import os
import argparse
from os.path import join, abspath, isfile, exists
from twisted.internet import defer
from scrapy.commands import parse
from scrapy.settings import Settings
from scrapy.utils.testsite import SiteTest
from scrapy.utils.testproc import ProcessTest
from scrapy.utils.python import to_unicode
from tests.test_commands import CommandTest


def _textmode(bstr):
    """Normalize input the same as writing to a file
    and reading from it in text mode"""
    return to_unicode(bstr).replace(os.linesep, '\n')


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

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


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

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

    def parse_request_with_meta(self, response):
        foo = response.meta.get('foo', 'bar')

        if foo == 'bar':
            self.logger.debug('It Does Not Work :(')
        else:
            self.logger.debug('It Works!')

    def parse_request_with_cb_kwargs(self, response, foo=None, key=None):
        if foo == 'bar' and key == 'value':
            self.logger.debug('It Works!')
        else:
            self.logger.debug('It Does Not Work :(')

    def parse_request_without_meta(self, response):
        foo = response.meta.get('foo', 'bar')

        if foo == 'bar':
            self.logger.debug('It Works!')
        else:
            self.logger.debug('It Does Not Work :(')

class MyGoodCrawlSpider(CrawlSpider):
    name = 'goodcrawl{self.spider_name}'

    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{self.spider_name}'

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

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

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

class MyPipeline:
    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(f"""
ITEM_PIPELINES = {{'{self.project_name}.pipelines.MyPipeline': 1}}
""")

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

    @defer.inlineCallbacks
    def test_request_with_meta(self):
        raw_json_string = '{"foo" : "baz"}'
        _, _, stderr = yield self.execute(['--spider', self.spider_name,
                                           '--meta', raw_json_string,
                                           '-c', 'parse_request_with_meta',
                                           '--verbose',
                                           self.url('/html')])
        self.assertIn("DEBUG: It Works!", _textmode(stderr))

        _, _, stderr = yield self.execute(['--spider', self.spider_name,
                                           '-m', raw_json_string,
                                           '-c', 'parse_request_with_meta',
                                           '--verbose',
                                           self.url('/html')])
        self.assertIn("DEBUG: It Works!", _textmode(stderr))

    @defer.inlineCallbacks
    def test_request_with_cb_kwargs(self):
        raw_json_string = '{"foo" : "bar", "key": "value"}'
        _, _, stderr = yield self.execute(['--spider', self.spider_name,
                                           '--cbkwargs', raw_json_string,
                                           '-c', 'parse_request_with_cb_kwargs',
                                           '--verbose',
                                           self.url('/html')])
        self.assertIn("DEBUG: It Works!", _textmode(stderr))

    @defer.inlineCallbacks
    def test_request_without_meta(self):
        _, _, stderr = yield self.execute(['--spider', self.spider_name,
                                           '-c', 'parse_request_without_meta',
                                           '--nolinks',
                                           self.url('/html')])
        self.assertIn("DEBUG: It Works!", _textmode(stderr))

    @defer.inlineCallbacks
    def test_pipelines(self):
        _, _, stderr = yield self.execute(['--spider', self.spider_name,
                                           '--pipelines',
                                           '-c', 'parse',
                                           '--verbose',
                                           self.url('/html')])
        self.assertIn("INFO: It Works!", _textmode(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'}]""", _textmode(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'}]""", _textmode(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.assertRegex(_textmode(out), r"""# Scraped Items  -+\n\[\]""")
        self.assertIn("""Cannot find callback""", _textmode(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'}]""", _textmode(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'}]""", _textmode(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.assertRegex(_textmode(out), r"""# Scraped Items  -+\n\[\]""")
        self.assertIn("""No CrawlSpider rules found""", _textmode(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.assertRegex(_textmode(out), r"""# 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.assertRegex(_textmode(out), r"""# Scraped Items  -+\n\[\]""")
        self.assertIn("""Cannot find a rule that matches""", _textmode(stderr))

    @defer.inlineCallbacks
    def test_output_flag(self):
        """Checks if a file was created successfully having
        correct format containing correct data in it.
        """
        file_name = 'data.json'
        file_path = join(self.proj_path, file_name)
        yield self.execute([
            '--spider', self.spider_name,
            '-c', 'parse',
            '-o', file_name,
            self.url('/html')
        ])

        self.assertTrue(exists(file_path))
        self.assertTrue(isfile(file_path))

        content = '[\n{},\n{"foo": "bar"}\n]'
        with open(file_path, 'r') as f:
            self.assertEqual(f.read(), content)

    def test_parse_add_options(self):
        command = parse.Command()
        command.settings = Settings()
        parser = argparse.ArgumentParser(
            prog='scrapy', formatter_class=argparse.HelpFormatter,
            conflict_handler='resolve', prefix_chars='-'
        )
        command.add_options(parser)
        namespace = parser.parse_args(
            ['--verbose', '--nolinks', '-d', '2', '--spider', self.spider_name]
        )
        self.assertTrue(namespace.nolinks)
        self.assertEqual(namespace.depth, 2)
        self.assertEqual(namespace.spider, self.spider_name)
        self.assertTrue(namespace.verbose)
