import paho.mqtt.client as mqtt
import json
import logging
import time
import re
import asyncio

logger = logging.getLogger("mqtt_client")

# ── 설정 ──────────────────────────────────────────────────
BROKER_HOST = "localhost"
BROKER_PORT = 1883

# MQTT 토픽 규칙:
#   장비→서버(읽기):  /{prefix}/m/in, /{prefix}/d/in, /{prefix}/event
#   서버→장비(쓰기):  /{prefix}/m/out, /{prefix}/d/out

_client: mqtt.Client = None


from .line_manager import line_manager

def _get_equipment_id_by_prefix(prefix: str) -> int:
    """
    토픽 프리픽스를 기반으로 DB의 설비 ID를 반환합니다 (LineManager 연동).
    """
    return line_manager.get_equipment_id(prefix)


def _publish_hmi_update(equipment_id: int):
    """
    HMI 실시간 상태 업데이트 데이터를 조회하여 WebSocket으로 브로드캐스트합니다.
    MQTT 수신 스레드가 블로킹되는 현상을 피하기 위해 Future 대기 없이 이벤트 루프에 비동기 처리만 위임합니다.
    """
    try:
        from equipment.db_manager import get_machine_status_detail_joined
        from communication.websocket_manager import ws_manager
        
        result = get_machine_status_detail_joined(equipment_id)
        if result:
            # Decimal 타입 등의 변환 오류 방지 안전 필터 적용
            # 그룹 0,5(순환펌프 재작동 시간)만 정수, 나머지 d_read와 모든 d_write는 PLC REAL이므로 소수점 보존
            for i in range(10):
                key = f"d_read_g{i}"
                if key in result and result[key] is not None:
                    try:
                        result[key] = int(result[key]) if i in (0, 5) else float(result[key])
                    except:
                        result[key] = 0
            for i in range(4):
                key = f"d_write_g{i}"
                if key in result and result[key] is not None:
                    try:
                        result[key] = float(result[key])
                    except:
                        result[key] = 0

            # 웹소켓 매니저의 메인 이벤트 루프로 비동기 브로드캐스트 위임
            loop = getattr(ws_manager, 'loop', None)
            if loop and loop.is_running():
                asyncio.run_coroutine_threadsafe(
                    ws_manager.broadcast({
                        "type": "equipment_update",
                        "equipment_id": equipment_id,
                        "data": result,
                        "timestamp": int(time.time() * 1000)
                    }),
                    loop
                )
    except Exception as e:
        logger.error(f"[WS BROADCAST ERROR] Failed to broadcast for equipment_id {equipment_id}: {e}", exc_info=True)


def _on_connect(client, userdata, flags, rc):
    if rc == 0:
        logger.info("[MQTT] Connected to broker successfully.")
        
        # line_config.json에 등록된 모든 라인의 토픽 동적 구독
        prefixes = line_manager.get_all_prefixes()
        for prefix in prefixes:
            client.subscribe(f"/{prefix}/m/in")
            client.subscribe(f"/{prefix}/d/in")
            client.subscribe(f"/{prefix}/event")
            client.subscribe(f"/{prefix}/ack")
            client.subscribe(f"/{prefix}/status")
        
        logger.info(f"[MQTT] Dynamically subscribed to topics for prefixes: {prefixes}")
    else:
        logger.error(f"[MQTT] Connection failed: rc={rc}")


def _on_message(client, userdata, msg):
    """
    배치 데이터 [[id, val], ...] 수집 및 DB 동기화, HMI 실시간 전계 (성능 모니터링 포함)
    """
    start_time = time.time()
    topic = msg.topic
    try:
        payload_str = msg.payload.decode()
        logger.info(f"[MQTT RECEIVE] Topic: {topic} | Payload: {payload_str}")
        
        payload = json.loads(payload_str)
        
        # 토픽 프리픽스 동적 해석
        match = re.search(r'/([^/]+)/(m|d|event|ack|status)', topic)
        line_prefix = match.group(1) if match else "line1"
        equipment_id = _get_equipment_id_by_prefix(line_prefix)

        from database.connection import get_db_connection

        if "/ack" in topic:
            command_id = payload.get("command_id")
            status = payload.get("status")
            applied_value = payload.get("applied_value") # 적용 데이터 파싱
            logger.info(f"[MQTT ACK Callback] Received Event command {command_id} status={status} applied_value={applied_value} for prefix: {line_prefix}")
            
            # DB 상태 및 적용값 분리 저장 업데이트
            from equipment.db_manager import update_control_command_status
            update_control_command_status(command_id, status, applied_value)
            
            # WebSocket HMI 브로드캐스트
            from communication.websocket_manager import ws_manager
            loop = getattr(ws_manager, 'loop', None)
            if loop and loop.is_running():
                asyncio.run_coroutine_threadsafe(
                    ws_manager.broadcast({
                        "type": "command_ack",
                        "command_id": command_id,
                        "status": status,
                        "applied_value": applied_value,
                        "timestamp": int(time.time() * 1000)
                    }),
                    loop
                )

        elif "/status" in topic:
            gateway = payload.get("gateway", "OFFLINE")
            plc_state = payload.get("plc_state", "OFFLINE")
        
            logger.info(
                f"[MQTT STATUS Callback] gateway={gateway}, "
                f"plc_state={plc_state} for prefix: {line_prefix}"
            )
        
            # 상태 토픽을 기준으로 장비 상태와 동기화 상태를 함께 갱신
            sync_state = None
        
            if gateway == "OFFLINE" or plc_state == "OFFLINE":
                device_state = "OFFLINE"
            elif gateway == "SYNCING":
                device_state = "SYNCING"
                sync_state = "SYNCING"
            else:
                device_state = "ONLINE"
                sync_state = "IDLE"
        
            with get_db_connection() as conn:
                with conn.cursor() as cursor:
                    cursor.execute(
                        """
                        UPDATE machine_status
                        SET gateway_state = %s,
                            plc_state = %s,
                            device_state = %s,
                            sync_state = COALESCE(%s, sync_state),
                            timestamp = CURRENT_TIMESTAMP
                        WHERE equipment_id = %s
                        """,
                        (
                            gateway,
                            plc_state,
                            device_state,
                            sync_state,
                            equipment_id
                        )
                    )
                    conn.commit()
        
            _publish_hmi_update(equipment_id)

        elif "/event" in topic:
            event_id = payload.get("id")
            event_val = payload.get("val")
            logger.info(f"[MQTT Event Callback] Received Event {event_id} (value={event_val}) for prefix: {line_prefix}")
            
            # Full-Sync 혹은 PLC 오프라인 상태값 업데이트
            device_state = "ONLINE"
            sync_state = "IDLE"
            if event_id == 999:    # Full-Sync 시작 (STATE_INIT 진입)
                device_state = "SYNCING"
                sync_state = "SYNCING"
            elif event_id == 998:  # PLC Modbus 통신 실패 감지
                device_state = "OFFLINE"
            elif event_id == 997:  # Full-Sync 완료 (정상 루프 진입)
                device_state = "ONLINE"
                sync_state = "IDLE"

            with get_db_connection() as conn:
                with conn.cursor() as cursor:
                    if event_id == 998:
                        cursor.execute(
                            "UPDATE machine_status SET device_state = %s, plc_state = 'OFFLINE', timestamp = CURRENT_TIMESTAMP WHERE equipment_id = %s",
                            (device_state, equipment_id)
                        )
                    else:
                        cursor.execute(
                            "UPDATE machine_status SET device_state = %s, sync_state = %s, timestamp = CURRENT_TIMESTAMP WHERE equipment_id = %s",
                            (device_state, sync_state, equipment_id)
                        )
                    conn.commit()
            
            logger.info(f"[MQTT Event DB Update Completed] device_state updated to: {device_state}")
            _publish_hmi_update(equipment_id)

        elif "/m/in" in topic:
            if not isinstance(payload, list):
                raise ValueError("M_in payload is not a JSON list")
            logger.info(f"[MQTT Processing M_in] Size of incoming batch: {len(payload)} for prefix: {line_prefix}")
            # 1. 기존 m_read_raw 및 m_write_raw JSON 데이터 조회
            with get_db_connection() as conn:
                with conn.cursor(dictionary=True) as cursor:
                    cursor.execute("SELECT m_read_raw, m_write_raw FROM machine_status WHERE equipment_id = %s", (equipment_id,))
                    row = cursor.fetchone()
                    
                    m_read = {}
                    if row and row.get("m_read_raw"):
                        try:
                            m_read = json.loads(row["m_read_raw"])
                        except:
                            pass
                            
                    m_write = {}
                    if row and row.get("m_write_raw"):
                        try:
                            m_write = json.loads(row["m_write_raw"])
                        except:
                            pass
                    
                    # 2. 배치 배열 수신값 머지 [[bit_id, val], ...]
                    for item in payload:
                        if isinstance(item, list) and len(item) == 2:
                            bit_id = str(item[0])
                            val = int(item[1])
                            m_read[bit_id] = val
                    
                    # 3. 모멘터리 비트 정리: 쓰기 버퍼(m_write_raw) 중 1로 켜져있던 비트들을 0으로 복구
                    # (ESP32 측에서 이미 쓰기 실행 및 자동 리셋을 처리했으므로 서버측 DB만 동기화하고 패킷은 송신 안함)
                    for k, v in m_write.items():
                        if v == 1:
                            m_write[k] = 0
                    
                    # 4. DB에 병합된 M 데이터 업데이트
                    cursor.execute(
                        "UPDATE machine_status SET m_read_raw = %s, m_write_raw = %s, device_state = 'ONLINE', timestamp = CURRENT_TIMESTAMP WHERE equipment_id = %s",
                        (json.dumps(m_read), json.dumps(m_write), equipment_id)
                    )
                    conn.commit()
            
            logger.info(f"[MQTT Processing M_in Completed] Successfully merged and saved {len(payload)} bits to DB.")
            _publish_hmi_update(equipment_id)

        elif "/d/in" in topic:
            if not isinstance(payload, list):
                raise ValueError("D_in payload is not a JSON list")
            logger.info(f"[MQTT Processing D_in] Size of incoming batch: {len(payload)} for prefix: {line_prefix}")
            # D영역 업데이트: [[group_id, val], ...]
            with get_db_connection() as conn:
                with conn.cursor() as cursor:
                    for item in payload:
                        if isinstance(item, list) and len(item) == 2:
                            group_id = int(item[0])
                            # 그룹 0,5(순환펌프 재작동 시간)는 UINT16 정수, 그 외는 PLC REAL이므로 소수점 보존
                            val = int(item[1]) if group_id in (0, 5) else float(item[1])
                            if 0 <= group_id <= 9:
                                sql = f"UPDATE machine_status SET d_read_g{group_id} = %s, device_state = 'ONLINE', timestamp = CURRENT_TIMESTAMP WHERE equipment_id = %s"
                                cursor.execute(sql, (val, equipment_id))
                    conn.commit()
            
            logger.info(f"[MQTT Processing D_in Completed] Successfully saved {len(payload)} D-registers to DB.")
            _publish_hmi_update(equipment_id)

        # 성공 처리 시간 기록
        duration_ms = (time.time() - start_time) * 1000
        from monitoring.metrics import record_metric
        record_metric(topic, duration_ms)

    except Exception as e:
        duration_ms = (time.time() - start_time) * 1000
        from monitoring.metrics import record_metric
        record_metric(topic, duration_ms, error=True, error_msg=str(e))
        logger.error(f"[MQTT ERROR] Message parse/update error: {e}", exc_info=True)


def start_mqtt_client(db=None):
    """
    FastAPI 어플리케이션 구동 시 호출됩니다.
    """
    global _client
    _client = mqtt.Client(client_id="ChemiFactory_HMI_Server")
    
    # MQTT 인증 계정 정보 적용 (rc=5 방지)
    _client.username_pw_set("ctnt_root", "Umsang6595!!")
    
    _client.on_connect = _on_connect
    _client.on_message = _on_message
    
    try:
        logger.info(f"[MQTT INIT] Connecting to broker at {BROKER_HOST}:{BROKER_PORT}...")
        _client.connect(BROKER_HOST, BROKER_PORT, 60)
        _client.loop_start()
        logger.info("[MQTT INIT] Background client started and loop active.")
    except Exception as e:
        logger.error(f"[MQTT INIT ERROR] Startup failed: {e}", exc_info=True)


def stop_mqtt_client():
    global _client
    if _client:
        _client.loop_stop()
        _client.disconnect()
        logger.info("[MQTT] Background client stopped successfully.")