from fastapi import APIRouter, Depends, HTTPException, status, Response
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.orm import Session
from datetime import datetime, timezone
from typing import Optional

from database import get_db
from auth import (
    verify_password,
    get_password_hash,
    create_access_token,
    create_refresh_token,
    verify_token,
    get_current_user,
    create_default_admin,
)
from models import User
from schemas import UserCreate, UserOut, LoginPayload, Token, TokenRefresh

router = APIRouter(prefix="/api/auth", tags=["auth"])


@router.post("/register", response_model=UserOut, status_code=status.HTTP_201_CREATED)
def register(payload: UserCreate, db: Session = Depends(get_db)):
    existing = db.query(User).filter(User.username == payload.username).first()
    if existing:
        raise HTTPException(status_code=400, detail="Username already exists")
    user = User(
        username=payload.username,
        password_hash=get_password_hash(payload.password),
        role="viewer",
    )
    db.add(user)
    db.commit()
    db.refresh(user)
    return user


@router.post("/login", response_model=Token)
def login(
    response: Response,
    form_data: OAuth2PasswordRequestForm = Depends(),
    db: Session = Depends(get_db),
):
    create_default_admin(db)
    user = db.query(User).filter(User.username == form_data.username).first()
    if not user or not verify_password(form_data.password, user.password_hash):
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid credentials")
    access = create_access_token({"sub": user.username, "role": user.role})
    refresh = create_refresh_token({"sub": user.username, "role": user.role})
    response.set_cookie(
        key="access_token",
        value=access,
        httponly=True,
        max_age=1800,
        samesite="lax",
    )
    return {"access_token": access, "refresh_token": refresh}


@router.post("/refresh", response_model=Token)
def refresh(payload: TokenRefresh, response: Response, db: Session = Depends(get_db)):
    data = verify_token(payload.refresh_token, "refresh")
    if not data or "sub" not in data:
        raise HTTPException(status_code=401, detail="Invalid refresh token")
    user = db.query(User).filter(User.username == data["sub"]).first()
    if not user:
        raise HTTPException(status_code=401, detail="User not found")
    access = create_access_token({"sub": user.username, "role": user.role})
    refresh = create_refresh_token({"sub": user.username, "role": user.role})
    response.set_cookie(
        key="access_token",
        value=access,
        httponly=True,
        max_age=1800,
        samesite="lax",
    )
    return {"access_token": access, "refresh_token": refresh}


@router.get("/me", response_model=UserOut)
def me(user: User = Depends(get_current_user)):
    return user


@router.post("/logout")
def logout(response: Response):
    response.delete_cookie("access_token")
    return {"ok": True}