"""
Worker Manager - Coordinates all sync workers.
"""
import asyncio
from motor.motor_asyncio import AsyncIOMotorClient
from sqlalchemy.ext.asyncio import create_async_engine
from sqlalchemy import text
import redis.asyncio as redis

from app.core.config import settings
from app.core.logging import get_logger, log_service_lifecycle

logger = get_logger(__name__)


class WorkerManager:
    """Manages all sync workers."""
    
    def __init__(self):
        self.mongo_client = None
        self.mongo_db = None
        self.pg_engine = None
        self.redis_client = None
        self.sync_services = {}
    
    async def initialize(self):
        """Initialize database connections."""
        log_service_lifecycle(logger, "connections_init")

        # MongoDB
        log_service_lifecycle(logger, "mongodb_connecting", host=settings.MONGODB_URI.split("@")[-1])
        self.mongo_client = AsyncIOMotorClient(settings.MONGODB_URI)
        self.mongo_db = self.mongo_client[settings.MONGODB_DB_NAME]
        await self.mongo_client.admin.command('ping')
        log_service_lifecycle(logger, "mongodb_connected", db=settings.MONGODB_DB_NAME)

        # PostgreSQL
        pg_url = f"postgresql+asyncpg://{settings.POSTGRES_USER}:{settings.POSTGRES_PASSWORD}@{settings.POSTGRES_HOST}:{settings.POSTGRES_PORT}/{settings.POSTGRES_DB}"
        log_service_lifecycle(logger, "postgres_connecting", host=settings.POSTGRES_HOST, port=settings.POSTGRES_PORT)
        self.pg_engine = create_async_engine(
            pg_url, echo=False, pool_pre_ping=True,
            pool_size=3, max_overflow=2, pool_timeout=30
        )
        async with self.pg_engine.begin() as conn:
            await conn.execute(text("SELECT 1"))
        log_service_lifecycle(logger, "postgres_connected", db=settings.POSTGRES_DB)

        # Redis
        log_service_lifecycle(logger, "redis_connecting", host=settings.REDIS_HOST, port=settings.REDIS_PORT)
        pool = redis.ConnectionPool(
            host=settings.REDIS_HOST,
            port=settings.REDIS_PORT,
            password=settings.REDIS_PASSWORD,
            db=settings.REDIS_DB,
            decode_responses=True,
            max_connections=50,  # 2 pods × ~18 workers + headroom for stats/enqueue calls
            socket_keepalive=True,
            socket_connect_timeout=5,
            retry_on_timeout=True,
            health_check_interval=30,
        )
        self.redis_client = redis.Redis(connection_pool=pool)
        await self.redis_client.ping()
        log_service_lifecycle(logger, "redis_connected", max_connections=15)

        await self._initialize_sync_services()
    
    async def _initialize_sync_services(self):
        """Initialize all sync services."""
        from app.sync.catalogues.service import CatalogueSyncService
        from app.sync.employees.service import EmployeeSyncService
        from app.sync.merchants.service import MerchantSyncService
        from app.sync.warehouses.service import WarehouseSyncService
        from app.sync.uom.service import UOMSyncService

        log_service_lifecycle(logger, "sync_services_init")

        self.sync_services = {
            "catalogues": CatalogueSyncService(
                mongo_db=self.mongo_db, pg_engine=self.pg_engine, redis_client=self.redis_client,
                max_queue_size=10000, worker_count=settings.CATALOGUE_WORKERS, max_retries=3,
            ),
            "employees": EmployeeSyncService(
                mongo_db=self.mongo_db, pg_engine=self.pg_engine, redis_client=self.redis_client,
                max_queue_size=10000, worker_count=settings.EMPLOYEE_WORKERS, max_retries=3,
            ),
            "merchants": MerchantSyncService(
                mongo_db=self.mongo_db, pg_engine=self.pg_engine, redis_client=self.redis_client,
                max_queue_size=10000, worker_count=settings.MERCHANT_WORKERS, max_retries=3,
            ),
            "warehouses": WarehouseSyncService(
                mongo_db=self.mongo_db, pg_engine=self.pg_engine, redis_client=self.redis_client,
                max_queue_size=10000, worker_count=settings.WAREHOUSE_WORKERS, max_retries=3,
            ),
            "uom": UOMSyncService(
                mongo_db=self.mongo_db, pg_engine=self.pg_engine, redis_client=self.redis_client,
                max_queue_size=5000, worker_count=settings.UOM_WORKERS, max_retries=3,
            ),
        }

        log_service_lifecycle(logger, "sync_services_ready", count=len(self.sync_services),
                              services=list(self.sync_services.keys()))
    
    async def start_all_workers(self):
        """Start all sync workers."""
        log_service_lifecycle(logger, "workers_starting", count=len(self.sync_services))

        for entity_type, service in self.sync_services.items():
            try:
                await service.start_workers()
                log_service_lifecycle(logger, "workers_started", entity_type=entity_type,
                                      worker_count=service.worker_count)
            except Exception as e:
                logger.error("Failed to start workers", exc_info=True,
                             extra={"event": "workers_start_error", "entity_type": entity_type, "error": str(e)})

        total_workers = sum(s.worker_count for s in self.sync_services.values())
        log_service_lifecycle(logger, "all_workers_started", total_workers=total_workers,
                              service_count=len(self.sync_services))

    async def stop_all_workers(self):
        """Stop all sync workers."""
        log_service_lifecycle(logger, "workers_stopping")

        for entity_type, service in self.sync_services.items():
            try:
                await service.stop_workers()
                log_service_lifecycle(logger, "workers_stopped", entity_type=entity_type)
            except Exception as e:
                logger.error("Failed to stop workers", exc_info=True,
                             extra={"event": "workers_stop_error", "entity_type": entity_type, "error": str(e)})

        if self.redis_client:
            await self.redis_client.aclose()
            log_service_lifecycle(logger, "redis_disconnected")

        if self.pg_engine:
            await self.pg_engine.dispose()
            log_service_lifecycle(logger, "postgres_disconnected")

        if self.mongo_client:
            self.mongo_client.close()
            log_service_lifecycle(logger, "mongodb_disconnected")