from os.path import join, abspath
from twisted.trial import unittest
from twisted.internet import defer
from scrapy.utils.testsite import SiteTest
from scrapy.utils.testproc import ProcessTest
from scrapy.utils.python import to_native_str
from tests.test_commands import CommandTest


class ParseCommandTest(ProcessTest, SiteTest, CommandTest):
    command = 'parse'

    def setUp(self):
        super(ParseCommandTest, self).setUp()
        self.spider_name = 'parse_spider'
        fname = abspath(join(self.proj_mod_path, 'spiders', 'myspider.py'))
        with open(fname, 'w') as f:
            f.write("""
import scrapy
from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule


class MySpider(scrapy.Spider):
    name = '{0}'

    def parse(self, response):
        if getattr(self, 'test_arg', None):
            self.logger.debug('It Works!')
        return [scrapy.Item(), dict(foo='bar')]


class MyGoodCrawlSpider(CrawlSpider):
    name = 'goodcrawl{0}'

    rules = (
        Rule(LinkExtractor(allow=r'/html'), callback='parse_item', follow=True),
        Rule(LinkExtractor(allow=r'/text'), follow=True),
    )

    def parse_item(self, response):
        return [scrapy.Item(), dict(foo='bar')]

    def parse(self, response):
        return [scrapy.Item(), dict(nomatch='default')]


class MyBadCrawlSpider(CrawlSpider):
    '''Spider which doesn't define a parse_item callback while using it in a rule.'''
    name = 'badcrawl{0}'

    rules = (
        Rule(LinkExtractor(allow=r'/html'), callback='parse_item', follow=True),
    )

    def parse(self, response):
        return [scrapy.Item(), dict(foo='bar')]
""".format(self.spider_name))

        fname = abspath(join(self.proj_mod_path, 'pipelines.py'))
        with open(fname, 'w') as f:
            f.write("""
import logging

class MyPipeline(object):
    component_name = 'my_pipeline'

    def process_item(self, item, spider):
        logging.info('It Works!')
        return item
""")

        fname = abspath(join(self.proj_mod_path, 'settings.py'))
        with open(fname, 'a') as f:
            f.write("""
ITEM_PIPELINES = {'%s.pipelines.MyPipeline': 1}
""" % self.project_name)

    @defer.inlineCallbacks
    def test_spider_arguments(self):
        _, _, stderr = yield self.execute(['--spider', self.spider_name,
                                           '-a', 'test_arg=1',
                                           '-c', 'parse',
                                           self.url('/html')])
        self.assertIn("DEBUG: It Works!", to_native_str(stderr))

    @defer.inlineCallbacks
    def test_pipelines(self):
        _, _, stderr = yield self.execute(['--spider', self.spider_name,
                                           '--pipelines',
                                           '-c', 'parse',
                                           self.url('/html')])
        self.assertIn("INFO: It Works!", to_native_str(stderr))

    @defer.inlineCallbacks
    def test_parse_items(self):
        status, out, stderr = yield self.execute(
            ['--spider', self.spider_name, '-c', 'parse', self.url('/html')]
        )
        self.assertIn("""[{}, {'foo': 'bar'}]""", to_native_str(out))

    @defer.inlineCallbacks
    def test_parse_items_no_callback_passed(self):
        status, out, stderr = yield self.execute(
            ['--spider', self.spider_name, self.url('/html')]
        )
        self.assertIn("""[{}, {'foo': 'bar'}]""", to_native_str(out))

    @defer.inlineCallbacks
    def test_wrong_callback_passed(self):
        status, out, stderr = yield self.execute(
            ['--spider', self.spider_name, '-c', 'dummy', self.url('/html')]
        )
        self.assertRegexpMatches(to_native_str(out), """# Scraped Items  -+\n\[\]""")
        self.assertIn("""Cannot find callback""", to_native_str(stderr))

    @defer.inlineCallbacks
    def test_crawlspider_matching_rule_callback_set(self):
        """If a rule matches the URL, use it's defined callback."""
        status, out, stderr = yield self.execute(
            ['--spider', 'goodcrawl'+self.spider_name, '-r', self.url('/html')]
        )
        self.assertIn("""[{}, {'foo': 'bar'}]""", to_native_str(out))

    @defer.inlineCallbacks
    def test_crawlspider_matching_rule_default_callback(self):
        """If a rule match but it has no callback set, use the 'parse' callback."""
        status, out, stderr = yield self.execute(
            ['--spider', 'goodcrawl'+self.spider_name, '-r', self.url('/text')]
        )
        self.assertIn("""[{}, {'nomatch': 'default'}]""", to_native_str(out))

    @defer.inlineCallbacks
    def test_spider_with_no_rules_attribute(self):
        """Using -r with a spider with no rule should not produce items."""
        status, out, stderr = yield self.execute(
            ['--spider', self.spider_name, '-r', self.url('/html')]
        )
        self.assertRegexpMatches(to_native_str(out), """# Scraped Items  -+\n\[\]""")
        self.assertIn("""No CrawlSpider rules found""", to_native_str(stderr))

    @defer.inlineCallbacks
    def test_crawlspider_missing_callback(self):
        status, out, stderr = yield self.execute(
            ['--spider', 'badcrawl'+self.spider_name, '-r', self.url('/html')]
        )
        self.assertRegexpMatches(to_native_str(out), """# Scraped Items  -+\n\[\]""")

    @defer.inlineCallbacks
    def test_crawlspider_no_matching_rule(self):
        """The requested URL has no matching rule, so no items should be scraped"""
        status, out, stderr = yield self.execute(
            ['--spider', 'badcrawl'+self.spider_name, '-r', self.url('/enc-gb18030')]
        )
        self.assertRegexpMatches(to_native_str(out), """# Scraped Items  -+\n\[\]""")
        self.assertIn("""Cannot find a rule that matches""", to_native_str(stderr))
