# Copyright 2010-2011 Florent Le Coz <louiz@louiz.org>
#
# This file is part of Poezio.
#
# Poezio is free software: you can redistribute it and/or modify
# it under the terms of the zlib license. See the COPYING file.

"""
Various useful functions.
"""

from datetime import datetime, timedelta
from sleekxmpp import JID, InvalidJID
import base64
import os
import mimetypes
import hashlib
import subprocess
import time
import string
import shlex

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

    :param str path: The path of the file to convert.
    :return: A tuple of (encoded data, mime type, sha1 hash) if
        the file exists and does not exceeds the upper size limit of 16384.
    :return: (None, None, error message) if it fails
    :rtype: :py:class:`tuple`

    """
    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.

    :param str command: The command to run.
    :return: The output or None
    :rtype: :py:class:`str`
    """
    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):
    """
    Check if *command* is in the $PATH or not.

    :param str command: The command to be checked.
    :param bool return_abs_path: Return the absolute path of the command instead
        of True if the command is found.
    :return: True if the command is found, the command path if the command is found
        and *return_abs_path* is True, otherwise False.

    """
    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

    :rtype: str
    """
    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, encoding='utf-8')
                    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 a timestamp using strptime and the format: %Y%m%dT%H:%M:%S.

    Because 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 '-' chars removed to meet the above format.

    :param str timestamp: The string containing the formatted date.
    :return: The date.
    :rtype: :py:class:`datetime.datetime`

    >>> common.datetime_tuple('20130226T06:23:12')
    datetime.datetime(2013, 2, 26, 8, 23, 12)
    """
    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 find_delayed_tag(message):
    """
    Check if a message is delayed or not.

    :param sleekxmpp.Message message: The message to check.
    :return: A tuple containing (True, the datetime) or (False, None)
    :rtype: :py:class:`tuple`
    """

    delay_tag = message.find('{urn:xmpp:delay}delay')
    if delay_tag is not None:
        delayed = True
        date = datetime_tuple(delay_tag.attrib['stamp'])
    else:
        # We support the OLD and deprecated XEP: http://xmpp.org/extensions/xep-0091.html
        # But it sucks, please, Jabber servers, don't do this :(
        delay_tag = message.find('{jabber:x:delay}x')
        if delay_tag is not None:
            delayed = True
            date = datetime_tuple(delay_tag.attrib['stamp'])
        else:
            delayed = False
            date = None
    return (delayed, date)

def shell_split(st):
    """
    Split a string correctly according to the quotes
    around the elements.

    :param str st: The string to split.
    :return: A list of the different of the string.
    :rtype: :py:class:`list`

    >>> shell_split('"sdf 1" "toto 2"')
    ['sdf 1', 'toto 2']
    """
    sh = shlex.shlex(st, posix=True)
    sh.commenters = ''
    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 parse_str_to_secs(duration=''):
    """
    Parse a string of with a number of d, h, m, s.

    :param str duration: The formatted string.
    :return: The number of seconds represented by the string
    :rtype: :py:class:`int`

    >>> parse_str_to_secs("1d3m1h")
    90180
    """
    values = {'s': 1, 'm': 60, 'h': 3600, 'd': 86400}
    result = 0
    tmp = '0'
    for char in duration:
        if char in string.digits:
            tmp += char
        elif char in values:
            tmp_i = int(tmp)
            result += tmp_i * values[char]
            tmp = '0'
        else:
            return 0
    if tmp != '0':
        result += int(tmp)
    return result

def parse_secs_to_str(duration=0):
    """
    Do the reverse operation of :py:func:`parse_str_to_secs`.

    Parse a number of seconds to a human-readable string.
    The string has the form XdXhXmXs. 0 units are removed.

    :param int duration: The duration, in seconds.
    :return: A formatted string containing the duration.
    :rtype: :py:class:`str`

    >>> parse_secs_to_str(3601)
    1h1s
    """
    secs, mins, hours, days = 0, 0, 0, 0
    result = ''
    secs = duration % 60
    mins = (duration % 3600) // 60
    hours = (duration % 86400) // 3600
    days = duration // 86400

    result += '%sd' % days if days else ''
    result += '%sh' % hours if hours else ''
    result += '%sm' % mins if mins else ''
    result += '%ss' % secs if secs else ''
    if not result:
        result = '0s'
    return result

def format_tune_string(infos):
    """
    Contruct a string from a dict created from an "User tune" event.

    :param dict infos: The informations
    :return: The formatted string
    :rtype: :py:class:`str`
    """
    elems = []
    track = infos.get('track')
    if track:
        elems.append(track)
    title = infos.get('title')
    if title:
        elems.append(title)
    else:
        elems.append('Unknown title')
    elems.append('-')
    artist = infos.get('artist')
    if artist:
        elems.append(artist)
    else:
        elems.append('Unknown artist')

    rating = infos.get('rating')
    if rating:
        elems.append('[ ' + rating + '/10' + ' ]')
    length = infos.get('length')
    if length:
        length = int(length)
        secs = length % 60
        mins = length // 60
        secs = str(secs).zfill(2)
        mins = str(mins).zfill(2)
        elems.append('[' + mins + ':' + secs + ']')
    return ' '.join(elems)

def format_gaming_string(infos):
    """
    Construct a string from a dict containing the "user gaming"
    informations.
    (for now, only use address and name)

    :param dict infos: The informations
    :returns: The formatted string
    :rtype: :py:class:`str`
    """
    name = infos.get('name')
    if not name:
        return ''

    server_address = infos.get('server_address')
    if server_address:
        return '%s on %s' % (name, server_address)
    return name

def safeJID(*args, **kwargs):
    """
    Construct a :py:class:`sleekxmpp.JID` object from a string.

    Used to avoid tracebacks during is stringprep fails
    (fall back to a JID with an empty string).
    """
    try:
        return JID(*args, **kwargs)
    except InvalidJID:
        return JID('')