from typing import Any, List, Mapping, Optional

import orjson
from django.http import HttpResponse, HttpResponseNotAllowed
from django.utils.translation import ugettext as _

from zerver.lib.exceptions import JsonableError


class HttpResponseUnauthorized(HttpResponse):
    status_code = 401

    def __init__(self, realm: str, www_authenticate: Optional[str]=None) -> None:
        HttpResponse.__init__(self)
        if www_authenticate is None:
            self["WWW-Authenticate"] = f'Basic realm="{realm}"'
        elif www_authenticate == "session":
            self["WWW-Authenticate"] = f'Session realm="{realm}"'
        else:
            raise AssertionError("Invalid www_authenticate value!")

def json_unauthorized(message: Optional[str]=None,
                      www_authenticate: Optional[str]=None) -> HttpResponse:
    if message is None:
        message = _("Not logged in: API authentication or user session required")
    resp = HttpResponseUnauthorized("zulip", www_authenticate=www_authenticate)
    resp.content = orjson.dumps(
        {"result": "error", "msg": message}, option=orjson.OPT_APPEND_NEWLINE,
    )
    return resp

def json_method_not_allowed(methods: List[str]) -> HttpResponseNotAllowed:
    resp = HttpResponseNotAllowed(methods)
    resp.content = orjson.dumps({"result": "error",
                                 "msg": "Method Not Allowed",
                                 "allowed_methods": methods})
    return resp

def json_response(res_type: str="success",
                  msg: str="",
                  data: Mapping[str, Any]={},
                  status: int=200) -> HttpResponse:
    content = {"result": res_type, "msg": msg}
    content.update(data)

    # Because we don't pass a default handler, OPT_PASSTHROUGH_DATETIME
    # actually causes orjson to raise a TypeError on datetime objects. This
    # helps us avoid relying on the particular serialization used by orjson.
    return HttpResponse(
        content=orjson.dumps(
            content,
            option=orjson.OPT_APPEND_NEWLINE | orjson.OPT_PASSTHROUGH_DATETIME,
        ),
        content_type='application/json',
        status=status,
    )

def json_success(data: Mapping[str, Any]={}) -> HttpResponse:
    return json_response(data=data)

def json_response_from_error(exception: JsonableError) -> HttpResponse:
    '''
    This should only be needed in middleware; in app code, just raise.

    When app code raises a JsonableError, the JsonErrorHandler
    middleware takes care of transforming it into a response by
    calling this function.
    '''
    response = json_response('error',
                             msg=exception.msg,
                             data=exception.data,
                             status=exception.http_status_code)

    for header, value in exception.extra_headers.items():
        response[header] = value

    return response

def json_error(msg: str, data: Mapping[str, Any]={}, status: int=400) -> HttpResponse:
    return json_response(res_type="error", msg=msg, data=data, status=status)