app.py

from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
import bcrypt
import os
import ssl

# Database setup
DATABASE_URL = os.getenv("DATABASE_URL")
ssl_cert = os.getenv("MYSQL_CA_CERT")
ssl_context = ssl.create_default_context(cadata=ssl_cert)
engine = create_engine(DATABASE_URL)
Base = declarative_base()
SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False)

# User model
class User(Base):
    __tablename__ = "Users"
    id = Column(Integer, primary_key=True, index=True)
    name = Column(String(100), nullable=False)
    email = Column(String(100), unique=True, nullable=False)
    hashed_password = Column(String(255), nullable=False)

Base.metadata.create_all(bind=engine)

class UserCreate(BaseModel):
    username: str  
    email: str
    password: str  

class UserLogin(BaseModel):
    email: str
    password: str  

# FastAPI app
app = FastAPI()

@app.post("/register")
def register(user: UserCreate):
    db = SessionLocal()
    try:
        # Check if email already exists
        existing_user = db.query(User).filter(User.email == user.email).first()
        if existing_user:
            raise HTTPException(status_code=400, detail="Email already registered")
        
        # Hash password (user sends plain password, we hash it)
        hashed_password = bcrypt.hashpw(user.password.encode('utf-8'), bcrypt.gensalt())
        
        # Create new user (map username to name field in database)
        new_user = User(
            name=user.username,  # Map username to name
            email=user.email, 
            hashed_password=hashed_password.decode('utf-8')
        )
        db.add(new_user)
        db.commit()
        db.refresh(new_user)
        
        return {"message": "User created successfully", "username": new_user.name}
    finally:
        db.close()

@app.post("/login")
def login(user: UserLogin):
    db = SessionLocal()
    try:
        # Find user by email
        db_user = db.query(User).filter(User.email == user.email).first()
        if not db_user:
            raise HTTPException(status_code=400, detail="User not found")
        
        # Verify password (user sends plain password, we check against hash)
        if not bcrypt.checkpw(user.password.encode('utf-8'), db_user.hashed_password.encode('utf-8')):
            raise HTTPException(status_code=400, detail="Incorrect password")
        
        return {"message": "Login successful", "username": db_user.name}
    finally:
        db.close()