import logging
from django.db import transaction, IntegrityError
from time import perf_counter
from system.models import ShipLatestStatus

logger = logging.getLogger(__name__)

def safe_bulk_upsert(ship_data_list):
    start_time = perf_counter()
    created = updated = 0
    try:
        # 验证数据格式
        valid_data = []
        for data in ship_data_list:
            if 'mmsi' not in data:
                logger.warning("Missing MMSI in data: %s", data)
                continue
            valid_data.append(data)
        
        if not valid_data:
            return 0, 0
        
        # 执行批量操作
        with transaction.atomic():
            current_mmsi = {item['mmsi'] for item in valid_data}
            existing_map = ShipLatestStatus.objects.in_bulk(
                current_mmsi, field_name='mmsi'
            )
            
            to_create = []
            to_update = []
            
            for data in valid_data:
                mmsi = data['mmsi']
                if mmsi in existing_map:
                    ship = existing_map[mmsi]
                    for field, value in data.items():
                        setattr(ship, field, value)
                    to_update.append(ship)
                else:
                    to_create.append(ShipLatestStatus(**data))
            
            if to_create:
                created = len(ShipLatestStatus.objects.bulk_create(to_create))
            
            if to_update:
                update_fields = [f.name for f in ShipLatestStatus._meta.fields 
                                if f.name not in ['id', 'mmsi']]
                ShipLatestStatus.objects.bulk_update(to_update, update_fields)
                updated = len(to_update)
        
    except IntegrityError as e:
        logger.error("Integrity error in bulk upsert: %s", str(e))
        # 这里可以添加重试或更精细的错误处理
        raise
    except Exception as e:
        logger.exception("Unexpected error in bulk upsert")
        raise
    
    elapsed = (perf_counter() - start_time) * 1000
    logger.info(f"Processed {len(valid_data)} ships in {elapsed:.2f}ms: "
                f"{created} created, {updated} updated")
    
    return created, updated



def get_nearby_ships(latitude: float, longitude: float, radius_nm: float = 20.0):
    # 将海里转换为公里（Haversine公式使用公里）
    radius_km = radius_nm * 1.852
    
    # 使用原生SQL计算
    return ShipLatestStatus.objects.raw("""
        SELECT *,
            (6371 * acos(
                cos(radians(%s)) 
                * cos(radians(latitude)) 
                * cos(radians(longitude) - radians(%s)) 
                + sin(radians(%s)) 
                * sin(radians(latitude))
            )) AS distance
        FROM ship_latest_status
        HAVING distance <= %s
        ORDER BY distance
    """, [latitude, longitude, latitude, radius_km])