from __future__ import annotations

from dataclasses import replace
from datetime import UTC, datetime
import hashlib
from pathlib import Path

import pytest

from govoplan_xrechnung.backend.profiles import KoSITProfileApproval, KoSITProfileRegistry
from govoplan_xrechnung.backend.validation import (
    KoSITValidationProfile,
    XRechnungValidationError,
    configuration_tree_sha256,
)


def _profile(tmp_path: Path, profile_id: str = "profile-a") -> KoSITValidationProfile:
    root = tmp_path / profile_id
    root.mkdir()
    java = root / "java"
    java.write_bytes(b"#!/bin/sh\n")
    java.chmod(0o700)
    jar = root / "validator.jar"
    jar.write_bytes(b"validator")
    config = root / "config"
    config.mkdir()
    scenarios = config / "scenarios.xml"
    scenarios.write_text("<scenarios/>", encoding="utf-8")
    return KoSITValidationProfile(
        profile_id=profile_id,
        xrechnung_version="configured-version",
        validator_version="configured-validator",
        configuration_version="configured-rules",
        java_executable=java.resolve(),
        validator_jar=jar.resolve(),
        validator_jar_sha256=hashlib.sha256(jar.read_bytes()).hexdigest(),
        configuration_root=config.resolve(),
        configuration_tree_sha256=configuration_tree_sha256(config),
        scenarios_file=scenarios.resolve(),
        minimum_validation_steps=1,
    )


def _approval(tmp_path: Path) -> KoSITProfileApproval:
    return KoSITProfileApproval.approve(
        _profile(tmp_path),
        approved_at=datetime(2026, 8, 23, tzinfo=UTC),
        approved_by="configuration-board",
        decision_reference="decision:xrechnung-profile-a",
        accept_from=datetime(2026, 9, 1, tzinfo=UTC),
        accept_until=datetime(2027, 1, 1, tzinfo=UTC),
    )


def test_registry_requires_explicit_selection_without_default(tmp_path: Path) -> None:
    registry = KoSITProfileRegistry((_approval(tmp_path),))

    with pytest.raises(XRechnungValidationError, match="no default"):
        registry.select(received_at=datetime(2026, 10, 1, tzinfo=UTC))


def test_explicit_or_configured_default_selects_only_inside_window(tmp_path: Path) -> None:
    approval = _approval(tmp_path)
    registry = KoSITProfileRegistry(
        (approval,),
        default_profile_id=approval.profile.profile_id,
    )

    selected = registry.select(received_at=datetime(2026, 10, 1, tzinfo=UTC))
    assert selected.profile_id == "profile-a"

    with pytest.raises(XRechnungValidationError, match="receive time"):
        registry.select(received_at=datetime(2027, 1, 1, tzinfo=UTC))


@pytest.mark.parametrize("status", ["suspended", "retired"])
def test_non_approved_profile_cannot_be_selected(tmp_path: Path, status: str) -> None:
    approval = replace(_approval(tmp_path), status=status)
    registry = KoSITProfileRegistry((approval,), default_profile_id="profile-a")

    with pytest.raises(XRechnungValidationError, match="not approved"):
        registry.select(received_at=datetime(2026, 10, 1, tzinfo=UTC))


def test_changed_artifact_is_rejected_after_approval(tmp_path: Path) -> None:
    approval = _approval(tmp_path)
    registry = KoSITProfileRegistry((approval,), default_profile_id="profile-a")
    approval.profile.validator_jar.write_bytes(b"changed")

    with pytest.raises(XRechnungValidationError, match="digest"):
        registry.select(received_at=datetime(2026, 10, 1, tzinfo=UTC))


def test_default_must_reference_allow_list(tmp_path: Path) -> None:
    with pytest.raises(ValueError, match="not present"):
        KoSITProfileRegistry((_approval(tmp_path),), default_profile_id="missing")