# -*- coding: utf-8 -*-
"""
    rhodecode.lib.utils
    ~~~~~~~~~~~~~~~~~~~

    Some simple helper functions

    :created_on: Jan 5, 2011
    :author: marcink
    :copyright: (C) 2011-2012 Marcin Kuzminski <marcin@python-works.com>
    :license: GPLv3, see COPYING for more details.
"""
# 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, either version 3 of the License, or
# (at your option) any later version.
#
# 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/>.

import re
from datetime import datetime
from pylons.i18n.translation import _, ungettext
from rhodecode.lib.vcs.utils.lazy import LazyProperty


def __get_lem():
    """
    Get language extension map based on what's inside pygments lexers
    """
    from pygments import lexers
    from string import lower
    from collections import defaultdict

    d = defaultdict(lambda: [])

    def __clean(s):
        s = s.lstrip('*')
        s = s.lstrip('.')

        if s.find('[') != -1:
            exts = []
            start, stop = s.find('['), s.find(']')

            for suffix in s[start + 1:stop]:
                exts.append(s[:s.find('[')] + suffix)
            return map(lower, exts)
        else:
            return map(lower, [s])

    for lx, t in sorted(lexers.LEXERS.items()):
        m = map(__clean, t[-2])
        if m:
            m = reduce(lambda x, y: x + y, m)
            for ext in m:
                desc = lx.replace('Lexer', '')
                d[ext].append(desc)

    return dict(d)

def str2bool(_str):
    """
    returs True/False value from given string, it tries to translate the
    string into boolean

    :param _str: string value to translate into boolean
    :rtype: boolean
    :returns: boolean from given string
    """
    if _str is None:
        return False
    if _str in (True, False):
        return _str
    _str = str(_str).strip().lower()
    return _str in ('t', 'true', 'y', 'yes', 'on', '1')


def convert_line_endings(line, mode):
    """
    Converts a given line  "line end" accordingly to given mode

    Available modes are::
        0 - Unix
        1 - Mac
        2 - DOS

    :param line: given line to convert
    :param mode: mode to convert to
    :rtype: str
    :return: converted line according to mode
    """
    from string import replace

    if mode == 0:
            line = replace(line, '\r\n', '\n')
            line = replace(line, '\r', '\n')
    elif mode == 1:
            line = replace(line, '\r\n', '\r')
            line = replace(line, '\n', '\r')
    elif mode == 2:
            line = re.sub("\r(?!\n)|(?<!\r)\n", "\r\n", line)
    return line


def detect_mode(line, default):
    """
    Detects line break for given line, if line break couldn't be found
    given default value is returned

    :param line: str line
    :param default: default
    :rtype: int
    :return: value of line end on of 0 - Unix, 1 - Mac, 2 - DOS
    """
    if line.endswith('\r\n'):
        return 2
    elif line.endswith('\n'):
        return 0
    elif line.endswith('\r'):
        return 1
    else:
        return default


def generate_api_key(username, salt=None):
    """
    Generates unique API key for given username, if salt is not given
    it'll be generated from some random string

    :param username: username as string
    :param salt: salt to hash generate KEY
    :rtype: str
    :returns: sha1 hash from username+salt
    """
    from tempfile import _RandomNameSequence
    import hashlib

    if salt is None:
        salt = _RandomNameSequence().next()

    return hashlib.sha1(username + salt).hexdigest()


def safe_unicode(str_, from_encoding=None):
    """
    safe unicode function. Does few trick to turn str_ into unicode

    In case of UnicodeDecode error we try to return it with encoding detected
    by chardet library if it fails fallback to unicode with errors replaced

    :param str_: string to decode
    :rtype: unicode
    :returns: unicode object
    """
    if isinstance(str_, unicode):
        return str_

    if not from_encoding:
        import rhodecode
        DEFAULT_ENCODING = rhodecode.CONFIG.get('default_encoding','utf8')
        from_encoding = DEFAULT_ENCODING

    try:
        return unicode(str_)
    except UnicodeDecodeError:
        pass

    try:
        return unicode(str_, from_encoding)
    except UnicodeDecodeError:
        pass

    try:
        import chardet
        encoding = chardet.detect(str_)['encoding']
        if encoding is None:
            raise Exception()
        return str_.decode(encoding)
    except (ImportError, UnicodeDecodeError, Exception):
        return unicode(str_, from_encoding, 'replace')


def safe_str(unicode_, to_encoding=None):
    """
    safe str function. Does few trick to turn unicode_ into string

    In case of UnicodeEncodeError we try to return it with encoding detected
    by chardet library if it fails fallback to string with errors replaced

    :param unicode_: unicode to encode
    :rtype: str
    :returns: str object
    """

    # if it's not basestr cast to str
    if not isinstance(unicode_, basestring):
        return str(unicode_)

    if isinstance(unicode_, str):
        return unicode_

    if not to_encoding:
        import rhodecode
        DEFAULT_ENCODING = rhodecode.CONFIG.get('default_encoding','utf8')
        to_encoding = DEFAULT_ENCODING

    try:
        return unicode_.encode(to_encoding)
    except UnicodeEncodeError:
        pass

    try:
        import chardet
        encoding = chardet.detect(unicode_)['encoding']
        if encoding is None:
            raise UnicodeEncodeError()

        return unicode_.encode(encoding)
    except (ImportError, UnicodeEncodeError):
        return unicode_.encode(to_encoding, 'replace')

    return safe_str


def engine_from_config(configuration, prefix='sqlalchemy.', **kwargs):
    """
    Custom engine_from_config functions that makes sure we use NullPool for
    file based sqlite databases. This prevents errors on sqlite. This only
    applies to sqlalchemy versions < 0.7.0

    """
    import sqlalchemy
    from sqlalchemy import engine_from_config as efc
    import logging

    if int(sqlalchemy.__version__.split('.')[1]) < 7:

        # This solution should work for sqlalchemy < 0.7.0, and should use
        # proxy=TimerProxy() for execution time profiling

        from sqlalchemy.pool import NullPool
        url = configuration[prefix + 'url']

        if url.startswith('sqlite'):
            kwargs.update({'poolclass': NullPool})
        return efc(configuration, prefix, **kwargs)
    else:
        import time
        from sqlalchemy import event
        from sqlalchemy.engine import Engine

        log = logging.getLogger('sqlalchemy.engine')
        BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = xrange(30, 38)
        engine = efc(configuration, prefix, **kwargs)

        def color_sql(sql):
            COLOR_SEQ = "\033[1;%dm"
            COLOR_SQL = YELLOW
            normal = '\x1b[0m'
            return ''.join([COLOR_SEQ % COLOR_SQL, sql, normal])

        if configuration['debug']:
            #attach events only for debug configuration

            def before_cursor_execute(conn, cursor, statement,
                                    parameters, context, executemany):
                context._query_start_time = time.time()
                log.info(color_sql(">>>>> STARTING QUERY >>>>>"))


            def after_cursor_execute(conn, cursor, statement,
                                    parameters, context, executemany):
                total = time.time() - context._query_start_time
                log.info(color_sql("<<<<< TOTAL TIME: %f <<<<<" % total))

            event.listen(engine, "before_cursor_execute",
                         before_cursor_execute)
            event.listen(engine, "after_cursor_execute",
                         after_cursor_execute)

    return engine


def age(prevdate):
    """
    turns a datetime into an age string.

    :param prevdate: datetime object
    :rtype: unicode
    :returns: unicode words describing age
    """

    order = ['year', 'month', 'day', 'hour', 'minute', 'second']
    deltas = {}

    # Get date parts deltas
    now = datetime.now()
    for part in order:
        deltas[part] = getattr(now, part) - getattr(prevdate, part)

    # Fix negative offsets (there is 1 second between 10:59:59 and 11:00:00,
    # not 1 hour, -59 minutes and -59 seconds)

    for num, length in [(5, 60), (4, 60), (3, 24)]:  # seconds, minutes, hours
        part = order[num]
        carry_part = order[num - 1]

        if deltas[part] < 0:
            deltas[part] += length
            deltas[carry_part] -= 1

    # Same thing for days except that the increment depends on the (variable)
    # number of days in the month
    month_lengths = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    if deltas['day'] < 0:
        if prevdate.month == 2 and (prevdate.year % 4 == 0 and
            (prevdate.year % 100 != 0 or prevdate.year % 400 == 0)):
            deltas['day'] += 29
        else:
            deltas['day'] += month_lengths[prevdate.month - 1]

        deltas['month'] -= 1

    if deltas['month'] < 0:
        deltas['month'] += 12
        deltas['year'] -= 1

    # Format the result
    fmt_funcs = {
        'year': lambda d: ungettext(u'%d year', '%d years', d) % d,
        'month': lambda d: ungettext(u'%d month', '%d months', d) % d,
        'day': lambda d: ungettext(u'%d day', '%d days', d) % d,
        'hour': lambda d: ungettext(u'%d hour', '%d hours', d) % d,
        'minute': lambda d: ungettext(u'%d minute', '%d minutes', d) % d,
        'second': lambda d: ungettext(u'%d second', '%d seconds', d) % d,
    }

    for i, part in enumerate(order):
        value = deltas[part]
        if value == 0:
            continue

        if i < 5:
            sub_part = order[i + 1]
            sub_value = deltas[sub_part]
        else:
            sub_value = 0

        if sub_value == 0:
            return _(u'%s ago') % fmt_funcs[part](value)

        return _(u'%s and %s ago') % (fmt_funcs[part](value),
            fmt_funcs[sub_part](sub_value))

    return _(u'just now')


def uri_filter(uri):
    """
    Removes user:password from given url string

    :param uri:
    :rtype: unicode
    :returns: filtered list of strings
    """
    if not uri:
        return ''

    proto = ''

    for pat in ('https://', 'http://'):
        if uri.startswith(pat):
            uri = uri[len(pat):]
            proto = pat
            break

    # remove passwords and username
    uri = uri[uri.find('@') + 1:]

    # get the port
    cred_pos = uri.find(':')
    if cred_pos == -1:
        host, port = uri, None
    else:
        host, port = uri[:cred_pos], uri[cred_pos + 1:]

    return filter(None, [proto, host, port])


def credentials_filter(uri):
    """
    Returns a url with removed credentials

    :param uri:
    """

    uri = uri_filter(uri)
    #check if we have port
    if len(uri) > 2 and uri[2]:
        uri[2] = ':' + uri[2]

    return ''.join(uri)


def get_changeset_safe(repo, rev):
    """
    Safe version of get_changeset if this changeset doesn't exists for a
    repo it returns a Dummy one instead

    :param repo:
    :param rev:
    """
    from rhodecode.lib.vcs.backends.base import BaseRepository
    from rhodecode.lib.vcs.exceptions import RepositoryError
    if not isinstance(repo, BaseRepository):
        raise Exception('You must pass an Repository '
                        'object as first argument got %s', type(repo))

    try:
        cs = repo.get_changeset(rev)
    except RepositoryError:
        from rhodecode.lib.utils import EmptyChangeset
        cs = EmptyChangeset(requested_revision=rev)
    return cs


MENTIONS_REGEX = r'(?:^@|\s@)([a-zA-Z0-9]{1}[a-zA-Z0-9\-\_\.]+)(?:\s{1})'


def extract_mentioned_users(s):
    """
    Returns unique usernames from given string s that have @mention

    :param s: string to get mentions
    """
    usrs = set()
    for username in re.findall(MENTIONS_REGEX, s):
        usrs.add(username)

    return sorted(list(usrs), key=lambda k: k.lower())