"""Unit tests for devx.molecule.molecule_changed.

Verifies that the script correctly detects changed roles, fails open on
unmapped ansible paths, and only emits roles that exist on disk.
"""

from __future__ import annotations

from pathlib import Path
from unittest.mock import patch

import pytest
from click.testing import CliRunner

from devx.molecule.molecule_changed import (
    detect_changed_roles,
    get_changed_files,
    main,
    role_to_target,
    roles_to_targets,
)

TESTABLE_ROLES = ("docker_base", "app_container", "restore", "observability")


@pytest.fixture()
def roles_dir(tmp_path: Path) -> Path:
    """Fake roles dir: 4 testable roles (molecule/ present) + 1 untestable."""
    for role in TESTABLE_ROLES:
        (tmp_path / role / "molecule" / "default").mkdir(parents=True)
    (tmp_path / "untested_role").mkdir()  # exists but no molecule/ dir
    return tmp_path


def test_detect_role_change(roles_dir: Path):
    """A file in ansible/roles/<role>/ maps to that role."""
    roles = detect_changed_roles(["ansible/roles/docker_base/tasks/main.yml"], roles_dir)
    assert roles == {"docker_base"}


def test_detect_role_not_on_disk_is_dropped(roles_dir: Path):
    """Changed role absent from roles_dir selects nothing (REQ-2)."""
    roles = detect_changed_roles(["ansible/roles/sso_config/tasks/main.yml"], roles_dir)
    assert roles == set()


def test_detect_playbook_change(roles_dir: Path):
    """A mapped playbook maps to its included roles, filtered to disk."""
    files = ["ansible/playbooks/deploy-observability.yml"]
    roles = detect_changed_roles(files, roles_dir)
    # zitadel + crowdsec are mapped but absent from the fake roles dir.
    assert roles == {"observability", "docker_base"}


def test_detect_shared_infra_triggers_all(roles_dir: Path):
    """ansible.cfg change triggers all testable roles only."""
    roles = detect_changed_roles(["ansible/ansible.cfg"], roles_dir)
    assert roles == set(TESTABLE_ROLES)


def test_detect_molecule_shared_path(roles_dir: Path):
    """ansible/molecule/ change triggers all testable roles."""
    roles = detect_changed_roles(["ansible/molecule/Dockerfile"], roles_dir)
    assert roles == set(TESTABLE_ROLES)


def test_detect_requirements_yml_triggers_all(roles_dir: Path):
    """ansible/requirements.yml change triggers all testable roles."""
    roles = detect_changed_roles(["ansible/requirements.yml"], roles_dir)
    assert roles == set(TESTABLE_ROLES)


def test_detect_group_vars_triggers_all(roles_dir: Path):
    """ansible/group_vars/ change triggers all testable roles (REQ-1)."""
    roles = detect_changed_roles(["ansible/group_vars/all/images.yml"], roles_dir)
    assert roles == set(TESTABLE_ROLES)


def test_unmapped_playbook_fails_open(roles_dir: Path):
    """An unmapped playbook selects all testable roles (REQ-1)."""
    roles = detect_changed_roles(["ansible/playbooks/new-deploy.yml"], roles_dir)
    assert roles == set(TESTABLE_ROLES)


def test_playbook_tasks_dir_fails_open(roles_dir: Path):
    """Shared playbook task files select all testable roles (REQ-1)."""
    roles = detect_changed_roles(["ansible/playbooks/_tasks/upgrade-postgres-database.yml"], roles_dir)
    assert roles == set(TESTABLE_ROLES)


def test_mapped_playbooks(roles_dir: Path):
    """Each newly mapped playbook selects its roles (REQ-1)."""
    expectations = {
        "ansible/playbooks/restore.yml": {"restore"},
        "ansible/playbooks/upgrade-postgres.yml": {"app_container"},
        "ansible/playbooks/rolling-update-gitea.yml": {"app_container"},
        "ansible/playbooks/update-alertmanager.yml": {"observability"},
        "ansible/playbooks/build-image.yml": {"docker_base"},
        "ansible/playbooks/deploy-sso-bridge.yml": set(),
    }
    for playbook, expected in expectations.items():
        assert detect_changed_roles([playbook], roles_dir) == expected, playbook


def test_detect_prepare_vms_playbook(roles_dir: Path):
    """prepare-vms.yml maps to all base roles present on disk."""
    roles = detect_changed_roles(["ansible/playbooks/prepare-vms.yml"], roles_dir)
    assert roles == {"docker_base"}


def test_detect_deploy_customer_playbook(roles_dir: Path):
    """deploy-customer.yml maps to its roles present on disk."""
    roles = detect_changed_roles(["ansible/playbooks/deploy-customer.yml"], roles_dir)
    assert roles == {"app_container", "docker_base"}


def test_detect_no_ansible_changes(roles_dir: Path):
    """Non-Ansible files don't trigger any roles."""
    roles = detect_changed_roles(["scripts/x.py", "Makefile"], roles_dir)
    assert roles == set()


def test_detect_environments_not_molecule_covered(roles_dir: Path):
    """ansible/environments/ data is not molecule-covered (documented)."""
    roles = detect_changed_roles(["ansible/environments/staging/customers.yml"], roles_dir)
    assert roles == set()


def test_detect_missing_roles_dir():
    """A nonexistent roles_dir yields no roles (honest: nothing testable)."""
    roles = detect_changed_roles(["ansible/roles/docker_base/tasks/main.yml"], "/nonexistent")
    assert roles == set()


def test_role_to_target():
    """Role names map to conventional make targets."""
    assert role_to_target("docker_base") == "molecule-docker-base"
    assert role_to_target("app_hardening") == "molecule-app-hardening"


def test_roles_to_targets():
    """Role names map to make targets."""
    targets = roles_to_targets({"docker_base", "zitadel"})
    assert targets == ["molecule-docker-base", "molecule-zitadel"]


def test_main_no_changes():
    """When no files changed, outputs message to stderr."""
    with patch("devx.molecule.molecule_changed.get_changed_files", return_value=[]):
        result = CliRunner().invoke(main, ["--print-targets"])
        assert result.exit_code == 0
        assert "No changed files" in result.output


def test_main_print_targets(roles_dir: Path):
    """--print-targets outputs make targets for existing roles."""
    with patch(
        "devx.molecule.molecule_changed.get_changed_files",
        return_value=["ansible/roles/docker_base/tasks/main.yml"],
    ):
        result = CliRunner().invoke(main, ["--print-targets", "--roles-dir", str(roles_dir)])
        assert result.exit_code == 0
        assert "molecule-docker-base" in result.output


def test_main_print_roles(roles_dir: Path):
    """--print-roles outputs role names."""
    with patch(
        "devx.molecule.molecule_changed.get_changed_files",
        return_value=["ansible/roles/restore/tasks/main.yml"],
    ):
        result = CliRunner().invoke(main, ["--print-roles", "--roles-dir", str(roles_dir)])
        assert result.exit_code == 0
        assert "restore" in result.output


def test_main_no_ansible_changes(roles_dir: Path):
    """When only non-Ansible files changed, outputs no scenarios message."""
    with patch(
        "devx.molecule.molecule_changed.get_changed_files",
        return_value=["scripts/molecule_changed.py"],
    ):
        result = CliRunner().invoke(main, ["--print-targets", "--roles-dir", str(roles_dir)])
        assert result.exit_code == 0
        assert "No molecule scenarios" in result.output


def test_get_changed_files_with_mock():
    """get_changed_files returns files from git diff."""
    with patch("devx.molecule.molecule_changed._run_git", return_value="file1\nfile2\n"):
        files = get_changed_files("origin/master")
        assert files == ["file1", "file2"]


def test_get_changed_files_falls_back_to_master():
    """When base ref has no diff, falls back to master."""
    calls: list[list[str]] = []

    def mock_git(args):
        calls.append(args)
        if "origin/master...HEAD" in args[2]:
            return ""
        return "ansible/roles/docker_base/tasks/main.yml\n"

    with patch("devx.molecule.molecule_changed._run_git", side_effect=mock_git):
        files = get_changed_files("origin/master")
        assert files == ["ansible/roles/docker_base/tasks/main.yml"]
        assert len(calls) == 2


def test_get_changed_files_empty():
    """When no changes in either ref, returns empty list."""
    with patch("devx.molecule.molecule_changed._run_git", return_value=""):
        files = get_changed_files("origin/master")
        assert files == []


def test_main_default_base(roles_dir: Path):
    """main() with no --base uses origin/master."""
    with patch(
        "devx.molecule.molecule_changed.get_changed_files",
        return_value=["ansible/roles/restore/tasks/main.yml"],
    ) as mock:
        result = CliRunner().invoke(main, ["--print-roles", "--roles-dir", str(roles_dir)])
        assert result.exit_code == 0
        mock.assert_called_once_with("origin/master")