"""Tests for prune_runner_images.py."""

from __future__ import annotations

from unittest.mock import MagicMock, patch

from scripts.prune_runner_images import (
    filter_runner_images,
    list_docker_images,
    main,
    remove_images,
)


class TestListDockerImages:
    """Tests for list_docker_images()."""

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_returns_images_from_docker(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            stdout="repo1:tag1\nrepo2:tag2\n",
            returncode=0,
        )
        result = list_docker_images()
        assert result == ["repo1:tag1", "repo2:tag2"]

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_filters_none_entries(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            stdout="repo:tag\n<none>:<none>\nother:v1\n",
            returncode=0,
        )
        result = list_docker_images()
        assert result == ["repo:tag", "other:v1"]

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_empty_output(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(stdout="", returncode=0)
        result = list_docker_images()
        assert result == []

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_strips_whitespace(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            stdout="  repo:tag  \n\n  other:v2  \n",
            returncode=0,
        )
        result = list_docker_images()
        assert result == ["repo:tag", "other:v2"]


class TestFilterRunnerImages:
    """Tests for filter_runner_images()."""

    def test_matches_runner_images(self) -> None:
        images = [
            "git.oblachno.oblachno.fyi/oblachno-oss/runner-images/ci-base:latest",
            "git.oblachno.oblachno.fyi/oblachno-oss/runner-images/ci-quality:latest",
            "git.oblachno.oblachno.fyi/oblachno-oss/runner-images/ci-full:latest",
        ]
        result = filter_runner_images(images)
        assert len(result) == 3

    def test_excludes_non_runner_images(self) -> None:
        images = [
            "docker.io/library/python:3.12",
            "docker.io/library/nginx:latest",
            "git.oblachno.oblachno.fyi/oblachno-oss/runner-images/ci-base:latest",
        ]
        result = filter_runner_images(images)
        assert len(result) == 1
        assert "ci-base" in result[0]

    def test_empty_list(self) -> None:
        assert filter_runner_images([]) == []

    def test_no_matches(self) -> None:
        images = ["python:3.12", "nginx:latest"]
        assert filter_runner_images(images) == []


class TestRemoveImages:
    """Tests for remove_images()."""

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_removes_images(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(returncode=0, stderr="")
        images = ["repo/ci-base:latest", "repo/ci-quality:latest"]
        removed = remove_images(images)
        assert removed == images
        assert mock_run.call_count == 2

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_dry_run_does_not_call_docker(self, mock_run: MagicMock) -> None:
        images = ["repo/ci-base:latest"]
        removed = remove_images(images, dry_run=True)
        assert removed == images
        mock_run.assert_not_called()

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_failed_removal_not_in_result(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(returncode=1, stderr="image in use")
        images = ["repo/ci-base:latest"]
        removed = remove_images(images)
        assert removed == []

    @patch("scripts.prune_runner_images.subprocess.run")
    def test_empty_list(self, mock_run: MagicMock) -> None:
        removed = remove_images([])
        assert removed == []
        mock_run.assert_not_called()


class TestMain:
    """Tests for main()."""

    @patch("scripts.prune_runner_images.list_docker_images")
    @patch("scripts.prune_runner_images.remove_images")
    def test_no_images(self, mock_remove: MagicMock, mock_list: MagicMock) -> None:
        mock_list.return_value = []
        assert main([]) == 0
        mock_remove.assert_not_called()

    @patch("scripts.prune_runner_images.list_docker_images")
    @patch("scripts.prune_runner_images.remove_images")
    def test_with_images(self, mock_remove: MagicMock, mock_list: MagicMock) -> None:
        mock_list.return_value = [
            "repo/runner-images/ci-base:latest",
            "python:3.12",
        ]
        mock_remove.return_value = ["repo/runner-images/ci-base:latest"]
        assert main([]) == 0
        mock_remove.assert_called_once()

    @patch("scripts.prune_runner_images.list_docker_images")
    @patch("scripts.prune_runner_images.remove_images")
    def test_dry_run_flag(self, mock_remove: MagicMock, mock_list: MagicMock) -> None:
        mock_list.return_value = ["repo/runner-images/ci-base:latest"]
        mock_remove.return_value = ["repo/runner-images/ci-base:latest"]
        assert main(["--dry-run"]) == 0
        mock_remove.assert_called_once_with(
            ["repo/runner-images/ci-base:latest"],
            dry_run=True,
        )