// 初始化地图
const map = L.map('map').setView([31.2304, 121.4737], 13);
L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
    attribution: '© OpenStreetMap contributors'
}).addTo(map);

let markers = [];
let routeLine = null;
let userMarker = null;

// 获取用户位置（模拟为上海中心）
const userLat = 31.2304, userLng = 121.4737;
userMarker = L.marker([userLat, userLng], { icon: L.divIcon({ className: 'user-marker', html: '📍', iconSize: [24, 24] }) }).addTo(map).bindPopup('您的位置');

// 搜索按钮
document.getElementById('searchBtn').addEventListener('click', async () => {
    const destination = document.getElementById('destination').value;
    const budget = document.getElementById('budget').value;
    const preferences = Array.from(document.querySelectorAll('.checkboxes input:checked')).map(cb => cb.value);

    const res = await fetch('/api/recommend', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ destination, budget, preferences, lat: userLat, lng: userLng })
    });
    const data = await res.json();
    renderHotels(data.hotels);
    renderMarkers(data.hotels);
});

function renderHotels(hotels) {
    const list = document.getElementById('hotelList');
    list.innerHTML = '';
    hotels.forEach((h, i) => {
        const card = document.createElement('div');
        card.className = 'hotel-card';
        card.innerHTML = `
            <h3>${h.name}</h3>
            <div class="meta"><span>⭐ ${h.rating}</span><span>¥${h.price}/晚</span></div>
            <div class="meta"><span>📏 ${h.distance} km</span><span>🎯 ${h.score}分</span></div>
            <div class="tags">${h.tags.map(t => `<span>${t}</span>`).join('')}</div>
        `;
        card.addEventListener('click', () => {
            document.querySelectorAll('.hotel-card').forEach(c => c.classList.remove('active'));
            card.classList.add('active');
            showRoute(h);
        });
        list.appendChild(card);
    });
}

function renderMarkers(hotels) {
    markers.forEach(m => map.removeLayer(m));
    markers = [];
    if (routeLine) { map.removeLayer(routeLine); routeLine = null; }
    const bounds = [[userLat, userLng]];
    hotels.forEach(h => {
        const marker = L.marker([h.lat, h.lng]).addTo(map)
            .bindPopup(`<b>${h.name}</b><br>¥${h.price}/晚 · ⭐${h.rating}<br>距离: ${h.distance} km`);
        markers.push(marker);
        bounds.push([h.lat, h.lng]);
    });
    map.fitBounds(bounds, { padding: [50, 50] });
}

function showRoute(hotel) {
    if (routeLine) map.removeLayer(routeLine);
    // 直线路线（实际可接入路由API）
    const points = [[userLat, userLng], [hotel.lat, hotel.lng]];
    routeLine = L.polyline(points, { color: '#667eea', weight: 4, dashArray: '8,8' }).addTo(map);
    map.fitBounds(routeLine.getBounds(), { padding: [50, 50] });
    L.popup()
        .setLatLng([(userLat + hotel.lat) / 2, (userLng + hotel.lng) / 2])
        .setContent(`距离: ${hotel.distance} km`)
        .openOn(map);
}