from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.firefox.options import Options 
from selenium.webdriver.firefox.service import Service
import time
import os

from logger import get_logger
logger = get_logger()

def get_webdriver():
    options = Options()
    options.add_argument('--headless')  # Optional
    options.binary_location = '/opt/firefox/firefox'

    service = Service('/usr/local/bin/geckodriver')

    driver = webdriver.Firefox(options=options, service=service)
    return driver


class MissingKidsFetcher():
    def __init__(self) -> None:
        pass

    def get_missing_kids_urls(self, first_n_pages=-1):
        logger.info("Get MissingKids, #pages: {}".format(first_n_pages))
        # Poster URL
        url = "https://www.missingkids.org/gethelpnow/search/poster-search-results"
        # URLs
        set_urls = set()

        try:
            driver = get_webdriver()
            # Go to URL
            driver.get(url)
            # Iterate
            i, continue_iterating, num_exceptions = 1, True, 0
            while (continue_iterating):
                logger.debug("Processing page: {}...".format(i))

                try:
                    time.sleep(int(os.getenv("SELENIUM_SLEEP_PER_PAGE", 4))) #driver.implicitly_wait(3)
                    # Fetch poster URLs
                    for element_type in ["a"]: # ["a", "p", "div"]:
                        for elem in driver.find_elements(By.TAG_NAME, element_type):
                            href = elem.get_attribute('href')
                            if (href is not None) and ("missingkids.org/poster" in href):
                                set_urls.add(href)

                    logger.debug("#URLS: {}".format(len(set_urls)))

                    # Next page
                    elem = driver.find_element(By.LINK_TEXT, str(i+1))
                    logger.debug("Clicking: {}...".format(elem.text))
                    elem.click()
                    # Ok
                    processed_ok = True
                except Exception as e:
                    # +1 exception
                    num_exceptions += 1
                    processed_ok = False

                    if (num_exceptions == 2):
                        continue_iterating = False
                    else:
                        logger.info("Exception while clicking page {}, retrying...".format(i+1))
                        
                        start_print = False
                        for e in driver.find_elements(By.PARTIAL_LINK_TEXT, ""):
                            if (e.text == "<<"):
                                start_print = True
                            if (e.text == ">>"):
                                break
                            if (start_print):
                                logger.info(e.text)

                        # driver.refresh()
                        time.sleep(int(os.getenv("SELENIUM_SLEEP_PER_PAGE", 4)))

                if (i == first_n_pages):
                    continue_iterating = False
                if (processed_ok):
                    i += 1
                    num_exceptions = 0
        except Exception as e:
            logger.warning("Exception while fetching MissingKids {}".format(str(e)), exc_info=True)
            set_urls = set()

        return set_urls