# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html
import logging
from typing import Optional
from scrapy import signals

# useful for handling different item types with a single interface
from itemadapter import ItemAdapter
from scrapy.http.headers import Headers

from science_article_cssci.scripts.get_cookie import GetSessionID
logger = logging.getLogger(__name__)


class ScienceArticleCssciSpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, or item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request or item objects.
        pass

    async def process_start(self, start):
        # Called with an async iterator over the spider start() method or the
        # maching method of an earlier spider middleware.
        async for item_or_request in start:
            yield item_or_request

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class ScienceArticleCssciDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class CssciCookieMiddleware:
    ss: Optional[GetSessionID]

    def __init__(self, custom_headers: dict, cookie_cfg: dict):
        self.custom_headers = custom_headers
        self.headers = Headers(self.custom_headers)
        self.cookies_pool_config = cookie_cfg

    @classmethod
    def from_crawler(cls, crawler):
        settings = crawler.settings
        post_headers = crawler.settings.getdict('POST_HEADERS_CONFIG')
        s = cls(
            custom_headers=post_headers,
            cookie_cfg=dict(
                redis_uri=settings.get("COOKIE_POOL_CONFIG"),
                pool_key=settings.get("COOKIE_POOL_REDIS_KEY"),
                ttl=settings.get("COOKIE_REDIS_TTL")
            )
        )
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def spider_opened(self, spider):
        self.ss = GetSessionID(**self.cookies_pool_config)

    async def process_request(self, request, spider):
        cookie_1 = await self.ss.get_cookie_from_redis()
        if not cookie_1:
            cookie_1 = await self.ss.get_cookie_to_redis()
            logger.info("""
            没有可用cookie
            重新获取:    %s""" % cookie_1)

        request.cookies = cookie_1
        request.headers = self.headers