# Copyright (C) 2018 Philipp Hörist <philipp AT hoerist.com>
#
# This file is part of nbxmpp.
#
# SPDX-License-Identifier: GPL-3.0-or-later

from __future__ import annotations

from typing import TYPE_CHECKING

import hashlib
from dataclasses import dataclass

from nbxmpp.errors import StanzaError
from nbxmpp.modules.base import BaseModule
from nbxmpp.namespaces import Namespace
from nbxmpp.protocol import Iq
from nbxmpp.protocol import Message
from nbxmpp.simplexml import Node
from nbxmpp.structs import MessageProperties
from nbxmpp.structs import StanzaHandler
from nbxmpp.task import iq_request_task
from nbxmpp.util import from_xs_boolean

if TYPE_CHECKING:
    from nbxmpp.client import Client


class SecurityLabels(BaseModule):
    def __init__(self, client: Client) -> None:
        BaseModule.__init__(self, client)

        self._client = client
        self.handlers = [
            StanzaHandler(
                name="message",
                callback=self._process_message_security_label,
                ns=Namespace.SECLABEL,
                priority=15,
            ),
        ]

    def _process_message_security_label(
        self, _client: Client, stanza: Message, properties: MessageProperties
    ) -> None:
        security = stanza.getTag("securitylabel", namespace=Namespace.SECLABEL)
        if security is None:
            return

        try:
            security_label = SecurityLabel.from_node(security)
        except ValueError as error:
            self._log.warning(error)
            return

        properties.security_label = security_label

    @iq_request_task
    def request_catalog(self, jid: str):
        _task = yield

        response = yield _make_catalog_request(self._client.domain, jid)
        if response.isError():
            raise StanzaError(response)

        catalog_node = response.getTag("catalog", namespace=Namespace.SECLABEL_CATALOG)

        try:
            restrict = from_xs_boolean(catalog_node.getAttr("restrict"))
        except Exception:
            restrict = False

        items = catalog_node.getTags("item")

        labels: dict[str, SecurityLabel | None] = {}
        default: str | None = None
        for item in items:
            selector = item.getAttr("selector")
            if selector is None:
                continue

            if item.getAttr("default") == "true":
                default = selector

            security = item.getTag("securitylabel", namespace=Namespace.SECLABEL)
            if security is None:
                labels[selector] = None
                continue

            try:
                security_label = SecurityLabel.from_node(security)
            except ValueError:
                continue

            labels[selector] = security_label

        yield Catalog(labels=labels, default=default, restrict=restrict)


def _make_catalog_request(domain: str | None, jid: str) -> Iq:
    iq = Iq(typ="get", to=domain)
    iq.addChild(name="catalog", namespace=Namespace.SECLABEL_CATALOG, attrs={"to": jid})
    return iq


@dataclass
class Displaymarking:
    name: str
    fgcolor: str
    bgcolor: str

    def to_node(self) -> Node:
        displaymarking = Node(tag="displaymarking")
        if self.fgcolor and self.fgcolor != "#000":
            displaymarking.setAttr("fgcolor", self.fgcolor)

        if self.bgcolor and self.bgcolor != "#FFF":
            displaymarking.setAttr("bgcolor", self.bgcolor)

        if self.name:
            displaymarking.setData(self.name)

        return displaymarking

    @classmethod
    def from_node(cls, node: Node) -> Displaymarking:
        return cls(
            name=node.getData(),
            fgcolor=node.getAttr("fgcolor") or "#000",
            bgcolor=node.getAttr("bgcolor") or "#FFF",
        )


@dataclass
class SecurityLabel:
    displaymarking: Displaymarking | None
    label: Node

    def to_node(self) -> Node:
        security = Node(tag="securitylabel", attrs={"xmlns": Namespace.SECLABEL})
        if self.displaymarking is not None:
            security.addChild(node=self.displaymarking.to_node())
        security.addChild(node=self.label)
        return security

    @classmethod
    def from_node(cls, security: Node) -> SecurityLabel:
        displaymarking = security.getTag("displaymarking")
        if displaymarking is not None:
            displaymarking = Displaymarking.from_node(displaymarking)

        label = security.getTag("label")
        if label is None:
            raise ValueError("label node missing")

        return cls(displaymarking=displaymarking, label=label)

    def get_label_hash(self) -> str:
        sha = hashlib.sha512()
        sha.update(str(self.label).encode())
        return sha.hexdigest()


@dataclass
class Catalog:
    labels: dict[str, SecurityLabel | None]
    default: str
    restrict: bool

    def get_label_names(self) -> list[str]:
        return list(self.labels.keys())