"""Tests for the pure, read-only predicates in _compliance_state.py."""

from __future__ import annotations

from datetime import UTC, date, datetime
import json
from typing import TYPE_CHECKING
from unittest.mock import patch

import freedays

from screen_locker._compliance_state import (
    has_logged_today,
    is_early_bird_pending,
    is_scheduled_skip_today,
    is_sick_day_today,
)
from screen_locker.tests._sick_helpers import mark_sick

if TYPE_CHECKING:
    from pathlib import Path


def _today() -> str:
    return datetime.now(tz=UTC).strftime("%Y-%m-%d")


class TestIsScheduledSkipToday:
    """Mirrors test_scheduled_skip.py's coverage, for the standalone function."""

    def test_empty_pool(self, tmp_path: Path) -> None:
        """An empty pool means today is not a free day."""
        assert is_scheduled_skip_today() is False

    def test_today_marked(self, tmp_path: Path) -> None:
        """Today in the shared pool makes it a free day."""
        freedays.mark(
            freedays.today(), paths=freedays.Paths.under(tmp_path / "freedays")
        )
        assert is_scheduled_skip_today() is True

    def test_today_not_marked(self, tmp_path: Path) -> None:
        """A pool holding some other date is not today's free day."""
        freedays.mark(
            date(2026, 12, 24),
            paths=freedays.Paths.under(tmp_path / "freedays"),
        )
        assert is_scheduled_skip_today() is False

    def test_corrupt_pool(self, tmp_path: Path) -> None:
        """Unparsable JSON fails closed: not a free day, the chain continues."""
        pool = tmp_path / "freedays"
        pool.mkdir(exist_ok=True)
        (pool / "free_days.json").write_text("{bad}")
        assert is_scheduled_skip_today() is False

    def test_explicit_day_override(self, tmp_path: Path) -> None:
        """The `today` argument overrides the real date."""
        freedays.mark(
            date(2026, 12, 24),
            paths=freedays.Paths.under(tmp_path / "freedays"),
        )
        assert is_scheduled_skip_today(date(2026, 12, 24)) is True


class TestHasLoggedToday:
    """Mirrors test_init_and_log.py's HMAC branches, for the standalone function."""

    def test_missing_file(self, tmp_path: Path) -> None:
        """A missing log means nothing was logged today."""
        assert has_logged_today(tmp_path / "log.json") is False

    def test_corrupt_json(self, tmp_path: Path) -> None:
        """Unparsable JSON fails closed: nothing logged."""
        log_file = tmp_path / "log.json"
        log_file.write_text("{bad}")
        assert has_logged_today(log_file) is False

    def test_no_entry_for_today(self, tmp_path: Path) -> None:
        """An entry for another day does not count as today's."""
        log_file = tmp_path / "log.json"
        log_file.write_text(json.dumps({"1999-01-01": {}}))
        assert has_logged_today(log_file) is False

    def test_valid_hmac(self, tmp_path: Path) -> None:
        """A correctly signed entry for today counts."""
        log_file = tmp_path / "log.json"
        log_file.write_text(json.dumps({_today(): {"hmac": "sig"}}))
        with patch(
            "screen_locker._compliance_predicates.verify_entry_hmac", return_value=True
        ):
            assert has_logged_today(log_file) is True

    def test_unsigned_accepted_when_key_unavailable(self, tmp_path: Path) -> None:
        """With no HMAC key on the machine, an unsigned entry is accepted."""
        log_file = tmp_path / "log.json"
        log_file.write_text(json.dumps({_today(): {}}))
        with (
            patch(
                "screen_locker._compliance_predicates.verify_entry_hmac",
                return_value=False,
            ),
            patch(
                "screen_locker._compliance_predicates.compute_entry_hmac",
                return_value=None,
            ),
        ):
            assert has_logged_today(log_file) is True

    def test_rejected_when_key_available(self, tmp_path: Path) -> None:
        """With a key available, an unsigned entry is rejected as tampering."""
        log_file = tmp_path / "log.json"
        log_file.write_text(json.dumps({_today(): {}}))
        with (
            patch(
                "screen_locker._compliance_predicates.verify_entry_hmac",
                return_value=False,
            ),
            patch(
                "screen_locker._compliance_predicates.compute_entry_hmac",
                return_value="sig",
            ),
        ):
            assert has_logged_today(log_file) is False

    def test_rejected_when_signed_but_invalid(self, tmp_path: Path) -> None:
        """A signature that does not verify is rejected."""
        log_file = tmp_path / "log.json"
        log_file.write_text(json.dumps({_today(): {"hmac": "tampered"}}))
        with (
            patch(
                "screen_locker._compliance_predicates.verify_entry_hmac",
                return_value=False,
            ),
            patch(
                "screen_locker._compliance_predicates.compute_entry_hmac",
                return_value=None,
            ),
        ):
            assert has_logged_today(log_file) is False


class TestIsEarlyBirdPending:
    """Mirrors test_early_bird.py's HMAC branches, for the standalone function."""

    def test_missing_file(self, tmp_path: Path) -> None:
        """A missing pending file means no early bird is pending."""
        assert is_early_bird_pending(tmp_path / "pending.json") is False

    def test_corrupt_json(self, tmp_path: Path) -> None:
        """Unparsable JSON fails closed: nothing pending."""
        pending_file = tmp_path / "pending.json"
        pending_file.write_text("{bad}")
        assert is_early_bird_pending(pending_file) is False

    def test_not_a_dict(self, tmp_path: Path) -> None:
        """A JSON list where a dict is expected fails closed."""
        pending_file = tmp_path / "pending.json"
        pending_file.write_text(json.dumps(["not", "a", "dict"]))
        assert is_early_bird_pending(pending_file) is False

    def test_stale_date(self, tmp_path: Path) -> None:
        """A pending record from an earlier day no longer applies."""
        pending_file = tmp_path / "pending.json"
        pending_file.write_text(json.dumps({"date": "2000-01-01", "hmac": "sig"}))
        assert is_early_bird_pending(pending_file) is False

    def test_valid_hmac(self, tmp_path: Path) -> None:
        """A correctly signed pending record for today counts."""
        pending_file = tmp_path / "pending.json"
        pending_file.write_text(json.dumps({"date": _today(), "hmac": "sig"}))
        with patch(
            "screen_locker._compliance_predicates.verify_entry_hmac", return_value=True
        ):
            assert is_early_bird_pending(pending_file) is True

    def test_unsigned_accepted_when_key_unavailable(self, tmp_path: Path) -> None:
        """With no HMAC key, an unsigned pending record is accepted."""
        pending_file = tmp_path / "pending.json"
        pending_file.write_text(json.dumps({"date": _today()}))
        with (
            patch(
                "screen_locker._compliance_predicates.verify_entry_hmac",
                return_value=False,
            ),
            patch(
                "screen_locker._compliance_predicates.compute_entry_hmac",
                return_value=None,
            ),
        ):
            assert is_early_bird_pending(pending_file) is True

    def test_rejected_when_key_available(self, tmp_path: Path) -> None:
        """With a key available, an unsigned pending record is rejected."""
        pending_file = tmp_path / "pending.json"
        pending_file.write_text(json.dumps({"date": _today()}))
        with (
            patch(
                "screen_locker._compliance_predicates.verify_entry_hmac",
                return_value=False,
            ),
            patch(
                "screen_locker._compliance_predicates.compute_entry_hmac",
                return_value="sig",
            ),
        ):
            assert is_early_bird_pending(pending_file) is False

    def test_rejected_when_signed_but_invalid(self, tmp_path: Path) -> None:
        """A pending record whose signature fails to verify is rejected."""
        pending_file = tmp_path / "pending.json"
        pending_file.write_text(json.dumps({"date": _today(), "hmac": "bad"}))
        with (
            patch(
                "screen_locker._compliance_predicates.verify_entry_hmac",
                return_value=False,
            ),
            patch(
                "screen_locker._compliance_predicates.compute_entry_hmac",
                return_value=None,
            ),
        ):
            assert is_early_bird_pending(pending_file) is False


class TestIsSickDayToday:
    """Today's sick-day status, from the shared sickdays pool."""

    def test_true_when_in_pool(self) -> None:
        """Today in the pool is a sick day."""
        mark_sick()
        assert is_sick_day_today() is True

    def test_false_when_not_in_pool(self) -> None:
        """Another day in the pool does not make today sick."""
        mark_sick("1999-01-01")
        assert is_sick_day_today() is False

    def test_explicit_day(self) -> None:
        """The day argument picks which date is asked."""
        mark_sick("2020-05-05")
        assert is_sick_day_today(date(2020, 5, 5)) is True