"""Unit tests for scripts/auto_merge.py."""

from unittest.mock import MagicMock, patch

import pytest
import requests

from scripts.auto_merge import (
    CONVENTIONAL_RE,
    GITEA_API,
    TASK_ID_RE,
    extract_task_id,
    main,
    merge_pr,
    validate_pr_title,
)


class TestRegexes:
    def test_task_id_re_matches(self) -> None:
        assert TASK_ID_RE.search("GRM-19-fix-bug")
        assert TASK_ID_RE.search("feature/GRM-42")

    def test_task_id_re_no_match(self) -> None:
        assert not TASK_ID_RE.search("feature-no-id")

    def test_conventional_re_matches(self) -> None:
        assert CONVENTIONAL_RE.match("feat: add feature")
        assert CONVENTIONAL_RE.match("fix(api): handle timeout")

    def test_conventional_re_rejects(self) -> None:
        assert not CONVENTIONAL_RE.match("random message")
        assert not CONVENTIONAL_RE.match("feat:")


class TestExtractTaskId:
    def test_extracts_from_branch(self) -> None:
        assert extract_task_id("GRM-19-fix-bug") == "GRM-19"

    def test_extracts_from_feature_branch(self) -> None:
        assert extract_task_id("feature/GRM-42-add-x") == "GRM-42"

    def test_returns_empty_when_missing(self) -> None:
        assert extract_task_id("feature-no-id") == ""


class TestValidatePrTitle:
    def test_valid_title_passes(self) -> None:
        validate_pr_title("fix: resolve timeout")

    def test_valid_title_with_scope_passes(self) -> None:
        validate_pr_title("feat(cli): add --url option")

    def test_invalid_title_exits(self) -> None:
        with pytest.raises(SystemExit) as exc:
            validate_pr_title("random message")
        assert exc.value.code == 1


class TestMergePr:
    @patch("scripts.auto_merge.requests.post")
    def test_successful_merge(self, mock_post: MagicMock) -> None:
        mock_response = MagicMock()
        mock_post.return_value = mock_response
        merge_pr("tok", "owner/repo", "7", "GRM-19: fix: bug")
        mock_post.assert_called_once()
        args, kwargs = mock_post.call_args
        assert kwargs["headers"]["Authorization"] == "token tok"
        assert kwargs["json"]["Do"] == "squash"
        assert kwargs["json"]["MergeTitleField"] == "GRM-19: fix: bug"
        assert GITEA_API in args[0]

    @patch("scripts.auto_merge.requests.post")
    def test_merge_raises_on_http_error(self, mock_post: MagicMock) -> None:
        mock_response = MagicMock()
        mock_response.raise_for_status.side_effect = requests.HTTPError("500")
        mock_post.return_value = mock_response
        with pytest.raises(requests.HTTPError):
            merge_pr("tok", "owner/repo", "7", "title")


class TestMain:
    @patch.dict("os.environ", {"GITEA_TOKEN": "tok"})
    @patch("scripts.auto_merge.merge_pr")
    def test_successful_flow(self, mock_merge: MagicMock, capsys: pytest.CaptureFixture[str]) -> None:
        main(["auto_merge.py", "GRM-19-fix-bug", "fix: resolve timeout", "owner/repo", "7"])
        mock_merge.assert_called_once_with("tok", "owner/repo", "7", "GRM-19: fix: resolve timeout")
        captured = capsys.readouterr()
        assert "squash-merged" in captured.out

    @patch.dict("os.environ", {"GITEA_TOKEN": ""}, clear=True)
    def test_missing_token_exits(self) -> None:
        with pytest.raises(SystemExit) as exc:
            main(["auto_merge.py", "branch", "title", "repo", "1"])
        assert exc.value.code == 1

    @patch.dict("os.environ", {"GITEA_TOKEN": "tok"})
    def test_missing_task_id_exits(self) -> None:
        with pytest.raises(SystemExit) as exc:
            main(["auto_merge.py", "feature-no-id", "fix: bug", "repo", "1"])
        assert exc.value.code == 1

    @patch.dict("os.environ", {"GITEA_TOKEN": "tok"})
    def test_invalid_pr_title_exits(self) -> None:
        with pytest.raises(SystemExit) as exc:
            main(["auto_merge.py", "GRM-19-fix", "random title", "repo", "1"])
        assert exc.value.code == 1

    @patch.dict("os.environ", {"GITEA_TOKEN": "tok"})
    @patch("scripts.auto_merge.merge_pr")
    def test_merge_pr_failure_propagates(self, mock_merge: MagicMock) -> None:
        mock_merge.side_effect = requests.HTTPError("500")
        with pytest.raises(requests.HTTPError):
            main(["auto_merge.py", "GRM-19-fix", "fix: bug", "repo", "1"])