import logging

from scrapy import signals
from scrapy.http import HtmlResponse
from selenium import webdriver
from selenium.common.exceptions import TimeoutException
from selenium.webdriver.chrome.options import Options
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.ui import WebDriverWait


logger = logging.getLogger(__name__)


class SeleniumDownloaderMiddleware:
    def __init__(self, wait_seconds, driver_arguments):
        self.wait_seconds = wait_seconds
        self.driver_arguments = driver_arguments
        self.driver = None

    @classmethod
    def from_crawler(cls, crawler):
        middleware = cls(
            wait_seconds=crawler.settings.getint("SELENIUM_WAIT_SECONDS", 10),
            driver_arguments=crawler.settings.getlist("SELENIUM_DRIVER_ARGUMENTS"),
        )
        crawler.signals.connect(middleware.spider_opened, signal=signals.spider_opened)
        crawler.signals.connect(middleware.spider_closed, signal=signals.spider_closed)
        return middleware

    def spider_opened(self, spider):
        options = Options()
        for argument in self.driver_arguments:
            options.add_argument(argument)
        self.driver = webdriver.Chrome(options=options)

    def spider_closed(self, spider, reason):
        if self.driver is not None:
            self.driver.quit()
            self.driver = None

    def process_request(self, request):
        if not request.meta.get("selenium"):
            return None

        if self.driver is None:
            raise RuntimeError("Selenium WebDriver is not initialized.")

        self.driver.get(request.url)

        wait_css = request.meta.get("selenium_wait_css")
        if wait_css:
            try:
                WebDriverWait(self.driver, self.wait_seconds).until(
                    EC.presence_of_element_located((By.CSS_SELECTOR, wait_css))
                )
            except TimeoutException:
                logger.warning("Timed out waiting for selector: %s", wait_css)

        return HtmlResponse(
            url=self.driver.current_url,
            body=self.driver.page_source,
            encoding="utf-8",
            request=request,
        )