from __future__ import annotations

import json
import logging
import time
import urllib.parse
import urllib.request
from datetime import datetime

from config import Config
from state import State

log = logging.getLogger(__name__)

ICONS = {"CRITICAL": "🔴", "WARNING": "🟡", "INFO": "🟢"}


class Alerter:
    def __init__(self, config: Config, state: State) -> None:
        self.config = config
        self.state = state

    # ── Persistent Alerting ───────────────────────────────────
    # Gleiche Logik wie im Bash-Script:
    #   - Neuer Fehler       → sofort melden, runs = 0
    #   - Fehler bleibt      → runs++, melden wenn runs >= repeat_runs
    #   - Fehler weg         → Entwarnung, State löschen

    def should_alert(self, key: str, level: str) -> bool:
        repeat = (
            self.config.alert.critical_repeat_runs
            if level == "CRITICAL"
            else self.config.alert.warning_repeat_runs
        )
        active = self.state.get(f"{key}_active")
        runs: int = self.state.get(f"{key}_runs", 0)

        if active != "1":
            self.state.set(f"{key}_active", "1")
            self.state.set(f"{key}_runs", 0)
            return True

        runs += 1
        self.state.set(f"{key}_runs", runs)

        if repeat == 0:
            return False
        if runs >= repeat:
            self.state.set(f"{key}_runs", 0)
            return True
        return False

    def clear_alert(self, key: str) -> bool:
        """Clear state and return True if the alert was previously active."""
        was_active = self.state.get(f"{key}_active") == "1"
        self.state.delete(f"{key}_active", f"{key}_runs")
        return was_active

    # ── Sending ───────────────────────────────────────────────

    def send_alert(self, level: str, title: str, body: str, key: str = "") -> None:
        icon = ICONS.get(level, "⚪")
        suffix = ""
        if key:
            runs: int = self.state.get(f"{key}_runs", 0)
            if runs > 0:
                suffix = f" <i>(Erinnerung #{runs})</i>"

        ts = datetime.now().strftime("%d.%m.%Y %H:%M:%S")
        msg = (
            f"{icon} <b>[{level}] {self.config.hostname}</b>{suffix}\n"
            f"<b>{title}</b>\n\n"
            f"{body}\n\n"
            f"🕐 {ts}"
        )
        log.info("ALERT %s: %s", level, title)
        self._send_telegram(msg)

    def _send_telegram(self, text: str) -> bool:
        url = f"https://api.telegram.org/bot{self.config.telegram.token}/sendMessage"
        data = urllib.parse.urlencode({
            "chat_id": self.config.telegram.chat_id,
            "text": text,
            "parse_mode": "HTML",
        }).encode()

        for attempt in range(1, 4):
            try:
                with urllib.request.urlopen(url, data=data, timeout=10) as resp:
                    result = json.loads(resp.read())
                    if result.get("ok"):
                        return True
            except Exception as e:
                log.warning("Telegram Fehler (Versuch %d/3): %s", attempt, e)
                if attempt < 3:
                    time.sleep(attempt * 2)

        log.error("Telegram: Alert konnte nicht gesendet werden!")
        return False