import warnings
import unittest

import scrapy
from scrapy.crawler import Crawler, CrawlerRunner, CrawlerProcess
from scrapy.settings import Settings, default_settings
from scrapy.spiderloader import SpiderLoader
from scrapy.utils.spider import DefaultSpider
from scrapy.utils.misc import load_object
from scrapy.extensions.throttle import AutoThrottle


class BaseCrawlerTest(unittest.TestCase):

    def assertOptionIsDefault(self, settings, key):
        self.assertIsInstance(settings, Settings)
        self.assertEqual(settings[key], getattr(default_settings, key))


class CrawlerTestCase(BaseCrawlerTest):

    def setUp(self):
        self.crawler = Crawler(DefaultSpider, Settings())

    def test_deprecated_attribute_spiders(self):
        with warnings.catch_warnings(record=True) as w:
            spiders = self.crawler.spiders
            self.assertEqual(len(w), 1)
            self.assertIn("Crawler.spiders", str(w[0].message))
            sl_cls = load_object(self.crawler.settings['SPIDER_LOADER_CLASS'])
            self.assertIsInstance(spiders, sl_cls)

            self.crawler.spiders
            self.assertEqual(len(w), 1, "Warn deprecated access only once")

    def test_populate_spidercls_settings(self):
        spider_settings = {'TEST1': 'spider', 'TEST2': 'spider'}
        project_settings = {'TEST1': 'project', 'TEST3': 'project'}

        class CustomSettingsSpider(DefaultSpider):
            custom_settings = spider_settings

        settings = Settings()
        settings.setdict(project_settings, priority='project')
        crawler = Crawler(CustomSettingsSpider, settings)

        self.assertEqual(crawler.settings.get('TEST1'), 'spider')
        self.assertEqual(crawler.settings.get('TEST2'), 'spider')
        self.assertEqual(crawler.settings.get('TEST3'), 'project')

        self.assertFalse(settings.frozen)
        self.assertTrue(crawler.settings.frozen)

    def test_crawler_accepts_dict(self):
        crawler = Crawler(DefaultSpider, {'foo': 'bar'})
        self.assertEqual(crawler.settings['foo'], 'bar')
        self.assertOptionIsDefault(crawler.settings, 'RETRY_ENABLED')

    def test_crawler_accepts_None(self):
        crawler = Crawler(DefaultSpider)
        self.assertOptionIsDefault(crawler.settings, 'RETRY_ENABLED')


class SpiderSettingsTestCase(unittest.TestCase):
    def test_spider_custom_settings(self):
        class MySpider(scrapy.Spider):
            name = 'spider'
            custom_settings = {
                'AUTOTHROTTLE_ENABLED': True
            }

        crawler = Crawler(MySpider, {})
        enabled_exts = [e.__class__ for e in crawler.extensions.middlewares]
        self.assertIn(AutoThrottle, enabled_exts)


class SpiderLoaderWithWrongInterface(object):

    def unneeded_method(self):
        pass


class CustomSpiderLoader(SpiderLoader):
    pass


class CrawlerRunnerTestCase(BaseCrawlerTest):

    def test_spider_manager_verify_interface(self):
        settings = Settings({
            'SPIDER_LOADER_CLASS': 'tests.test_crawler.SpiderLoaderWithWrongInterface'
        })
        with warnings.catch_warnings(record=True) as w, \
                self.assertRaises(AttributeError):
            CrawlerRunner(settings)
            self.assertEqual(len(w), 1)
            self.assertIn("SPIDER_LOADER_CLASS", str(w[0].message))
            self.assertIn("scrapy.interfaces.ISpiderLoader", str(w[0].message))

    def test_crawler_runner_accepts_dict(self):
        runner = CrawlerRunner({'foo': 'bar'})
        self.assertEqual(runner.settings['foo'], 'bar')
        self.assertOptionIsDefault(runner.settings, 'RETRY_ENABLED')

    def test_crawler_runner_accepts_None(self):
        runner = CrawlerRunner()
        self.assertOptionIsDefault(runner.settings, 'RETRY_ENABLED')

    def test_deprecated_attribute_spiders(self):
        with warnings.catch_warnings(record=True) as w:
            runner = CrawlerRunner(Settings())
            spiders = runner.spiders
            self.assertEqual(len(w), 1)
            self.assertIn("CrawlerRunner.spiders", str(w[0].message))
            self.assertIn("CrawlerRunner.spider_loader", str(w[0].message))
            sl_cls = load_object(runner.settings['SPIDER_LOADER_CLASS'])
            self.assertIsInstance(spiders, sl_cls)

    def test_spidermanager_deprecation(self):
        with warnings.catch_warnings(record=True) as w:
            runner = CrawlerRunner({
                'SPIDER_MANAGER_CLASS': 'tests.test_crawler.CustomSpiderLoader'
            })
            self.assertIsInstance(runner.spider_loader, CustomSpiderLoader)
            self.assertEqual(len(w), 1)
            self.assertIn('Please use SPIDER_LOADER_CLASS', str(w[0].message))


class CrawlerProcessTest(BaseCrawlerTest):
    def test_crawler_process_accepts_dict(self):
        runner = CrawlerProcess({'foo': 'bar'})
        self.assertEqual(runner.settings['foo'], 'bar')
        self.assertOptionIsDefault(runner.settings, 'RETRY_ENABLED')

    def test_crawler_process_accepts_None(self):
        runner = CrawlerProcess()
        self.assertOptionIsDefault(runner.settings, 'RETRY_ENABLED')