import os
import requests

from packaging.version import Version

from artemis.utils.constants import Constants, Messages
from artemis.utils.sql_utils import ArtemisDatabase
from artemis.utils.sys_utils import is_windows, is_linux, is_macos


class NetworkManager:
    """ Class that checks for DB or software updates
    """

    def __init__(self, parent):
        self._parent = parent
        self.sigid_db_path = Constants.DB_DIR / 'sigID' / Constants.SQL_NAME

        self.show_popup = False
        self.db_update = None
        self.art_update = None

        self.remote_db_url = None
        self.remote_db_hash = None
        self.remote_db_version = None
        self.remote_db_size = None

        self.remote_art_version = None

        self.check_updates()


    def check_updates(self):
        """ Checks if a new DB update is available.

            Args:
                popup (bool, optional): Suppress the "already up-to-date" message on startup.
                                        Defaults to False.
        """
        latest_json = self.fetch_remote_json(Constants.LATEST_VERSION_URL)
        if latest_json:
            local_db = self.load_local_db()
            remote_db = latest_json['sigID_DB']

            self.remote_db_version = remote_db['version']
            self.remote_db_url = remote_db['url']
            self.remote_db_hash = remote_db['sha256_hash']
            self.remote_db_size = remote_db['total_bytes']

            if is_windows():
                self.remote_art_version = latest_json['windows']['version']
            elif is_linux():
                self.remote_art_version = latest_json['linux']['version']
            elif is_macos():
                self.remote_art_version = latest_json['mac']['version']

            if Version(self.remote_art_version) > Version(Constants.APPLICATION_VERSION):
                self.art_update = True
            else:
                self.art_update = False         

            if self.art_update:
                self.show_popup_art_update()
            else:
                if local_db:
                    if self.remote_db_version > local_db.version:
                        self.show_popup_db_update()
                    elif self.show_popup:
                        self.show_popup_up_to_date()
                else:
                    self.show_popup_initial_db_download()


    def fetch_remote_json(self, url):
        """ Fetches the remote json from a url
        """
        try:
            response = requests.get(url)
            response.raise_for_status()
            return response.json()
        except requests.exceptions.RequestException as e:
            if self.show_popup:
                self._parent.dialog_popup(
                    Messages.DIALOG_TYPE_ERROR,
                    Messages.NO_CONNECTION,
                    Messages.NO_CONNECTION_MSG.format(e)
                )
            return None


    def load_local_db(self):
        """ Loads the local database if exists
        """
        if os.path.exists(self.sigid_db_path):
            local_db = ArtemisDatabase('sigID')
            local_db.load()
            return local_db
        return None


    def show_popup_db_update(self):
        """Prompts the user to download the updated version of the database."""
        self._parent.dialog_download_db(
            Messages.DIALOG_TYPE_WARN,
            Messages.DB_NEW_VER,
            Messages.DB_NEW_VER_MSG.format(self.remote_db_version)
        )


    def show_popup_art_update(self):
        """Prompts the user to download the updated version of the database."""
        self._parent.dialog_download_artemis(
            Messages.DIALOG_TYPE_WARN,
            Messages.ART_NEW_VER,
            Messages.ART_NEW_VER_MSG.format(self.remote_art_version)
        )


    def show_popup_up_to_date(self):
        """Notifies the user that the database is up to date."""
        self._parent.dialog_popup(
            Messages.DIALOG_TYPE_INFO,
            Messages.UP_TO_DATE,
            Messages.UP_TO_DATE_MSG
        )


    def show_popup_initial_db_download(self):
        """Prompts the user to download the database for the first time."""
        self._parent.dialog_download_db(
            Messages.DIALOG_TYPE_QUEST,
            Messages.NO_DB_DETECTED,
            Messages.NO_DB_DETECTED_MSG
        )