Implement comprehensive Task Manager API with FastAPI

Added complete task management functionality including:
- CRUD operations for tasks (create, read, update, delete)
- Task model with status (pending/in_progress/completed) and priority (low/medium/high)
- SQLite database with SQLAlchemy ORM
- Alembic migrations for database schema
- Pydantic schemas for request/response validation
- FastAPI routers with proper error handling
- Filtering and pagination support
- Health check endpoint
- CORS configuration
- Comprehensive API documentation
- Proper project structure following FastAPI best practices

README.md

@@ -1,3 +1,112 @@
-# 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, SQLAlchemy, and SQLite. This API provides full CRUD operations for managing tasks with status tracking, priority levels, and timestamps.
+
+## Features
+
+- ✅ Create, read, update, and delete tasks
+- ✅ Task status management (pending, in_progress, completed)
+- ✅ Priority levels (low, medium, high)
+- ✅ Automatic timestamps (created_at, updated_at)
+- ✅ Filtering by status and priority
+- ✅ Pagination support
+- ✅ FastAPI automatic documentation
+- ✅ SQLite database with SQLAlchemy ORM
+- ✅ Database migrations with Alembic
+- ✅ CORS enabled for cross-origin requests
+- ✅ Health check endpoint
+
+## API Endpoints
+
+### Base URL
+- **GET** `/` - API information and links
+- **GET** `/health` - Health check endpoint
+
+### Tasks
+- **POST** `/api/v1/tasks/` - Create a new task
+- **GET** `/api/v1/tasks/` - Get all tasks (with optional filtering and pagination)
+- **GET** `/api/v1/tasks/{task_id}` - Get a specific task by ID
+- **PUT** `/api/v1/tasks/{task_id}` - Update a specific task
+- **DELETE** `/api/v1/tasks/{task_id}` - Delete a specific task
+
+### Query Parameters for GET /api/v1/tasks/
+- `skip` (int): Number of tasks to skip (default: 0)
+- `limit` (int): Maximum number of tasks to return (default: 100, max: 1000)
+- `status` (string): Filter by status (`pending`, `in_progress`, `completed`)
+- `priority` (string): Filter by priority (`low`, `medium`, `high`)
+
+## Task Schema
+
+```json
+{
+  "id": 1,
+  "title": "Example Task",
+  "description": "This is an example task description",
+  "status": "pending",
+  "priority": "medium",
+  "created_at": "2025-06-20T12:00:00",
+  "updated_at": "2025-06-20T12:00:00"
+}
+```
+
+### Status Values
+- `pending` - Task is not yet started
+- `in_progress` - Task is currently being worked on
+- `completed` - Task has been finished
+
+### Priority Values
+- `low` - Low priority task
+- `medium` - Medium priority task (default)
+- `high` - High priority task
+
+## Installation and Setup
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+2. Run database migrations:
+```bash
+alembic upgrade head
+```
+
+3. Start the development server:
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at `http://localhost:8000`
+
+## Documentation
+
+- **Swagger UI**: http://localhost:8000/docs
+- **ReDoc**: http://localhost:8000/redoc
+- **OpenAPI JSON**: http://localhost:8000/openapi.json
+
+## Environment Variables
+
+No environment variables are required for basic operation. The application uses SQLite with a local database file stored in `/app/storage/db/db.sqlite`.
+
+## Development
+
+The application uses the following structure:
+- `main.py` - FastAPI application entry point
+- `app/models/` - SQLAlchemy database models
+- `app/schemas/` - Pydantic request/response schemas
+- `app/crud/` - Database operations
+- `app/routers/` - API route handlers
+- `app/db/` - Database configuration and session management
+- `alembic/` - Database migration files
+
+## Testing
+
+Run the linter and formatter:
+```bash
+ruff check .
+ruff format .
+```
+
+## Production Deployment
+
+For production deployment, ensure proper database configuration and consider using PostgreSQL instead of SQLite for better performance and concurrent access.

alembic.ini

@@ -0,0 +1,41 @@
+[alembic]
+script_location = alembic
+prepend_sys_path = .
+version_path_separator = os
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+[post_write_hooks]
+
+[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

alembic/env.py

@@ -0,0 +1,50 @@
+from logging.config import fileConfig
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from alembic import context
+import sys
+import os
+
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from app.db.base import Base
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

alembic/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() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

alembic/versions/001_initial_migration.py

@@ -0,0 +1,46 @@
+"""Create tasks table
+
+Revision ID: 001
+Revises:
+Create Date: 2025-06-20 12:00:00.000000
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = "001"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "tasks",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("title", sa.String(length=255), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column(
+            "status",
+            sa.Enum("PENDING", "IN_PROGRESS", "COMPLETED", name="taskstatus"),
+            nullable=False,
+        ),
+        sa.Column(
+            "priority",
+            sa.Enum("LOW", "MEDIUM", "HIGH", name="taskpriority"),
+            nullable=False,
+        ),
+        sa.Column("created_at", sa.DateTime(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(), nullable=False),
+        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)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_tasks_title"), table_name="tasks")
+    op.drop_index(op.f("ix_tasks_id"), table_name="tasks")
+    op.drop_table("tasks")

app/crud/__init__.py

@@ -0,0 +1,3 @@
+from . import task
+
+__all__ = ["task"]

app/crud/task.py

@@ -0,0 +1,63 @@
+from typing import List, Optional
+from sqlalchemy.orm import Session
+from app.models.task import Task
+from app.schemas.task import TaskCreate, TaskUpdate
+
+
+def get_task(db: Session, task_id: int) -> Optional[Task]:
+    return db.query(Task).filter(Task.id == task_id).first()
+
+
+def get_tasks(db: Session, skip: int = 0, limit: int = 100) -> List[Task]:
+    return db.query(Task).offset(skip).limit(limit).all()
+
+
+def create_task(db: Session, task: TaskCreate) -> Task:
+    db_task = Task(
+        title=task.title,
+        description=task.description,
+        status=task.status,
+        priority=task.priority,
+    )
+    db.add(db_task)
+    db.commit()
+    db.refresh(db_task)
+    return db_task
+
+
+def update_task(db: Session, task_id: int, task_update: TaskUpdate) -> Optional[Task]:
+    db_task = db.query(Task).filter(Task.id == task_id).first()
+    if db_task is None:
+        return None
+
+    update_data = task_update.model_dump(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(db_task, field, value)
+
+    db.commit()
+    db.refresh(db_task)
+    return db_task
+
+
+def delete_task(db: Session, task_id: int) -> bool:
+    db_task = db.query(Task).filter(Task.id == task_id).first()
+    if db_task is None:
+        return False
+
+    db.delete(db_task)
+    db.commit()
+    return True
+
+
+def get_tasks_by_status(
+    db: Session, status: str, skip: int = 0, limit: int = 100
+) -> List[Task]:
+    return db.query(Task).filter(Task.status == status).offset(skip).limit(limit).all()
+
+
+def get_tasks_by_priority(
+    db: Session, priority: str, skip: int = 0, limit: int = 100
+) -> List[Task]:
+    return (
+        db.query(Task).filter(Task.priority == priority).offset(skip).limit(limit).all()
+    )

app/db/base.py

@@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/session.py

@@ -0,0 +1,22 @@
+from pathlib import Path
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+DB_DIR = Path("/app/storage/db")
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1,3 @@
+from .task import Task, TaskStatus, TaskPriority
+
+__all__ = ["Task", "TaskStatus", "TaskPriority"]

app/models/task.py

@@ -0,0 +1,30 @@
+from datetime import datetime
+from sqlalchemy import Column, Integer, String, Text, DateTime, Enum
+from app.db.base import Base
+import enum
+
+
+class TaskStatus(enum.Enum):
+    PENDING = "pending"
+    IN_PROGRESS = "in_progress"
+    COMPLETED = "completed"
+
+
+class TaskPriority(enum.Enum):
+    LOW = "low"
+    MEDIUM = "medium"
+    HIGH = "high"
+
+
+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.PENDING, nullable=False)
+    priority = Column(Enum(TaskPriority), default=TaskPriority.MEDIUM, nullable=False)
+    created_at = Column(DateTime, default=datetime.utcnow, nullable=False)
+    updated_at = Column(
+        DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False
+    )

app/routers/__init__.py

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+from .tasks import router as tasks_router
+
+__all__ = ["tasks_router"]

app/routers/tasks.py

@@ -0,0 +1,68 @@
+from typing import List
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.orm import Session
+from app.db.session import get_db
+from app.crud import task as crud_task
+from app.schemas.task import Task, TaskCreate, TaskUpdate
+from app.models.task import TaskStatus, TaskPriority
+
+router = APIRouter(prefix="/tasks", tags=["tasks"])
+
+
+@router.post("/", response_model=Task, status_code=201)
+def create_task(task: TaskCreate, db: Session = Depends(get_db)):
+    return crud_task.create_task(db=db, task=task)
+
+
+@router.get("/", response_model=List[Task])
+def get_tasks(
+    skip: int = Query(0, ge=0, description="Number of tasks to skip"),
+    limit: int = Query(
+        100, ge=1, le=1000, description="Maximum number of tasks to return"
+    ),
+    status: str = Query(None, description="Filter by task status"),
+    priority: str = Query(None, description="Filter by task priority"),
+    db: Session = Depends(get_db),
+):
+    if status:
+        try:
+            status_enum = TaskStatus(status)
+            return crud_task.get_tasks_by_status(
+                db=db, status=status_enum, skip=skip, limit=limit
+            )
+        except ValueError:
+            raise HTTPException(status_code=400, detail="Invalid status value")
+
+    if priority:
+        try:
+            priority_enum = TaskPriority(priority)
+            return crud_task.get_tasks_by_priority(
+                db=db, priority=priority_enum, skip=skip, limit=limit
+            )
+        except ValueError:
+            raise HTTPException(status_code=400, detail="Invalid priority value")
+
+    return crud_task.get_tasks(db=db, skip=skip, limit=limit)
+
+
+@router.get("/{task_id}", response_model=Task)
+def get_task(task_id: int, db: Session = Depends(get_db)):
+    db_task = crud_task.get_task(db=db, task_id=task_id)
+    if db_task is None:
+        raise HTTPException(status_code=404, detail="Task not found")
+    return db_task
+
+
+@router.put("/{task_id}", response_model=Task)
+def update_task(task_id: int, task_update: TaskUpdate, db: Session = Depends(get_db)):
+    db_task = crud_task.update_task(db=db, task_id=task_id, task_update=task_update)
+    if db_task is None:
+        raise HTTPException(status_code=404, detail="Task not found")
+    return db_task
+
+
+@router.delete("/{task_id}", status_code=204)
+def delete_task(task_id: int, db: Session = Depends(get_db)):
+    deleted = crud_task.delete_task(db=db, task_id=task_id)
+    if not deleted:
+        raise HTTPException(status_code=404, detail="Task not found")

app/schemas/__init__.py

@@ -0,0 +1,3 @@
+from .task import Task, TaskCreate, TaskUpdate, TaskBase, TaskInDB
+
+__all__ = ["Task", "TaskCreate", "TaskUpdate", "TaskBase", "TaskInDB"]

app/schemas/task.py

@@ -0,0 +1,35 @@
+from datetime import datetime
+from typing import Optional
+from pydantic import BaseModel
+from app.models.task import TaskStatus, TaskPriority
+
+
+class TaskBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    status: TaskStatus = TaskStatus.PENDING
+    priority: TaskPriority = TaskPriority.MEDIUM
+
+
+class TaskCreate(TaskBase):
+    pass
+
+
+class TaskUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    status: Optional[TaskStatus] = None
+    priority: Optional[TaskPriority] = None
+
+
+class TaskInDB(TaskBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class Task(TaskInDB):
+    pass

main.py

@@ -0,0 +1,42 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from app.routers.tasks import router as tasks_router
+from app.db.session import engine
+from app.db.base import Base
+
+Base.metadata.create_all(bind=engine)
+
+app = FastAPI(
+    title="Task Manager API",
+    description="A simple task management API built with FastAPI",
+    version="1.0.0",
+    docs_url="/docs",
+    redoc_url="/redoc",
+    openapi_url="/openapi.json",
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(tasks_router, prefix="/api/v1")
+
+
+@app.get("/")
+def root():
+    return {
+        "title": "Task Manager API",
+        "description": "A simple task management API built with FastAPI",
+        "version": "1.0.0",
+        "documentation": "/docs",
+        "health_check": "/health",
+    }
+
+
+@app.get("/health")
+def health_check():
+    return {"status": "healthy", "service": "Task Manager API", "version": "1.0.0"}

requirements.txt

@@ -0,0 +1,7 @@
+fastapi==0.104.1
+uvicorn[standard]==0.24.0
+sqlalchemy==2.0.23
+alembic==1.12.1
+pydantic==2.5.0
+python-multipart==0.0.6
+ruff==0.1.6