from datetime import datetime
from django.conf import settings
from django.core.cache import get_cache
from rosetta.conf import settings as rosetta_settings
import django
import os

try:
    from django.utils import timezone
except:
    timezone = None


try:
    set
except NameError:
    from sets import Set as set   # Python 2.3 fallback

cache = get_cache(rosetta_settings.ROSETTA_CACHE_NAME)


def timestamp_with_timezone(dt=None):
    """
    Return a timestamp with a timezone for the configured locale.  If all else
    fails, consider localtime to be UTC.
    """
    dt = dt or datetime.now()
    if timezone is None:
        return dt.strftime('%Y-%m-%d %H:%M%z')
    if not dt.tzinfo:
        tz = timezone.get_current_timezone()
        if not tz:
            tz = timezone.utc
        dt = dt.replace(tzinfo=timezone.get_current_timezone())
    return dt.strftime("%Y-%m-%d %H:%M%z")


def find_pos(lang, project_apps=True, django_apps=False, third_party_apps=False):
    """
    scans a couple possible repositories of gettext catalogs for the given
    language code

    """

    paths = []

    # project/locale
    parts = settings.SETTINGS_MODULE.split('.')
    project = __import__(parts[0], {}, {}, [])
    abs_project_path = os.path.normpath(os.path.abspath(os.path.dirname(project.__file__)))
    if project_apps:
        if os.path.exists(os.path.abspath(os.path.join(os.path.dirname(project.__file__), 'locale'))):
            paths.append(os.path.abspath(os.path.join(os.path.dirname(project.__file__), 'locale')))
        if os.path.exists(os.path.abspath(os.path.join(os.path.dirname(project.__file__), '..', 'locale'))):
            paths.append(os.path.abspath(os.path.join(os.path.dirname(project.__file__), '..', 'locale')))

    # django/locale
    if django_apps:
        django_paths = cache.get('rosetta_django_paths')
        if django_paths is None:
            django_paths = []
            for root, dirnames, filename in os.walk(os.path.abspath(os.path.dirname(django.__file__))):
                if 'locale' in dirnames:
                    django_paths.append(os.path.join(root, 'locale'))
                    continue
            cache.set('rosetta_django_paths', django_paths, 60 * 60)
        paths = paths + django_paths
    # settings
    for localepath in settings.LOCALE_PATHS:
        if os.path.isdir(localepath):
            paths.append(localepath)

    # project/app/locale
    for appname in settings.INSTALLED_APPS:
        if rosetta_settings.EXCLUDED_APPLICATIONS and appname in rosetta_settings.EXCLUDED_APPLICATIONS:
            continue
        p = appname.rfind('.')
        if p >= 0:
            app = getattr(__import__(appname[:p], {}, {}, [str(appname[p + 1:])]), appname[p + 1:])
        else:
            app = __import__(appname, {}, {}, [])

        apppath = os.path.normpath(os.path.abspath(os.path.join(os.path.dirname(app.__file__), 'locale')))

        # django apps
        if 'contrib' in apppath and 'django' in apppath and not django_apps:
            continue

        # third party external
        if not third_party_apps and abs_project_path not in apppath:
            continue

        # local apps
        if not project_apps and abs_project_path in apppath:
            continue

        if os.path.isdir(apppath):
            paths.append(apppath)

    ret = set()
    langs = [lang, ]
    if u'-' in lang:
        _l, _c = map(lambda x: x.lower(), lang.split(u'-'))
        langs += [u'%s_%s' % (_l, _c), u'%s_%s' % (_l, _c.upper()), ]
    elif u'_' in lang:
        _l, _c = map(lambda x: x.lower(), lang.split(u'_'))
        langs += [u'%s-%s' % (_l, _c), u'%s-%s' % (_l, _c.upper()), ]

    paths = map(os.path.normpath, paths)
    paths = list(set(paths))
    for path in paths:
        for lang_ in langs:
            dirname = os.path.join(path, lang_, 'LC_MESSAGES')
            #print dirname
            for fn in ('django.po', 'djangojs.po',):
                filename = os.path.join(dirname, fn)
                if os.path.isfile(filename):
                    ret.add(os.path.abspath(filename))
    return list(sorted(ret))


def pagination_range(first, last, current):
    r = []

    r.append(first)
    if first + 1 < last:
        r.append(first + 1)

    if current - 2 > first and current - 2 < last:
        r.append(current - 2)
    if current - 1 > first and current - 1 < last:
        r.append(current - 1)
    if current > first and current < last:
        r.append(current)
    if current + 1 < last and current + 1 > first:
        r.append(current + 1)
    if current + 2 < last and current + 2 > first:
        r.append(current + 2)

    if last - 1 > first:
        r.append(last - 1)
    r.append(last)

    r = list(set(r))
    r.sort()
    prev = 10000
    for e in r[:]:
        if prev + 1 < e:
            try:
                r.insert(r.index(e), '...')
            except ValueError:
                pass
        prev = e
    return r