from os import environ
from pathlib import Path
from contextlib import contextmanager
from tempfile import TemporaryDirectory
from textwrap import dedent
import pytest

from sanic import Sanic
from sanic.exceptions import PyFileError


@contextmanager
def temp_path():
    """ a simple cross platform replacement for NamedTemporaryFile """
    with TemporaryDirectory() as td:
        yield Path(td, "file")


def test_load_from_object(app):
    class Config:
        not_for_config = "should not be used"
        CONFIG_VALUE = "should be used"

    app.config.from_object(Config)
    assert "CONFIG_VALUE" in app.config
    assert app.config.CONFIG_VALUE == "should be used"
    assert "not_for_config" not in app.config


def test_auto_load_env():
    environ["SANIC_TEST_ANSWER"] = "42"
    app = Sanic()
    assert app.config.TEST_ANSWER == 42
    del environ["SANIC_TEST_ANSWER"]


def test_dont_load_env():
    environ["SANIC_TEST_ANSWER"] = "42"
    app = Sanic(load_env=False)
    assert getattr(app.config, "TEST_ANSWER", None) is None
    del environ["SANIC_TEST_ANSWER"]


def test_load_env_prefix():
    environ["MYAPP_TEST_ANSWER"] = "42"
    app = Sanic(load_env="MYAPP_")
    assert app.config.TEST_ANSWER == 42
    del environ["MYAPP_TEST_ANSWER"]


def test_load_env_prefix_float_values():
    environ["MYAPP_TEST_ROI"] = "2.3"
    app = Sanic(load_env="MYAPP_")
    assert app.config.TEST_ROI == 2.3
    del environ["MYAPP_TEST_ROI"]


def test_load_env_prefix_string_value():
    environ["MYAPP_TEST_TOKEN"] = "somerandomtesttoken"
    app = Sanic(load_env="MYAPP_")
    assert app.config.TEST_TOKEN == "somerandomtesttoken"
    del environ["MYAPP_TEST_TOKEN"]


def test_load_from_file(app):
    config = dedent(
        """
    VALUE = 'some value'
    condition = 1 == 1
    if condition:
        CONDITIONAL = 'should be set'
    """
    )
    with temp_path() as config_path:
        config_path.write_text(config)
        app.config.from_pyfile(str(config_path))
        assert "VALUE" in app.config
        assert app.config.VALUE == "some value"
        assert "CONDITIONAL" in app.config
        assert app.config.CONDITIONAL == "should be set"
        assert "condition" not in app.config


def test_load_from_missing_file(app):
    with pytest.raises(IOError):
        app.config.from_pyfile("non-existent file")


def test_load_from_envvar(app):
    config = "VALUE = 'some value'"
    with temp_path() as config_path:
        config_path.write_text(config)
        environ["APP_CONFIG"] = str(config_path)
        app.config.from_envvar("APP_CONFIG")
        assert "VALUE" in app.config
        assert app.config.VALUE == "some value"


def test_load_from_missing_envvar(app):
    with pytest.raises(RuntimeError) as e:
        app.config.from_envvar("non-existent variable")
        assert str(e.value) == (
            "The environment variable 'non-existent "
            "variable' is not set and thus configuration "
            "could not be loaded."
        )


def test_load_config_from_file_invalid_syntax(app):
    config = "VALUE = some value"
    with temp_path() as config_path:
        config_path.write_text(config)

        with pytest.raises(PyFileError):
            app.config.from_pyfile(config_path)


def test_overwrite_exisiting_config(app):
    app.config.DEFAULT = 1

    class Config:
        DEFAULT = 2

    app.config.from_object(Config)
    assert app.config.DEFAULT == 2


def test_overwrite_exisiting_config_ignore_lowercase(app):
    app.config.default = 1

    class Config:
        default = 2

    app.config.from_object(Config)
    assert app.config.default == 1


def test_missing_config(app):
    with pytest.raises(AttributeError) as e:
        app.config.NON_EXISTENT
        assert str(e.value) == ("Config has no 'NON_EXISTENT'")