"""Backend/config tests, plus the structural read-only guarantees.

No network here either: the token/unreachable paths are exercised with a
bogus token_path and a base_url nothing listens on, and the WebSocket
allowlist is asserted on the constant, not by dialing an instance.
"""
import sys
from pathlib import Path

import pytest

from ha_mcp import backend as backend_mod
from ha_mcp import config as cfg
from ha_mcp.backend import BackendError, LiveBackend
from ha_mcp.config import ConfigError, get_instance

SERVICE_DIR = Path(__file__).resolve().parents[1]


# --- read-only by construction ------------------------------------------


def test_rest_client_has_no_mutating_method(repo_root):
    """scripts/ha/lib/ha_api.Client is GET-only — nothing to call by accident."""
    sys.path.insert(0, str(cfg.ha_lib_dir(repo_root)))
    import ha_api

    public = {n for n in dir(ha_api.Client) if not n.startswith("_")}
    assert public == {"get", "get_raw_text"}
    for forbidden in ("post", "put", "patch", "delete", "post_config", "call_service"):
        assert not hasattr(ha_api.Client, forbidden)


def test_ws_allowlist_contains_only_list_reads():
    for command in backend_mod.READ_ONLY_WS_COMMANDS:
        assert command.endswith("/list"), command
    for mutating in (
        "config/area_registry/create",
        "config/entity_registry/update",
        "config/device_registry/update",
        "call_service",
    ):
        assert mutating not in backend_mod.READ_ONLY_WS_COMMANDS


def test_no_write_verbs_anywhere_in_the_package():
    """A grep-level guard: this package must never learn to POST."""
    forbidden = ("requests.post", "requests.put", "requests.delete", "call_service", "post_config")
    for path in (SERVICE_DIR / "src" / "ha_mcp").glob("*.py"):
        text = path.read_text(encoding="utf-8")
        for token in forbidden:
            # backend.py names the mutating commands only inside comments
            code = "\n".join(
                line for line in text.splitlines() if not line.strip().startswith("#")
            )
            assert token not in code, f"{path.name} references {token}"


# --- instances.yaml ------------------------------------------------------


def test_default_instance_is_ken(repo_root):
    name, instance = get_instance(None, repo_root)
    assert name == "ken"
    assert instance["adapter"] == "api"
    assert instance["status"] == "active"


def test_unknown_instance_lists_the_known_ones(repo_root):
    with pytest.raises(ConfigError) as exc:
        get_instance("nope", repo_root)
    assert "ken" in str(exc.value) and "chelsty-ha" in str(exc.value)


# --- failure paths: reportable, never a crash ---------------------------


def test_missing_token_is_a_readable_error(repo_root, tmp_path):
    backend = LiveBackend(
        "ken",
        {"base_url": "http://127.0.0.1:1", "status": "active", "token_path": str(tmp_path / "absent")},
        repo_root,
    )
    with pytest.raises(BackendError) as exc:
        backend.states()
    message = str(exc.value)
    assert "no HA token" in message
    assert "absent" in message  # says which path it looked at


def test_offline_instance_never_opens_a_socket(repo_root):
    name, instance = get_instance("chelsty-ha", repo_root)
    backend = LiveBackend(name, instance, repo_root)
    with pytest.raises(BackendError) as exc:
        backend.states()
    assert "status: offline" in str(exc.value)


def test_timeout_default_is_short():
    assert backend_mod.DEFAULT_TIMEOUT == 5


# --- area index ----------------------------------------------------------


def test_area_index_prefers_entity_area_over_device_area():
    index = backend_mod._index_from_registries(
        [{"area_id": "salon", "name": "Salon"}, {"area_id": "hall", "name": "Hall"}],
        [{"entity_id": "light.x", "area_id": "hall", "device_id": "d1"}],
        [{"id": "d1", "area_id": "salon"}],
        "websocket",
    )
    assert index.area_of("light.x") == "Hall"


def test_offline_area_index_falls_back_to_storage_export(repo_root):
    index = backend_mod.load_offline_area_index("ken", repo_root)
    assert index.source == "storage-export"
    assert {a["name"] for a in index.areas} >= {"Salon", "Kuchnia", "Sypialnia"}
    # and it says out loud what the offline export cannot resolve
    assert "device" in index.note


def test_offline_area_index_for_an_instance_without_an_export(repo_root):
    index = backend_mod.load_offline_area_index("chelsty-ha", repo_root)
    assert index.source == "none"
    assert index.entity_area == {}


def test_automation_files_are_repo_relative(repo_root):
    files = backend_mod.automation_files("ken", repo_root)
    assert len(files) > 100
    rel, absolute = files[0]
    assert rel.startswith("services/home-assistant/config/ken/automations/")
    assert absolute.is_file()