from __future__ import unicode_literals, absolute_import

import os
import sys
import unittest

from django.test import LiveServerTestCase
from django.utils import six
from django.utils.module_loading import import_string
from django.utils.text import capfirst


class SeleniumTestCaseBase(type(LiveServerTestCase)):
    # List of browsers to dynamically create test classes for.
    browsers = []
    # Sentinel value to differentiate browser-specific instances.
    browser = None

    def __new__(cls, name, bases, attrs):
        """
        Dynamically create new classes and add them to the test module when
        multiple browsers specs are provided (e.g. --selenium=firefox,chrome).
        """
        test_class = super(SeleniumTestCaseBase, cls).__new__(cls, name, bases, attrs)
        # If the test class is either browser-specific or a test base, return it.
        is_test_attr = lambda n: n.startswith('test') and callable(getattr(test_class, n))
        if test_class.browser or not any(is_test_attr(name) for name in dir(test_class)):
            return test_class
        elif test_class.browsers:
            # Reuse the created test class to make it browser-specific.
            # We can't rename it to include the browser name or create a
            # subclass like we do with the remaining browsers as it would
            # either duplicate tests or prevent pickling of its instances.
            first_browser = test_class.browsers[0]
            test_class.browser = first_browser
            # Create subclasses for each of the remaining browsers and expose
            # them through the test's module namespace.
            module = sys.modules[test_class.__module__]
            for browser in test_class.browsers[1:]:
                browser_test_class = cls.__new__(
                    cls,
                    str("%s%s" % (capfirst(browser), name)),
                    (test_class,),
                    {'browser': browser, '__module__': test_class.__module__}
                )
                setattr(module, browser_test_class.__name__, browser_test_class)
            return test_class
        # If no browsers were specified, skip this class (it'll still be discovered).
        return unittest.skip('No browsers specified.')(test_class)

    @classmethod
    def import_webdriver(cls, browser):
        return import_string("selenium.webdriver.%s.webdriver.WebDriver" % browser)

    def create_webdriver(self):
        if False and all([os.environ.get(k) for k in ['SAUCE_USERNAME', 'SAUCE_ACCESS_KEY', 'TRAVIS']]):
            from selenium import webdriver

            username = os.environ['SAUCE_USERNAME']
            access_key = os.environ['SAUCE_ACCESS_KEY']

            desired_capabilities = webdriver.DesiredCapabilities.CHROME
            desired_capabilities['browserName'] = 'chrome'
            desired_capabilities['version'] = '50.0'
            desired_capabilities['platform'] = "OS X 10.11"
            desired_capabilities['tunnel-identifier'] = os.environ.get('TRAVIS_JOB_NUMBER')
            if os.environ.get('TRAVIS_BUILD_NUMBER'):
                desired_capabilities["build"] = os.environ["TRAVIS_BUILD_NUMBER"]
            if os.environ.get('TRAVIS_PYTHON_VERSION'):
                desired_capabilities["tags"] = [os.environ["TRAVIS_PYTHON_VERSION"], "CI"]

            hub_url = "http://%s:%s@localhost:4445/wd/hub" % (username, access_key)
            driver = webdriver.Remote(
                command_executor=hub_url,
                desired_capabilities=desired_capabilities)
            driver.implicitly_wait(10)
            self.browser = 'chrome'
            return driver

        return self.import_webdriver(self.browser)()


class SeleniumTestCase(six.with_metaclass(SeleniumTestCaseBase, LiveServerTestCase)):

    @classmethod
    def setUpClass(cls):
        cls.selenium = cls.create_webdriver()
        cls.selenium.implicitly_wait(10)
        super(SeleniumTestCase, cls).setUpClass()

    @classmethod
    def _tearDownClassInternal(cls):
        # quit() the WebDriver before attempting to terminate and join the
        # single-threaded LiveServerThread to avoid a dead lock if the browser
        # kept a connection alive.
        if hasattr(cls, 'selenium'):
            cls.selenium.quit()
        super(SeleniumTestCase, cls)._tearDownClassInternal()