main.py

import os
import secrets
import requests
from fastapi import FastAPI, Depends, HTTPException, Header
from sqlalchemy import create_engine, Column, Integer, String, Boolean, DateTime, func
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, Session
from pydantic import BaseModel
from dotenv import load_dotenv

# Load environment variables from .env file
load_dotenv()

# Environment variables for MySQL and main API settings
MYSQL_USER = os.getenv("MYSQL_USER")
MYSQL_PASSWORD = os.getenv("MYSQL_PASSWORD")
MYSQL_HOST = os.getenv("MYSQL_HOST")
MYSQL_DB = os.getenv("MYSQL_DB")
MAIN_API_KEY = os.getenv("MAIN_API_KEY")
MAIN_API_URL = os.getenv("MAIN_API_URL", "https://api.typegpt.net/v1/chat/completions")
MODEL_NAME = os.getenv("MODEL_NAME", "Image-Generator")

DATABASE_URL = f"mysql+pymysql://{MYSQL_USER}:{MYSQL_PASSWORD}@{MYSQL_HOST}/{MYSQL_DB}"

# SQLAlchemy setup
engine = create_engine(DATABASE_URL)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()

# User model
class User(Base):
    __tablename__ = "users"
    id = Column(Integer, primary_key=True, index=True)
    username = Column(String(50), unique=True, index=True, nullable=False)
    hashed_password = Column(String(128), nullable=False)
    api_key = Column(String(64), unique=True, index=True, nullable=False)
    is_admin = Column(Boolean, default=False)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

# Create tables
Base.metadata.create_all(bind=engine)

app = FastAPI(title="API Key Generator & Proxy Service")

# Dependency: Database session
def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

# Utility: Generate a unique API key
def generate_api_key() -> str:
    return secrets.token_hex(16)

# Pydantic models
class UserCreate(BaseModel):
    username: str
    password: str

class UserOut(BaseModel):
    id: int
    username: str
    api_key: str
    is_admin: bool

    class Config:
        orm_mode = True

# Dependency: Validate API key from header and return current user
def get_current_user(x_api_key: str = Header(...), db: Session = Depends(get_db)) -> User:
    user = db.query(User).filter(User.api_key == x_api_key).first()
    if not user:
        raise HTTPException(status_code=401, detail="Invalid API Key")
    return user

# --- Endpoints ---

# 1. User Registration (generates a unique API key)
@app.post("/register", response_model=UserOut)
def register(user: UserCreate, db: Session = Depends(get_db)):
    if db.query(User).filter(User.username == user.username).first():
        raise HTTPException(status_code=400, detail="Username already exists")
    new_api_key = generate_api_key()
    # In production, use proper password hashing
    new_user = User(username=user.username, hashed_password=user.password, api_key=new_api_key, is_admin=False)
    db.add(new_user)
    db.commit()
    db.refresh(new_user)
    return new_user

# 2. User Panel: Get current user info
@app.get("/user/me", response_model=UserOut)
def read_user_me(current_user: User = Depends(get_current_user)):
    return current_user

# 3. Admin Panel: List all users (admin-only)
@app.get("/admin/users", response_model=list[UserOut])
def list_users(current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    if not current_user.is_admin:
        raise HTTPException(status_code=403, detail="Not authorized")
    users = db.query(User).all()
    return users

# 4. Endpoint to access the main API (proxying request using main API key)
class RequestPayload(BaseModel):
    prompt: str

@app.post("/generate")
def generate_image(payload: RequestPayload, current_user: User = Depends(get_current_user)):
    headers = {
        "Authorization": f"Bearer {MAIN_API_KEY}",
        "Content-Type": "application/json"
    }
    data = {
        "model": MODEL_NAME,
        "prompt": payload.prompt
    }
    response = requests.post(MAIN_API_URL, json=data, headers=headers)
    if response.status_code != 200:
        raise HTTPException(status_code=response.status_code, detail="Error from main API")
    return response.json()