"""Auth API router: login, register, refresh, logout, MFA, password change."""

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

from app.core.dependencies import get_current_user
from app.database import get_db
from app.models.user import User
from app.schemas.auth import (
    ChangePasswordRequest,
    LoginRequest,
    MFASetupResponse,
    MFAVerifyRequest,
    RefreshRequest,
    RegisterRequest,
    TokenResponse,
)
from app.schemas.user import UserResponse
from app.services.auth_service import (
    activate_mfa,
    authenticate_user,
    change_password,
    create_tokens,
    refresh_access_token,
    register_user,
    revoke_refresh_token,
    setup_mfa,
)

router = APIRouter()


# ---------------------------------------------------------------------------
# Public endpoints (no auth required)
# ---------------------------------------------------------------------------


@router.post("/login", response_model=TokenResponse)
def login(data: LoginRequest, db: Session = Depends(get_db)):
    """Authenticate with email/password (+ optional MFA) and receive tokens."""
    user = authenticate_user(db, data.email, data.password, data.mfa_code)
    access, refresh = create_tokens(db, user)
    return TokenResponse(
        access_token=access,
        refresh_token=refresh,
        user=UserResponse.model_validate(user),
    )


@router.post("/register", response_model=UserResponse)
def register(data: RegisterRequest, db: Session = Depends(get_db)):
    """Self-service registration (invitation token or whitelisted domain)."""
    user = register_user(
        db,
        username=data.username,
        email=data.email,
        password=data.password,
        invitation_token=data.invitation_token,
    )
    return UserResponse.model_validate(user)


@router.post("/refresh", response_model=TokenResponse)
def refresh(data: RefreshRequest, db: Session = Depends(get_db)):
    """Exchange a valid refresh token for a new access token."""
    access, user = refresh_access_token(db, data.refresh_token)
    return TokenResponse(
        access_token=access,
        refresh_token=data.refresh_token,
        user=UserResponse.model_validate(user),
    )


# ---------------------------------------------------------------------------
# Authenticated endpoints
# ---------------------------------------------------------------------------


@router.post("/logout")
def logout(
    data: RefreshRequest,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Revoke the supplied refresh token (logout)."""
    revoke_refresh_token(db, data.refresh_token)
    return {"detail": "Logged out"}


@router.post("/mfa/setup", response_model=MFASetupResponse)
def mfa_setup(current_user: User = Depends(get_current_user)):
    """Generate a new TOTP secret and QR provisioning URI.

    The client must store the returned *secret* and send it back together
    with a valid TOTP code to ``POST /mfa/verify`` to finalise activation.
    """
    secret, uri = setup_mfa(current_user)
    return MFASetupResponse(secret=secret, qr_uri=uri)


@router.post("/mfa/verify")
def mfa_verify(
    data: MFAVerifyRequest,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Verify the TOTP code against the secret from /mfa/setup and enable MFA.

    MFA setup flow:
      1. ``POST /mfa/setup``  -->  ``{secret, qr_uri}``
      2. User scans QR in authenticator app.
      3. ``POST /mfa/verify``  with ``{secret, code}``  -->  MFA enabled.
    """
    activate_mfa(db, current_user, data.secret, data.code)
    return {"detail": "MFA enabled"}


@router.post("/change-password")
def change_password_endpoint(
    data: ChangePasswordRequest,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Change the authenticated user's password."""
    change_password(db, current_user, data.old_password, data.new_password)
    return {"detail": "Password changed"}


@router.get("/me", response_model=UserResponse)
def me(current_user: User = Depends(get_current_user)):
    """Return the currently authenticated user's profile."""
    return UserResponse.model_validate(current_user)