"""Authentication endpoints."""
from datetime import datetime, timedelta
from typing import Annotated

from fastapi import APIRouter, BackgroundTasks, Depends, HTTPException, status
from jose import JWTError, jwt
from sqlalchemy.orm import Session

from app.core.config import settings
from app.core.deps import get_db
from app.core.security import create_access_token, get_password_hash, verify_password
from app.models.user import User
from app.schemas.auth import EmailVerificationRequest, LoginRequest, UserRegister
from app.schemas.user import Token
from app.services.email_service import send_email

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


@router.post("/login", response_model=Token)
def login(
    login_data: LoginRequest,
    db: Annotated[Session, Depends(get_db)],
) -> Token:
    """
    Login with email and password.

    Returns JWT token for authenticated requests.
    """
    user = db.query(User).filter(User.email == login_data.email).first()

    if not user or not verify_password(login_data.password, str(user.hashed_password)):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email or password",
            headers={"WWW-Authenticate": "Bearer"},
        )

    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="User account is disabled",
        )

    access_token = create_access_token(subject=int(user.id))

    return Token(access_token=access_token, token_type="bearer")


@router.post("/register", status_code=201)
async def register(
    data: UserRegister,
    background_tasks: BackgroundTasks,
    db: Annotated[Session, Depends(get_db)],
) -> dict:
    """
    Register new user with email verification.

    Creates an inactive user account and sends verification email.
    """
    # Check if email already exists
    existing = db.query(User).filter(User.email == data.email).first()
    if existing:
        raise HTTPException(status_code=400, detail="Email already registered")

    # Create user (inactive until verified)
    user = User(
        email=data.email,
        hashed_password=get_password_hash(data.password),
        full_name=data.full_name,
        organization=data.organization,
        role="user",  # Default role
        is_active=False,  # Inactive until email verified
    )

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

    # Generate verification token (JWT, expires in 24h)
    verification_token = jwt.encode(
        {
            "sub": str(user.id),
            "type": "email_verification",
            "exp": datetime.utcnow() + timedelta(hours=24),
        },
        settings.secret_key,
        algorithm="HS256",
    )

    # Send verification email (background task)
    verification_link = f"{settings.frontend_url}/verify?token={verification_token}"

    subject = "Verifică contul tău - Space Booking"
    body = f"""Bună ziua {user.full_name},

Bine ai venit pe platforma Space Booking!

Pentru a-ți activa contul, te rugăm să accesezi link-ul de mai jos:

{verification_link}

Link-ul va expira în 24 de ore.

Dacă nu ai creat acest cont, te rugăm să ignori acest email.

Cu stimă,
Echipa Space Booking
"""

    background_tasks.add_task(send_email, user.email, subject, body)

    return {
        "message": "Registration successful. Please check your email to verify your account.",
        "email": user.email,
    }


@router.post("/verify")
def verify_email(
    data: EmailVerificationRequest,
    db: Annotated[Session, Depends(get_db)],
) -> dict:
    """
    Verify email address with token.

    Activates the user account if token is valid.
    """
    try:
        # Decode token
        payload = jwt.decode(
            data.token,
            settings.secret_key,
            algorithms=["HS256"],
        )

        # Check token type
        if payload.get("type") != "email_verification":
            raise HTTPException(status_code=400, detail="Invalid verification token")

        user_id = int(payload.get("sub"))

        # Get user
        user = db.query(User).filter(User.id == user_id).first()
        if not user:
            raise HTTPException(status_code=404, detail="User not found")

        # Check if already verified
        if user.is_active:
            return {"message": "Email already verified"}

        # Activate user
        user.is_active = True
        db.commit()

        return {"message": "Email verified successfully. You can now log in."}

    except jwt.ExpiredSignatureError:
        raise HTTPException(
            status_code=400,
            detail="Verification link expired. Please request a new one.",
        )
    except JWTError:
        raise HTTPException(status_code=400, detail="Invalid verification token")


@router.post("/resend-verification")
async def resend_verification(
    email: str,
    background_tasks: BackgroundTasks,
    db: Annotated[Session, Depends(get_db)],
) -> dict:
    """
    Resend verification email.

    For security, always returns success even if email doesn't exist.
    """
    user = db.query(User).filter(User.email == email).first()
    if not user:
        # Don't reveal if email exists
        return {"message": "If the email exists, a verification link has been sent."}

    if user.is_active:
        raise HTTPException(status_code=400, detail="Account already verified")

    # Generate new token
    verification_token = jwt.encode(
        {
            "sub": str(user.id),
            "type": "email_verification",
            "exp": datetime.utcnow() + timedelta(hours=24),
        },
        settings.secret_key,
        algorithm="HS256",
    )

    # Send email
    verification_link = f"{settings.frontend_url}/verify?token={verification_token}"

    subject = "Verifică contul tău - Space Booking"
    body = f"""Bună ziua {user.full_name},

Ai solicitat un nou link de verificare pentru contul tău pe Space Booking.

Pentru a-ți activa contul, te rugăm să accesezi link-ul de mai jos:

{verification_link}

Link-ul va expira în 24 de ore.

Cu stimă,
Echipa Space Booking
"""

    background_tasks.add_task(send_email, user.email, subject, body)

    return {"message": "If the email exists, a verification link has been sent."}