// 推荐功能脚本

let currentUserId = null;

// DOM元素
const loginSection = document.getElementById('loginSection');
const requestSection = document.getElementById('requestSection');
const recommendationsSection = document.getElementById('recommendationsSection');
const messageArea = document.getElementById('messageArea');

const loginBtn = document.getElementById('loginBtn');
const userIdInput = document.getElementById('userId');
const getRecommendationBtn = document.getElementById('getRecommendationBtn');
const mealTypeSelect = document.getElementById('mealType');
const recommendationsList = document.getElementById('recommendationsList');

// 显示消息
function showMessage(message, type = 'info') {
    messageArea.textContent = message;
    messageArea.className = `message-area ${type}`;
    messageArea.style.display = 'block';
    setTimeout(() => {
        messageArea.className = 'message-area';
        messageArea.style.display = 'none';
    }, 3000);
}

// 用户登录
loginBtn.addEventListener('click', async () => {
    const userId = userIdInput.value.trim();
    
    if (!userId) {
        showMessage('请输入用户ID', 'error');
        return;
    }
    
    loginBtn.disabled = true;
    loginBtn.textContent = '登录中...';
    
    try {
        const response = await fetch('/api/user/login', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json; charset=utf-8'
            },
            body: JSON.stringify({
                user_id: userId
            })
        });
        
        const data = await response.json();
        
        if (data.success) {
            currentUserId = userId;
            loginSection.style.display = 'none';
            requestSection.style.display = 'block';
            showMessage(`欢迎，${data.name || userId}！`, 'success');
        } else {
            showMessage(data.message || '登录失败', 'error');
        }
    } catch (error) {
        console.error('登录失败:', error);
        showMessage('登录失败，请检查网络连接', 'error');
    } finally {
        loginBtn.disabled = false;
        loginBtn.textContent = '登录';
    }
});

// 获取推荐
getRecommendationBtn.addEventListener('click', async () => {
    const mealType = mealTypeSelect.value;
    
    getRecommendationBtn.disabled = true;
    getRecommendationBtn.textContent = '获取中...';
    
    try {
        const response = await fetch('/api/recommendation/get', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json; charset=utf-8'
            },
            body: JSON.stringify({
                user_id: currentUserId,
                meal_type: mealType,
                preferences: {},
                context: {}
            })
        });
        
        const data = await response.json();
        
        if (data.success && data.recommendations && data.recommendations.length > 0) {
            displayRecommendations(data.recommendations);
            recommendationsSection.style.display = 'block';
            showMessage('推荐获取成功！', 'success');
        } else {
            showMessage(data.message || '暂无推荐内容，请先完善个人数据', 'info');
        }
    } catch (error) {
        console.error('获取推荐失败:', error);
        showMessage('获取推荐失败，请检查网络连接', 'error');
    } finally {
        getRecommendationBtn.disabled = false;
        getRecommendationBtn.textContent = '获取推荐';
    }
});

// 显示推荐结果
function displayRecommendations(recommendations) {
    recommendationsList.innerHTML = '';
    
    recommendations.forEach((rec, index) => {
        const card = document.createElement('div');
        card.className = 'recommendation-card';
        
        let foods = [];
        if (rec.foods && Array.isArray(rec.foods)) {
            foods = rec.foods;
        } else if (rec.food) {
            foods = [rec.food];
        }
        
        const foodsHtml = foods.map(food => 
            `<div class="food-item">${escapeHtml(food)}</div>`
        ).join('');
        
        const confidenceHtml = rec.confidence 
            ? `<div class="confidence">置信度: ${(rec.confidence * 100).toFixed(1)}%</div>` 
            : '';
        
        const reasonHtml = rec.reason 
            ? `<div style="margin-top: 10px; color: #666;">推荐理由: ${escapeHtml(rec.reason)}</div>` 
            : '';
        
        card.innerHTML = `
            <h3>推荐方案 ${index + 1}</h3>
            <div class="food-list">
                ${foodsHtml}
            </div>
            ${confidenceHtml}
            ${reasonHtml}
        `;
        
        recommendationsList.appendChild(card);
    });
}

// HTML转义函数，防止XSS攻击
function escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}