from fastapi import APIRouter, Depends, HTTPException, Request
from fastapi.responses import JSONResponse, Response
from pydantic import BaseModel
from sqlalchemy import func, select
from sqlalchemy.orm import Session

from app.auth.jwt_auth import CurrentUser, create_access_token, get_current_user
from app.auth.stream_cookie import clear_stream_auth_cookie, set_stream_auth_cookie
from app.config import get_settings
from app.database import get_db
from app.services.login_rate_limit import (
    ensure_login_allowed,
    record_login_failure,
    record_login_success,
)
from app.services.user_auth import authenticate_user

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


class LoginRequest(BaseModel):
    username: str
    password: str


class TokenResponse(BaseModel):
    access_token: str
    token_type: str = "bearer"
    username: str
    role: str


class MeResponse(BaseModel):
    username: str
    role: str


@router.post("/login", response_model=TokenResponse)
def login(body: LoginRequest, request: Request, db: Session = Depends(get_db)) -> JSONResponse:
    settings = get_settings()
    if not settings.sac_admin_password and not _has_any_user(db):
        raise HTTPException(
            status_code=503,
            detail="SAC UI users are not configured (run alembic upgrade and set SAC_ADMIN_PASSWORD for bootstrap)",
        )

    ip_address = ensure_login_allowed(db, request)

    user = authenticate_user(db, body.username, body.password)
    if user is None:
        record_login_failure(db, ip_address=ip_address, username=body.username)
        db.commit()
        raise HTTPException(status_code=401, detail="Invalid username or password")

    record_login_success(db, ip_address=ip_address, username=user.username)
    db.commit()

    token = create_access_token(user.username, user.role)
    payload = TokenResponse(
        access_token=token,
        username=user.username,
        role=user.role,
    )
    response = JSONResponse(content=payload.model_dump())
    set_stream_auth_cookie(response, token, settings)
    return response


@router.post("/logout", status_code=204)
def logout() -> Response:
    settings = get_settings()
    response = Response(status_code=204)
    clear_stream_auth_cookie(response, settings)
    return response


@router.get("/me", response_model=MeResponse)
def me(current_user: CurrentUser = Depends(get_current_user)) -> MeResponse:
    return MeResponse(username=current_user.username, role=current_user.role)


def _has_any_user(db: Session) -> bool:
    from app.models.user import User

    try:
        count = db.scalar(select(func.count()).select_from(User)) or 0
        return count > 0
    except Exception:
        db.rollback()
        return False