import json
from dataclasses import dataclass
from enum import Enum, StrEnum
from typing import Optional

import aiofiles
import nio

from alerting.common import CREDS_FILE, ROOM_ID


class AlertType(StrEnum):
    TEST = "TEST"
    RAM = "RAM"  # TODO
    CPU = "CPU"  # TODO
    TEMP = "TEMP"
    LOGIN = "LOGIN"  # TODO
    SMART = "SMART"  # TODO
    RAID = "RAID"  # TODO


class Severity(Enum):
    INFO = 1
    WARNING = 2
    CRITICAL = 3


@dataclass
class Alert:
    alert_type: AlertType
    message: str
    severity: Severity


async def get_client() -> nio.AsyncClient:
    """
    Returns a Matrix client.
    It is better to call get_client once and use it for multiple send_alert calls
    """
    async with aiofiles.open(CREDS_FILE) as f:
        contents = await f.read()
    creds = json.loads(contents)
    client = nio.AsyncClient(creds["homeserver"])
    client.access_token = creds["access_token"]
    client.user_id = creds["user_id"]
    client.device_id = creds["device_id"]
    return client


def format_message(alert: Alert) -> str:
    match alert.severity:
        case Severity.INFO:
            severity_emoji = "ℹ️"
        case Severity.WARNING:
            severity_emoji = "⚠️"
        case Severity.CRITICAL:
            severity_emoji = "🆘"
    message = f"{severity_emoji} {alert.alert_type} Alert\n{alert.message}"
    return message


async def send_alert(alert: Alert, client: Optional[nio.AsyncClient] = None) -> None:
    if client is None:
        temp_client = True
        client = await get_client()
    else:
        temp_client = False
    message = format_message(alert)
    await client.room_send(
        room_id=ROOM_ID,
        message_type="m.room.message",
        content={
            "msgtype": "m.text",
            "body": message,
        },
    )
    if temp_client:
        await client.close()