from __future__ import annotations

import json
from pathlib import Path

import pytest

from pyMCPBroker.config import load_config


def test_env_substitution(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("BROKER_CMD", "python fake.py")
    path = tmp_path / "config.json"
    path.write_text(
        json.dumps(
            {
                "tree": [
                    {
                        "path": "/repo",
                        "type": "node",
                        "source": {"backend": "stdio", "command": "${BROKER_CMD}"},
                    }
                ]
            }
        ),
        encoding="utf-8",
    )
    cfg = load_config(path)
    assert cfg.tree[0].source is not None
    assert cfg.tree[0].source.command == "python fake.py"


def test_env_missing_raises(tmp_path: Path) -> None:
    path = tmp_path / "config.json"
    path.write_text(
        json.dumps(
            {
                "tree": [
                    {
                        "path": "/repo",
                        "type": "node",
                        "source": {"backend": "stdio", "command": "${MISSING_VAR}"},
                    }
                ]
            }
        ),
        encoding="utf-8",
    )
    with pytest.raises(ValueError):
        load_config(path)


def test_invalid_path_alias_raises(tmp_path: Path) -> None:
    path = tmp_path / "config.json"
    path.write_text(
        json.dumps(
            {
                "tree": [
                    {
                        "path": "/repo",
                        "type": "node",
                        "source": {
                            "backend": "stdio",
                            "command": "echo test",
                            "path_aliases": {"get_file_contents": "bad/name"},
                        },
                    }
                ]
            }
        ),
        encoding="utf-8",
    )
    with pytest.raises(Exception):
        load_config(path)