from __future__ import annotations

import importlib.util
import sys
from datetime import datetime, timedelta, timezone
from pathlib import Path
from types import SimpleNamespace

ROOT = Path(__file__).resolve().parents[3]
SCRIPT = ROOT / "scripts" / "ops" / "docker-disk-pressure-retention-cleanup.py"
spec = importlib.util.spec_from_file_location("docker_disk_pressure_retention_cleanup", SCRIPT)
module = importlib.util.module_from_spec(spec)
assert spec and spec.loader
sys.modules[spec.name] = module
spec.loader.exec_module(module)
UTC = timezone.utc  # noqa: UP017 - mirrors supported Python 3.9 runtime.


def image(image_id: str, created_at: datetime, tags: tuple[str, ...] = ()):
    return module.ImageInfo(
        image_id=image_id,
        created_at=created_at,
        size_bytes=1024,
        repo_tags=tags,
    )


def test_select_dangling_images_keeps_newest_and_protects_running_images() -> None:
    now = datetime(2026, 7, 1, 12, tzinfo=UTC)
    images = [
        image("sha256:running", now - timedelta(hours=72)),
        image("oldest", now - timedelta(hours=72)),
        image("middle", now - timedelta(hours=48)),
        image("newest", now - timedelta(hours=30)),
        image("too_recent", now - timedelta(hours=2)),
        image("tagged", now - timedelta(hours=72), ("repo:tag",)),
    ]

    selected = module.select_dangling_image_removals(
        images,
        {"running"},
        now=now,
        min_age_hours=24,
        keep_newest=1,
    )

    assert [item.image_id for item in selected] == ["oldest", "middle"]


def test_builder_prune_command_is_bounded_by_age_and_keep_storage() -> None:
    args = SimpleNamespace(
        docker_bin="docker",
        min_age_hours=36,
        builder_keep_storage="40GB",
    )

    assert module.builder_prune_command(args) == [
        "docker",
        "builder",
        "prune",
        "--force",
        "--filter",
        "until=36h",
        "--keep-storage",
        "40GB",
    ]


def test_parse_docker_datetime_accepts_nanosecond_fraction() -> None:
    parsed = module.parse_docker_datetime("2026-07-01T23:29:21.919867918+08:00")

    assert parsed.isoformat() == "2026-07-01T15:29:21.919867+00:00"


def test_summary_never_reports_volumes_or_container_cleanup_boundary() -> None:
    now = datetime(2026, 7, 1, 12, tzinfo=UTC)
    selected = module.select_dangling_image_removals(
        [image("old", now - timedelta(days=3))],
        set(),
        now=now,
        min_age_hours=24,
        keep_newest=0,
    )
    summary = module.summarize_images(selected)

    assert summary["count"] == 1
    assert summary["sample_image_ids"] == ["old"]


def test_tagged_cleanup_preserves_running_and_repository_rollback_window() -> None:
    now = datetime(2026, 7, 14, 12, tzinfo=UTC)
    images = [
        image("running", now - timedelta(days=30), ("registry:5000/app:running",)),
        image("latest", now - timedelta(days=1), ("registry:5000/app:latest",)),
        image("rollback-1", now - timedelta(days=2), ("registry:5000/app:sha-1",)),
        image("rollback-2", now - timedelta(days=3), ("registry:5000/app:sha-2",)),
        image("expired", now - timedelta(days=14), ("registry:5000/app:sha-old",)),
        image("other-repo", now - timedelta(days=14), ("registry:5000/other:only",)),
    ]

    selected = module.select_tagged_image_removals(
        images,
        {"running"},
        now=now,
        min_age_hours=7 * 24,
        keep_newest_per_repository=3,
    )

    assert [item.image_id for item in selected] == ["expired"]


def test_multi_repository_image_is_retained_when_any_repository_needs_it() -> None:
    now = datetime(2026, 7, 14, 12, tzinfo=UTC)
    shared = image(
        "shared",
        now - timedelta(days=30),
        ("registry:5000/app:old", "registry:5000/critical:latest"),
    )
    selected = module.select_tagged_image_removals(
        [shared, image("app-new", now - timedelta(days=1), ("registry:5000/app:new",))],
        set(),
        now=now,
        min_age_hours=7 * 24,
        keep_newest_per_repository=1,
    )

    assert selected == []


def test_repository_parser_preserves_registry_port() -> None:
    assert module.repository_from_tag("registry:5000/team/app:sha") == "registry:5000/team/app"


def test_single_apply_image_removal_is_count_bounded() -> None:
    now = datetime(2026, 7, 14, 12, tzinfo=UTC)
    candidates = [
        image(f"image-{index}", now - timedelta(days=index + 1))
        for index in range(5)
    ]

    selected = module.limit_image_removals(candidates, max_removals=2)

    assert [item.image_id for item in selected] == ["image-4", "image-3"]


def test_remove_images_batches_tagged_references(monkeypatch) -> None:
    calls: list[list[str]] = []

    def fake_docker(args: list[str], _docker_bin: str):
        calls.append(args)
        return SimpleNamespace(stdout="", stderr="", returncode=0)

    monkeypatch.setattr(module, "docker", fake_docker)
    now = datetime(2026, 7, 14, 12, tzinfo=UTC)

    removed = module.remove_images(
        [
            image("dangling", now),
            image("tagged-a", now, ("repo-a:old", "repo-b:old")),
            image("tagged-b", now, ("repo-c:old",)),
        ],
        "docker",
    )

    assert removed == ["dangling", "tagged-a", "tagged-b"]
    assert calls == [
        ["image", "rm", "dangling"],
        ["image", "rm", "repo-a:old", "repo-b:old", "repo-c:old"],
    ]


def test_cli_exposes_builder_cache_only_flag() -> None:
    help_text = module.run_command(["python3", str(SCRIPT), "--help"]).stdout

    assert "--skip-dangling-images" in help_text


def test_zero_age_builder_prune_omits_until_filter() -> None:
    args = SimpleNamespace(
        docker_bin="docker",
        min_age_hours=0,
        builder_keep_storage="1GB",
    )

    assert module.builder_prune_command(args) == [
        "docker",
        "builder",
        "prune",
        "--force",
        "--keep-storage",
        "1GB",
    ]