from fastapi import FastAPI, HTTPException, Depends
from fastapi.middleware.cors import CORSMiddleware
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from . import schemas, database, models, auth
from passlib.context import CryptContext
import logging

app = FastAPI(
    title="Auth Service",
    root_path="/auth",
    docs_url="/docs",
    openapi_url="/openapi.json"
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

@app.on_event("startup")
async def startup():
    await database.init_db()

async def get_db():
    async with database.AsyncSessionLocal() as session:
        yield session

@app.get("/")
def root():
    return {
        "service": "auth",
        "message": "Auth service is running"
    }

@app.post("/users/", response_model=schemas.User)
async def create_user(user: schemas.UserCreate, db: AsyncSession = Depends(get_db)):
    stmt = select(models.User).where(models.User.username == user.username)
    result = await db.execute(stmt)
    if result.scalars().first():
        raise HTTPException(status_code=400, detail="Username already exists")
    hashed_password = pwd_context.hash(user.password)
    db_user = models.User(username=user.username, hashed_password=hashed_password)
    db.add(db_user)
    await db.commit()
    await db.refresh(db_user)
    return db_user

@app.get("/users/", response_model=list[schemas.User])
async def get_users(db: AsyncSession = Depends(get_db), current_user: schemas.User = Depends(auth.get_current_user)):
    stmt = select(models.User)
    result = await db.execute(stmt)
    return result.scalars().all()

@app.get("/users/{username}", response_model=schemas.User)
async def get_user(username: str, db: AsyncSession = Depends(get_db), current_user: schemas.User = Depends(auth.get_current_user)):
    stmt = select(models.User).where(models.User.username == username)
    result = await db.execute(stmt)
    user = result.scalars().first()
    if not user:
        raise HTTPException(status_code=404, detail="User not found")
    return user

@app.put("/users/{username}", response_model=schemas.User)
async def update_user(username: str, user_update: schemas.UserCreate, db: AsyncSession = Depends(get_db), current_user: schemas.User = Depends(auth.get_current_user)):
    stmt = select(models.User).where(models.User.username == username)
    result = await db.execute(stmt)
    db_user = result.scalars().first()
    if not db_user:
        raise HTTPException(status_code=404, detail="User not found")
    db_user.hashed_password = pwd_context.hash(user_update.password)
    await db.commit()
    await db.refresh(db_user)
    return db_user

@app.delete("/users/{username}", status_code=204)
async def delete_user(username: str, db: AsyncSession = Depends(get_db), current_user: schemas.User = Depends(auth.get_current_user)):
    stmt = select(models.User).where(models.User.username == username)
    result = await db.execute(stmt)
    db_user = result.scalars().first()
    if not db_user:
        raise HTTPException(status_code=404, detail="User not found")
    await db.delete(db_user)
    await db.commit()
    return {
        "message": "User deleted."
    }

@app.post("/token", response_model=schemas.Token)
async def login_for_access_token(form_data: OAuth2PasswordRequestForm = Depends(), db: AsyncSession = Depends(get_db)):
    stmt = select(models.User).where(models.User.username == form_data.username)
    result = await db.execute(stmt)
    user = result.scalars().first()
    if not user or not pwd_context.verify(form_data.password, user.hashed_password):
        raise HTTPException(status_code=401, detail="Incorrect username or password")
    access_token = auth.create_access_token(data={"sub": user.username})
    return {"access_token": access_token, "token_type": "bearer"}