"""
The checks module contains the functionality to get information and test certain
functionality of a site or individual pages.
"""

import logging

from checks import certificate
from checks import charset
from checks import dns_resolution
from checks import domain_variations
from checks import duplicate_content
from checks import frameset
from checks import generator
from checks import html_head
from checks import http_and_https
from checks import hyperlinks
from checks import load_favicons
from checks import load_feeds
from checks import load_in_browser
from checks import page_content
from checks import url_canonicalization
from checks import url_reachability

from checks.config import Config


def perform_checks(input_url):
    """
    Executes all our URL/site checks and returns a big-ass result dict.
    """

    # The sequence of checks to run. Order is important!
    # Checks which expand the URLs list must come first.
    # After that, dependencies (encoded in the checks) have to be fulfilled.
    check_modules = [
        ('domain_variations', domain_variations),
        ('http_and_https', http_and_https),
        ('dns_resolution', dns_resolution),
        ('url_reachability', url_reachability),
        ('certificate', certificate),
        ('url_canonicalization', url_canonicalization),
        ('page_content', page_content),
        ('duplicate_content', duplicate_content),
        ('charset', charset),
        ('html_head', html_head),
        ('frameset', frameset),
        ('hyperlinks', hyperlinks),
        ('generator', generator),
        ('load_favicons', load_favicons),
        ('load_feeds', load_feeds),
        ('load_in_browser', load_in_browser),
    ]

    results = {}

    # TODO:
    # Set screenshot_bucket_name and storage_credentials_path
    # based on flags.
    config = Config(urls=[input_url],
        user_agent='Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) ' +
                   'AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 ' +
                   'Safari/537.36 green-spider/0.2',
        screenshot_bucket_name='green-spider-screenshots.sendung.de',
        screenshot_datastore_kind='webscreenshot',
        storage_credentials_path='/secrets/screenshots-uploader.json',
        datastore_credentials_path='/secrets/datastore-writer.json')

    # Iterate over all checks.
    for check_name, check in check_modules:

        # checker is the individual test/assertion handler we instantiate
        # for each check step.
        checker = check.Checker(config=config,
                                previous_results=results)

        # Ensure that dependencies are met for the checker.
        dependencies = checker.depends_on_results()
        if dependencies != []:
            for dep in dependencies:
                if (dep not in results or results[dep] is None or results[dep] == {} or results[dep] == []):
                    logging.debug("Skipping check %s as dependency %s is not met" % (check_name, dep))
                    continue

        # Execute the checker's main function.
        result = checker.run()
        results[check_name] = result

        # Execute any cleanup/aftermath function (if given) for the checker.
        modified_results = checker.post_hook(result)
        if modified_results is not None:
            results[check_name] = modified_results

        # Update config for the next check(s) in the sequence.
        config = checker.config
        logging.debug("config after check %s: %r" % (check_name, config))
    
    return results