import os

import gettext as gettext_module

from django import http

from django.conf import settings

from django.utils import importlib

from django.utils.translation import check_for_language, activate, to_locale, get_language

from django.utils.text import javascript_quote

from django.utils.encoding import smart_unicode

from django.utils.formats import get_format_modules

def set_language(request):

    """

    Redirect to a given url while setting the chosen language in the

    session or cookie. The url and the language code need to be

    specified in the request parameters.

    Since this view changes how the user will see the rest of the site, it must

    only be accessed as a POST request. If called as a GET request, it will

    redirect to the page in the request (the 'next' parameter) without changing

    any state.

    """

    next = request.REQUEST.get('next', None)

    if not next:

        next = request.META.get('HTTP_REFERER', None)

    if not next:

        next = '/'

    response = http.HttpResponseRedirect(next)

    if request.method == 'POST':

        lang_code = request.POST.get('language', None)

        if lang_code and check_for_language(lang_code):

            if hasattr(request, 'session'):

                request.session['django_language'] = lang_code

            else:

                response.set_cookie(settings.LANGUAGE_COOKIE_NAME, lang_code)

    return response

def get_formats():

    """

    Returns all formats strings required for i18n to work

    """

    FORMAT_SETTINGS = (

        'DATE_FORMAT', 'DATETIME_FORMAT', 'TIME_FORMAT',

        'YEAR_MONTH_FORMAT', 'MONTH_DAY_FORMAT', 'SHORT_DATE_FORMAT',

        'SHORT_DATETIME_FORMAT', 'FIRST_DAY_OF_WEEK', 'DECIMAL_SEPARATOR',

        'THOUSAND_SEPARATOR', 'NUMBER_GROUPING',

        'DATE_INPUT_FORMATS', 'TIME_INPUT_FORMATS', 'DATETIME_INPUT_FORMATS'

    )

    result = {}

    for module in [settings] + get_format_modules(reverse=True):

        for attr in FORMAT_SETTINGS:

            try:

                result[attr] = getattr(module, attr)

            except AttributeError:

                pass

    src = []

    for k, v in result.items():

        if isinstance(v, (basestring, int)):

            src.append("formats['%s'] = '%s';\n" % (javascript_quote(k), javascript_quote(smart_unicode(v))))

        elif isinstance(v, (tuple, list)):

            v = [javascript_quote(smart_unicode(value)) for value in v]

            src.append("formats['%s'] = ['%s'];\n" % (javascript_quote(k), "', '".join(v)))

    return ''.join(src)

NullSource = """

/* gettext identity library */

function gettext(msgid) { return msgid; }

function ngettext(singular, plural, count) { return (count == 1) ? singular : plural; }

function gettext_noop(msgid) { return msgid; }

"""

LibHead = """

/* gettext library */

var catalog = new Array();

"""

LibFoot = """

function gettext(msgid) {

  var value = catalog[msgid];

  if (typeof(value) == 'undefined') {

    return msgid;

  } else {

    return (typeof(value) == 'string') ? value : value[0];

  }

}

function ngettext(singular, plural, count) {

  value = catalog[singular];

  if (typeof(value) == 'undefined') {

    return (count == 1) ? singular : plural;

  } else {

    return value[pluralidx(count)];

  }

}

function gettext_noop(msgid) { return msgid; }

"""

LibFormatHead = """

/* formatting library */

var formats = new Array();

"""

LibFormatFoot = """

function get_format(format_type) {

    var value = formats[format_type];

    if (typeof(value) == 'undefined') {

      return msgid;

    } else {

      return value;

    }

}

"""

SimplePlural = """

function pluralidx(count) { return (count == 1) ? 0 : 1; }

"""

InterPolate = r"""

function interpolate(fmt, obj, named) {

  if (named) {

    return fmt.replace(/%\(\w+\)s/g, function(match){return String(obj[match.slice(2,-2)])});

  } else {

    return fmt.replace(/%s/g, function(match){return String(obj.shift())});

  }

}

"""

PluralIdx = r"""

function pluralidx(n) {

  var v=%s;

  if (typeof(v) == 'boolean') {

    return v ? 1 : 0;

  } else {

    return v;

  }

}

"""

def null_javascript_catalog(request, domain=None, packages=None):

    """

    Returns "identity" versions of the JavaScript i18n functions -- i.e.,

    versions that don't actually do anything.

    """

    src = [NullSource, InterPolate, LibFormatHead, get_formats(), LibFormatFoot]

    return http.HttpResponse(''.join(src), 'text/javascript')

def javascript_catalog(request, domain='djangojs', packages=None):

    """

    Returns the selected language catalog as a javascript library.

    Receives the list of packages to check for translations in the

    packages parameter either from an infodict or as a +-delimited

    string from the request. Default is 'django.conf'.

    Additionally you can override the gettext domain for this view,

    but usually you don't want to do that, as JavaScript messages

    go to the djangojs domain. But this might be needed if you

    deliver your JavaScript source from Django templates.

    """

    if request.GET:

        if 'language' in request.GET:

            if check_for_language(request.GET['language']):

                activate(request.GET['language'])

    if packages is None:

        packages = ['django.conf']

    if isinstance(packages, basestring):

        packages = packages.split('+')

    packages = [p for p in packages if p == 'django.conf' or p in settings.INSTALLED_APPS]

    default_locale = to_locale(settings.LANGUAGE_CODE)

    locale = to_locale(get_language())

    t = {}

    paths = []

    en_catalog_missing = False

    # first load all english languages files for defaults

    for package in packages:

        p = importlib.import_module(package)

        path = os.path.join(os.path.dirname(p.__file__), 'locale')

        paths.append(path)

        try:

            catalog = gettext_module.translation(domain, path, ['en'])

            t.update(catalog._catalog)

        except IOError:

            # 'en' catalog was missing.

            if locale.startswith('en'):

                # If 'en' is the selected language this would cause issues

                # later on if default_locale is something other than 'en'.

                en_catalog_missing = True

            # Otherwise it is harmless.

            pass

    # next load the settings.LANGUAGE_CODE translations if it isn't english

    if default_locale != 'en':

        for path in paths:

            try:

                catalog = gettext_module.translation(domain, path, [default_locale])

            except IOError:

                catalog = None

            if catalog is not None:

                t.update(catalog._catalog)

    # last load the currently selected language, if it isn't identical to the default.

    if locale != default_locale:

        # If the flag en_catalog_missing has been set, the currently

        # selected language is English but it doesn't have a translation

        # catalog (presumably due to being the language translated from).

        # If that is the case, a wrong language catalog might have been

        # loaded in the previous step. It needs to be discarded.

        if en_catalog_missing:

            t = {}

        else:

            locale_t = {}

            for path in paths:

                try:

                    catalog = gettext_module.translation(domain, path, [locale])

                except IOError:

                    catalog = None

                if catalog is not None:

                    locale_t.update(catalog._catalog)

            if locale_t:

                t = locale_t

    src = [LibHead]

    plural = None

    if '' in t:

        for l in t[''].split('\n'):

            if l.startswith('Plural-Forms:'):

                plural = l.split(':',1)[1].strip()

    if plural is not None:

        # this should actually be a compiled function of a typical plural-form:

        # Plural-Forms: nplurals=3; plural=n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2;

        plural = [el.strip() for el in plural.split(';') if el.strip().startswith('plural=')][0].split('=',1)[1]

        src.append(PluralIdx % plural)

    else:

        src.append(SimplePlural)

    csrc = []

    pdict = {}

    for k, v in t.items():

        if k == '':

            continue

        if isinstance(k, basestring):

            csrc.append("catalog['%s'] = '%s';\n" % (javascript_quote(k), javascript_quote(v)))

        elif isinstance(k, tuple):

            if k[0] not in pdict:

                pdict[k[0]] = k[1]

            else:

                pdict[k[0]] = max(k[1], pdict[k[0]])

            csrc.append("catalog['%s'][%d] = '%s';\n" % (javascript_quote(k[0]), k[1], javascript_quote(v)))

        else:

            raise TypeError(k)

    csrc.sort()

    for k, v in pdict.items():

        src.append("catalog['%s'] = [%s];\n" % (javascript_quote(k), ','.join(["''"]*(v+1))))

    src.extend(csrc)

    src.append(LibFoot)

    src.append(InterPolate)

    src.append(LibFormatHead)

    src.append(get_formats())

    src.append(LibFormatFoot)

    src = ''.join(src)

    return http.HttpResponse(src, 'text/javascript')