from __future__ import annotations

from collections.abc import Sequence
from typing import Any

import requests

from .base import Message, Notifier, NotifierError

EMBEDS_PER_MESSAGE = 10
COLOR_URGENT = 0xE74C3C
COLOR_NORMAL = 0x3498DB
USERNAME = "Admin Alerts"


class FluxerWebhookNotifier(Notifier):
    def __init__(self, webhook_url: str, timeout: float) -> None:
        self._url = webhook_url
        self._timeout = timeout

    def send(self, messages: Sequence[Message]) -> None:
        for start in range(0, len(messages), EMBEDS_PER_MESSAGE):
            batch = messages[start : start + EMBEDS_PER_MESSAGE]
            payload = {"username": USERNAME, "embeds": [_embed(m) for m in batch]}
            try:
                resp = requests.post(self._url, json=payload, timeout=self._timeout)
            except requests.RequestException as exc:
                # The exception text contains the webhook URL, which holds the token, so only the type is kept.
                raise NotifierError(f"Fluxer webhook request failed ({type(exc).__name__})") from None
            if not resp.ok:
                raise NotifierError(f"Fluxer webhook returned {resp.status_code}")


def _embed(message: Message) -> dict[str, Any]:
    embed: dict[str, Any] = {
        "title": message.title[:256],
        "description": message.body[:4096],
        "color": COLOR_URGENT if message.urgent else COLOR_NORMAL,
    }
    if message.link:
        embed["url"] = message.link
    return embed