// 初始化地图
const map = new google.maps.Map(document.getElementById('map'), {
  zoom: 13,
  center: {lat: 51.501, lng: -0.142}
});

// 创建标记
const marker = new google.maps.Marker({
  position: {lat: 51.501, lng: -0.142},
  map: map
});

// 目标位置
const targetPosition = {lat: 51.503, lng: -0.135};

// 动画参数
const duration = 2000; // 动画持续时间(毫秒)
const steps = 60; // 动画步数
const stepTime = duration / steps;

let currentStep = 0;

// 计算每一步的增量
const latIncrement = (targetPosition.lat - marker.getPosition().lat()) / steps;
const lngIncrement = (targetPosition.lng - marker.getPosition().lng()) / steps;

// 启动动画
const animation = setInterval(() => {
  if (currentStep >= steps) {
    clearInterval(animation);
    return;
  }
  
  const currentPosition = marker.getPosition();
  const newPosition = new google.maps.LatLng(
    currentPosition.lat() + latIncrement,
    currentPosition.lng() + lngIncrement
  );
  
  marker.setPosition(newPosition);
  currentStep++;
}, stepTime);

function easeInOutQuad(t) {
  return t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t;
}

function animateMarker(marker, targetPosition, duration) {
  const startPosition = marker.getPosition();
  const startTime = performance.now();
  
  function animate(currentTime) {
    const elapsed = currentTime - startTime;
    const progress = Math.min(elapsed / duration, 1);
    const easedProgress = easeInOutQuad(progress);
    
    const newLat = startPosition.lat() + 
      (targetPosition.lat - startPosition.lat()) * easedProgress;
    const newLng = startPosition.lng() + 
      (targetPosition.lng - startPosition.lng()) * easedProgress;
    
    marker.setPosition(new google.maps.LatLng(newLat, newLng));
    
    if (progress < 1) {
      requestAnimationFrame(animate);
    }
  }
  
  requestAnimationFrame(animate);
}

// 使用示例
animateMarker(marker, targetPosition, 2000);

function moveAlongPath(marker, path, duration) {
  const startTime = performance.now();
  const pathLength = path.length;
  
  function animate(currentTime) {
    const elapsed = currentTime - startTime;
    const progress = Math.min(elapsed / duration, 1);
    const index = Math.floor(progress * (pathLength - 1));
    
    if (index < pathLength - 1) {
      const segmentProgress = (progress * (pathLength - 1)) % 1;
      const currentPoint = path[index];
      const nextPoint = path[index + 1];
      
      const newLat = currentPoint.lat() + 
        (nextPoint.lat() - currentPoint.lat()) * segmentProgress;
      const newLng = currentPoint.lng() + 
        (nextPoint.lng() - currentPoint.lng()) * segmentProgress;
      
      marker.setPosition(new google.maps.LatLng(newLat, newLng));
      requestAnimationFrame(animate);
    } else {
      marker.setPosition(path[pathLength - 1]);
    }
  }
  
  requestAnimationFrame(animate);
}