import json
import os
import pytest
from cpl.core.configuration.configuration import Configuration
from cpl.core.configuration.configuration_model_abc import ConfigurationModelABC


class AppSettings(ConfigurationModelABC):
    def __init__(self, src: dict = None):
        ConfigurationModelABC.__init__(self, src or {})
        self.option("app_name", str, default="default-app")
        self.option("version", str, default="0.0.0")


class ServerSettings(ConfigurationModelABC):
    def __init__(self, src: dict = None):
        ConfigurationModelABC.__init__(self, src or {})
        self.option("host", str, default="localhost")
        self.option("port", int, default=8080)


@pytest.fixture(autouse=True)
def clear_config():
    """Reset Configuration state before each test."""
    Configuration._config.clear()
    yield
    Configuration._config.clear()


# --- set / get ---


def test_set_and_get_by_class():
    settings = AppSettings({"app_name": "TestApp", "version": "1.0.0"})
    Configuration.set(AppSettings, settings)
    result = Configuration.get(AppSettings)
    assert result.app_name == "TestApp"
    assert result.version == "1.0.0"


def test_set_and_get_by_string_key():
    Configuration.set("my_key", "my_value")
    assert Configuration.get("my_key") == "my_value"


def test_get_missing_returns_default():
    assert Configuration.get("nonexistent", "fallback") == "fallback"


def test_get_missing_returns_none():
    assert Configuration.get("nonexistent") is None


def test_get_model_auto_instantiates():
    # Getting an unregistered ConfigurationModelABC subclass should auto-create it
    result = Configuration.get(ServerSettings)
    assert isinstance(result, ServerSettings)
    assert result.host == "localhost"
    assert result.port == 8080


def test_overwrite_existing():
    Configuration.set("key", "first")
    Configuration.set("key", "second")
    assert Configuration.get("key") == "second"


def test_multiple_models():
    Configuration.set(AppSettings, AppSettings({"app_name": "App"}))
    Configuration.set(ServerSettings, ServerSettings({"port": 9000}))
    assert Configuration.get(AppSettings).app_name == "App"
    assert Configuration.get(ServerSettings).port == 9000


# --- add_json_file ---


def test_add_json_file_loads_model(tmp_path):
    config_data = {"AppSettings": {"app_name": "FromFile", "version": "2.0.0"}}
    config_file = tmp_path / "appsettings.json"
    config_file.write_text(json.dumps(config_data), encoding="utf-8")

    Configuration.add_json_file(str(config_file), output=False)

    result = Configuration.get(AppSettings)
    assert result.app_name == "FromFile"
    assert result.version == "2.0.0"


def test_add_json_file_not_found_exits(tmp_path):
    with pytest.raises(SystemExit):
        Configuration.add_json_file(str(tmp_path / "missing.json"), output=False)


def test_add_json_file_optional_missing_returns_none(tmp_path):
    result = Configuration.add_json_file(str(tmp_path / "missing.json"), optional=True, output=False)
    assert result is None


def test_add_json_file_invalid_json(tmp_path):
    # _load_json_file catches parse errors and returns {} — no SystemExit.
    # add_json_file then proceeds with an empty config (no models loaded).
    bad_file = tmp_path / "bad.json"
    bad_file.write_text("not valid json", encoding="utf-8")
    Configuration.add_json_file(str(bad_file), output=False)
    # No model should be registered since the file was invalid
    assert Configuration.get("AppSettings") is None