# some functions coming from gajim sources (thanks)

## Copyright (C) 2003-2008 Yann Leboulanger <asterix AT lagaule.org>
## Copyright (C) 2005-2006 Dimitur Kirov <dkirov AT gmail.com>
##                         Nikos Kouremenos <kourem AT gmail.com>
## Copyright (C) 2006 Alex Mauer <hawke AT hawkesnest.net>
## Copyright (C) 2006-2007 Travis Shirk <travis AT pobox.com>
## Copyright (C) 2006-2008 Jean-Marie Traissard <jim AT lapin.org>
## Copyright (C) 2007 Lukas Petrovicky <lukas AT petrovicky.net>
##                    James Newton <redshodan AT gmail.com>
##                    Julien Pivotto <roidelapluie AT gmail.com>
## Copyright (C) 2007-2008 Stephan Erb <steve-e AT h3c.de>
## Copyright (C) 2008 Brendan Taylor <whateley AT gmail.com>
##                    Jonathan Schleifer <js-gajim AT webkeks.org>
##

# Copyright 2010-2011, Florent Le Coz <louiz@louiz.org>

# This program 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 3 of the License.

# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

"""
various useful functions
"""

from datetime import datetime, timedelta
import base64
import os
import mimetypes
import hashlib
import subprocess
import curses
import time
import shlex

from config import config

ROOM_STATE_NONE = 11
ROOM_STATE_CURRENT = 10
ROOM_STATE_PRIVATE = 15
ROOM_STATE_MESSAGE = 12
ROOM_STATE_HL = 13

def get_base64_from_file(path):
    """
    Convert the content of a file to base64
    """
    if not os.path.isfile(path):
        return (None, None, "File does not exist")
    size = os.path.getsize(path)
    if size > 16384:
        return (None, None,"File is too big")
    fdes = open(path, 'rb')
    data = fdes.read()
    encoded = base64.encodestring(data)
    sha1 = hashlib.sha1(data).hexdigest()
    mime_type = mimetypes.guess_type(path)[0]
    return (encoded, mime_type, sha1)

def get_output_of_command(command):
    """
    Runs a command and returns its output
    """
    try:
        return subprocess.check_output(command.split()).decode('utf-8').split('\n')
    except subprocess.CalledProcessError:
        return None

def is_in_path(command, return_abs_path=False):
    """
    Return True if 'command' is found in one of the directories in the user's
    path. If 'return_abs_path' is True, return the absolute path of the first
    found command instead. Return False otherwise and on errors
    """
    for directory in os.getenv('PATH').split(os.pathsep):
        try:
            if command in os.listdir(directory):
                if return_abs_path:
                    return os.path.join(directory, command)
                else:
                    return True
        except OSError:
            # If the user has non directories in his path
            pass
    return False

DISTRO_INFO = {
        'Arch Linux': '/etc/arch-release',
        'Aurox Linux': '/etc/aurox-release',
        'Conectiva Linux': '/etc/conectiva-release',
        'CRUX': '/usr/bin/crux',
        'Debian GNU/Linux': '/etc/debian_version',
        'Fedora Linux': '/etc/fedora-release',
        'Gentoo Linux': '/etc/gentoo-release',
        'Linux from Scratch': '/etc/lfs-release',
        'Mandrake Linux': '/etc/mandrake-release',
        'Slackware Linux': '/etc/slackware-version',
        'Solaris/Sparc': '/etc/release',
        'Source Mage': '/etc/sourcemage_version',
        'SUSE Linux': '/etc/SuSE-release',
        'Sun JDS': '/etc/sun-release',
        'PLD Linux': '/etc/pld-release',
        'Yellow Dog Linux': '/etc/yellowdog-release',
        # many distros use the /etc/redhat-release for compatibility
        # so Redhat is the last
        'Redhat Linux': '/etc/redhat-release'
}

def get_os_info():
    """
    Returns a detailed and well formated string containing
    informations about the operating system
    """
    if os.name == 'posix':
        executable = 'lsb_release'
        params = ' --description --codename --release --short'
        full_path_to_executable = is_in_path(executable, return_abs_path = True)
        if full_path_to_executable:
            command = executable + params
            process = subprocess.Popen([command], shell=True,
                                       stdin=subprocess.PIPE,
                                       stdout=subprocess.PIPE,
                                       close_fds=True)
            process.wait()
            output = process.stdout.readline().decode('utf-8').strip()
            # some distros put n/a in places, so remove those
            output = output.replace('n/a', '').replace('N/A', '')
            return output

        # lsb_release executable not available, so parse files
        for distro_name in DISTRO_INFO:
            path_to_file = DISTRO_INFO[distro_name]
            if os.path.exists(path_to_file):
                if os.access(path_to_file, os.X_OK):
                    # the file is executable (f.e. CRUX)
                    # yes, then run it and get the first line of output.
                    text = get_output_of_command(path_to_file)[0]
                else:
                    fdes = open(path_to_file)
                    text = fdes.readline().strip() # get only first line
                    fdes.close()
                    if path_to_file.endswith('version'):
                        # sourcemage_version and slackware-version files
                        # have all the info we need (name and version of distro)
                        if not os.path.basename(path_to_file).startswith(
                        'sourcemage') or not\
                        os.path.basename(path_to_file).startswith('slackware'):
                            text = distro_name + ' ' + text
                    elif path_to_file.endswith('aurox-release') or \
                    path_to_file.endswith('arch-release'):
                        # file doesn't have version
                        text = distro_name
                    elif path_to_file.endswith('lfs-release'):
                        # file just has version
                        text = distro_name + ' ' + text
                os_info = text.replace('\n', '')
                return os_info

        # our last chance, ask uname and strip it
        uname_output = get_output_of_command('uname -sr')
        if uname_output is not None:
            os_info = uname_output[0] # only first line
            return os_info
    os_info = 'N/A'
    return os_info

def datetime_tuple(timestamp):
    """
    Convert timestamp using strptime and the format: %Y%m%dT%H:%M:%S

    Because of various datetime formats are used the following exceptions
    are handled:
            - Optional milliseconds appened to the string are removed
            - Optional Z (that means UTC) appened to the string are removed
            - XEP-082 datetime strings have all '-' cahrs removed to meet
              the above format.
    """
    timestamp = timestamp.split('.')[0]
    timestamp = timestamp.replace('-', '')
    try:
        ret = datetime.strptime(timestamp, '%Y%m%dT%H:%M:%SZ')
    except ValueError:      # Support the deprecated format, XEP 0091 :(
        ret = datetime.strptime(timestamp, '%Y%m%dT%H:%M:%S')
    # convert UTC to local time, with DST etc.
    dst = timedelta(seconds=time.altzone)
    ret -= dst
    return ret

def shell_split(st):
    sh = shlex.shlex(st, posix=True)
    sh.whitespace_split = True
    sh.quotes = '"'
    ret = list()
    try:
        w = sh.get_token()
        while w is not None:
            ret.append(w)
            w = sh.get_token()
        return ret
    except ValueError:
        return st.split(" ")

def curses_color_pair(color):
    if color < 0:
        return curses.color_pair(-color) | curses.A_BOLD
    return curses.color_pair(color)

def replace_key_with_bound(key):
    if config.has_option('bindings', key):
        return config.get(key, key, 'bindings')
    else:
        return key