from utils import get_webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import TimeoutException
import time
import os

from logger import get_logger
logger = get_logger()

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

    def verify_missing_kid_url(self, url):
        def load_finished(driver):
            # Find all <img> tags with src attributes. Extract src URLs
            image_urls = [img.get_attribute("src") for img in driver.find_elements(By.XPATH, "//img[@src]")]
            # If base64 image exists, loading finished
            finished = any(["data:image/png;base64" in i for i in image_urls])
            # logger.debug("Finished loading URL")
            return finished

        try:
            # Initialize
            logger.debug("Initializing driver")
            driver = get_webdriver()
            # Load URL
            logger.debug("Get URL: {}".format(url))
            driver.get(url)
            # Wait for 404?
            try:
                WebDriverWait(driver, 2).until(EC.title_contains("404"))
                logger.debug("WebDriverWait -> title contains 404")
            except TimeoutException:
                logger.debug("WebDriverWait timeout, no 404 appeared")

            if ("404" in driver.title):
                # Status invalid
                results = {"status": "invalid"}
            else:
                # Check until finished loading
                num_checks = 5
                while (not load_finished(driver)) and (num_checks>=0):
                    time.sleep(1)
                    num_checks -= 1

                # Find all <img> tags with src attributes. Extract src URLs
                image_urls = [img.get_attribute("src") for img in driver.find_elements(By.XPATH, "//img[@src]")]

                # Redirects to 404?
                if ("missingkids.org/404" in driver.current_url) or (any(["thumb-404.png" in i for i in image_urls])):
                    # Status invalid
                    results = {"status": "invalid"}
                # Redirection to valid URL? -> Duplicate
                elif (driver.current_url != url):
                    # Redirection (duplicate)
                    results = {"status": "duplicate", "redirection": driver.current_url}
                # Valid
                elif ("Have you seen this child?" in driver.title):
                    # Status valid
                    results = {"status": "valid"}
                else:
                    results = {"status": "unknown"}
        except Exception as e:
            logger.warning("Exception while verifying MissingKid URL {}\n{}".format(url, str(e)), exc_info=True)
            results = {}

        # Release memory
        try:
            driver.quit() #driver.close()
            time.sleep(1)
            # import atexit
            # atexit.register(driver.quit)  # Will always be called on exit
        except Exception as e:
            logger.warning("Exception while closing/quitting driver: {}".format(str(e)), exc_info=True)
        logger.info("Results: {} for URL: {}".format(str(results), url))
        return results
        

    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:
            logger.debug("Initializing driver")
            driver = get_webdriver()
            logger.debug("Get URL: {}".format(url))
            # 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(float(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(float(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()

        # Release memory
        try:
            driver.quit() #driver.close()
            time.sleep(1)
            # import atexit
            # atexit.register(driver.quit)  # Will always be called on exit
        except Exception as e:
            logger.warning("Exception while closing/quitting driver: {}".format(str(e)), exc_info=True)

        return set_urls