# SPDX-License-Identifier: GPL-3.0-or-later

"""
Common fixtures for Haketilo unit tests
"""

# This file is part of Haketilo.
#
# Copyright (C) 2021 Wojtek Kosior <koszko@koszko.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
# I, Wojtek Kosior, thereby promise not to sue for violation of this file's
# license. Although I request that you do not make use this code in a
# proprietary program, I am not going to enforce this in court.

import pytest

from ..profiles      import firefox_safe_mode
from ..server        import do_an_internet
from ..script_loader import load_script

@pytest.fixture(scope="package")
def proxy():
    httpd = do_an_internet()
    yield httpd
    httpd.shutdown()

@pytest.fixture(scope="package")
def driver(proxy):
    with firefox_safe_mode() as driver:
        yield driver
        driver.quit()

script_injecting_script = '''\
/*
 * Selenium by default executes scripts in some weird one-time context. We want
 * separately-loaded scripts to be able to access global variables defined
 * before, including those declared with `const` or `let`. To achieve that, we
 * run our scripts by injecting them into the page inside a <script> tag. We use
 * custom properties of the `window` object to communicate with injected code.
 */

const script_elem = document.createElement('script');
script_elem.textContent = arguments[0];

delete window.haketilo_selenium_return_value;
delete window.haketilo_selenium_exception;
window.returnval = (val => window.haketilo_selenium_return_value = val);
window.arguments = arguments[1];

document.body.append(script_elem);

/*
 * To ease debugging, we want this script to forward signal all exceptions from
 * the injectee.
 */
try {
    if (window.haketilo_selenium_exception !== false)
        throw 'Error in injected script! Check your geckodriver.log!';
} finally {
    script_elem.remove();
}

return window.haketilo_selenium_return_value;
'''

def _execute_in_page_context(driver, script, *args):
    script = script + '\n;\nwindow.haketilo_selenium_exception = false;'
    try:
        return driver.execute_script(script_injecting_script, script, args)
    except Exception as e:
        import sys
        lines = enumerate(script.split('\n'), 1)
        for err_info in [('Failing script\n',), *lines]:
            print(*err_info, file=sys.stderr)

        raise e from None

@pytest.fixture(scope="package")
def execute_in_page(driver):
    def do_execute(script, *args, **kwargs):
        if 'page' in kwargs:
            driver.get(kwargs['page'])

        return _execute_in_page_context(driver, script, args)

    yield do_execute

@pytest.fixture(scope="package")
def load_into_page(driver):
    def do_load(path, import_dirs, *args, **kwargs):
        if 'page' in kwargs:
            driver.get(kwargs['page'])

        _execute_in_page_context(driver, load_script(path, import_dirs), args)

    yield do_load