"""Test main connection module."""

import os
import pytest

from owsmysql import db


def test_session_rollback(mocker):
    """Check that session will rollback on errors."""
    mock = mocker.patch.object(db.default, 'session_maker')
    with pytest.raises(Exception):
        with db.default.session():
            raise Exception
    assert mock.return_value.rollback.called


def test_db_env_test_configuration(mocker):
    """Check DB in tests can be configured though env variables."""
    mocker.patch.object(os, 'environ', {
        'TEST_DB_USER': 'test_user',
        'TEST_DB_PASSWORD': 'test_pass',
        'TEST_DB_HOST': 'test_host',
        'TEST_DB_NAME': 'test_db',
    })
    mocker.patch.object(db, '_db_config', {'smth': None})
    mocker.patch.object(db, 'connections')
    conn = db.TestConnection('smth')
    url = 'mysql+pymysql://test_user:test_pass@test_host/test_db?charset=utf8'
    assert str(conn.engine.url) == url


def test_url_configuration(mocker):
    """Check that connection can be configured by URL."""
    url = 'mysql+pymysql://user:pass@host/db?charset=utf8'
    mocker.patch.object(db, '_db_config', {'smth': {'url': url}})
    mocker.patch.object(db, 'connections')
    mocker.patch.object(db, '_environment', 'dev')
    conn = db.MySQLConnection('smth')
    assert str(conn.engine.url) == url


def test_param_configuration(mocker):
    """Check that connection can be configured by params."""
    config = {
        'user': 'test_user',
        'password': 'test_pass',
        'host': 'test_host',
        'database': 'test_db',
    }
    mocker.patch.object(db, '_db_config', {'smth': config})
    mocker.patch.object(db, 'connections')
    mocker.patch.object(db, '_environment', 'dev')

    conn = db.MySQLConnection('smth')
    url = 'mysql+pymysql://test_user:test_pass@test_host/test_db?charset=utf8'
    assert str(conn.engine.url) == url


def test_connection_no_init(mocker):
    """Check create connection will fail if db is not configured."""
    mocker.patch.object(db, '_db_config', None)
    with pytest.raises(db.ImproperlyConfigured) as ctx:
        db.MySQLConnection()
    msg = 'Please call db.configure() before creating connections'
    assert ctx.value.args[0] == msg


def test_unknown_connection(mocker):
    """Check create connection will fail with unknown name."""
    mocker.patch.object(db, '_db_config', {})
    with pytest.raises(db.ImproperlyConfigured) as ctx:
        db.MySQLConnection()
    msg = 'Connection default name is not configured'
    assert ctx.value.args[0] == msg


def test_shema_creation_only_in_tests(mocker):
    """Check that schema can not be created outside of test environment."""
    mocker.patch.object(db, '_db_config', {'smth': None})
    mocker.patch.object(db, 'connections')
    mocker.patch.object(db, '_environment', 'dev')

    conn = db.MySQLConnection('smth')
    with pytest.raises(db.ImproperlyConfigured) as ctx:
        conn.create_all()
    assert ctx.value.args[0] == 'Schema creation is only for test environment'

    with pytest.raises(db.ImproperlyConfigured) as ctx:
        conn.drop_all()
    assert ctx.value.args[0] == 'Dropping schema is only for test environment'


def test_session_commit(mocker):
    """Check that session commits only when not read_only."""
    mock = mocker.patch.object(db.default, 'session_maker')
    with db.default.session(read_only=True):
        return
    assert not mock.return_value.commit.called

    with db.default.session(read_only=False):
        return
    assert mock.return_value.commit.called