"""config-dir resolution + config-dir/.env loading (REQ-048/010 CHG-20260609-01)."""
from __future__ import annotations

import os

import pytest

from trex_core.runtime.config import _load_dotenv, resolve_config_toml

_K = "TREX_TEST_RESOLVE_KEY"


@pytest.fixture(autouse=True)
def _clean(monkeypatch):
    monkeypatch.delenv(_K, raising=False)


# --- resolve_config_toml (REQ-048 AC-7/8) ---------------------------------- #
def test_resolve_name_default_dir():
    assert resolve_config_toml("test") == os.path.join("config", "test.toml")


def test_resolve_appends_toml():
    assert resolve_config_toml("test.toml") == os.path.join("config", "test.toml")


def test_resolve_with_config_path():
    assert resolve_config_toml("prod", "/etc/trex") == os.path.join("/etc/trex", "prod.toml")


def test_resolve_path_form_passthrough():
    # AC-8: a slash-bearing value is an explicit path (backward-compat).
    assert resolve_config_toml("config/test.toml") == "config/test.toml"
    assert resolve_config_toml("config/test.toml", "/etc/trex") == "config/test.toml"


# --- _load_dotenv config-dir resolution (REQ-010 AC-6/7) ------------------- #
def test_dotenv_loaded_from_config_dir_cwd_independent(tmp_path, monkeypatch):
    cfgdir = tmp_path / "cfg"
    cfgdir.mkdir()
    (cfgdir / ".env").write_text(f"{_K}=from_config_dir\n")
    toml = str(cfgdir / "inst.toml")
    # chdir somewhere with no .env to prove CWD-independence.
    other = tmp_path / "elsewhere"
    other.mkdir()
    monkeypatch.chdir(other)
    _load_dotenv(toml)
    assert os.environ[_K] == "from_config_dir"


def test_dotenv_env_file_wins(tmp_path, monkeypatch):
    cfgdir = tmp_path / "cfg"
    cfgdir.mkdir()
    (cfgdir / ".env").write_text(f"{_K}=from_config_dir\n")
    explicit = tmp_path / "explicit.env"
    explicit.write_text(f"{_K}=from_env_file\n")
    monkeypatch.chdir(tmp_path)
    _load_dotenv(str(cfgdir / "inst.toml"), env_file=str(explicit))
    assert os.environ[_K] == "from_env_file"


def test_dotenv_os_env_takes_precedence(tmp_path, monkeypatch):
    cfgdir = tmp_path / "cfg"
    cfgdir.mkdir()
    (cfgdir / ".env").write_text(f"{_K}=from_config_dir\n")
    monkeypatch.setenv(_K, "from_os_env")
    _load_dotenv(str(cfgdir / "inst.toml"))
    assert os.environ[_K] == "from_os_env"  # override=False


def test_dotenv_absent_is_noop(tmp_path):
    # config dir has no .env -> no crash, key stays unset.
    _load_dotenv(str(tmp_path / "inst.toml"))
    assert _K not in os.environ


# --- CLI --config-path instance routing (REQ-048 AC-9) --------------------- #
def test_cli_resolve_instance_honors_config_path(tmp_path):
    from types import SimpleNamespace

    from trex_core.runtime.cli import _resolve_instance

    cfgdir = tmp_path / "cfg"
    cfgdir.mkdir()
    (cfgdir / "inst.toml").write_text('instance_key = "inst-xyz"\n')
    args = SimpleNamespace(instance=None, config="inst", config_path=str(cfgdir))
    assert _resolve_instance(args) == "inst-xyz"