import html
import os

import httpx

from .base import ImageAttachment, Notifier
from .image_utils import (
    TELEGRAM_PHOTO_MAX_BYTES,
    compressed_preview,
)


def esc(value: object) -> str:
    return html.escape(str(value or ""))


class TelegramNotifier(Notifier):
    name = "telegram"

    def __init__(self, token: str = '', chat_ids: list[str] | None = None,
                 token_env: str = "TELEGRAM_BOT_TOKEN",
                 chat_ids_env: str = "TELEGRAM_NOTIFY_CHAT_ID") -> None:
        self.token = token or os.environ.get(token_env, "")
        raw = ""
        if chat_ids:
            raw = ",".join(chat_ids)
        else:
            raw = os.getenv(chat_ids_env) or (
                os.getenv("TELEGRAM_HOME_CHANNEL") if chat_ids_env == "TELEGRAM_NOTIFY_CHAT_ID" else ""
            ) or ""
        # FIX vs old code: fan-out to ALL chat ids, not just split(',',1)[0].
        self.chat_ids = [c.strip() for c in raw.split(",") if c.strip()]
        if not self.token:
            raise RuntimeError("Telegram token is not configured")
        if not self.chat_ids:
            raise RuntimeError("Telegram notification target is not configured")
        self.proxy = os.getenv("TELEGRAM_PROXY") or None

    async def send(self, title: str, text: str,
                   images: list[ImageAttachment] | None = None) -> None:
        body = f"<b>{esc(title)}</b>\n{text}" if title else text
        failures = 0
        async with httpx.AsyncClient(timeout=90, proxy=self.proxy, trust_env=False) as client:
            for chat_id in self.chat_ids:
                try:
                    response = await client.post(
                        f"https://api.telegram.org/bot{self.token}/sendMessage",
                        json={"chat_id": chat_id, "text": body[:4096], "parse_mode": "HTML", "disable_web_page_preview": True},
                    )
                    ok = response.status_code < 400 and response.json().get("ok") is True
                    if ok:
                        for image in images or []:
                            upload = (
                                image if len(image.data) <= TELEGRAM_PHOTO_MAX_BYTES
                                else compressed_preview(image)
                            )
                            response = await client.post(
                                f"https://api.telegram.org/bot{self.token}/sendPhoto",
                                data={"chat_id": chat_id},
                                files={"photo": (
                                    upload.filename, upload.data, upload.content_type
                                )},
                            )
                            if response.status_code >= 400 or response.json().get("ok") is not True:
                                ok = False
                                break
                except Exception:
                    ok = False
                if not ok:
                    failures += 1
        if failures:
            raise RuntimeError(f"Telegram delivery failed for {failures} target(s)")