# 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, 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 sys
import select
import errno
import time
import traceback

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

def debug(string):
    """
    Print a string in a file.
    Useful since debuging cannot be displayed on screen because it's
    a CLI software
    """
    fdes = open("/tmp/debug", 'a')
    fdes.write(string)
    fdes.close()

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:
        child_stdin, child_stdout = os.popen2(command)
    except ValueError:
        return None

    output = child_stdout.readlines()
    child_stdout.close()
    child_stdin.close()

    return output

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

def is_jid(jid):
    """
    Return True if this is a valid JID
    """
    if jid.find('@') != -1:
        return True
    return False

def jid_get_node(jid):
    """
    nick@server/resource -> nick
    """
    return jid.split('@', 1)[0]

def jid_get_domain(jid):
    """
    nick@server/resource -> server
    """
    return jid.split('@',1)[-1].split('/', 1)[0]

def jid_get_resource(fulljid):
    """
    nick@server/resource -> resource
    """
    if '/' in fulljid:
        return fulljid.split('/', 1)[-1]
    else:
        return ''

def jid_get_bare(fulljid):
    """
    nick@server/resource -> nick@server
    """
    return '%s@%s' % (jid_get_domain(fulljid), jid_get_node(fulljid))

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 temp_failure_retry(func, *args, **kwargs):
    """
    workaround for a temporary and specific failure
    """
    while True:
        try:
            return func(*args, **kwargs)
        except (os.error, IOError, select.error) as ex:
            if ex.errno == errno.EINTR:
                continue
            else:
                raise

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 = temp_failure_retry(process.stdout.readline).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