from __future__ import annotations

from pathlib import Path

import pytest

from config import (
    Config,
    ensure_writable_directory,
    load_config,
    save_config,
    validate_config,
)


def test_save_and_load_utf8_lf(tmp_path: Path) -> None:
    path = tmp_path / "commonwealth-server.json"
    cfg = Config(
        host="0.0.0.0",
        port=7777,
        server_name="Café Server",
        server_description="résumé",
        max_players=8,
        log_verbosity="info",
        admin_port=7779,
        enable_gns_transport=True,
        gns_bridge_path="/opt/commonwealth/libcommonwealth_online_gns_bridge.so",
    )
    save_config(cfg, str(path))

    raw = path.read_bytes()
    assert b"\r\n" not in raw
    assert "Café Server".encode("utf-8") in raw

    loaded = load_config(str(path))
    assert loaded.server_name == "Café Server"
    assert loaded.server_description == "résumé"
    assert loaded.admin_port == 7779
    assert loaded.enable_gns_transport is True
    assert loaded.gns_bridge_path == "/opt/commonwealth/libcommonwealth_online_gns_bridge.so"


def test_gns_boolean_config_parsing_does_not_treat_false_string_as_true() -> None:
    assert Config.from_dict({"enable_gns_transport": "false"}).enable_gns_transport is False
    assert Config.from_dict({"enable_gns_transport": "off"}).enable_gns_transport is False
    assert Config.from_dict({"enable_gns_transport": "0"}).enable_gns_transport is False
    assert Config.from_dict({"enable_gns_transport": "true"}).enable_gns_transport is True
    assert Config.from_dict({"enable_gns_transport": "yes"}).enable_gns_transport is True
    assert Config.from_dict({"enable_gns_transport": 1}).enable_gns_transport is True
    assert Config.from_dict({"enable_gns_transport": 0}).enable_gns_transport is False
    with pytest.raises(ValueError, match="enable_gns_transport"):
        Config.from_dict({"enable_gns_transport": "sometimes"})


def test_gns_bridge_path_normalizes_blank_to_none_and_rejects_nonstring() -> None:
    assert Config.from_dict({"gns_bridge_path": ""}).gns_bridge_path is None
    assert Config.from_dict({"gns_bridge_path": "   "}).gns_bridge_path is None
    assert Config.from_dict({"gns_bridge_path": None}).gns_bridge_path is None
    with pytest.raises(ValueError, match="gns_bridge_path"):
        Config.from_dict({"gns_bridge_path": 123})


def test_validate_rejects_bad_ports_and_max_players() -> None:
    cfg = Config(port=70000, admin_port=7777, max_players=0)
    ok, errors = validate_config(cfg)
    assert not ok
    assert any("port must be 1-65535" in error for error in errors)
    assert any("max_players must be >= 1" in error for error in errors)

    collide = Config(port=7777, admin_port=7777)
    ok, errors = validate_config(collide)
    assert not ok
    assert any("admin_port must differ" in error for error in errors)


def test_validate_rejects_unresolvable_host() -> None:
    cfg = Config(host="this-host-should-not-resolve.invalid")
    ok, errors = validate_config(cfg)
    assert not ok
    assert any("not a valid IPv4" in error for error in errors)


def test_gns_requires_explicit_ipv4_bind_host() -> None:
    explicit = Config(host="127.0.0.1", enable_gns_transport=True)
    ok, errors = validate_config(explicit)
    assert ok, errors

    wildcard = Config(host="0.0.0.0", enable_gns_transport=True)
    ok, errors = validate_config(wildcard)
    assert ok, errors

    hostname = Config(host="localhost", enable_gns_transport=True)
    ok, errors = validate_config(hostname)
    assert not ok
    assert any("explicit IPv4 bind address" in error for error in errors)


def test_ensure_writable_directory(tmp_path: Path) -> None:
    target = tmp_path / "state"
    ensure_writable_directory(target)
    assert target.is_dir()
    assert not (target / ".commonwealth-write-probe").exists()


def test_load_invalid_json(tmp_path: Path) -> None:
    path = tmp_path / "bad.json"
    path.write_text("{not json", encoding="utf-8")
    with pytest.raises(Exception):
        load_config(str(path))