# -*- coding: UTF-8 -*-

# Copyright (c) 2010 - 2012, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.common

    ~~~~~~~~~~~~~~~~~~~~~~~~~

    Some common functions

"""

import locale

import os

import re

import stat

from VirtualMailManager import ENCODING

from VirtualMailManager.constants import INVALID_MAIL_LOCATION, \

     NOT_EXECUTABLE, NO_SUCH_BINARY, TYPE_ACCOUNT, TYPE_ALIAS, TYPE_RELOCATED

from VirtualMailManager.errors import VMMError

VERSION_RE = re.compile(r'^(\d+)\.(\d+)\.(?:(\d+)|(alpha|beta|rc)(\d+))$')

_version_level = dict(alpha=0xA, beta=0xB, rc=0xC)

_version_cache = {}

_ = lambda msg: msg

def expand_path(path):

    """Expands paths, starting with ``.`` or ``~``, to an absolute path."""

    if path.startswith('.'):

        return os.path.abspath(path)

    if path.startswith('~'):

        return os.path.expanduser(path)

    return path

def get_unicode(string):

    """Converts `string` to `unicode`, if necessary."""

    if isinstance(string, str):

        return string

    return str(string, ENCODING, 'replace')

def lisdir(path):

    """Checks if `path` is a directory.  Doesn't follow symbolic links.

    Returns bool.

    """

    try:

        lstat = os.lstat(path)

    except OSError:

        return False

    return stat.S_ISDIR(lstat.st_mode)

def exec_ok(binary):

    """Checks if the `binary` exists and if it is executable.

    Throws a `VMMError` if the `binary` isn't a file or is not

    executable.

    """

    binary = expand_path(binary)

    if not os.path.isfile(binary):

        raise VMMError(_("No such file: '%s'") % get_unicode(binary),

                       NO_SUCH_BINARY)

    if not os.access(binary, os.X_OK):

        raise VMMError(_("File is not executable: '%s'") %

                       get_unicode(binary), NOT_EXECUTABLE)

    return binary

def human_size(size):

    """Converts the `size` in bytes in human readable format."""

    if not isinstance(size, int):

        try:

            size = int(size)

        except ValueError:

            raise TypeError("'size' must be a positive integer.")

    if size < 0:

        raise ValueError("'size' must be a positive integer.")

    if size < 1024:

        return str(size)

    # TP: abbreviations of gibibyte, tebibyte kibibyte and mebibyte

    prefix_multiply = ((_('TiB'), 1 << 40), (_('GiB'), 1 << 30),

                       (_('MiB'), 1 << 20), (_('KiB'), 1 << 10))

    for prefix, multiply in prefix_multiply:

        if size >= multiply:

            # TP: e.g.: '%(size)s %(prefix)s' -> '118.30 MiB'

            return _('%(size)s %(prefix)s') % {

                    'size': locale.format('%.2f', float(size) / multiply,

                                          True),

                    'prefix': prefix}

def size_in_bytes(size):

    """Converts the string `size` to an integer (size in bytes).

    The string `size` can be suffixed with *b* (bytes), *k* (kilobytes),

    *M* (megabytes) or *G* (gigabytes).

    """

    if not isinstance(size, str) or not size:

        raise TypeError('size must be a non empty string.')

    if size[-1].upper() in ('B', 'K', 'M', 'G'):

        try:

            num = int(size[:-1])

        except ValueError:

            raise ValueError('Not a valid integer value: %r' % size[:-1])

        unit = size[-1].upper()

        if unit == 'B':

            return num

        elif unit == 'K':

            return num << 10

        elif unit == 'M':

            return num << 20

        else:

            return num << 30

    else:

        try:

            num = int(size)

        except ValueError:

            raise ValueError('Not a valid size value: %r' % size)

        return num

def validate_transport(transport, maillocation):

    """Checks if the `transport` is usable for the given `maillocation`.

    Throws a `VMMError` if the chosen `transport` is unable to write

    messages in the `maillocation`'s mailbox format.

    Arguments:

    `transport` : VirtualMailManager.transport.Transport

      a Transport object

    `maillocation` : VirtualMailManager.maillocation.MailLocation

      a MailLocation object

    """

    if transport.transport in ('virtual', 'virtual:') and \

      not maillocation.postfix:

        raise VMMError(_("Invalid transport '%(transport)s' for mailbox "

                         "format '%(mbfmt)s'.") %

                       {'transport': transport.transport,

                        'mbfmt': maillocation.mbformat}, INVALID_MAIL_LOCATION)

def version_hex(version_string):

    """Converts a Dovecot version, e.g.: '1.2.3' or '2.0.beta4', to an int.

    Raises a `ValueError` if the *version_string* has the wrong™ format.

    version_hex('1.2.3') -> 270548736

    hex(version_hex('1.2.3')) -> '0x10203f00'

    """

    global _version_cache

    if version_string in _version_cache:

        return _version_cache[version_string]

    version = 0

    version_mo = VERSION_RE.match(version_string)

    if not version_mo:

        raise ValueError('Invalid version string: %r' % version_string)

    major, minor, patch, level, serial = version_mo.groups()

    major = int(major)

    minor = int(minor)

    if patch:

        patch = int(patch)

    if serial:

        serial = int(serial)

    if major > 0xFF or minor > 0xFF or \

      patch and patch > 0xFF or serial and serial > 0xFF:

        raise ValueError('Invalid version string: %r' % version_string)

    version += major << 28

    version += minor << 20

    if patch:

        version += patch << 12

    version += _version_level.get(level, 0xF) << 8

    if serial:

        version += serial

    _version_cache[version_string] = version

    return version

def version_str(version):

    """Converts a Dovecot version previously converted with version_hex back to

    a string.

    Raises a `TypeError` if *version* is not an integer.

    Raises a `ValueError` if *version* is an incorrect int version.

    """

    global _version_cache

    if version in _version_cache:

        return _version_cache[version]

    if not isinstance(version, int):

        raise TypeError('Argument is not a integer: %r', version)

    major = (version >> 28) & 0xFF

    minor = (version >> 20) & 0xFF

    patch = (version >> 12) & 0xFF

    level = (version >> 8) & 0x0F

    serial = version & 0xFF

    levels = dict(list(zip(list(_version_level.values()),

                  list(_version_level.keys()))))

    if level == 0xF and not serial:

        version_string = '%u.%u.%u' % (major, minor, patch)

    elif level in levels and not patch:

        version_string = '%u.%u.%s%u' % (major, minor, levels[level], serial)

    else:

        raise ValueError('Invalid version: %r' % hex(version))

    _version_cache[version] = version_string

    return version_string

def format_domain_default(domaindata):

    """Format info output when the value displayed is the domain default."""

    # TP: [domain default] indicates that a user's setting is the same as

    # configured in the user's domain.

    # e.g.: [  0.84%] 42/5,000 [domain default]

    return _('%s [domain default]') % domaindata

def search_addresses(dbh, typelimit=None, lpattern=None, llike=False,

                     dpattern=None, dlike=False):

    """'Search' for addresses by *pattern* in the database.

    The search is limited by *typelimit*, a bitfield with values TYPE_ACCOUNT,

    TYPE_ALIAS, TYPE_RELOCATED, or a bitwise OR thereof. If no limit is

    specified, all types will be searched.

    *lpattern* may be a local part or a partial local part - starting and/or

    ending with a '%' sign.  When the *lpattern* starts or ends with a '%' sign

    *llike* has to be `True` to perform a wildcard search. To retrieve all

    available addresses use the arguments' default values.

    *dpattern* and *dlike* behave analogously for the domain part of an

    address, allowing for separate pattern matching: testuser%@example.%

    The return value of this function is a tuple. The first element is a list

    of domain IDs sorted alphabetically by the corresponding domain names. The

    second element is a dictionary indexed by domain ID, holding lists to

    associated addresses. Each address is itself actually a tuple of address,

    type, and boolean indicating whether the address stems from an alias

    domain.

    """

    if typelimit is None:

            typelimit = TYPE_ACCOUNT | TYPE_ALIAS | TYPE_RELOCATED

    queries = []

    if typelimit & TYPE_ACCOUNT:

        queries.append('SELECT gid, local_part, %d AS type FROM users'

                       % TYPE_ACCOUNT)

    if typelimit & TYPE_ALIAS:

        queries.append('SELECT DISTINCT gid, address as local_part, '

                       '%d AS type FROM alias' % TYPE_ALIAS)

    if typelimit & TYPE_RELOCATED:

        queries.append('SELECT gid, address as local_part, %d AS type '

                       'FROM relocated' % TYPE_RELOCATED)

    sql = "SELECT gid, local_part || '@' || domainname AS address, "

    sql += 'type, NOT is_primary AS from_aliasdomain FROM ('

    sql += ' UNION '.join(queries)

    sql += ') a JOIN domain_name USING (gid)'

    nextkw = 'WHERE'

    sqlargs = []

    for like, field, pattern in ((dlike, 'domainname', dpattern),

                                 (llike, 'local_part', lpattern)):

        if like:

            match = 'LIKE'

        else:

            if not pattern:

                continue

            match = '='

        sql += ' %s %s %s %%s' % (nextkw, field, match)

        sqlargs.append(pattern)

        nextkw = 'AND'

    sql += ' ORDER BY domainname, local_part'

    dbc = dbh.cursor()

    dbc.execute(sql, sqlargs)

    result = dbc.fetchall()

    dbc.close()

    gids = []

    daddrs = {}

    for gid, address, addrtype, aliasdomain in result:

        if gid not in daddrs:

            gids.append(gid)

            daddrs[gid] = []

        daddrs[gid].append((address, addrtype, aliasdomain))

    return gids, daddrs

del _