import os
from typing import Any, Dict, Optional, Union

import orjson
from django.conf import settings
from django.core.management.base import CommandError, CommandParser
from django.test import Client
from typing_extensions import override

from zerver.lib.management import ZulipBaseCommand
from zerver.lib.webhooks.common import standardize_headers
from zerver.models.realms import get_realm


class Command(ZulipBaseCommand):
    help = """
Create webhook message based on given fixture
Example:
./manage.py send_webhook_fixture_message \
    [--realm=zulip] \
    --fixture=zerver/webhooks/integration/fixtures/name.json \
    '--url=/api/v1/external/integration?stream=stream_name&api_key=api_key'

To pass custom headers along with the webhook message use the --custom-headers
command line option.
Example:
    --custom-headers='{"X-Custom-Header": "value"}'

The format is a JSON dictionary, so make sure that the header names do
not contain any spaces in them and that you use the precise quoting
approach shown above.
"""

    @override
    def add_arguments(self, parser: CommandParser) -> None:
        parser.add_argument(
            "-f", "--fixture", help="The path to the fixture you'd like to send into Zulip"
        )

        parser.add_argument(
            "-u", "--url", help="The URL on your Zulip server that you want to post the fixture to"
        )

        parser.add_argument(
            "-H",
            "--custom-headers",
            help="The headers you want to provide along with your mock request to Zulip.",
        )

        self.add_realm_args(
            parser, help="Specify which realm/subdomain to connect to; default is zulip"
        )

    def parse_headers(self, custom_headers: Union[None, str]) -> Union[None, Dict[str, str]]:
        if not custom_headers:
            return {}
        try:
            custom_headers_dict = orjson.loads(custom_headers)
        except orjson.JSONDecodeError as ve:
            raise CommandError(
                f"Encountered an error while attempting to parse custom headers: {ve}\n"
                "Note: all strings must be enclosed within \"\" instead of ''"
            )
        return standardize_headers(custom_headers_dict)

    @override
    def handle(self, *args: Any, **options: Optional[str]) -> None:
        if options["fixture"] is None or options["url"] is None:
            self.print_help("./manage.py", "send_webhook_fixture_message")
            raise CommandError

        full_fixture_path = os.path.join(settings.DEPLOY_ROOT, options["fixture"])

        if not self._does_fixture_path_exist(full_fixture_path):
            raise CommandError("Fixture {} does not exist".format(options["fixture"]))

        headers = self.parse_headers(options["custom_headers"])
        json = self._get_fixture_as_json(full_fixture_path)
        realm = self.get_realm(options)
        if realm is None:
            realm = get_realm("zulip")

        client = Client()
        if headers:
            result = client.post(
                options["url"],
                json,
                content_type="application/json",
                HTTP_HOST=realm.host,
                extra=headers,
            )
        else:
            result = client.post(
                options["url"], json, content_type="application/json", HTTP_HOST=realm.host
            )
        if result.status_code != 200:
            raise CommandError(f"Error status {result.status_code}: {result.content!r}")

    def _does_fixture_path_exist(self, fixture_path: str) -> bool:
        return os.path.exists(fixture_path)

    def _get_fixture_as_json(self, fixture_path: str) -> bytes:
        with open(fixture_path, "rb") as f:
            return orjson.dumps(orjson.loads(f.read()))