import random
import math
from ninja import Router

from django.utils import timezone
from datetime import timedelta
from system.models import GpsStatus, ShipLatestStatus, MessageFlag
from fuadmin.settings import OWN_SHIP_MMSI


router = Router()

def haversine(lat1, lon1, lat2, lon2):
    """计算两点间的大圆距离（公里）"""
    R = 6371  # 地球半径(公里)
    
    # 将角度转换为弧度
    lat1, lon1, lat2, lon2 = map(math.radians, [lat1, lon1, lat2, lon2])
    
    # 差值
    dlat = lat2 - lat1
    dlon = lon2 - lon1
    
    # Haversine公式
    a = math.sin(dlat/2)**2 + math.cos(lat1) * math.cos(lat2) * math.sin(dlon/2)**2
    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1-a))
    
    return R * c


def calculate_relative_bearing(own_lat, own_lon, own_course, target_lat, target_lon):
    """
    计算目标点相对本船航向的方向角（相对方位，单位°，0~360，顺时针）
    """
    d_lon = math.radians(target_lon - own_lon)
    lat1 = math.radians(own_lat)
    lat2 = math.radians(target_lat)

    x = math.sin(d_lon) * math.cos(lat2)
    y = math.cos(lat1)*math.sin(lat2) - math.sin(lat1)*math.cos(lat2)*math.cos(d_lon)
    initial_bearing = math.atan2(x, y)
    initial_bearing_deg = (math.degrees(initial_bearing) + 360) % 360  # 转换为 0~360 度

    # 相对航向（目标相对于本船正前的角度）
    relative_bearing = (initial_bearing_deg - own_course + 360) % 360
    return relative_bearing


@router.get("/header")
def get_header_info(request):
    # 固定本船MMSI
    ownship_mmsi = OWN_SHIP_MMSI
    # current_time = datetime.now()
    # current_date = current_time.strftime('%Y-%m-%d')
    # current_time_str = current_time.strftime('%H:%M')
    
    # # 检查是否是第一次调用，如果是则初始化位置
    # if not hasattr(get_header_info, 'ship_data'):
    #     # 初始位置 (30.9918, 122.2788)
    #     get_header_info.ship_data = {
    #         'mmsi': ownship_mmsi,
    #         'latitude': 30.9918,
    #         'longitude': 122.2788,
    #         'speed': 12.0,
    #         'course': 45,
    #         'date': current_date,
    #         'time': current_time_str
    #     }
    # else:
    #     # 更新位置和航向
    #     get_header_info.ship_data['latitude'] = round(get_header_info.ship_data['latitude'] + 0.001, 4)
    #     get_header_info.ship_data['longitude'] = round(get_header_info.ship_data['longitude'] + 0.001, 4)
    #     get_header_info.ship_data['course'] = round((get_header_info.ship_data['course'] + 5) % 360, 1)
    #     get_header_info.ship_data['date'] = current_date
    #     get_header_info.ship_data['time'] = current_time_str
    
    # # 将数据保存到GpsStatus模型
    # GpsStatus.objects.create(
    #     utc_time=current_time,
    #     longitude=get_header_info.ship_data['longitude'],
    #     latitude=get_header_info.ship_data['latitude'],
    #     altitude=0.0,  # 固定值
    #     used_satellites=10,  # 固定值
    #     gps_satellites=6,  # 固定值
    #     beidou_satellites=4,  # 固定值
    #     gps_status=1,  # 固定值，1表示正常
    #     fix_mode=3,  # 固定值，3表示3D定位
    #     hdop=1.2,  # 固定值
    #     speed=get_header_info.ship_data['speed'],
    #     direction=get_header_info.ship_data['course']
    # )
    
    #查询最新经纬度数据
    latest_gps = GpsStatus.objects.order_by('-utc_time').first()

    # 计算 10 分钟前的时间，基于 GpsStatus 中的时间
    ten_minutes_ago = latest_gps.utc_time - timedelta(minutes=10)
    # 筛选出 10 分钟内的船只记录
    recent_ships = ShipLatestStatus.objects.filter(timestamp__gte=ten_minutes_ago)
    closest_ship = None
    min_distance_km = float('inf')
    for ship in recent_ships:
        # 计算本船与当前船只的距离（公里）
        distance_km = haversine(latest_gps.latitude, latest_gps.longitude, ship.latitude, ship.longitude)
        if distance_km < min_distance_km:
            min_distance_km = distance_km
            closest_ship = ship
    # 判断是否小于 5 海里（1 海里 = 1.852 公里）
    warning_message = ''
    # min_distance_km = random.randint(1, 20)
    print(min_distance_km)
    if 3 * 1.852 < min_distance_km < 5 * 1.852:
        warning_message = '注意，5海里范围内有其他船只'
        print(warning_message)
    elif min_distance_km <= 3 * 1.852:
        relative_bearing = calculate_relative_bearing(
            latest_gps.latitude,
            latest_gps.longitude,
            latest_gps.direction,  # 本船航向
            closest_ship.latitude,
            closest_ship.longitude
        )
        warning_message = f'警告：有船靠近，相对方位 {relative_bearing:.1f}°，相距 {min_distance_km / 1.852:.2f} 海里， 速度{closest_ship.speed}节'
    else:
        warning_message = '保持正常航行'
    flag = MessageFlag.objects.first()
    has_message = flag.has_new_message
    if has_message:
        flag.has_new_message = False
        flag.save()
    return {
            'mmsi': ownship_mmsi,  # 固定本船MMSI
            'latitude': latest_gps.latitude,
            'longitude': latest_gps.longitude,
            'speed': latest_gps.speed,
            'course': latest_gps.direction,
            'date': latest_gps.utc_time.strftime('%Y-%m-%d'),
            'time': latest_gps.utc_time.strftime('%H:%M'),
            "satelliteCount": random.randint(0, 12),
            "messageCount": 12,
            "reminderCount": random.randint(0, 20),
            "alertCount": random.randint(0, 15),
            "approachingCount": random.randint(0, 5),
            "trackStatus": False,
            "gpsSignal": round(random.uniform(0, 5), 1),
            "beidouSignal": round(random.uniform(0, 5), 1),
            "vdesSignal": round(random.uniform(0, 5), 1),
            "warning_message": warning_message,
            "is_receive_vdes_data": has_message
        }
    # return get_header_info.ship_data