from os import path

from jinja2 import Environment
from jinja2 import PackageLoader
from werkzeug.exceptions import HTTPException
from werkzeug.exceptions import NotFound
from werkzeug.routing import RequestRedirect
from werkzeug.wrappers import BaseResponse
from werkzeug.wrappers import Request as _Request

from .urls import map

TEMPLATES = path.join(path.dirname(__file__), "templates")
views = {}


def expose(name):
    """Register the function as view."""

    def wrapped(f):
        views[name] = f
        return f

    return wrapped


class Request(_Request):
    def __init__(self, environ, urls):
        super(Request, self).__init__(environ)
        self.urls = urls
        self.matched_url = None

    def url_for(self, endpoint, **args):
        if "lang_code" not in args:
            args["lang_code"] = self.language
        if endpoint == "this":
            endpoint = self.matched_url[0]
            tmp = self.matched_url[1].copy()
            tmp.update(args)
            args = tmp
        return self.urls.build(endpoint, args)


class Response(BaseResponse):
    pass


class TemplateResponse(Response):
    jinja_env = Environment(loader=PackageLoader("i18nurls"), autoescape=True)

    def __init__(self, template_name, **values):
        self.template_name = template_name
        self.template_values = values
        Response.__init__(self, mimetype="text/html")

    def __call__(self, environ, start_response):
        req = environ["werkzeug.request"]
        values = self.template_values.copy()
        values["req"] = req
        self.data = self.render_template(self.template_name, values)
        return super(TemplateResponse, self).__call__(environ, start_response)

    def render_template(self, name, values):
        template = self.jinja_env.get_template(name)
        return template.render(values)


class Application(object):
    def __init__(self):
        from i18nurls import views

        self.not_found = views.page_not_found

    def __call__(self, environ, start_response):
        urls = map.bind_to_environ(environ)
        req = Request(environ, urls)
        try:
            endpoint, args = urls.match(req.path)
            req.matched_url = (endpoint, args)
            if endpoint == "#language_select":
                lng = req.accept_languages.best
                lng = lng and lng.split("-")[0].lower() or "en"
                index_url = urls.build("index", {"lang_code": lng})
                resp = Response("Moved to %s" % index_url, status=302)
                resp.headers["Location"] = index_url
            else:
                req.language = args.pop("lang_code", None)
                resp = views[endpoint](req, **args)
        except NotFound:
            resp = self.not_found(req)
        except (RequestRedirect, HTTPException) as e:
            resp = e
        return resp(environ, start_response)