stov/lib_stov/configuration.py

#   This file is part of stov, written by Helmut Pozimski 2012-2015.
#
#   stov is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, version 2 of the License.
#
#   stov is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with stov.  If not, see <http://www.gnu.org/licenses/>.


# -*- coding: utf8 -*-

"""This file takes care of reading, storing and updating the configuration of
stov, the configuration file is expected to be in json format and reside in
~/.stov/stov.json.
"""

import os
import subprocess
import json

from lib_stov import stov_exceptions


class Conf(object):
    """This class is used to create the object which is responsible for all
    configuration operations.
    """
    def __init__(self):
        """Constructor

        Constructs the conf object with some reasonable default values which
        should work on most systems, existence of a local mail server is
        assumed.

        """
        self.values = {
            "database": "stov.sqlite",
            "downloaddir": str(os.environ['HOME']) + "/stov",
            "maxvideos": "25",
            "mailhost": "localhost",
            "mailto": "root",
            "mailfrom": "stov@localhost",
            "smtpport": "25",
            "auth_needed": "no",
            "user_name": "",
            "password": "",
            "youtube-dl": "",
            "notify": "yes",
            "config_version": "9",
            "db_version": "3",
            "videocodec": "mp4",
            "maxresolution": "1080p",
            "maxfails": 50,
            "check_title": "no"
        }

        self.__explanations = {
            "database": _("the name of your database file"),
            "downloaddir": _("the directory where downloaded videos are "
                             "saved"),
            "maxvideos": _("the maximum number of videos to retrieve for each "
                           "subscription"),
            "mailhost": _("the host name of your mail server"),
            "mailto": _("the address used for notifications"),
            "mailfrom": _("the sender address of notification e-mails"),
            "smtpport": _("the port to use on your mail server"),
            "auth_needed": _("if your mail server requires authentication"),
            "user_name": _("the user name used to authenticate to your mail "
                           "server"),
            "password": _("the password used to authenticate to your mail "
                          "server"),
            "youtube-dl": _("the path to your youtube-dl installation"),
            "notify": _("if you want to be notified via e-mail about new "
                        "videos"),
            "videocodec": _("which video codec you prefer (h264, webm or "
                            "flv)"),
            "maxresolution": _("which resolution you prefer (360p, 480p, 720p "
                               "or 1080p)"),
            "check_title": _("if you want to compare the title of a video "
                             "with the subscription search string")
        }
        self.dbpath = str(os.environ['HOME']) + "/.stov/" + \
            self.values["database"]
        self.outputlevel = "default"

    def write_config(self):
        """Writes the configuration from the dictionary into the configuration
        file for stov. The configuration is written into the home directory of
        the user by default.

        """
        try:
            configfile = open(str(os.environ['HOME']) +
                              "/.stov/stov.json", "w")
        except IOError:
            raise stov_exceptions.ConfigFileWriteErrorException()
        else:
            json.dump(self.values, configfile, indent=0)
            configfile.close()

    def initialize(self):
        """Creates the necessary directory for the stov configuration and
        calls the internal methods to create the database and the
        configuration file.

        """
        try:
            os.mkdir(str(os.environ['HOME']) + "/.stov", 0o750)
        except os.error:
            raise stov_exceptions.DirectoryCreationFailedException()
        else:
            process = subprocess.Popen(["which", "youtube-dl"],
                                       stdout=subprocess.PIPE)
            self.values["youtube-dl"] = process.communicate()[0].strip()
            self.write_config()

    def read_old_config(self):
        """Reads the existing plain text configuration file and places the
        values in the dictionary. Existing values (such as default values)
        are overwritten.

        """
        try:
            configfile = open(str(os.environ['HOME']) +
                              "/.stov/stov.config", "r")
        except IOError:
            raise stov_exceptions.ConfigFileReadErrorException()
        for lines in configfile:
            tmpline = lines.strip()
            tmplist = tmpline.split("=")
            self.values[tmplist[0].lower()] = tmplist[1]
        configfile.close()
        self.dbpath = str(os.environ['HOME']) + "/.stov/" + \
            self.values["database"]

    def read_config(self):
        """Reads the existing json configuration files and loads the values in
        the dictionary.
        """
        try:
            configfile = open(str(os.environ['HOME']) + "/.stov/stov.json",
                              "r")
        except IOError:
            raise stov_exceptions.ConfigFileReadErrorException()
        else:
            self.values.update(json.load(configfile))
            configfile.close()

    def check_config(self):
        """Checks if the configuration is up-to-date with the running
        stov version.

        """
        try:
            currentversion = int(self.values["config_version"])
        except ValueError:
            raise stov_exceptions.InvalidConfigurationVersionException()
        self.values["config_version"] = "0"
        self.read_config()
        if self.values["config_version"] == "0" \
                or int(self.values["config_version"]) < currentversion:
            self.values["config_version"] = str(currentversion)
            return False
        else:
            self.values["config_version"] = currentversion
            return True

    def update_config(self):
        """Update the configuration to the latest version"""
        versionbuffer = self.values["config_version"]
        self.read_config()
        self.values["config_version"] = versionbuffer
        self.write_config()

    def check_db(self):
        """Checks the database if it is up-to-date"""
        currentdbversion = int(self.values["db_version"])
        self.values["db_version"] = "0"
        self.read_config()
        if self.values["db_version"] == "0" or \
                int(self.values["db_version"]) <\
                int(currentdbversion):
            self.values["db_version"] = str(currentdbversion)
            return False
        else:
            self.values["db_version"] = str(currentdbversion)
            return True

    def get_youtube_parameter(self):
        """Determines which itag value results from codec and resolution
        settings and returns it

        """
        itag_value = 0
        if self.values["videocodec"] == "flv":
            if self.values["maxresolution"] == "240p":
                itag_value = 5
            elif self.values["maxresolution"] == "270p":
                itag_value = 6
            elif self.values["maxresolution"] == "360p":
                itag_value = 34
            elif self.values["maxresolution"] == "480p":
                itag_value = 35
        elif self.values["videocodec"] == "webm":
            if self.values["maxresolution"] == "360p":
                itag_value = 43
            elif self.values["maxresolution"] == "480p":
                itag_value = 44
            elif self.values["maxresolution"] == "720p":
                itag_value = 45
            elif self.values["maxresolution"] == "1080p":
                itag_value = 46
        elif self.values["videocodec"] == "mp4":
            if self.values["maxresolution"] == "360p":
                itag_value = 18
            elif self.values["maxresolution"] == "720p":
                itag_value = 22
            elif self.values["maxresolution"] == "1080p":
                itag_value = 37
            elif self.values["maxresolution"] == "3072p":
                itag_value = 38
        return itag_value

    def assist(self):
        """ Ask the user to set all required configuration parameters """

        print(_("This assistant will help you to perform the initial "
                "configuration of stov. \nThe default value will be "
                "displayed in brackets.\n"
                "Please specify now :\n"))
        for value in self.__explanations:
            print(self.__explanations[value] + " [" + self.values[value] +
                  "]:" +
                  " ")
            user_input = input()

            if user_input != "":
                self.values[value] = user_input
        self.dbpath = str(os.environ['HOME']) + "/.stov/" + \
            self.values["database"]

    def migrate_config(self):
        """Migrates the configuration from the old plain text config to
        the new and shiny json configuration file.
        """
        try:
            self.read_old_config()
            self.write_config()
        except stov_exceptions.ConfigFileReadErrorException:
            raise stov_exceptions.ConfigurationMigrationFailed()
        except stov_exceptions.ConfigFileWriteErrorException:
            raise stov_exceptions.ConfigurationMigrationFailed
        else:
            os.remove(str(os.environ['HOME']) + "/.stov/stov.config")