derp/plugins/alert.py

"""Plugin: keyword alert subscriptions across multiple platforms."""

from __future__ import annotations

import asyncio
import json
import re
import ssl
import urllib.request
from datetime import datetime, timezone

from derp.plugin import command, event

# -- Constants ---------------------------------------------------------------

_NAME_RE = re.compile(r"^[a-z0-9][a-z0-9-]{0,19}$")
_MAX_KEYWORD_LEN = 100
_MAX_SEEN = 200
_MAX_ANNOUNCE = 5
_DEFAULT_INTERVAL = 300
_MAX_INTERVAL = 3600
_FETCH_TIMEOUT = 15
_MAX_TITLE_LEN = 80
_MAX_SUBS = 20
_YT_SEARCH_URL = "https://www.youtube.com/youtubei/v1/search"
_YT_CLIENT_VERSION = "2.20250101.00.00"
_GQL_URL = "https://gql.twitch.tv/gql"
_GQL_CLIENT_ID = "kimne78kx3ncx6brgo4mv6wki5h1ko"

# -- Module-level tracking ---------------------------------------------------

_pollers: dict[str, asyncio.Task] = {}
_subscriptions: dict[str, dict] = {}
_errors: dict[str, int] = {}


# -- Pure helpers ------------------------------------------------------------

def _state_key(channel: str, name: str) -> str:
    """Build composite state key."""
    return f"{channel}:{name}"


def _validate_name(name: str) -> bool:
    """Check name against allowed pattern."""
    return bool(_NAME_RE.match(name))


def _truncate(text: str, max_len: int = _MAX_TITLE_LEN) -> str:
    """Truncate text with ellipsis if needed."""
    if len(text) <= max_len:
        return text
    return text[: max_len - 3].rstrip() + "..."


# -- YouTube InnerTube search (blocking) ------------------------------------

def _extract_videos(obj: object, depth: int = 0) -> list[dict]:
    """Recursively walk YouTube JSON to find video results.

    Finds all objects containing both 'videoId' and 'title' keys.
    Resilient to YouTube rearranging wrapper layers.
    """
    if depth > 20:
        return []
    results = []
    if isinstance(obj, dict):
        video_id = obj.get("videoId")
        title_obj = obj.get("title")
        if isinstance(video_id, str) and video_id and title_obj is not None:
            if isinstance(title_obj, dict):
                runs = title_obj.get("runs", [])
                title = "".join(r.get("text", "") for r in runs if isinstance(r, dict))
            elif isinstance(title_obj, str):
                title = title_obj
            else:
                title = ""
            if title:
                results.append({
                    "id": video_id,
                    "title": title,
                    "url": f"https://www.youtube.com/watch?v={video_id}",
                    "extra": "",
                })
        for val in obj.values():
            results.extend(_extract_videos(val, depth + 1))
    elif isinstance(obj, list):
        for item in obj:
            results.extend(_extract_videos(item, depth + 1))
    return results


def _search_youtube(keyword: str) -> list[dict]:
    """Search YouTube via InnerTube API. Blocking."""
    payload = json.dumps({
        "context": {
            "client": {
                "clientName": "WEB",
                "clientVersion": _YT_CLIENT_VERSION,
            },
        },
        "query": keyword,
    }).encode()

    req = urllib.request.Request(_YT_SEARCH_URL, data=payload, method="POST")
    req.add_header("Content-Type", "application/json")

    ctx = ssl.create_default_context()
    resp = urllib.request.urlopen(req, timeout=_FETCH_TIMEOUT, context=ctx)
    raw = resp.read()
    resp.close()

    data = json.loads(raw)
    videos = _extract_videos(data)
    # Deduplicate by videoId (same video can appear in multiple sections)
    seen_ids: set[str] = set()
    unique: list[dict] = []
    for v in videos:
        if v["id"] not in seen_ids:
            seen_ids.add(v["id"])
            unique.append(v)
    return unique


# -- Twitch GQL search (blocking) ------------------------------------------

def _search_twitch(keyword: str) -> list[dict]:
    """Search Twitch via public GQL. Blocking."""
    query = (
        'query{searchFor(userQuery:"'
        + keyword.replace("\\", "\\\\").replace('"', '\\"')
        + '",options:{targets:[{index:STREAM},{index:VOD}]})'
        "{streams{items{id broadcaster{login displayName}title game{name}"
        "viewersCount}}videos{items{id owner{login displayName}title"
        " game{name}viewCount}}}}"
    )
    body = json.dumps({"query": query}).encode()

    req = urllib.request.Request(_GQL_URL, data=body, method="POST")
    req.add_header("Client-Id", _GQL_CLIENT_ID)
    req.add_header("Content-Type", "application/json")

    ctx = ssl.create_default_context()
    resp = urllib.request.urlopen(req, timeout=_FETCH_TIMEOUT, context=ctx)
    raw = resp.read()
    resp.close()

    data = json.loads(raw)
    results: list[dict] = []

    try:
        search = data["data"]["searchFor"]
    except (KeyError, TypeError):
        return results
    if not search:
        return results

    # Live streams
    streams = search.get("streams") or {}
    for item in streams.get("items") or []:
        stream_id = str(item.get("id", ""))
        if not stream_id:
            continue
        broadcaster = item.get("broadcaster") or {}
        login = broadcaster.get("login", "")
        display = broadcaster.get("displayName", login)
        title = item.get("title", "")
        game = (item.get("game") or {}).get("name", "")
        line = f"{display} is live: {title}"
        if game:
            line += f" ({game})"
        results.append({
            "id": f"stream:{stream_id}",
            "title": line,
            "url": f"https://twitch.tv/{login}",
            "extra": "",
        })

    # VODs
    videos = search.get("videos") or {}
    for item in videos.get("items") or []:
        vod_id = str(item.get("id", ""))
        if not vod_id:
            continue
        title = item.get("title", "")
        results.append({
            "id": f"vod:{vod_id}",
            "title": title,
            "url": f"https://twitch.tv/videos/{vod_id}",
            "extra": "",
        })

    return results


# -- Backend registry -------------------------------------------------------

_BACKENDS: dict[str, callable] = {
    "yt": _search_youtube,
    "tw": _search_twitch,
}


# -- State helpers -----------------------------------------------------------

def _save(bot, key: str, data: dict) -> None:
    """Persist subscription data to bot.state."""
    bot.state.set("alert", key, json.dumps(data))


def _load(bot, key: str) -> dict | None:
    """Load subscription data from bot.state."""
    raw = bot.state.get("alert", key)
    if raw is None:
        return None
    try:
        return json.loads(raw)
    except json.JSONDecodeError:
        return None


def _delete(bot, key: str) -> None:
    """Remove subscription data from bot.state."""
    bot.state.delete("alert", key)


# -- Polling -----------------------------------------------------------------

async def _poll_once(bot, key: str, announce: bool = True) -> None:
    """Single poll cycle for one alert subscription (all backends)."""
    data = _subscriptions.get(key)
    if data is None:
        data = _load(bot, key)
    if data is None:
        return
    _subscriptions[key] = data

    keyword = data["keyword"]
    now = datetime.now(timezone.utc).isoformat()
    data["last_poll"] = now

    had_error = False
    loop = asyncio.get_running_loop()

    for tag, backend in _BACKENDS.items():
        try:
            items = await loop.run_in_executor(None, backend, keyword)
        except Exception as exc:
            data["last_error"] = f"{tag}: {exc}"
            had_error = True
            continue

        seen_set = set(data.get("seen", {}).get(tag, []))
        seen_list = list(data.get("seen", {}).get(tag, []))
        new_items = [item for item in items if item["id"] not in seen_set]

        if announce and new_items:
            channel = data["channel"]
            name = data["name"]
            shown = new_items[:_MAX_ANNOUNCE]
            for item in shown:
                title = _truncate(item["title"]) if item["title"] else "(no title)"
                url = item["url"]
                line = f"[{name}/{tag}] {title}"
                if url:
                    line += f" -- {url}"
                await bot.send(channel, line)
            remaining = len(new_items) - len(shown)
            if remaining > 0:
                await bot.send(channel, f"[{name}/{tag}] ... and {remaining} more")

        for item in new_items:
            seen_list.append(item["id"])
        if len(seen_list) > _MAX_SEEN:
            seen_list = seen_list[-_MAX_SEEN:]
        data.setdefault("seen", {})[tag] = seen_list

    if had_error:
        _errors[key] = _errors.get(key, 0) + 1
    else:
        data["last_error"] = ""
        _errors[key] = 0

    _subscriptions[key] = data
    _save(bot, key, data)


async def _poll_loop(bot, key: str) -> None:
    """Infinite poll loop for one alert subscription."""
    try:
        while True:
            data = _subscriptions.get(key) or _load(bot, key)
            if data is None:
                return
            interval = data.get("interval", _DEFAULT_INTERVAL)
            errs = _errors.get(key, 0)
            if errs >= 5:
                interval = min(interval * 2, _MAX_INTERVAL)
            await asyncio.sleep(interval)
            await _poll_once(bot, key, announce=True)
    except asyncio.CancelledError:
        pass


def _start_poller(bot, key: str) -> None:
    """Create and track a poller task."""
    existing = _pollers.get(key)
    if existing and not existing.done():
        return
    task = asyncio.create_task(_poll_loop(bot, key))
    _pollers[key] = task


def _stop_poller(key: str) -> None:
    """Cancel and remove a poller task."""
    task = _pollers.pop(key, None)
    if task and not task.done():
        task.cancel()
    _subscriptions.pop(key, None)
    _errors.pop(key, 0)


# -- Restore on connect -----------------------------------------------------

def _restore(bot) -> None:
    """Rebuild pollers from persisted state."""
    for key in bot.state.keys("alert"):
        existing = _pollers.get(key)
        if existing and not existing.done():
            continue
        data = _load(bot, key)
        if data is None:
            continue
        _subscriptions[key] = data
        _start_poller(bot, key)


@event("001")
async def on_connect(bot, message):
    """Restore alert subscription pollers on connect."""
    _restore(bot)


# -- Command handler ---------------------------------------------------------

@command("alert", help="Alert: !alert add|del|list|check")
async def cmd_alert(bot, message):
    """Per-channel keyword alert subscriptions across platforms.

    Usage:
        !alert add <name> <keyword...>   Add keyword alert (admin)
        !alert del <name>                Remove alert (admin)
        !alert list                      List alerts
        !alert check <name>              Force-poll now
    """
    parts = message.text.split(None, 3)
    if len(parts) < 2:
        await bot.reply(message, "Usage: !alert <add|del|list|check> [args]")
        return

    sub = parts[1].lower()

    # -- list (any user, channel only) ----------------------------------------
    if sub == "list":
        if not message.is_channel:
            await bot.reply(message, "Use this command in a channel")
            return
        channel = message.target
        prefix = f"{channel}:"
        subs = []
        for key in bot.state.keys("alert"):
            if key.startswith(prefix):
                data = _load(bot, key)
                if data:
                    name = data["name"]
                    err = data.get("last_error", "")
                    if err:
                        subs.append(f"{name} (error)")
                    else:
                        subs.append(name)
        if not subs:
            await bot.reply(message, "No alerts in this channel")
            return
        await bot.reply(message, f"Alerts: {', '.join(subs)}")
        return

    # -- check (any user, channel only) ---------------------------------------
    if sub == "check":
        if not message.is_channel:
            await bot.reply(message, "Use this command in a channel")
            return
        if len(parts) < 3:
            await bot.reply(message, "Usage: !alert check <name>")
            return
        name = parts[2].lower()
        channel = message.target
        key = _state_key(channel, name)
        data = _load(bot, key)
        if data is None:
            await bot.reply(message, f"No alert '{name}' in this channel")
            return
        _subscriptions[key] = data
        await _poll_once(bot, key, announce=True)
        data = _subscriptions.get(key, data)
        if data.get("last_error"):
            await bot.reply(message, f"{name}: error -- {data['last_error']}")
        else:
            await bot.reply(message, f"{name}: checked")
        return

    # -- add (admin, channel only) -------------------------------------------
    if sub == "add":
        if not bot._is_admin(message):
            await bot.reply(message, "Permission denied: add requires admin")
            return
        if not message.is_channel:
            await bot.reply(message, "Use this command in a channel")
            return
        if len(parts) < 4:
            await bot.reply(message, "Usage: !alert add <name> <keyword...>")
            return

        name = parts[2].lower()
        keyword = parts[3]

        if not _validate_name(name):
            await bot.reply(
                message,
                "Invalid name (lowercase alphanumeric + hyphens, 1-20 chars)",
            )
            return

        if len(keyword) > _MAX_KEYWORD_LEN:
            await bot.reply(message, f"Keyword too long (max {_MAX_KEYWORD_LEN} chars)")
            return

        irc_channel = message.target
        key = _state_key(irc_channel, name)

        if _load(bot, key) is not None:
            await bot.reply(message, f"Alert '{name}' already exists in this channel")
            return

        ch_prefix = f"{irc_channel}:"
        count = sum(1 for k in bot.state.keys("alert") if k.startswith(ch_prefix))
        if count >= _MAX_SUBS:
            await bot.reply(message, f"Alert limit reached ({_MAX_SUBS})")
            return

        # Seed: query all backends to populate seen lists (prevents flood)
        loop = asyncio.get_running_loop()
        seen: dict[str, list[str]] = {}
        for tag, backend in _BACKENDS.items():
            try:
                items = await loop.run_in_executor(None, backend, keyword)
                ids = [item["id"] for item in items]
                if len(ids) > _MAX_SEEN:
                    ids = ids[-_MAX_SEEN:]
                seen[tag] = ids
            except Exception:
                seen[tag] = []

        now = datetime.now(timezone.utc).isoformat()
        data = {
            "keyword": keyword,
            "name": name,
            "channel": irc_channel,
            "interval": _DEFAULT_INTERVAL,
            "added_by": message.nick,
            "added_at": now,
            "last_poll": now,
            "last_error": "",
            "seen": seen,
        }
        _save(bot, key, data)
        _subscriptions[key] = data
        _start_poller(bot, key)

        counts = ", ".join(f"{len(seen.get(t, []))} {t}" for t in _BACKENDS)
        await bot.reply(
            message,
            f"Alert '{name}' added for: {keyword} ({counts} existing)",
        )
        return

    # -- del (admin, channel only) -------------------------------------------
    if sub == "del":
        if not bot._is_admin(message):
            await bot.reply(message, "Permission denied: del requires admin")
            return
        if not message.is_channel:
            await bot.reply(message, "Use this command in a channel")
            return
        if len(parts) < 3:
            await bot.reply(message, "Usage: !alert del <name>")
            return

        name = parts[2].lower()
        channel = message.target
        key = _state_key(channel, name)

        if _load(bot, key) is None:
            await bot.reply(message, f"No alert '{name}' in this channel")
            return

        _stop_poller(key)
        _delete(bot, key)
        await bot.reply(message, f"Removed '{name}'")
        return

    await bot.reply(message, "Usage: !alert <add|del|list|check> [args]")