from datetime import datetime, timezone

from app.models import Employee
from app.services.dataset_versions import get_or_create_current_version, sync_employees_payload


def _employee(profile_key: str, checksum: str, *, status: str = "active") -> Employee:
    return Employee(
        profile_key=profile_key,
        profile_type=profile_key.split(":", 1)[0],
        profile_id=profile_key.split(":", 1)[1],
        canonical_url=f"https://www.hse.ru/{profile_key}",
        full_name=profile_key,
        status=status,
        first_seen_at=datetime.now(timezone.utc),
        last_seen_at=datetime.now(timezone.utc),
        current_data={"profile_key": profile_key},
        current_checksum=checksum,
    )


def test_dataset_version_hash_is_stable_for_same_employee_state(db_session):
    db_session.add(_employee("staff:alpha", "a" * 64))
    db_session.commit()

    first = get_or_create_current_version(db_session)
    db_session.commit()
    second = get_or_create_current_version(db_session)

    assert second.id == first.id
    assert second.hash == first.hash
    assert second.employee_count == 1


def test_dataset_version_hash_changes_when_employee_checksum_changes(db_session):
    employee = _employee("staff:alpha", "a" * 64)
    db_session.add(employee)
    db_session.commit()
    first = get_or_create_current_version(db_session)
    db_session.commit()

    employee.current_checksum = "b" * 64
    db_session.commit()
    second = get_or_create_current_version(db_session)

    assert second.hash != first.hash
    assert second.previous_hash == first.hash


def test_sync_employees_diff_spans_multiple_intermediate_versions(db_session):
    alpha = _employee("staff:alpha", "a" * 64)
    db_session.add(alpha)
    db_session.commit()
    first = get_or_create_current_version(db_session)
    db_session.commit()

    beta = _employee("staff:beta", "b" * 64)
    db_session.add(beta)
    db_session.commit()
    get_or_create_current_version(db_session)
    db_session.commit()

    alpha.current_checksum = "c" * 64
    alpha.current_data = {"profile_key": "staff:alpha", "changed": True}
    db_session.commit()

    payload = sync_employees_payload(db_session, client_hash=first.hash, include_data=False)

    assert payload["mode"] == "delta"
    assert [item["profile_key"] for item in payload["changes"]["added"]] == ["staff:beta"]
    assert [item["profile_key"] for item in payload["changes"]["updated"]] == ["staff:alpha"]
    assert payload["changes"]["dismissed"] == []
    assert payload["changes"]["removed"] == []


def test_sync_employees_reports_dismissed_as_tombstone(db_session):
    alpha = _employee("staff:alpha", "a" * 64)
    db_session.add(alpha)
    db_session.commit()
    first = get_or_create_current_version(db_session)
    db_session.commit()

    alpha.status = "dismissed"
    db_session.commit()
    payload = sync_employees_payload(db_session, client_hash=first.hash, include_data=False)

    assert payload["changes"]["dismissed"][0]["profile_key"] == "staff:alpha"
    assert payload["changes"]["dismissed"][0]["status"] == "dismissed"