import urllib
from enum import Enum
from typing import TYPE_CHECKING

from sentry_sdk.integrations._wsgi_common import _filter_headers
from sentry_sdk.scope import should_send_default_pii

if TYPE_CHECKING:
    from typing import Any, Dict, Optional, Union

    from typing_extensions import Literal

    from sentry_sdk.utils import AnnotatedValue


class _RootPathInPath(Enum):
    EXCLUDED = "excluded"
    EITHER = "either"


def _get_headers(asgi_scope: "Any") -> "Dict[str, str]":
    """
    Extract headers from the ASGI scope, in the format that the Sentry protocol expects.
    """
    headers: "Dict[str, str]" = {}
    for raw_key, raw_value in asgi_scope["headers"]:
        key = raw_key.decode("latin-1")
        value = raw_value.decode("latin-1")
        if key in headers:
            headers[key] = headers[key] + ", " + value
        else:
            headers[key] = value

    return headers


def _get_path(
    asgi_scope: "Dict[str, Any]", root_path_in_path: "_RootPathInPath"
) -> "str":
    if root_path_in_path is _RootPathInPath.EXCLUDED:
        return asgi_scope.get("root_path", "") + asgi_scope.get("path", "")

    # Inverse of https://github.com/Kludex/starlette/blob/de970d7b3facb853eb7ad077decbf3d94f2aab6c/starlette/_utils.py#L96
    path = asgi_scope["path"]
    root_path = asgi_scope.get("root_path", "")

    if not root_path or path == root_path or path.startswith(root_path + "/"):
        return path

    return root_path + path


def _get_url(
    asgi_scope: "Dict[str, Any]",
    default_scheme: "Literal['ws', 'http']",
    host: "Optional[Union[AnnotatedValue, str]]",
    path: str,
) -> str:
    """
    Extract URL from the ASGI scope, without also including the querystring.
    """
    scheme = asgi_scope.get("scheme", default_scheme)

    server = asgi_scope.get("server", None)

    if host:
        return "%s://%s%s" % (scheme, host, path)

    if server is not None:
        host, port = server
        default_port = {"http": 80, "https": 443, "ws": 80, "wss": 443}.get(scheme)
        if port != default_port:
            return "%s://%s:%s%s" % (scheme, host, port, path)
        return "%s://%s%s" % (scheme, host, path)
    return path


def _get_query(asgi_scope: "Any") -> "Any":
    """
    Extract querystring from the ASGI scope, in the format that the Sentry protocol expects.
    """
    qs = asgi_scope.get("query_string")
    if not qs:
        return None
    return urllib.parse.unquote(qs.decode("latin-1"))


def _get_ip(asgi_scope: "Any") -> str:
    """
    Extract IP Address from the ASGI scope based on request headers with fallback to scope client.
    """
    headers = _get_headers(asgi_scope)
    try:
        return headers["x-forwarded-for"].split(",")[0].strip()
    except (KeyError, IndexError):
        pass

    try:
        return headers["x-real-ip"]
    except KeyError:
        pass

    return asgi_scope.get("client")[0]


def _get_request_data(
    asgi_scope: "Any",
    root_path_in_path: "_RootPathInPath",
) -> "Dict[str, Any]":
    """
    Returns data related to the HTTP request from the ASGI scope.
    """
    request_data: "Dict[str, Any]" = {}
    ty = asgi_scope["type"]
    if ty in ("http", "websocket"):
        request_data["method"] = asgi_scope.get("method")

        request_data["headers"] = headers = _filter_headers(
            _get_headers(asgi_scope),
        )
        request_data["query_string"] = _get_query(asgi_scope)

        request_data["url"] = _get_url(
            asgi_scope,
            "http" if ty == "http" else "ws",
            headers.get("host"),
            path=_get_path(asgi_scope=asgi_scope, root_path_in_path=root_path_in_path),
        )

    client = asgi_scope.get("client")
    if client and should_send_default_pii():
        request_data["env"] = {"REMOTE_ADDR": _get_ip(asgi_scope)}

    return request_data


def _get_request_attributes(
    asgi_scope: "Any",
    root_path_in_path: "_RootPathInPath",
) -> "dict[str, Any]":
    """
    Return attributes related to the HTTP request from the ASGI scope.
    """
    attributes: "dict[str, Any]" = {}

    ty = asgi_scope["type"]
    if ty in ("http", "websocket"):
        if asgi_scope.get("method"):
            attributes["http.request.method"] = asgi_scope["method"].upper()

        headers = _filter_headers(_get_headers(asgi_scope), use_annotated_value=False)
        for header, value in headers.items():
            attributes[f"http.request.header.{header.lower()}"] = value

        if should_send_default_pii():
            query = _get_query(asgi_scope)
            if query:
                attributes["http.query"] = query

            path = _get_path(asgi_scope=asgi_scope, root_path_in_path=root_path_in_path)
            attributes["url.path"] = path

            url_without_query_string = _get_url(
                asgi_scope,
                "http" if ty == "http" else "ws",
                headers.get("host"),
                path=path,
            )
            query_string = _get_query(asgi_scope)
            attributes["url.full"] = (
                f"{url_without_query_string}?{query_string}"
                if query_string is not None
                else url_without_query_string
            )

    client = asgi_scope.get("client")
    if client and should_send_default_pii():
        ip = _get_ip(asgi_scope)
        attributes["client.address"] = ip

    return attributes