from twisted.trial import unittest

from scrapy.settings import Settings
from scrapy.exceptions import NotConfigured
from scrapy.middleware import MiddlewareManager


class M1:

    def open_spider(self, spider):
        pass

    def close_spider(self, spider):
        pass

    def process(self, response, request, spider):
        pass


class M2:

    def open_spider(self, spider):
        pass

    def close_spider(self, spider):
        pass

    pass


class M3:

    def process(self, response, request, spider):
        pass


class MOff:

    def open_spider(self, spider):
        pass

    def close_spider(self, spider):
        pass

    def __init__(self):
        raise NotConfigured


class TestMiddlewareManager(MiddlewareManager):

    @classmethod
    def _get_mwlist_from_settings(cls, settings):
        return [M1, MOff, M3]

    def _add_middleware(self, mw):
        super()._add_middleware(mw)
        if hasattr(mw, 'process'):
            self.methods['process'].append(mw.process)


class MiddlewareManagerTest(unittest.TestCase):

    def test_init(self):
        m1, m2, m3 = M1(), M2(), M3()
        mwman = TestMiddlewareManager(m1, m2, m3)
        self.assertEqual(list(mwman.methods['open_spider']), [m1.open_spider, m2.open_spider])
        self.assertEqual(list(mwman.methods['close_spider']), [m2.close_spider, m1.close_spider])
        self.assertEqual(list(mwman.methods['process']), [m1.process, m3.process])

    def test_methods(self):
        mwman = TestMiddlewareManager(M1(), M2(), M3())
        self.assertEqual(
            [x.__self__.__class__ for x in mwman.methods['open_spider']],
            [M1, M2])
        self.assertEqual(
            [x.__self__.__class__ for x in mwman.methods['close_spider']],
            [M2, M1])
        self.assertEqual(
            [x.__self__.__class__ for x in mwman.methods['process']],
            [M1, M3])

    def test_enabled(self):
        m1, m2, m3 = M1(), M2(), M3()
        mwman = MiddlewareManager(m1, m2, m3)
        self.assertEqual(mwman.middlewares, (m1, m2, m3))

    def test_enabled_from_settings(self):
        settings = Settings()
        mwman = TestMiddlewareManager.from_settings(settings)
        classes = [x.__class__ for x in mwman.middlewares]
        self.assertEqual(classes, [M1, M3])