"""Authentication endpoints."""

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

from app.auth.dependencies import get_current_user, verify_csrf
from app.auth.hashing import hash_password, verify_password
from app.auth.rate_limit import check_rate_limit, clear_attempts, record_failed_attempt
from app.auth.session import clear_session, create_session, verify_session
from app.config import settings
from app.db import get_db
from app.models.settings import Settings
from app.schemas.auth import AuthStatusResponse, ChangePasswordRequest, LoginRequest, SetupRequest

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


def get_client_ip(request: Request) -> str:
    """Helper to extract client IP for rate limiting."""
    forwarded = request.headers.get("X-Forwarded-For")
    if forwarded:
        return forwarded.split(",")[0].strip()
    return request.client.host if request.client else "unknown"


@router.get("/status", response_model=AuthStatusResponse)
def get_auth_status(request: Request, db: Session = Depends(get_db)) -> AuthStatusResponse:
    """Check if app requires setup and if user is logged in."""
    app_settings = db.query(Settings).first()
    if not app_settings:
        app_settings = Settings()
        db.add(app_settings)
        db.commit()
    
    setup_required = app_settings.password_hash is None
    
    token = request.cookies.get(settings.COOKIE_NAME)
    logged_in = False
    if token:
        user_id = verify_session(token)
        if user_id is not None:
            logged_in = True
            
    return AuthStatusResponse(setupRequired=setup_required, loggedIn=logged_in)


@router.post("/setup", dependencies=[Depends(verify_csrf)])
def setup_password(
    data: SetupRequest, 
    response: Response, 
    db: Session = Depends(get_db)
) -> dict[str, str]:
    """First-run setup."""
    app_settings = db.query(Settings).first()
    if app_settings and app_settings.password_hash:
        raise HTTPException(status_code=409, detail="Password already set")
        
    if not app_settings:
        app_settings = Settings()
        db.add(app_settings)
        
    app_settings.password_hash = hash_password(data.password)
    db.commit()
    
    # Log them in automatically
    create_session(response)
    return {"status": "ok"}


@router.post("/login", dependencies=[Depends(verify_csrf)])
def login(
    request: Request,
    data: LoginRequest,
    response: Response,
    db: Session = Depends(get_db)
) -> dict[str, str]:
    """Validate password and issue session cookie."""
    ip = get_client_ip(request)
    check_rate_limit(ip)
    
    app_settings = db.query(Settings).first()
    if not app_settings or not app_settings.password_hash:
        record_failed_attempt(ip)
        raise HTTPException(status_code=401, detail="Invalid credentials")
        
    if not verify_password(app_settings.password_hash, data.password):
        record_failed_attempt(ip)
        raise HTTPException(status_code=401, detail="Invalid credentials")
        
    clear_attempts(ip)
    create_session(response)
    return {"status": "ok"}


@router.post("/logout", dependencies=[Depends(verify_csrf)])
def logout(response: Response) -> dict[str, str]:
    """Clear session cookie."""
    clear_session(response)
    return {"status": "ok"}


@router.put("/password", dependencies=[Depends(verify_csrf), Depends(get_current_user)])
def change_password(
    request: Request,
    data: ChangePasswordRequest,
    db: Session = Depends(get_db)
) -> dict[str, str]:
    """Change an existing password."""
    ip = get_client_ip(request)
    check_rate_limit(ip)
    
    app_settings = db.query(Settings).first()
    if not app_settings or not app_settings.password_hash:
        raise HTTPException(status_code=400, detail="Setup required first")
        
    if not verify_password(app_settings.password_hash, data.current_password):
        record_failed_attempt(ip)
        raise HTTPException(status_code=401, detail="Invalid current password")
        
    clear_attempts(ip)
    app_settings.password_hash = hash_password(data.new_password)
    db.commit()
    
    return {"status": "ok"}