from __future__ import annotations

import ipaddress
import logging
import secrets
from urllib.parse import urljoin, urlparse

import httpx

from yuxi.channel.extensions.nextcloud_talk.format import convert_markdown_tables_to_ascii
from yuxi.channel.extensions.nextcloud_talk.normalize import strip_nextcloud_talk_target_prefix
from yuxi.channel.extensions.nextcloud_talk.signature import generate_nextcloud_talk_signature

logger = logging.getLogger(__name__)

OCS_MESSAGE_PATH = "/ocs/v2.php/apps/spreed/api/v1/bot/{token}/message"
OCS_REACTION_PATH = "/ocs/v2.php/apps/spreed/api/v1/bot/{token}/reaction/{message_id}"


class NextcloudTalkSendError(Exception):
    def __init__(self, message: str, status_code: int | None = None):
        super().__init__(message)
        self.status_code = status_code


def _check_ssrf(base_url: str, dangerously_allow_private_network: bool = False) -> None:
    if dangerously_allow_private_network:
        return

    try:
        parsed = urlparse(base_url)
    except ValueError:
        return

    hostname = parsed.hostname
    if not hostname:
        return

    from yuxi.channel.security.ssrf_guard import SsrfGuard

    guard = SsrfGuard(default_deny=False)

    try:
        ip_str = str(ipaddress.ip_address(hostname))
    except ValueError:
        return

    ip_result = guard.check_ip(ip_str)
    if not ip_result.safe:
        raise NextcloudTalkSendError(
            f"SSRF blocked: {hostname} — {ip_result.reason}. Set dangerously_allow_private_network=true to allow."
        )


async def send_message_nextcloud_talk(
    to: str,
    text: str,
    base_url: str,
    secret: str,
    *,
    reply_to: str | None = None,
    silent: bool = False,
    reference_id: str | None = None,
    timeout: float = 30.0,
    dangerously_allow_private_network: bool = False,
) -> dict:
    _check_ssrf(base_url, dangerously_allow_private_network)

    room_token = strip_nextcloud_talk_target_prefix(to)

    if not text.strip():
        raise NextcloudTalkSendError("Message must be non-empty")

    text = convert_markdown_tables_to_ascii(text)

    body = {"message": text}
    if reply_to:
        body["replyTo"] = reply_to
    if silent:
        body["silent"] = True
    if reference_id is None:
        reference_id = secrets.token_hex(16)
    body["referenceId"] = reference_id

    random, signature = generate_nextcloud_talk_signature(text, secret)

    url = urljoin(base_url.rstrip("/") + "/", OCS_MESSAGE_PATH.format(token=room_token))

    async with httpx.AsyncClient(timeout=timeout) as client:
        resp = await client.post(
            url,
            json=body,
            headers={
                "Content-Type": "application/json",
                "OCS-APIRequest": "true",
                "X-Nextcloud-Talk-Bot-Random": random,
                "X-Nextcloud-Talk-Bot-Signature": signature,
                "Accept": "application/json",
            },
        )

    if resp.status_code == 200:
        data = resp.json()
        ocs_data = data.get("ocs", {}).get("data", {})
        return {
            "message_id": str(ocs_data.get("id", "unknown")),
            "room_token": room_token,
            "timestamp": ocs_data.get("timestamp"),
            "reference_id": reference_id,
        }

    error_body = resp.text[:500]
    status_map = {
        400: f"Nextcloud Talk: bad request - {error_body}",
        401: "Nextcloud Talk: authentication failed - check bot secret",
        403: "Nextcloud Talk: forbidden - bot may not have permission in this room",
        404: f"Nextcloud Talk: room not found (token={room_token})",
    }
    msg = status_map.get(resp.status_code, f"Nextcloud Talk send failed: {error_body}")
    raise NextcloudTalkSendError(msg, resp.status_code)


async def send_reaction_nextcloud_talk(
    room_token: str,
    message_id: str,
    reaction: str,
    base_url: str,
    secret: str,
    *,
    timeout: float = 30.0,
    dangerously_allow_private_network: bool = False,
) -> bool:
    _check_ssrf(base_url, dangerously_allow_private_network)

    random, signature = generate_nextcloud_talk_signature(reaction, secret)

    url = urljoin(
        base_url.rstrip("/") + "/",
        OCS_REACTION_PATH.format(token=room_token, message_id=message_id),
    )

    async with httpx.AsyncClient(timeout=timeout) as client:
        resp = await client.post(
            url,
            json={"reaction": reaction},
            headers={
                "Content-Type": "application/json",
                "OCS-APIRequest": "true",
                "X-Nextcloud-Talk-Bot-Random": random,
                "X-Nextcloud-Talk-Bot-Signature": signature,
                "Accept": "application/json",
            },
        )

    return resp.status_code == 200