0,0 +1,149 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy import and_
+from sqlalchemy.orm import Session
+
+from app.core.deps import get_current_user, get_db
+from app.models.task import Task
+from app.models.user import User
+from app.schemas.user import User as UserSchema
+
+router = APIRouter()
+
+
+@router.get("/{task_id}/assignees", response_model=List[UserSchema])
+def read_task_assignees(
+    *,
+    db: Session = Depends(get_db),
+    task_id: int,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Get all assignees for a specific task.
+    """
+    task = db.query(Task).filter(
+        and_(
+            Task.id == task_id,
+            not Task.is_deleted
+        )
+    ).first()
+
+    if not task:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Task not found"
+        )
+
+    # Check if user has access to task
+    if task.owner_id != current_user.id and current_user not in task.assignees:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="You don't have access to this task"
+        )
+
+    return task.assignees
+
+
+@router.post("/{task_id}/assignees/{user_id}", status_code=status.HTTP_201_CREATED)
+def assign_user_to_task(
+    *,
+    db: Session = Depends(get_db),
+    task_id: int,
+    user_id: int,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Assign a user to a task.
+    """
+    # Get task
+    task = db.query(Task).filter(
+        and_(
+            Task.id == task_id,
+            not Task.is_deleted
+        )
+    ).first()
+
+    if not task:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Task not found"
+        )
+
+    # Only task owner can assign users
+    if task.owner_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Only the task owner can assign users"
+        )
+
+    # Get user to assign
+    user = db.query(User).filter(User.id == user_id).first()
+
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
+
+    # Check if user is already assigned
+    if user in task.assignees:
+        return {"message": "User is already assigned to this task"}
+
+    # Assign user to task
+    task.assignees.append(user)
+    db.commit()
+
+    return {"message": "User assigned to task successfully"}
+
+
+@router.delete("/{task_id}/assignees/{user_id}", status_code=status.HTTP_200_OK)
+def remove_user_from_task(
+    *,
+    db: Session = Depends(get_db),
+    task_id: int,
+    user_id: int,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Remove a user from a task.
+    """
+    # Get task
+    task = db.query(Task).filter(
+        and_(
+            Task.id == task_id,
+            not Task.is_deleted
+        )
+    ).first()
+
+    if not task:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Task not found"
+        )
+
+    # Only task owner can remove assignments
+    if task.owner_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Only the task owner can remove assignments"
+        )
+
+    # Get user to remove
+    user = db.query(User).filter(User.id == user_id).first()
+
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
+
+    # Check if user is assigned
+    if user not in task.assignees:
+        return {"message": "User is not assigned to this task"}
+
+    # Remove user from task
+    task.assignees.remove(user)
+    db.commit()
+
+    return {"message": "User removed from task successfully"}

app/api/v1/endpoints/tasks.py

@@ -0,0 +1,222 @@
+from datetime import datetime
+from typing import Any, List, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy import and_, or_
+from sqlalchemy.orm import Session
+
+from app.core.deps import get_current_user, get_db
+from app.models.task import Task, TaskPriority, TaskStatus
+from app.models.user import User
+from app.schemas.task import (
+    Task as TaskSchema,
+)
+from app.schemas.task import (
+    TaskCreate,
+    TaskUpdate,
+    TaskWithAssignees,
+)
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[TaskSchema])
+def read_tasks(
+    *,
+    db: Session = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+    skip: int = 0,
+    limit: int = 100,
+    status: Optional[TaskStatus] = None,
+    priority: Optional[TaskPriority] = None,
+    search: Optional[str] = None,
+) -> Any:
+    """
+    Retrieve tasks owned by current user or assigned to current user.
+    Optionally filter by status, priority, or search term.
+    """
+    query = db.query(Task).filter(
+        and_(
+            or_(
+                Task.owner_id == current_user.id,
+                Task.assignees.any(id=current_user.id)
+            ),
+            not Task.is_deleted
+        )
+    )
+
+    # Apply filters if provided
+    if status:
+        query = query.filter(Task.status == status)
+    if priority:
+        query = query.filter(Task.priority == priority)
+    if search:
+        query = query.filter(
+            or_(
+                Task.title.ilike(f"%{search}%"),
+                Task.description.ilike(f"%{search}%"),
+            )
+        )
+
+    # Apply pagination
+    tasks = query.order_by(Task.updated_at.desc()).offset(skip).limit(limit).all()
+
+    return tasks
+
+
+@router.post("/", response_model=TaskSchema)
+def create_task(
+    *,
+    db: Session = Depends(get_db),
+    task_in: TaskCreate,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Create a new task.
+    """
+    # Create task object
+    task = Task(
+        **task_in.model_dump(),
+        owner_id=current_user.id,
+    )
+
+    # Save to database
+    db.add(task)
+    db.commit()
+    db.refresh(task)
+
+    return task
+
+
+@router.get("/{task_id}", response_model=TaskWithAssignees)
+def read_task(
+    *,
+    db: Session = Depends(get_db),
+    task_id: int,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Get details of a specific task.
+    """
+    task = db.query(Task).filter(
+        and_(
+            Task.id == task_id,
+            not Task.is_deleted
+        )
+    ).first()
+
+    if not task:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Task not found"
+        )
+
+    # Check if user has access to task
+    if task.owner_id != current_user.id and current_user not in task.assignees:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="You don't have access to this task"
+        )
+
+    # Convert to TaskWithAssignees schema
+    result = TaskWithAssignees.model_validate(task)
+    result.assignee_ids = [user.id for user in task.assignees]
+
+    return result
+
+
+@router.put("/{task_id}", response_model=TaskSchema)
+def update_task(
+    *,
+    db: Session = Depends(get_db),
+    task_id: int,
+    task_in: TaskUpdate,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Update a task.
+    """
+    task = db.query(Task).filter(
+        and_(
+            Task.id == task_id,
+            not Task.is_deleted
+        )
+    ).first()
+
+    if not task:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Task not found"
+        )
+
+    # Only task owner can update a task
+    if task.owner_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Only the task owner can update the task"
+        )
+
+    # Update with new data
+    update_data = task_in.model_dump(exclude_unset=True)
+
+    # If status is being changed to completed, set completed_at
+    if "status" in update_data and update_data["status"] == TaskStatus.COMPLETED:
+        update_data["completed_at"] = datetime.utcnow()
+    # If status is being changed from completed to another status, clear completed_at
+    elif "status" in update_data and task.status == TaskStatus.COMPLETED:
+        update_data["completed_at"] = None
+
+    # Update task object
+    for field, value in update_data.items():
+        setattr(task, field, value)
+
+    # Save to database
+    db.add(task)
+    db.commit()
+    db.refresh(task)
+
+    return task
+
+
+@router.delete(
+    "/{task_id}",
+    status_code=status.HTTP_204_NO_CONTENT,
+    response_model=None
+)
+def delete_task(
+    *,
+    db: Session = Depends(get_db),
+    task_id: int,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Delete a task (soft delete).
+    """
+    task = db.query(Task).filter(
+        and_(
+            Task.id == task_id,
+            not Task.is_deleted
+        )
+    ).first()
+
+    if not task:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Task not found"
+        )
+
+    # Only task owner can delete a task
+    if task.owner_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Only the task owner can delete the task"
+        )
+
+    # Soft delete
+    task.is_deleted = True
+
+    # Save to database
+    db.add(task)
+    db.commit()
+
+    return None

app/api/v1/endpoints/users.py

@@ -0,0 +1,176 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.encoders import jsonable_encoder
+from sqlalchemy.orm import Session
+
+from app.core.deps import get_current_active_superuser, get_current_user, get_db
+from app.core.security import get_password_hash
+from app.models.user import User
+from app.schemas.user import User as UserSchema
+from app.schemas.user import UserCreate, UserUpdate
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[UserSchema])
+def read_users(
+    db: Session = Depends(get_db),
+    skip: int = 0,
+    limit: int = 100,
+    current_user: User = Depends(get_current_active_superuser),
+) -> Any:
+    """
+    Retrieve all users (superuser only).
+    """
+    users = db.query(User).offset(skip).limit(limit).all()
+    return users
+
+
+@router.post("/", response_model=UserSchema)
+def create_user(
+    *,
+    db: Session = Depends(get_db),
+    user_in: UserCreate,
+) -> Any:
+    """
+    Create a new user.
+    """
+    # Check if user with same email exists
+    user = db.query(User).filter(User.email == user_in.email).first()
+    if user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="A user with this email already exists.",
+        )
+
+    # Check if user with same username exists
+    user = db.query(User).filter(User.username == user_in.username).first()
+    if user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="A user with this username already exists.",
+        )
+
+    # Create user object
+    user_data = user_in.model_dump(exclude={"password"})
+    user = User(
+        **user_data,
+        hashed_password=get_password_hash(user_in.password),
+    )
+
+    # Save to database
+    db.add(user)
+    db.commit()
+    db.refresh(user)
+
+    return user
+
+
+@router.get("/me", response_model=UserSchema)
+def read_user_me(
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Get current user.
+    """
+    return current_user
+
+
+@router.put("/me", response_model=UserSchema)
+def update_user_me(
+    *,
+    db: Session = Depends(get_db),
+    user_in: UserUpdate,
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Update current user.
+    """
+    # Convert model to dict
+    user_data = jsonable_encoder(current_user)
+
+    # Update with new data
+    update_data = user_in.model_dump(exclude_unset=True)
+
+    # If password in update data, hash it
+    if "password" in update_data and update_data["password"]:
+        update_data["hashed_password"] = get_password_hash(update_data.pop("password"))
+
+    # Update user object
+    for field in user_data:
+        if field in update_data:
+            setattr(current_user, field, update_data[field])
+
+    # Save to database
+    db.add(current_user)
+    db.commit()
+    db.refresh(current_user)
+
+    return current_user
+
+
+@router.get("/{user_id}", response_model=UserSchema)
+def read_user_by_id(
+    user_id: int,
+    db: Session = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+) -> Any:
+    """
+    Get a specific user by id.
+    """
+    user = db.query(User).filter(User.id == user_id).first()
+
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+
+    # Only superusers can access other users' data
+    if user.id != current_user.id and not current_user.is_superuser:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="You don't have permission to access this user",
+        )
+
+    return user
+
+
+@router.put("/{user_id}", response_model=UserSchema)
+def update_user(
+    *,
+    db: Session = Depends(get_db),
+    user_id: int,
+    user_in: UserUpdate,
+    current_user: User = Depends(get_current_active_superuser),
+) -> Any:
+    """
+    Update a user (superuser only).
+    """
+    user = db.query(User).filter(User.id == user_id).first()
+
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+
+    # Update with new data
+    update_data = user_in.model_dump(exclude_unset=True)
+
+    # If password in update data, hash it
+    if "password" in update_data and update_data["password"]:
+        update_data["hashed_password"] = get_password_hash(update_data.pop("password"))
+
+    # Update user object
+    for field, value in update_data.items():
+        if hasattr(user, field):
+            setattr(user, field, value)
+
+    # Save to database
+    db.add(user)
+    db.commit()
+    db.refresh(user)
+
+    return user

app/core/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/core/config.py

@@ -0,0 +1,39 @@
+import os
+from pathlib import Path
+from typing import Optional
+
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    # API Information
+    PROJECT_NAME: str = "Task Manager API"
+    DESCRIPTION: str = "A FastAPI-based task management system"
+    VERSION: str = "0.1.0"
+    API_V1_STR: str = "/api/v1"
+
+    # Authentication settings
+    SECRET_KEY: str = os.environ.get(
+        "SECRET_KEY", "your-super-secret-key-for-development-only"
+    )
+    ALGORITHM: str = "HS256"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
+
+    # Database settings
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    SQLALCHEMY_DATABASE_URL: Optional[str] = None
+
+    class Config:
+        env_file = ".env"
+        env_file_encoding = "utf-8"
+        case_sensitive = True
+
+
+settings = Settings()
+
+# Ensure database directory exists
+settings.DB_DIR.mkdir(parents=True, exist_ok=True)
+
+# Set database URL after ensuring directory exists
+if settings.SQLALCHEMY_DATABASE_URL is None:
+    settings.SQLALCHEMY_DATABASE_URL = f"sqlite:///{settings.DB_DIR}/db.sqlite"

app/core/deps.py

@@ -0,0 +1,83 @@
+from typing import Optional
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import JWTError, jwt
+from pydantic import ValidationError
+from sqlalchemy.orm import Session
+
+from app.core.config import settings
+from app.core.security import verify_password
+from app.db.session import get_db
+from app.models.user import User
+from app.schemas.token import TokenPayload
+
+# OAuth2 token URL
+oauth2_scheme = OAuth2PasswordBearer(
+    tokenUrl=f"{settings.API_V1_STR}/auth/login"
+)
+
+
+def get_current_user(
+    db: Session = Depends(get_db),
+    token: str = Depends(oauth2_scheme)
+) -> User:
+    """
+    Get current user from token
+    """
+    try:
+        # Decode the token
+        payload = jwt.decode(
+            token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM]
+        )
+        token_data = TokenPayload(**payload)
+    except (JWTError, ValidationError):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Could not validate credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    # Get user from database
+    user = db.query(User).filter(User.id == token_data.sub).first()
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
+
+    if not user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Inactive user"
+        )
+
+    return user
+
+
+def get_current_active_superuser(
+    current_user: User = Depends(get_current_user),
+) -> User:
+    """
+    Get current superuser
+    """
+    if not current_user.is_superuser:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="The user doesn't have enough privileges"
+        )
+
+    return current_user
+
+
+def authenticate_user(
+    db: Session, username: str, password: str
+) -> Optional[User]:
+    """
+    Authenticate a user by username and password
+    """
+    user = db.query(User).filter(User.username == username).first()
+    if not user or not verify_password(password, user.hashed_password):
+        return None
+
+    return user

app/core/docs.py

@@ -0,0 +1,66 @@
+from fastapi.openapi.models import ExternalDocumentation
+
+# External documentation
+external_docs = ExternalDocumentation(
+    description="Task Manager API Documentation",
+    url="/redoc",
+)
+
+# API description
+api_description = """
+# Task Manager API
+
+A RESTful API for managing tasks and assignments built with FastAPI and SQLite.
+
+## Features
+
+* User authentication and registration
+* Task creation and management
+* Task status tracking
+* Task assignment to users
+* Filtering and searching tasks
+
+## Authentication
+
+This API uses OAuth2 with JWT tokens for authentication.
+Most endpoints require authentication.
+
+To authenticate:
+1. Use the `/api/v1/auth/login` endpoint with your username and password
+2. Use the returned token in the Authorization header as `Bearer {token}`
+
+## Rate Limiting
+
+There is no rate limiting implemented in this version of the API.
+
+## Pagination
+
+List endpoints support pagination with `skip` and `limit` parameters.
+"""
+
+# Tags metadata
+tags_metadata = [
+    {
+        "name": "Health",
+        "description": "Health check endpoints to verify API status.",
+    },
+    {
+        "name": "Authentication",
+        "description": "Operations for authentication, including login.",
+    },
+    {
+        "name": "Users",
+        "description": "Operations with users, including registration, profile "
+                    "and user management.",
+    },
+    {
+        "name": "Tasks",
+        "description": "CRUD operations for tasks, including creation, updates, "
+                    "and retrieval.",
+    },
+    {
+        "name": "Task Assignments",
+        "description": "Operations for assigning tasks to users and managing "
+                    "task assignments.",
+    },
+]

app/core/security.py

@@ -0,0 +1,44 @@
+from datetime import datetime, timedelta
+from typing import Any, Union
+
+from jose import jwt
+from passlib.context import CryptContext
+
+from app.core.config import settings
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def create_access_token(
+    subject: Union[str, Any], expires_delta: timedelta = None
+) -> str:
+    """
+    Create a JWT access token
+    """
+    if expires_delta:
+        expire = datetime.utcnow() + expires_delta
+    else:
+        expire = datetime.utcnow() + timedelta(
+            minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
+        )
+
+    to_encode = {"exp": expire, "sub": str(subject)}
+    encoded_jwt = jwt.encode(
+        to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM
+    )
+
+    return encoded_jwt
+
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    """
+    Verify a password against a hash
+    """
+    return pwd_context.verify(plain_password, hashed_password)
+
+
+def get_password_hash(password: str) -> str:
+    """
+    Hash a password
+    """
+    return pwd_context.hash(password)

app/db/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/db/base.py

@@ -0,0 +1,4 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+# Create a Base class for SQLAlchemy models
+Base = declarative_base()

app/db/base_class.py

@@ -0,0 +1,15 @@
+from typing import Any
+
+from sqlalchemy.ext.declarative import declared_attr
+from sqlalchemy.orm import as_declarative
+
+
+@as_declarative()
+class Base:
+    id: Any
+    __name__: str
+
+    # Generate tablename automatically based on class name
+    @declared_attr
+    def __tablename__(self) -> str:
+        return self.__name__.lower()

app/db/base_models.py

@@ -0,0 +1 @@
+# Import all the models here so that Alembic can discover them

app/db/session.py

@@ -0,0 +1,22 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+# Create SQLAlchemy engine
+engine = create_engine(
+    settings.SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}  # Only needed for SQLite
+)
+
+# Create sessionmaker
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+# Dependency for getting DB session
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/models/task.py

@@ -0,0 +1,66 @@
+from datetime import datetime
+from enum import Enum as PyEnum
+
+from sqlalchemy import (
+    Boolean,
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Table,
+    Text,
+)
+from sqlalchemy.orm import relationship
+
+from app.db.base import Base
+
+
+class TaskStatus(str, PyEnum):
+    TODO = "todo"
+    IN_PROGRESS = "in_progress"
+    COMPLETED = "completed"
+    CANCELLED = "cancelled"
+
+
+class TaskPriority(str, PyEnum):
+    LOW = "low"
+    MEDIUM = "medium"
+    HIGH = "high"
+    URGENT = "urgent"
+
+
+# Association table for task assignments
+task_assignments = Table(
+    "task_assignments",
+    Base.metadata,
+    Column("task_id", Integer, ForeignKey("tasks.id"), primary_key=True),
+    Column("user_id", Integer, ForeignKey("users.id"), primary_key=True),
+    Column("assigned_at", DateTime, default=datetime.utcnow),
+)
+
+
+class Task(Base):
+    __tablename__ = "tasks"
+
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String(255), nullable=False, index=True)
+    description = Column(Text, nullable=True)
+    status = Column(Enum(TaskStatus), default=TaskStatus.TODO, nullable=False)
+    priority = Column(Enum(TaskPriority), default=TaskPriority.MEDIUM, nullable=False)
+    due_date = Column(DateTime, nullable=True)
+    owner_id = Column(Integer, ForeignKey("users.id"), nullable=False)
+    is_deleted = Column(Boolean, default=False)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+    completed_at = Column(DateTime, nullable=True)
+
+    # Relationships
+    owner = relationship("User", back_populates="tasks")
+    assignees = relationship("User",
+                           secondary="task_assignments",
+                           back_populates="assigned_tasks")
+
+    def __repr__(self):
+        return f"<Task {self.title} ({self.status})>"

app/models/user.py

@@ -0,0 +1,29 @@
+from datetime import datetime
+
+from sqlalchemy import Boolean, Column, DateTime, Integer, String
+from sqlalchemy.orm import relationship
+
+from app.db.base import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, index=True)
+    email = Column(String, unique=True, index=True, nullable=False)
+    username = Column(String, unique=True, index=True, nullable=False)
+    hashed_password = Column(String, nullable=False)
+    full_name = Column(String, nullable=True)
+    is_active = Column(Boolean, default=True)
+    is_superuser = Column(Boolean, default=False)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+
+    # Relationships
+    tasks = relationship("Task", back_populates="owner")
+    assigned_tasks = relationship("Task",
+                                secondary="task_assignments",
+                                back_populates="assignees")
+
+    def __repr__(self):
+        return f"<User {self.username}>"

app/schemas/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/schemas/task.py

@@ -0,0 +1,56 @@
+from datetime import datetime
+from typing import List, Optional
+
+from pydantic import BaseModel, ConfigDict
+
+from app.models.task import TaskPriority, TaskStatus
+
+
+# Shared properties
+class TaskBase(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    status: Optional[TaskStatus] = None
+    priority: Optional[TaskPriority] = None
+    due_date: Optional[datetime] = None
+
+
+# Properties to receive via API on creation
+class TaskCreate(TaskBase):
+    title: str
+    status: TaskStatus = TaskStatus.TODO
+    priority: TaskPriority = TaskPriority.MEDIUM
+
+
+# Properties to receive via API on update
+class TaskUpdate(TaskBase):
+    pass
+
+
+# Properties shared by models stored in DB
+class TaskInDBBase(TaskBase):
+    id: int
+    title: str
+    status: TaskStatus
+    priority: TaskPriority
+    owner_id: int
+    created_at: datetime
+    updated_at: datetime
+    completed_at: Optional[datetime] = None
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+# Properties to return via API
+class Task(TaskInDBBase):
+    pass
+
+
+# Properties for tasks with assignee information
+class TaskWithAssignees(Task):
+    assignee_ids: List[int] = []
+
+
+# Properties stored in DB but not returned by API
+class TaskInDB(TaskInDBBase):
+    is_deleted: bool = False

app/schemas/token.py

@@ -0,0 +1,13 @@
+from typing import Optional
+
+from pydantic import BaseModel
+
+
+class Token(BaseModel):
+    access_token: str
+    token_type: str
+
+
+class TokenPayload(BaseModel):
+    sub: Optional[int] = None
+    exp: Optional[int] = None

app/schemas/user.py

@@ -0,0 +1,44 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, ConfigDict, EmailStr
+
+
+# Shared properties
+class UserBase(BaseModel):
+    email: Optional[EmailStr] = None
+    username: Optional[str] = None
+    is_active: Optional[bool] = True
+    is_superuser: bool = False
+    full_name: Optional[str] = None
+
+
+# Properties to receive via API on creation
+class UserCreate(UserBase):
+    email: EmailStr
+    username: str
+    password: str
+
+
+# Properties to receive via API on update
+class UserUpdate(UserBase):
+    password: Optional[str] = None
+
+
+# Properties shared by models stored in DB
+class UserInDBBase(UserBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+# Properties to return via API
+class User(UserInDBBase):
+    pass
+
+
+# Additional properties stored in DB but not returned by API
+class UserInDB(UserInDBBase):
+    hashed_password: str

app/services/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

app/utils/__init__.py

@@ -0,0 +1 @@
+# This file exists to make the directory a package

main.py

@@ -0,0 +1,61 @@
+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from starlette.responses import JSONResponse
+
+from app.api.v1.api import api_router
+from app.core.config import settings
+from app.core.docs import api_description, external_docs, tags_metadata
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    version=settings.VERSION,
+    description=api_description,
+    openapi_url="/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+    openapi_tags=tags_metadata,
+    openapi_extra={"externalDocs": external_docs.dict()},
+)
+
+# Add CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+
+@app.get("/", tags=["Root"])
+async def root():
+    """
+    Root endpoint that returns basic API information
+    """
+    return JSONResponse(
+        content={
+            "title": settings.PROJECT_NAME,
+            "docs": "/docs",
+            "health": "/health",
+        }
+    )
+
+
+@app.get("/health", tags=["Health"])
+async def health_check():
+    """
+    Health check endpoint to verify the service is running
+    """
+    return JSONResponse(
+        content={
+            "status": "healthy",
+            "version": settings.VERSION,
+        }
+    )
+
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/README

@@ -0,0 +1,17 @@
+# Alembic Migrations
+
+This directory contains database migrations for the application.
+
+To apply migrations:
+```
+alembic upgrade head
+```
+
+To create a new migration:
+```
+alembic revision --autogenerate -m "description of changes"
+```
+
+For SQLite, we use the `render_as_batch=True` option to enable 
+batch migrations, which allows for more complex schema changes
+that would otherwise not be supported by SQLite.

migrations/env.py

@@ -0,0 +1,84 @@
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+# Import all models for Alembic to detect
+# Import Base from our app for auto-generating migrations
+from app.db.base import Base
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+target_metadata = Base.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline():
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        # Use batch mode for SQLite (required for certain operations)
+        render_as_batch=True,
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        # Use batch mode for SQLite (required for certain operations)
+        is_sqlite = connection.dialect.name == 'sqlite'
+
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=is_sqlite,
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/001_initial_tables.py

@@ -0,0 +1,86 @@
+"""Initial tables
+
+Revision ID: 001
+Revises:
+Create Date: 2023-07-01
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Create enum types
+    task_status = sa.Enum(
+        'todo', 'in_progress', 'completed', 'cancelled',
+        name='taskstatus'
+    )
+    task_priority = sa.Enum('low', 'medium', 'high', 'urgent', name='taskpriority')
+
+    # Create tables
+    op.create_table(
+        'users',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('email', sa.String(), nullable=False),
+        sa.Column('username', sa.String(), nullable=False),
+        sa.Column('hashed_password', sa.String(), nullable=False),
+        sa.Column('full_name', sa.String(), nullable=True),
+        sa.Column('is_active', sa.Boolean(), default=True),
+        sa.Column('is_superuser', sa.Boolean(), default=False),
+        sa.Column('created_at', sa.DateTime(), default=sa.func.now()),
+        sa.Column('updated_at', sa.DateTime(),
+                  default=sa.func.now(), onupdate=sa.func.now()),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('email'),
+        sa.UniqueConstraint('username')
+    )
+    op.create_index(op.f('ix_users_id'), 'users', ['id'], unique=False)
+    op.create_index(op.f('ix_users_email'), 'users', ['email'], unique=True)
+    op.create_index(op.f('ix_users_username'), 'users', ['username'], unique=True)
+
+    op.create_table(
+        'tasks',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(255), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('status', task_status, nullable=False, default='todo'),
+        sa.Column('priority', task_priority, nullable=False, default='medium'),
+        sa.Column('due_date', sa.DateTime(), nullable=True),
+        sa.Column('owner_id', sa.Integer(), nullable=False),
+        sa.Column('is_deleted', sa.Boolean(), default=False),
+        sa.Column('created_at', sa.DateTime(), default=sa.func.now()),
+        sa.Column('updated_at', sa.DateTime(),
+                  default=sa.func.now(), onupdate=sa.func.now()),
+        sa.Column('completed_at', sa.DateTime(), nullable=True),
+        sa.ForeignKeyConstraint(['owner_id'], ['users.id'], ),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_tasks_id'), 'tasks', ['id'], unique=False)
+    op.create_index(op.f('ix_tasks_title'), 'tasks', ['title'], unique=False)
+
+    op.create_table(
+        'task_assignments',
+        sa.Column('task_id', sa.Integer(), nullable=False),
+        sa.Column('user_id', sa.Integer(), nullable=False),
+        sa.Column('assigned_at', sa.DateTime(), default=sa.func.now()),
+        sa.ForeignKeyConstraint(['task_id'], ['tasks.id'], ),
+        sa.ForeignKeyConstraint(['user_id'], ['users.id'], ),
+        sa.PrimaryKeyConstraint('task_id', 'user_id')
+    )
+
+
+def downgrade():
+    # Drop tables
+    op.drop_table('task_assignments')
+    op.drop_table('tasks')
+    op.drop_table('users')
+
+    # Drop enum types
+    op.execute('DROP TYPE taskstatus')
+    op.execute('DROP TYPE taskpriority')

pyproject.toml

@@ -0,0 +1,10 @@
+[tool.ruff]
+line-length = 88
+target-version = "py38"
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "W", "N", "UP"]
+ignore = []
+
+[tool.ruff.lint.isort]
+known-third-party = ["fastapi", "pydantic", "sqlalchemy", "starlette", "uvicorn"]

requirements.txt

@@ -0,0 +1,12 @@
+fastapi>=0.100.0
+uvicorn>=0.23.0
+sqlalchemy>=2.0.0
+alembic>=1.11.0
+pydantic>=2.0.0
+pydantic[email]>=2.0.0
+python-jose[cryptography]>=3.3.0
+passlib[bcrypt]>=1.7.4
+python-multipart>=0.0.6
+ruff>=0.0.270
+email-validator>=2.0.0
+python-dotenv>=1.0.0