"""
Message Queue — Redis
─────────────────────
Push sentiment results → Dashboard (Lovable AI) รับแบบ real-time

ใช้ Redis List + Pub/Sub:
  - LPUSH  sentiment:results  → queue สำหรับ polling
  - PUBLISH sentiment:live    → pub/sub สำหรับ WebSocket / SSE
"""

import json
import logging
import redis.asyncio as aioredis
from app.config import settings

logger = logging.getLogger(__name__)

QUEUE_KEY  = "sentiment:results"
ALERT_KEY  = "sentiment:alerts"
PUBSUB_CH  = "sentiment:live"
ALERT_CH   = "sentiment:alert_live"


class MessageQueue:
    def __init__(self):
        self._redis: aioredis.Redis | None = None

    async def _get_redis(self) -> aioredis.Redis:
        if self._redis is None:
            self._redis = await aioredis.from_url(
                settings.REDIS_URL,
                encoding="utf-8",
                decode_responses=True,
            )
        return self._redis

    async def push(self, data: dict) -> None:
        """
        Push sentiment result เข้า queue และ publish ให้ subscribers
        """
        try:
            r = await self._get_redis()
            serialized = json.dumps(data, ensure_ascii=False)

            # List (Lovable polling หรือ worker ดึงไปประมวลผลต่อ)
            await r.lpush(QUEUE_KEY, serialized)
            await r.ltrim(QUEUE_KEY, 0, 999)  # เก็บแค่ 1,000 รายการล่าสุด

            # Pub/Sub (real-time Dashboard WebSocket)
            await r.publish(PUBSUB_CH, serialized)

            logger.debug(f"✅ Queued: conv_id={data.get('conv_id')}")

        except Exception as e:
            logger.error(f"❌ Queue push failed: {e}")

    async def push_alert(self, data: dict) -> None:
        """Push high-negative alert แยก channel"""
        try:
            r = await self._get_redis()
            serialized = json.dumps(data, ensure_ascii=False)
            await r.lpush(ALERT_KEY, serialized)
            await r.publish(ALERT_CH, serialized)
            logger.warning(f"🚨 Alert pushed: {data}")
        except Exception as e:
            logger.error(f"❌ Alert push failed: {e}")

    async def get_recent(self, count: int = 50) -> list[dict]:
        """ดึง result ล่าสุดจาก queue สำหรับ initial load"""
        try:
            r = await self._get_redis()
            items = await r.lrange(QUEUE_KEY, 0, count - 1)
            return [json.loads(i) for i in items]
        except Exception as e:
            logger.error(f"❌ Queue read failed: {e}")
            return []


# Singleton instance
message_queue = MessageQueue()