Implement invoice generation service

- Create FastAPI app structure
- Set up SQLAlchemy with SQLite for database management
- Implement invoice and invoice item models
- Add Alembic for database migrations
- Create invoice generation and retrieval API endpoints
- Add health check endpoint
- Set up Ruff for linting
- Update README with project details

README.md

@@ -1,3 +1,96 @@
-# FastAPI Application
+# Invoice Generation Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+This is a FastAPI application for generating and managing invoices. It allows you to create, read, update, and delete invoices without requiring user signup.
+
+## Features
+
+- Generate invoices with automatic invoice number generation
+- Store invoice details in SQLite database
+- Retrieve invoice information by ID or invoice number
+- Update invoice details and status
+- Delete invoices
+- Health check endpoint
+
+## Technical Stack
+
+- **Framework**: FastAPI
+- **Database**: SQLite with SQLAlchemy ORM
+- **Migrations**: Alembic
+- **Validation**: Pydantic
+- **Linting**: Ruff
+
+## Project Structure
+
+```
+.
+├── alembic.ini               # Alembic configuration file
+├── app                       # Application package
+│   ├── api                   # API routes
+│   │   └── routes            # API route modules
+│   │       ├── __init__.py   # Routes initialization
+│   │       └── invoices.py   # Invoice routes
+│   ├── core                  # Core functionality
+│   │   ├── config.py         # Application settings
+│   │   ├── database.py       # Database connection setup
+│   │   └── utils.py          # Utility functions
+│   ├── models                # SQLAlchemy models
+│   │   ├── __init__.py       # Models initialization
+│   │   └── invoice.py        # Invoice and InvoiceItem models
+│   └── schemas               # Pydantic schemas
+│       ├── __init__.py       # Schemas initialization
+│       └── invoice.py        # Invoice-related schemas
+├── main.py                   # Application entry point
+├── migrations                # Alembic migrations
+│   ├── env.py                # Alembic environment
+│   ├── script.py.mako        # Migration script template
+│   └── versions              # Migration scripts
+│       └── ef0aaab3a275_initial_database_tables.py  # Initial migration
+├── requirements.txt          # Project dependencies
+└── pyproject.toml            # Ruff configuration
+```
+
+## API Endpoints
+
+### Health Check
+
+- `GET /health`: Check if the service is running
+
+### Invoice Management
+
+- `POST /api/v1/invoices`: Create a new invoice
+- `GET /api/v1/invoices`: List all invoices (with pagination)
+- `GET /api/v1/invoices/{invoice_id}`: Get a specific invoice by ID
+- `POST /api/v1/invoices/find`: Find an invoice by invoice number
+- `PATCH /api/v1/invoices/{invoice_id}`: Update an invoice
+- `PATCH /api/v1/invoices/{invoice_id}/status`: Update invoice status
+- `DELETE /api/v1/invoices/{invoice_id}`: Delete an invoice
+
+## Setup and Installation
+
+1. Clone the repository
+2. Install dependencies:
+   ```
+   pip install -r requirements.txt
+   ```
+3. Run migrations:
+   ```
+   alembic upgrade head
+   ```
+4. Start the application:
+   ```
+   uvicorn main:app --reload
+   ```
+
+## API Documentation
+
+Once the application is running, you can access:
+- Interactive API documentation at `/docs` (Swagger UI)
+- Alternative API documentation at `/redoc` (ReDoc)
+
+## Invoice Number Format
+
+Invoices are automatically assigned a unique invoice number with the format:
+- `INV-YYYYMM-XXXXXX`, where:
+  - `INV` is a fixed prefix
+  - `YYYYMM` is the year and month (e.g., 202307 for July 2023)
+  - `XXXXXX` is a random alphanumeric string

alembic.ini

@@ -0,0 +1,116 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration file names; The default value is %%(rev)s_%%(slug)s
+# Uncomment the line below if you want the files to be prepended with date and time
+# see https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file
+# for all available tokens
+# file_template = %%(year)d_%%(month).2d_%%(day).2d_%%(hour).2d%%(minute).2d-%%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
+# 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.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:migrations/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# set to 'true' to search source files recursively
+# in each "version_locations" directory
+# new in Alembic version 1.10
+# recursive_version_locations = false
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+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 REVISION_SCRIPT_FILENAME
+
+# lint with attempts to fix using "ruff" - use the exec runner, execute a binary directly
+# hooks = ruff
+# ruff.type = exec
+# ruff.executable = %(here)s/.venv/bin/ruff
+# ruff.options = --fix REVISION_SCRIPT_FILENAME
+
+# 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 is intentionally left empty to make the directory a Python package

app/api/__init__.py

@@ -0,0 +1 @@
+# This file is intentionally left empty to make the directory a Python package

app/api/routes/__init__.py

@@ -0,0 +1,6 @@
+from fastapi import APIRouter
+
+from app.api.routes import invoices
+
+api_router = APIRouter()
+api_router.include_router(invoices.router, prefix="/invoices", tags=["invoices"])

app/api/routes/invoices.py

@@ -0,0 +1,185 @@
+from datetime import datetime
+from typing import List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.core.database import get_db
+from app.core.utils import generate_invoice_number
+from app.models.invoice import Invoice, InvoiceItem
+from app.schemas.invoice import (
+    InvoiceCreate,
+    InvoiceDB,
+    InvoiceSearchQuery,
+    InvoiceStatusUpdate,
+    InvoiceUpdate,
+)
+
+router = APIRouter()
+
+
+@router.post("/", response_model=InvoiceDB, status_code=status.HTTP_201_CREATED)
+def create_invoice(invoice_data: InvoiceCreate, db: Session = Depends(get_db)):
+    """
+    Create a new invoice.
+    """
+    # Generate unique invoice number
+    invoice_number = generate_invoice_number()
+    
+    # Create new invoice
+    db_invoice = Invoice(
+        invoice_number=invoice_number,
+        date_created=datetime.utcnow(),
+        due_date=invoice_data.due_date,
+        customer_name=invoice_data.customer_name,
+        customer_email=invoice_data.customer_email,
+        customer_address=invoice_data.customer_address,
+        notes=invoice_data.notes,
+        status="PENDING",
+        total_amount=0,  # Will be calculated from items
+    )
+    
+    # Add to DB
+    db.add(db_invoice)
+    db.flush()  # Flush to get the ID
+    
+    # Create invoice items
+    total_amount = 0
+    for item_data in invoice_data.items:
+        item_amount = item_data.quantity * item_data.unit_price
+        total_amount += item_amount
+        
+        db_item = InvoiceItem(
+            invoice_id=db_invoice.id,
+            description=item_data.description,
+            quantity=item_data.quantity,
+            unit_price=item_data.unit_price,
+            amount=item_amount,
+        )
+        db.add(db_item)
+    
+    # Update total amount
+    db_invoice.total_amount = total_amount
+    
+    # Commit the transaction
+    db.commit()
+    db.refresh(db_invoice)
+    
+    return db_invoice
+
+
+@router.get("/", response_model=List[InvoiceDB])
+def get_invoices(
+    skip: int = 0, 
+    limit: int = 100, 
+    db: Session = Depends(get_db)
+):
+    """
+    Retrieve a list of invoices.
+    """
+    invoices = db.query(Invoice).offset(skip).limit(limit).all()
+    return invoices
+
+
+@router.get("/{invoice_id}", response_model=InvoiceDB)
+def get_invoice(invoice_id: int, db: Session = Depends(get_db)):
+    """
+    Retrieve a specific invoice by ID.
+    """
+    invoice = db.query(Invoice).filter(Invoice.id == invoice_id).first()
+    if invoice is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Invoice with ID {invoice_id} not found",
+        )
+    return invoice
+
+
+@router.post("/find", response_model=InvoiceDB)
+def find_invoice_by_number(query: InvoiceSearchQuery, db: Session = Depends(get_db)):
+    """
+    Find an invoice by its invoice number.
+    """
+    invoice = db.query(Invoice).filter(Invoice.invoice_number == query.invoice_number).first()
+    if invoice is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Invoice with number {query.invoice_number} not found",
+        )
+    return invoice
+
+
+@router.patch("/{invoice_id}", response_model=InvoiceDB)
+def update_invoice(
+    invoice_id: int, 
+    invoice_update: InvoiceUpdate, 
+    db: Session = Depends(get_db)
+):
+    """
+    Update an existing invoice.
+    """
+    # Get the invoice
+    invoice = db.query(Invoice).filter(Invoice.id == invoice_id).first()
+    if invoice is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Invoice with ID {invoice_id} not found",
+        )
+    
+    # Update invoice fields
+    update_data = invoice_update.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(invoice, field, value)
+    
+    # Commit changes
+    db.commit()
+    db.refresh(invoice)
+    
+    return invoice
+
+
+@router.patch("/{invoice_id}/status", response_model=InvoiceDB)
+def update_invoice_status(
+    invoice_id: int, 
+    status_update: InvoiceStatusUpdate, 
+    db: Session = Depends(get_db)
+):
+    """
+    Update the status of an invoice.
+    """
+    # Get the invoice
+    invoice = db.query(Invoice).filter(Invoice.id == invoice_id).first()
+    if invoice is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Invoice with ID {invoice_id} not found",
+        )
+    
+    # Update status
+    invoice.status = status_update.status
+    
+    # Commit changes
+    db.commit()
+    db.refresh(invoice)
+    
+    return invoice
+
+
+@router.delete("/{invoice_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+def delete_invoice(invoice_id: int, db: Session = Depends(get_db)):
+    """
+    Delete an invoice.
+    """
+    # Get the invoice
+    invoice = db.query(Invoice).filter(Invoice.id == invoice_id).first()
+    if invoice is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Invoice with ID {invoice_id} not found",
+        )
+    
+    # Delete the invoice
+    db.delete(invoice)
+    db.commit()
+    
+    return None

app/core/__init__.py

@@ -0,0 +1 @@
+# This file is intentionally left empty to make the directory a Python package

app/core/config.py

@@ -0,0 +1,29 @@
+from typing import List, Union
+
+from pydantic import AnyHttpUrl, validator
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    # API config
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Invoice Generation Service"
+    
+    # CORS settings
+    BACKEND_CORS_ORIGINS: List[Union[str, AnyHttpUrl]] = []
+
+    @validator("BACKEND_CORS_ORIGINS", pre=True)
+    def assemble_cors_origins(cls, v: Union[str, List[str]]) -> Union[List[str], str]:
+        if isinstance(v, str) and not v.startswith("["):
+            return [i.strip() for i in v.split(",")]
+        elif isinstance(v, (list, str)):
+            return v
+        raise ValueError(v)
+
+    class Config:
+        case_sensitive = True
+        env_file = ".env"
+
+
+# Create settings instance
+settings = Settings()

app/core/database.py

@@ -0,0 +1,29 @@
+from pathlib import Path
+
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+# Setup database directory
+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)
+
+Base = declarative_base()
+
+
+# Dependency
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/core/utils.py

@@ -0,0 +1,49 @@
+import datetime
+import random
+import string
+
+
+def generate_invoice_number(prefix="INV", length=6):
+    """
+    Generate a unique invoice number.
+    
+    Format: INV-{YEAR}{MONTH}-{RANDOM_ALPHANUMERIC}
+    Example: INV-202307-A1B2C3
+    
+    Args:
+        prefix (str): Prefix for the invoice number
+        length (int): Length of the random string
+    
+    Returns:
+        str: Generated invoice number
+    """
+    # Get current date for year-month part
+    today = datetime.datetime.now()
+    year_month = today.strftime("%Y%m")
+    
+    # Generate random alphanumeric string
+    characters = string.ascii_uppercase + string.digits
+    random_str = ''.join(random.choice(characters) for _ in range(length))
+    
+    # Combine to form invoice number
+    invoice_number = f"{prefix}-{year_month}-{random_str}"
+    
+    return invoice_number
+
+
+def calculate_total_amount(items):
+    """
+    Calculate the total amount of an invoice based on its items.
+    
+    Args:
+        items (list): List of invoice items, each with quantity and unit_price
+    
+    Returns:
+        float: Total amount
+    """
+    total = 0.0
+    for item in items:
+        item_amount = item.quantity * item.unit_price
+        total += item_amount
+    
+    return total

app/models/__init__.py

@@ -0,0 +1 @@
+from app.models.invoice import Invoice, InvoiceItem  # noqa: F401

app/models/invoice.py

@@ -0,0 +1,46 @@
+import datetime
+
+from sqlalchemy import (
+    Column,
+    String,
+    Integer,
+    Float,
+    DateTime,
+    ForeignKey,
+    Text,
+)
+from sqlalchemy.orm import relationship
+
+from app.core.database import Base
+
+
+class Invoice(Base):
+    __tablename__ = "invoices"
+
+    id = Column(Integer, primary_key=True, index=True)
+    invoice_number = Column(String(255), unique=True, index=True, nullable=False)
+    date_created = Column(DateTime, default=datetime.datetime.utcnow, nullable=False)
+    due_date = Column(DateTime, nullable=False)
+    customer_name = Column(String(255), nullable=False)
+    customer_email = Column(String(255), nullable=True)
+    customer_address = Column(Text, nullable=True)
+    total_amount = Column(Float, nullable=False)
+    status = Column(String(50), default="PENDING", nullable=False)
+    notes = Column(Text, nullable=True)
+
+    # Relationship with invoice items
+    items = relationship("InvoiceItem", back_populates="invoice", cascade="all, delete-orphan")
+
+
+class InvoiceItem(Base):
+    __tablename__ = "invoice_items"
+
+    id = Column(Integer, primary_key=True, index=True)
+    invoice_id = Column(Integer, ForeignKey("invoices.id"), nullable=False)
+    description = Column(String(255), nullable=False)
+    quantity = Column(Float, nullable=False)
+    unit_price = Column(Float, nullable=False)
+    amount = Column(Float, nullable=False)
+    
+    # Relationship with invoice
+    invoice = relationship("Invoice", back_populates="items")

app/schemas/__init__.py

@@ -0,0 +1,11 @@
+from app.schemas.invoice import (  # noqa: F401
+    InvoiceBase,
+    InvoiceCreate,
+    InvoiceDB,
+    InvoiceUpdate,
+    InvoiceItemBase,
+    InvoiceItemCreate,
+    InvoiceItemDB,
+    InvoiceSearchQuery,
+    InvoiceStatusUpdate
+)

app/schemas/invoice.py

@@ -0,0 +1,77 @@
+from datetime import datetime
+from typing import List, Optional
+
+from pydantic import BaseModel, Field, validator
+
+
+class InvoiceItemBase(BaseModel):
+    description: str
+    quantity: float
+    unit_price: float
+
+
+class InvoiceItemCreate(InvoiceItemBase):
+    pass
+
+
+class InvoiceItemDB(InvoiceItemBase):
+    id: int
+    invoice_id: int
+    amount: float
+
+    class Config:
+        from_attributes = True
+
+
+class InvoiceBase(BaseModel):
+    customer_name: str
+    customer_email: Optional[str] = None
+    customer_address: Optional[str] = None
+    due_date: datetime
+    notes: Optional[str] = None
+
+
+class InvoiceCreate(InvoiceBase):
+    items: List[InvoiceItemCreate]
+
+    @validator("items")
+    def validate_items(cls, v):
+        if not v or len(v) == 0:
+            raise ValueError("Invoice must have at least one item")
+        return v
+
+
+class InvoiceUpdate(BaseModel):
+    customer_name: Optional[str] = None
+    customer_email: Optional[str] = None
+    customer_address: Optional[str] = None
+    due_date: Optional[datetime] = None
+    status: Optional[str] = None
+    notes: Optional[str] = None
+
+
+class InvoiceDB(InvoiceBase):
+    id: int
+    invoice_number: str
+    date_created: datetime
+    total_amount: float
+    status: str
+    items: List[InvoiceItemDB]
+
+    class Config:
+        from_attributes = True
+
+
+class InvoiceSearchQuery(BaseModel):
+    invoice_number: str
+
+
+class InvoiceStatusUpdate(BaseModel):
+    status: str = Field(..., description="New status for the invoice")
+
+    @validator("status")
+    def validate_status(cls, v):
+        allowed_statuses = ["PENDING", "PAID", "CANCELLED"]
+        if v not in allowed_statuses:
+            raise ValueError(f"Status must be one of {', '.join(allowed_statuses)}")
+        return v

main.py

@@ -0,0 +1,37 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.routes import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    description="Invoice Generation Service API",
+    version="0.1.0",
+    openapi_url=f"{settings.API_V1_STR}/openapi.json",
+)
+
+# Set all CORS enabled origins
+if settings.BACKEND_CORS_ORIGINS:
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=[str(origin) for origin in settings.BACKEND_CORS_ORIGINS],
+        allow_credentials=True,
+        allow_methods=["*"],
+        allow_headers=["*"],
+    )
+
+# Include API router
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+
+@app.get("/health", status_code=200)
+def health():
+    """Health check endpoint"""
+    return {"status": "healthy"}
+
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/env.py

@@ -0,0 +1,78 @@
+import sys
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+# Add the project base directory to the Python path
+sys.path.append("")
+
+# 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.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# Import your models here to auto-generate migrations
+from app.core.database import Base  # noqa: E402
+
+# Set up target metadata
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    """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"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    """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:
+        is_sqlite = connection.dialect.name == "sqlite"
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=is_sqlite,  # For SQLite batch mode
+        )
+
+        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() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

migrations/versions/ef0aaab3a275_initial_database_tables.py

@@ -0,0 +1,58 @@
+"""Initial database tables
+
+Revision ID: ef0aaab3a275
+Revises: 
+Create Date: 2023-07-20 10:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'ef0aaab3a275'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('invoices',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('invoice_number', sa.String(length=255), nullable=False),
+        sa.Column('date_created', sa.DateTime(), nullable=False),
+        sa.Column('due_date', sa.DateTime(), nullable=False),
+        sa.Column('customer_name', sa.String(length=255), nullable=False),
+        sa.Column('customer_email', sa.String(length=255), nullable=True),
+        sa.Column('customer_address', sa.Text(), nullable=True),
+        sa.Column('total_amount', sa.Float(), nullable=False),
+        sa.Column('status', sa.String(length=50), nullable=False),
+        sa.Column('notes', sa.Text(), nullable=True),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_invoices_id'), 'invoices', ['id'], unique=False)
+    op.create_index(op.f('ix_invoices_invoice_number'), 'invoices', ['invoice_number'], unique=True)
+    
+    op.create_table('invoice_items',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('invoice_id', sa.Integer(), nullable=False),
+        sa.Column('description', sa.String(length=255), nullable=False),
+        sa.Column('quantity', sa.Float(), nullable=False),
+        sa.Column('unit_price', sa.Float(), nullable=False),
+        sa.Column('amount', sa.Float(), nullable=False),
+        sa.ForeignKeyConstraint(['invoice_id'], ['invoices.id'], ),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_invoice_items_id'), 'invoice_items', ['id'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_invoice_items_id'), table_name='invoice_items')
+    op.drop_table('invoice_items')
+    op.drop_index(op.f('ix_invoices_invoice_number'), table_name='invoices')
+    op.drop_index(op.f('ix_invoices_id'), table_name='invoices')
+    op.drop_table('invoices')
+    # ### end Alembic commands ###

pyproject.toml

@@ -0,0 +1,26 @@
+[tool.ruff]
+# Enable flake8-bugbear (`B`) rules.
+target-version = "py310"
+
+# Exclude a variety of commonly ignored directories.
+exclude = [
+    ".git",
+    ".env",
+    ".venv",
+    "__pycache__",
+    ".pytest_cache",
+]
+
+# Allow imports relative to the "app" directory to support absolute imports
+src = ["app"]
+
+[tool.ruff.lint]
+select = ["E", "F", "B"]
+ignore = ["E501", "B008"]  # Ignore line length violations and function calls in defaults
+
+[tool.ruff.lint.per-file-ignores]
+"__init__.py" = ["F401"]
+
+[tool.ruff.lint.isort]
+# Only known first party imports.
+known-first-party = ["app"]

requirements.txt

@@ -0,0 +1,10 @@
+fastapi>=0.100.0
+uvicorn>=0.22.0
+sqlalchemy>=2.0.0
+alembic>=1.11.1
+pydantic>=2.0.0
+pydantic-settings>=2.0.0
+python-dateutil>=2.8.2
+typing-extensions>=4.7.1
+ruff>=0.0.292
+python-dotenv>=1.0.0