import re
import unittest
from pathlib import Path


class TestDockerComposeTemplates(unittest.TestCase):
    # Search for all roles/*/templates/compose.yml.j2
    PROJECT_ROOT = Path(__file__).resolve().parents[2]
    TEMPLATE_PATTERN = "roles/*/templates/compose.yml.j2"

    # Allowed lines before BASE_INCLUDE
    ALLOWED_BEFORE_BASE = [
        re.compile(r"^\s*$"),  # empty line
        re.compile(r"^\s*version:.*$"),  # version: ...
        re.compile(r"^\s*#.*$"),  # YAML comment
        re.compile(r"^\s*\{\#.*\#\}\s*$"),  # Jinja comment {# ... #}
    ]

    BASE_INCLUDE = "{% include 'roles/sys-svc-compose/templates/base.yml.j2' %}"
    NET_INCLUDE = "{% include 'roles/sys-svc-compose/templates/networks.yml.j2' %}"
    HOST_MODE = 'network_mode: "host"'

    def test_docker_compose_includes(self):
        """
        Verifies for each found compose.yml.j2:
        1. BASE_INCLUDE is present exactly once
        2. If no host‑mode is set, NET_INCLUDE must appear exactly once
        3. BASE_INCLUDE appears before NET_INCLUDE when both are required
        4. Only allowed lines appear before BASE_INCLUDE (invalid lines issue warnings)
        """
        template_paths = sorted(self.PROJECT_ROOT.glob(self.TEMPLATE_PATTERN))
        self.assertTrue(
            template_paths, f"No templates found for pattern {self.TEMPLATE_PATTERN}"
        )

        for template_path in template_paths:
            with self.subTest(template=template_path):
                content = template_path.read_text(encoding="utf-8")
                lines = content.splitlines()

                # BASE_INCLUDE must always occur exactly once
                count_base = lines.count(self.BASE_INCLUDE)
                self.assertEqual(
                    count_base,
                    1,
                    f"{template_path}: '{self.BASE_INCLUDE}' occurs {count_base} times, expected once",
                )

                # Determine if host‑mode is in use
                host_mode = self.HOST_MODE in content

                # If not host‑mode, NET_INCLUDE must occur exactly once
                count_net = lines.count(self.NET_INCLUDE)
                if host_mode:
                    # No network include needed for host mode
                    self.assertEqual(
                        count_net,
                        0,
                        f"{template_path}: '{self.NET_INCLUDE}' should be omitted when using host networking",
                    )
                else:
                    # Must include networks.yml exactly once
                    self.assertEqual(
                        count_net,
                        1,
                        f"{template_path}: '{self.NET_INCLUDE}' occurs {count_net} times, expected once",
                    )

                # If both includes are present, check order
                if count_base and count_net:
                    idx_base = lines.index(self.BASE_INCLUDE)
                    idx_net = lines.index(self.NET_INCLUDE)
                    self.assertLess(
                        idx_base,
                        idx_net,
                        f"{template_path}: '{self.BASE_INCLUDE}' must come before '{self.NET_INCLUDE}'",
                    )


if __name__ == "__main__":
    unittest.main()