from datetime import datetime

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session

import auth
import database
import models
import schemas


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


def get_current_timestamp() -> str:
    return datetime.utcnow().strftime("%Y-%m-%dT%H:%M:%fZ")


def user_to_out(user: models.User) -> schemas.UserOut:
    return schemas.UserOut(
        id=user.id,
        username=user.username,
        display_name=user.display_name or user.username,
        role=user.role or "personal",
        created_at=user.created_at or get_current_timestamp(),
    )


@router.post("/register", response_model=schemas.Token)
def register(
    data: schemas.UserCreate,
    db: Session = Depends(database.get_db),
):
    username = (data.username or "").strip().lower()
    password = data.password or ""
    role = data.role or "personal"

    if len(username) < 3:
        raise HTTPException(status_code=400, detail="Username must be at least 3 characters")

    if len(password) < 6:
        raise HTTPException(status_code=400, detail="Password must be at least 6 characters")

    if role not in ("personal", "trainer"):
        role = "personal"

    exists = db.query(models.User).filter(models.User.username == username).first()
    if exists:
        raise HTTPException(status_code=400, detail="Username already exists")

    user = models.User(
        username=username,
        password_hash=auth.hash_password(password),
        display_name=(data.display_name or username).strip(),
        role=role,
        created_at=get_current_timestamp(),
    )

    db.add(user)
    db.commit()
    db.refresh(user)

    token = auth.create_access_token(user)

    return schemas.Token(
        access_token=token,
        token_type="bearer",
        user=user_to_out(user),
    )


@router.post("/login", response_model=schemas.Token)
def login(
    data: schemas.UserLogin,
    db: Session = Depends(database.get_db),
):
    username = (data.username or "").strip().lower()
    password = data.password or ""

    user = db.query(models.User).filter(models.User.username == username).first()
    if not user:
        raise HTTPException(status_code=401, detail="Invalid username or password")

    if not auth.verify_password(password, user.password_hash):
        raise HTTPException(status_code=401, detail="Invalid username or password")

    token = auth.create_access_token(user)

    return schemas.Token(
        access_token=token,
        token_type="bearer",
        user=user_to_out(user),
    )


@router.get("/me", response_model=schemas.UserOut)
def me(
    current_user: models.User = Depends(auth.get_current_user),
):
    return user_to_out(current_user)