from __future__ import annotations

import importlib.util
import json
from pathlib import Path
import sys
import tempfile
import unittest
import zipfile


SCRIPT = (
    Path(__file__).resolve().parents[1]
    / "tools"
    / "release"
    / "prepare-runtime-context.py"
)
SPEC = importlib.util.spec_from_file_location("prepare_runtime_context", SCRIPT)
assert SPEC is not None and SPEC.loader is not None
MODULE = importlib.util.module_from_spec(SPEC)
sys.modules[SPEC.name] = MODULE
SPEC.loader.exec_module(MODULE)


class RuntimeImageContextTests(unittest.TestCase):
    def test_builds_deterministic_network_free_context(self) -> None:
        with tempfile.TemporaryDirectory(prefix="govoplan-runtime-context-") as value:
            root = Path(value)
            wheelhouse = root / "input-wheels"
            web = root / "web"
            wheelhouse.mkdir()
            web.mkdir()
            self._wheel(
                wheelhouse / "govoplan_core-1.2.3-py3-none-any.whl",
                package="govoplan-core",
                version="1.2.3",
                module_ids=(),
            )
            self._wheel(
                wheelhouse / "govoplan_files-1.2.3-py3-none-any.whl",
                package="govoplan-files",
                version="1.2.3",
                module_ids=("files",),
            )
            self._wheel(
                wheelhouse / "sqlalchemy-2.0.0-py3-none-any.whl",
                package="SQLAlchemy",
                version="2.0.0",
                module_ids=(),
            )
            (web / "index.html").write_text("<main>GovOPlaN</main>\n", encoding="utf-8")

            composition = MODULE.prepare_context(
                wheelhouse=wheelhouse,
                web_dist=web,
                output=root / "context",
                required_modules=("files",),
                source_date_epoch=1_700_000_000,
            )

            self.assertEqual(["files"], composition["python"]["module_ids"])
            self.assertEqual(2, composition["python"]["wheel_count"])
            requirements = (root / "context" / "requirements-runtime.txt").read_text()
            self.assertEqual(
                "govoplan-core[server]==1.2.3\ngovoplan-files==1.2.3\n",
                requirements,
            )
            published = json.loads(
                (
                    root
                    / "context"
                    / "web-dist"
                    / ".well-known"
                    / "govoplan-composition.json"
                ).read_text()
            )
            self.assertEqual(composition, published)

    def test_rejects_missing_required_module(self) -> None:
        with tempfile.TemporaryDirectory(prefix="govoplan-runtime-context-") as value:
            root = Path(value)
            wheelhouse = root / "wheels"
            web = root / "web"
            wheelhouse.mkdir()
            web.mkdir()
            self._wheel(
                wheelhouse / "govoplan_core-1.0.0-py3-none-any.whl",
                package="govoplan-core",
                version="1.0.0",
                module_ids=(),
            )
            (web / "index.html").write_text("ok", encoding="utf-8")

            with self.assertRaisesRegex(MODULE.ContextError, "missing required"):
                MODULE.prepare_context(
                    wheelhouse=wheelhouse,
                    web_dist=web,
                    output=root / "context",
                    required_modules=("mail",),
                )

    def test_rejects_symlinked_web_payload(self) -> None:
        with tempfile.TemporaryDirectory(prefix="govoplan-runtime-context-") as value:
            root = Path(value)
            wheelhouse = root / "wheels"
            web = root / "web"
            wheelhouse.mkdir()
            web.mkdir()
            self._wheel(
                wheelhouse / "govoplan_core-1.0.0-py3-none-any.whl",
                package="govoplan-core",
                version="1.0.0",
                module_ids=(),
            )
            outside = root / "outside"
            outside.write_text("not part of dist", encoding="utf-8")
            (web / "index.html").symlink_to(outside)

            with self.assertRaisesRegex(MODULE.ContextError, "symlink"):
                MODULE.prepare_context(
                    wheelhouse=wheelhouse,
                    web_dist=web,
                    output=root / "context",
                )

    @staticmethod
    def _wheel(
        path: Path,
        *,
        package: str,
        version: str,
        module_ids: tuple[str, ...],
    ) -> None:
        dist_info = package.replace("-", "_") + f"-{version}.dist-info"
        with zipfile.ZipFile(path, "w") as archive:
            archive.writestr(
                f"{dist_info}/METADATA",
                f"Metadata-Version: 2.1\nName: {package}\nVersion: {version}\n",
            )
            if module_ids:
                rows = "\n".join(
                    f"{module_id} = example.module:manifest"
                    for module_id in module_ids
                )
                archive.writestr(
                    f"{dist_info}/entry_points.txt",
                    f"[govoplan.modules]\n{rows}\n",
                )
            archive.writestr(f"{package.replace('-', '_')}/__init__.py", "")


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