import io
import os

from django.core.management.base import BaseCommand
from django.utils.translation import activate
from django.utils.encoding import force_str

from statici18n.conf import settings
from statici18n.utils import get_filename, get_packages

from django.views.i18n import JavaScriptCatalog, JSONCatalog


class Command(BaseCommand):
    help = "Collect Javascript catalog files in a single location."
    requires_system_checks = []

    def add_arguments(self, parser):
        parser.add_argument(
            "--locale",
            "-l",
            dest="locale",
            help="The locale to process. Default is to process all "
            "but if for some reason I18N features are disabled, "
            "only `settings.LANGUAGE_CODE` will be processed.",
        ),
        parser.add_argument(
            "-d",
            "--domain",
            dest="domain",
            default=settings.STATICI18N_DOMAIN,
            help="Override the gettext domain. By default, "
            "the command uses the djangojs gettext domain.",
        ),
        parser.add_argument(
            "-p",
            "--packages",
            action="append",
            default=[],
            dest="packages",
            help="A list of packages to check for translations. "
            "Default is 'django.conf'. Use multiple times to "
            "add more.",
        ),
        parser.add_argument(
            "-o",
            "--output",
            dest="outputdir",
            metavar="OUTPUT_DIR",
            help="Output directory to store generated catalogs. "
            "Defaults to static/jsi18n.",
        )
        parser.add_argument(
            "-f",
            "--format",
            dest="outputformat",
            metavar="OUTPUT_FORMAT",
            choices=["js", "json"],
            default="js",
            help="Format of the output catalog. "
            "Options are: js, json. Defaults to js.",
        )
        parser.add_argument(
            "-n",
            "--namespace",
            dest="namespace",
            metavar="NAMESPACE",
            default=settings.STATICI18N_NAMESPACE,
            help="Javascript identifier to use as namespace.",
        )

    def _get_namespaced_catalog(self, rendered_js, namespace):
        template = """
            (function(global){{
                var {namespace} = {{
                  init: function() {{
                    {text}
                  }}
                }};
                {namespace}.init();
                global.{namespace} = {namespace};
            }}(this));
        """
        namespaced_catalog = template.format(text=rendered_js, namespace=namespace)
        return namespaced_catalog

    def _create_javascript_catalog(self, locale, domain, packages):
        activate(locale)
        catalog = JavaScriptCatalog()
        packages = get_packages(packages)
        # we are passing None as the request, as the request object is
        # currently not used by django
        response = catalog.get(self, None, domain=domain, packages=packages)
        return force_str(response.content)

    def _create_json_catalog(self, locale, domain, packages):
        activate(locale)
        catalog = JSONCatalog()
        packages = get_packages(packages)
        # we are passing None as the request, as the request object is
        # currently not used by django
        response = catalog.get(self, None, domain=domain, packages=packages)
        return force_str(response.content)

    def _create_output(
        self, outputdir, outputformat, locale, domain, packages, namespace
    ):
        outputfile = os.path.join(outputdir, get_filename(locale, domain, outputformat))
        basedir = os.path.dirname(outputfile)
        if not os.path.isdir(basedir):
            os.makedirs(basedir)

        if outputformat == "js":
            data = self._create_javascript_catalog(locale, domain, packages)
            if namespace:
                data = self._get_namespaced_catalog(data, namespace)
        elif outputformat == "json":
            data = self._create_json_catalog(locale, domain, packages)
        else:
            raise NotImplementedError("Unknown format %s" % (outputformat))

        with io.open(outputfile, "w", encoding="utf-8") as fp:
            fp.write(data)

    def handle(self, **options):
        locale = options.get("locale")
        domain = options["domain"]
        packages = options["packages"] or settings.STATICI18N_PACKAGES
        outputdir = options["outputdir"]
        outputformat = options["outputformat"]
        namespace = options["namespace"]
        verbosity = int(options.get("verbosity"))

        if locale is not None:
            languages = [locale]
        elif not settings.USE_I18N:
            languages = [settings.LANGUAGE_CODE]
        else:
            languages = [lang_code for (lang_code, lang_name) in settings.LANGUAGES]

        if outputdir is None:
            outputdir = os.path.join(
                settings.STATICI18N_ROOT, settings.STATICI18N_OUTPUT_DIR
            )

        for locale in languages:
            if verbosity > 0:
                self.stdout.write("processing language %s\n" % locale)

            self._create_output(
                outputdir, outputformat, locale, domain, packages, namespace
            )