"""Telegram alerts: notify on actionable signals so the dashboard isn't a
poll-only tool.

Triggers (each toggleable):
  - qualified setups: a (symbol, direction) setup that clears the activation gate
  - watchlist S/R proximity: a watched ticker's price entering a strong S/R zone
  - score deterioration: a watched ticker's composite dropping sharply vs a
    running watermark
  - daily digest: one end-of-day summary

Dedup is via the AlertLog table: cooldown-based for the first two and the digest,
watermark-based for score drops. Telegram credentials follow the usual
precedence DB > env; the bot token is write-only (never returned on read).
"""

from __future__ import annotations

import logging
from datetime import datetime, timedelta, timezone
from types import SimpleNamespace

import httpx
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.config import settings
from app.models.alert import AlertLog
from app.models.ohlcv import OHLCVRecord
from app.models.score import CompositeScore
from app.models.settings import SystemSetting
from app.models.sr_level import SRLevel
from app.models.ticker import Ticker
from app.models.watchlist import WatchlistEntry
from app.services.admin_service import get_activation_config, update_setting
from app.services.qualification import best_target_probability, setup_qualifies
from app.services.rr_scanner_service import get_trade_setups
from app.services.sr_service import cluster_sr_zones

logger = logging.getLogger(__name__)

# SystemSetting keys
KEY_ENABLED = "alerts_enabled"
KEY_TOKEN = "alerts_telegram_bot_token"
KEY_CHAT_ID = "alerts_telegram_chat_id"
KEY_QUALIFIED = "alerts_qualified_enabled"
KEY_SR = "alerts_sr_proximity_enabled"
KEY_SCORE_DROP = "alerts_score_drop_enabled"
KEY_DIGEST = "alerts_digest_enabled"

_BOOL_DEFAULTS = {
    KEY_ENABLED: False,
    KEY_QUALIFIED: True,
    KEY_SR: True,
    KEY_SCORE_DROP: True,
    KEY_DIGEST: True,
}

# Tunables (kept as constants for now; promote to settings if needed)
SR_PROXIMITY_PCT = 2.0      # within this % of a strong zone → alert
SR_MIN_STRENGTH = 60        # only strong zones are alert-worthy
SR_CLUSTER_TOLERANCE = 0.02  # merge levels within 2% into one zone (matches chart)
SCORE_DROP_POINTS = 15.0    # composite drop vs watermark that triggers an alert
COOLDOWN_HOURS = 72         # don't re-send the same key within this window
DIGEST_HOUR_UTC = 22        # send the daily digest on the first run at/after this hour

WATERMARK_TYPE = "score_watermark"


def _as_bool(value: str | None, default: bool) -> bool:
    if value is None:
        return default
    return value.strip().lower() == "true"


async def _settings_map(db: AsyncSession) -> dict[str, str]:
    keys = [KEY_ENABLED, KEY_TOKEN, KEY_CHAT_ID, KEY_QUALIFIED, KEY_SR, KEY_SCORE_DROP, KEY_DIGEST]
    result = await db.execute(select(SystemSetting).where(SystemSetting.key.in_(keys)))
    return {s.key: s.value for s in result.scalars().all()}


async def _resolve(db: AsyncSession) -> dict:
    stored = await _settings_map(db)

    db_token = (stored.get(KEY_TOKEN) or "").strip()
    if db_token:
        token, token_source = db_token, "database"
    elif settings.telegram_bot_token:
        token, token_source = settings.telegram_bot_token, "environment"
    else:
        token, token_source = "", "none"

    chat_id = (stored.get(KEY_CHAT_ID) or "").strip() or (settings.telegram_chat_id or "").strip()

    return {
        "enabled": _as_bool(stored.get(KEY_ENABLED), _BOOL_DEFAULTS[KEY_ENABLED]),
        "token": token,
        "token_source": token_source,
        "chat_id": chat_id,
        "qualified": _as_bool(stored.get(KEY_QUALIFIED), _BOOL_DEFAULTS[KEY_QUALIFIED]),
        "sr": _as_bool(stored.get(KEY_SR), _BOOL_DEFAULTS[KEY_SR]),
        "score_drop": _as_bool(stored.get(KEY_SCORE_DROP), _BOOL_DEFAULTS[KEY_SCORE_DROP]),
        "digest": _as_bool(stored.get(KEY_DIGEST), _BOOL_DEFAULTS[KEY_DIGEST]),
    }


async def get_alert_config(db: AsyncSession) -> dict:
    """Public config — never includes the raw bot token."""
    r = await _resolve(db)
    return {
        "enabled": r["enabled"],
        "telegram_chat_id": r["chat_id"],
        "bot_token_configured": bool(r["token"]),
        "bot_token_source": r["token_source"],
        "qualified_enabled": r["qualified"],
        "sr_proximity_enabled": r["sr"],
        "score_drop_enabled": r["score_drop"],
        "digest_enabled": r["digest"],
    }


async def update_alert_config(
    db: AsyncSession,
    *,
    enabled: bool | None = None,
    bot_token: str | None = None,
    telegram_chat_id: str | None = None,
    qualified_enabled: bool | None = None,
    sr_proximity_enabled: bool | None = None,
    score_drop_enabled: bool | None = None,
    digest_enabled: bool | None = None,
) -> dict:
    """Persist config. An empty/omitted bot_token leaves the stored token intact."""
    bool_updates = {
        KEY_ENABLED: enabled,
        KEY_QUALIFIED: qualified_enabled,
        KEY_SR: sr_proximity_enabled,
        KEY_SCORE_DROP: score_drop_enabled,
        KEY_DIGEST: digest_enabled,
    }
    for key, val in bool_updates.items():
        if val is not None:
            await update_setting(db, key, "true" if val else "false")

    if telegram_chat_id is not None:
        await update_setting(db, KEY_CHAT_ID, telegram_chat_id.strip())

    if bot_token:  # only overwrite when a non-empty token is supplied
        await update_setting(db, KEY_TOKEN, bot_token.strip())

    return await get_alert_config(db)


# ---------------------------------------------------------------------------
# Telegram transport
# ---------------------------------------------------------------------------

async def _send(client: httpx.AsyncClient, token: str, chat_id: str, text: str) -> None:
    resp = await client.post(
        f"https://api.telegram.org/bot{token}/sendMessage",
        json={
            "chat_id": chat_id,
            "text": text,
            "parse_mode": "HTML",
            "disable_web_page_preview": True,
        },
    )
    resp.raise_for_status()


# ---------------------------------------------------------------------------
# Dedup helpers
# ---------------------------------------------------------------------------

async def _recently_alerted(
    db: AsyncSession, alert_type: str, key: str, cooldown_hours: int = COOLDOWN_HOURS
) -> bool:
    cutoff = datetime.now(timezone.utc) - timedelta(hours=cooldown_hours)
    result = await db.execute(
        select(AlertLog.id)
        .where(
            AlertLog.alert_type == alert_type,
            AlertLog.dedup_key == key,
            AlertLog.created_at > cutoff,
        )
        .limit(1)
    )
    return result.first() is not None


def _log_alert(db: AsyncSession, alert_type: str, key: str, value: float | None = None) -> None:
    db.add(
        AlertLog(
            alert_type=alert_type,
            dedup_key=key,
            value=value,
            created_at=datetime.now(timezone.utc),
        )
    )


async def _watermark(db: AsyncSession, symbol: str) -> float | None:
    result = await db.execute(
        select(AlertLog.value)
        .where(AlertLog.alert_type == WATERMARK_TYPE, AlertLog.dedup_key == symbol)
        .order_by(AlertLog.created_at.desc())
        .limit(1)
    )
    row = result.first()
    return row[0] if row else None


# ---------------------------------------------------------------------------
# Trigger collectors
# ---------------------------------------------------------------------------

async def _watchlist_tickers(db: AsyncSession) -> list[tuple[int, str]]:
    """Distinct tickers across all watchlists (single-user app → one chat)."""
    result = await db.execute(
        select(WatchlistEntry.ticker_id, Ticker.symbol)
        .join(Ticker, WatchlistEntry.ticker_id == Ticker.id)
        .where(WatchlistEntry.entry_type != "dismissed")
        .distinct()
    )
    return [(tid, sym) for tid, sym in result.all()]


async def _qualified_setups(db: AsyncSession) -> list[dict]:
    setups = await get_trade_setups(db)
    config = await get_activation_config(db)
    return [s for s in setups if setup_qualifies(SimpleNamespace(**s), config)]


def _format_qualified(s: dict) -> str:
    prob = best_target_probability(SimpleNamespace(**s))
    arrow = "🟢" if s["direction"] == "long" else "🔴"
    return (
        f"{arrow} <b>{s['symbol']} {s['direction'].upper()}</b> — qualified setup\n"
        f"entry {s['entry_price']:.2f} → target {s['target']:.2f} "
        f"(R:R {s['rr_ratio']:.1f}:1)\n"
        f"confidence {(s.get('confidence_score') or 0):.0f}% · P(target) {prob:.0f}%"
    )


async def _collect_qualified(db: AsyncSession) -> list[tuple[str, str]]:
    out: list[tuple[str, str]] = []
    for s in await _qualified_setups(db):
        key = f"qualified:{s['symbol']}:{s['direction']}"
        out.append((key, _format_qualified(s)))
    return out


async def _latest_close(db: AsyncSession, ticker_id: int) -> float | None:
    result = await db.execute(
        select(OHLCVRecord.close)
        .where(OHLCVRecord.ticker_id == ticker_id)
        .order_by(OHLCVRecord.date.desc())
        .limit(1)
    )
    row = result.first()
    return float(row[0]) if row else None


async def _collect_sr_proximity(db: AsyncSession) -> list[tuple[str, str]]:
    """One alert per watchlist ticker for the NEAREST strong S/R zone within range.

    Levels are merged into zones with the same clusterer the chart uses, so a
    cluster of near-duplicate levels (e.g. 183 + 185) is a single zone and a
    single alert. Scoped to the watchlist only — qualified tickers already get
    their own 'qualified setup' alert, so S/R on them would be redundant.
    """
    out: list[tuple[str, str]] = []
    for tid, symbol in await _watchlist_tickers(db):
        price = await _latest_close(db, tid)
        if not price:
            continue

        levels_result = await db.execute(select(SRLevel).where(SRLevel.ticker_id == tid))
        levels = [
            {"price_level": lv.price_level, "strength": lv.strength, "type": lv.type}
            for lv in levels_result.scalars().all()
        ]
        if not levels:
            continue

        zones = cluster_sr_zones(levels, price, tolerance=SR_CLUSTER_TOLERANCE)
        strong = [z for z in zones if z["strength"] >= SR_MIN_STRENGTH]
        if not strong:
            continue

        # Nearest strong zone only.
        nearest = min(strong, key=lambda z: abs(price - z["midpoint"]))
        dist_pct = abs(price - nearest["midpoint"]) / price * 100
        if dist_pct > SR_PROXIMITY_PCT:
            continue

        label = (
            f"{nearest['low']:.2f}–{nearest['high']:.2f}"
            if nearest["level_count"] > 1
            else f"{nearest['midpoint']:.2f}"
        )
        key = f"sr:{symbol}:{nearest['type']}"  # one per side per ticker per cooldown
        out.append((
            key,
            f"📍 <b>{symbol}</b> approaching {nearest['type']} {label} "
            f"(now {price:.2f}, {dist_pct:.1f}% away)",
        ))
    return out


async def _collect_score_drops(db: AsyncSession) -> list[tuple[str, str]]:
    """Returns drop messages and (as a side effect) advances watermarks.

    Watermark = the reference composite. Alert when current drops
    SCORE_DROP_POINTS below it, then rebaseline to current so a single slide
    doesn't re-fire; let the watermark rise with the score so the next drop is
    measured from the new high.
    """
    out: list[tuple[str, str]] = []
    for tid, symbol in await _watchlist_tickers(db):
        comp_result = await db.execute(
            select(CompositeScore.score).where(CompositeScore.ticker_id == tid)
        )
        row = comp_result.first()
        if row is None or row[0] is None:
            continue
        current = float(row[0])

        base = await _watermark(db, symbol)
        if base is None:
            _log_alert(db, WATERMARK_TYPE, symbol, value=current)  # seed, no alert
            continue
        if current <= base - SCORE_DROP_POINTS:
            out.append((
                f"scoredrop:{symbol}",
                f"🔻 <b>{symbol}</b> composite score fell to {current:.0f} (from {base:.0f})",
            ))
            _log_alert(db, WATERMARK_TYPE, symbol, value=current)  # rebaseline
        elif current > base:
            _log_alert(db, WATERMARK_TYPE, symbol, value=current)  # track the rise
    return out


async def _collect_digest(db: AsyncSession) -> tuple[str, str] | None:
    now = datetime.now(timezone.utc)
    if now.hour < DIGEST_HOUR_UTC:
        return None
    key = f"digest:{now.date().isoformat()}"
    if await _recently_alerted(db, "digest", key, cooldown_hours=20):
        return None

    qualified = await _qualified_setups(db)
    lines = [f"📊 <b>Daily digest</b> — {now.date().isoformat()}"]
    if qualified:
        top = sorted(qualified, key=lambda s: s["rr_ratio"], reverse=True)[:5]
        lines.append(f"{len(qualified)} qualified setup(s):")
        for s in top:
            lines.append(
                f"• {s['symbol']} {s['direction'].upper()} "
                f"R:R {s['rr_ratio']:.1f}:1, conf {(s.get('confidence_score') or 0):.0f}%"
            )
    else:
        lines.append("No qualified setups today.")
    return key, "\n".join(lines)


# ---------------------------------------------------------------------------
# Dispatch
# ---------------------------------------------------------------------------

async def dispatch_alerts(db: AsyncSession) -> dict:
    """Gather all enabled triggers, dedup, and push to Telegram. Job entrypoint."""
    cfg = await _resolve(db)
    if not cfg["enabled"]:
        return {"status": "disabled", "sent": 0}
    if not cfg["token"] or not cfg["chat_id"]:
        return {"status": "no_credentials", "sent": 0}

    outgoing: list[tuple[str, str, str]] = []  # (alert_type, key, text)

    if cfg["qualified"]:
        for key, text in await _collect_qualified(db):
            if not await _recently_alerted(db, "qualified", key):
                outgoing.append(("qualified", key, text))

    if cfg["sr"]:
        for key, text in await _collect_sr_proximity(db):
            if not await _recently_alerted(db, "sr_proximity", key):
                outgoing.append(("sr_proximity", key, text))

    if cfg["score_drop"]:
        # also seeds/advances watermarks as a side effect
        for key, text in await _collect_score_drops(db):
            outgoing.append(("score_drop", key, text))

    if cfg["digest"]:
        digest = await _collect_digest(db)
        if digest is not None:
            outgoing.append(("digest", digest[0], digest[1]))

    sent = 0
    if outgoing:
        async with httpx.AsyncClient(timeout=15) as client:
            for alert_type, key, text in outgoing:
                try:
                    await _send(client, cfg["token"], cfg["chat_id"], text)
                    _log_alert(db, alert_type, key)
                    sent += 1
                except Exception:
                    logger.exception("Failed to send alert %s", key)

    await db.commit()  # persist watermark seeds/advances and sent-logs
    return {"status": "ok", "sent": sent, "candidates": len(outgoing)}


async def send_test_alert(db: AsyncSession) -> dict:
    """Send a fixed message to verify Telegram credentials."""
    cfg = await _resolve(db)
    if not cfg["token"] or not cfg["chat_id"]:
        return {"ok": False, "error": "Bot token and chat ID must both be configured."}
    try:
        async with httpx.AsyncClient(timeout=15) as client:
            await _send(
                client, cfg["token"], cfg["chat_id"],
                "✅ <b>Signal Platform</b> — test alert. Notifications are wired up correctly.",
            )
        return {"ok": True}
    except Exception as exc:
        logger.warning("Test alert failed: %s", exc)
        return {"ok": False, "error": str(exc)}