import uuid

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

from app.api.deps import get_db, require_operations_manager
from app.core.security import hash_password
from app.models.user import User
from app.schemas import CreateUserRequest, CurrentUser, UpdateUserRequest, UserOut
from app.services.audit import record_audit_event

router = APIRouter(prefix="/api/v1/users", tags=["users"])


def _to_out(user: User) -> UserOut:
    return UserOut(
        public_ref=user.public_ref,
        email=user.email,
        display_name=user.display_name,
        role=user.role,  # type: ignore[arg-type]
        active=user.active,
    )


@router.get("", response_model=list[UserOut])
def list_users(
    db: Session = Depends(get_db),
    _manager: CurrentUser = Depends(require_operations_manager),
) -> list[UserOut]:
    return [_to_out(user) for user in db.scalars(select(User).order_by(User.display_name)).all()]


@router.post("", response_model=UserOut, status_code=201)
def create_user(
    body: CreateUserRequest,
    db: Session = Depends(get_db),
    manager: CurrentUser = Depends(require_operations_manager),
) -> UserOut:
    email = body.email.strip().lower()
    if db.scalar(select(User.id).where(User.email == email)) is not None:
        raise HTTPException(status_code=409, detail="A user with this email already exists")
    user = User(
        public_ref=f"USR-{uuid.uuid4().hex[:8].upper()}",
        email=email,
        password_hash=hash_password(body.password),
        display_name=body.display_name.strip(),
        role=body.role,
        active=True,
    )
    db.add(user)
    db.flush()
    record_audit_event(
        db,
        actor_type="user",
        actor_label=manager.display_name,
        action="user_created",
        entity_type="user",
        entity_id=user.id,
        after={"public_ref": user.public_ref, "role": user.role, "active": user.active},
    )
    db.commit()
    return _to_out(user)


@router.patch("/{public_ref}", response_model=UserOut)
def update_user(
    public_ref: str,
    body: UpdateUserRequest,
    db: Session = Depends(get_db),
    manager: CurrentUser = Depends(require_operations_manager),
) -> UserOut:
    user = db.scalar(select(User).where(User.public_ref == public_ref).with_for_update())
    if user is None:
        raise HTTPException(status_code=404, detail="User not found")
    if user.public_ref == manager.public_ref and body.active is False:
        raise HTTPException(status_code=409, detail="You cannot deactivate your own account")
    if user.public_ref == manager.public_ref and body.role not in (None, "operations_manager"):
        raise HTTPException(status_code=409, detail="You cannot remove your own manager role")
    before = {"display_name": user.display_name, "role": user.role, "active": user.active}
    if body.display_name is not None:
        user.display_name = body.display_name.strip()
    if body.role is not None:
        user.role = body.role
    if body.active is not None:
        user.active = body.active
    if body.password is not None:
        user.password_hash = hash_password(body.password)
    record_audit_event(
        db,
        actor_type="user",
        actor_label=manager.display_name,
        action="user_updated",
        entity_type="user",
        entity_id=user.id,
        before=before,
        after={"display_name": user.display_name, "role": user.role, "active": user.active},
    )
    db.commit()
    return _to_out(user)