/**
 * Brain决策逻辑
 * 调用LLM分析产品信息并生成12张图的规划
 */

const fs = require('fs');
const path = require('path');
const axios = require('axios');

// 读取Brain System Prompt
const brainPromptPath = path.join(__dirname, '../prompts/brain-system.md');
let brainSystemPrompt = '';

try {
  brainSystemPrompt = fs.readFileSync(brainPromptPath, 'utf-8');
} catch (err) {
  console.error('Failed to load brain system prompt:', err.message);
}

/**
 * 调用LLM生成图片规划
 * @param {object} sku - SKU数据
 * @param {object} options - 选项
 * @param {string} options.apiKey - API密钥
 * @param {string} options.apiUrl - API地址
 * @param {string} options.model - 模型名称
 * @returns {Promise<object>} Brain输出的图片规划
 */
async function generateImagePlan(sku, options = {}) {
  const {
    apiKey = process.env.API_KEY,
    apiUrl = 'https://api2img.shubiaobiao.com/v1/chat/completions',
    model = 'gemini-3-pro-preview'
  } = options;

  if (!apiKey) {
    throw new Error('API_KEY is required');
  }

  // 构建用户消息
  const userMessage = `请根据以下产品信息，规划12张电商图片（6张主图 + 6张A+图）的内容策略。

## 产品信息

\`\`\`json
${JSON.stringify(sku, null, 2)}
\`\`\`

请严格按照System Prompt中的输出格式返回JSON。`;

  try {
    const response = await axios.post(apiUrl, {
      model: model,
      messages: [
        { role: 'system', content: brainSystemPrompt },
        { role: 'user', content: userMessage }
      ],
      temperature: 0.7,
      max_tokens: 8000
    }, {
      headers: {
        'Content-Type': 'application/json',
        'Authorization': `Bearer ${apiKey}`
      },
      timeout: 120000 // 2分钟超时
    });

    // 解析响应
    let content = response.data.choices?.[0]?.message?.content;
    
    if (!content) {
      throw new Error('Empty response from LLM');
    }

    // 清理响应内容
    content = cleanLLMResponse(content);

    // 解析JSON
    const plan = parseJSONFromResponse(content);
    
    // 验证输出格式
    validatePlan(plan);

    return plan;

  } catch (error) {
    console.error('Brain generation error:', error.message);
    throw error;
  }
}

/**
 * 清理LLM响应
 * @param {string} content - 原始响应内容
 * @returns {string} 清理后的内容
 */
function cleanLLMResponse(content) {
  // 移除 <think> 块
  content = content.replace(/<think>[\s\S]*?<\/think>/gi, '').trim();
  
  // 移除可能的markdown标记
  content = content.replace(/^```json\s*/i, '');
  content = content.replace(/\s*```$/i, '');
  
  return content.trim();
}

/**
 * 从响应中解析JSON
 * @param {string} content - 响应内容
 * @returns {object} 解析后的JSON对象
 */
function parseJSONFromResponse(content) {
  // 尝试直接解析
  try {
    return JSON.parse(content);
  } catch (e) {
    // 尝试提取JSON块
    const jsonMatch = content.match(/\{[\s\S]*\}/);
    if (jsonMatch) {
      try {
        return JSON.parse(jsonMatch[0]);
      } catch (e2) {
        // 尝试修复常见问题
        let fixed = jsonMatch[0];
        
        // 修复尾部逗号
        fixed = fixed.replace(/,\s*([}\]])/g, '$1');
        
        // 修复未闭合的字符串
        fixed = fixed.replace(/:\s*"([^"]*?)(?=\s*[,}\]])/g, ': "$1"');
        
        try {
          return JSON.parse(fixed);
        } catch (e3) {
          throw new Error('Failed to parse JSON from LLM response: ' + e.message);
        }
      }
    }
    throw new Error('No valid JSON found in LLM response');
  }
}

/**
 * 验证Brain输出的计划
 * @param {object} plan - 图片规划
 */
function validatePlan(plan) {
  if (!plan.analysis) {
    throw new Error('Missing analysis in plan');
  }
  
  if (!plan.images || !Array.isArray(plan.images)) {
    throw new Error('Missing or invalid images array in plan');
  }
  
  if (plan.images.length !== 12) {
    console.warn(`Expected 12 images, got ${plan.images.length}`);
  }
  
  // 检查必要字段
  const requiredFields = ['id', 'type', 'ai_prompt'];
  for (const image of plan.images) {
    for (const field of requiredFields) {
      if (!image[field]) {
        throw new Error(`Missing ${field} in image ${image.id || 'unknown'}`);
      }
    }
  }
  
  // 检查图片ID是否正确
  const expectedIds = [
    'Main_01', 'Main_02', 'Main_03', 'Main_04', 'Main_05', 'Main_06',
    'APlus_01', 'APlus_02', 'APlus_03', 'APlus_04', 'APlus_05', 'APlus_06'
  ];
  
  const actualIds = plan.images.map(img => img.id);
  const missingIds = expectedIds.filter(id => !actualIds.includes(id));
  
  if (missingIds.length > 0) {
    console.warn(`Missing image IDs: ${missingIds.join(', ')}`);
  }
}

/**
 * 生成默认的图片规划（当Brain调用失败时使用）
 * @param {object} sku - SKU数据
 * @returns {object} 默认的图片规划
 */
function generateDefaultPlan(sku) {
  const topSellingPoints = sku.selling_points.slice(0, 3).map(sp => sp.key);
  const productColor = sku.color.name;
  const productName = sku.product_name;
  
  return {
    analysis: {
      product_category: 'Pet Recovery Cone',
      core_selling_points: topSellingPoints,
      background_strategy: 'light',
      logo_color: 'red',
      visual_style: 'Warm, caring home environment'
    },
    images: [
      {
        id: 'Main_01',
        type: 'Hero Scene + Key Benefits',
        purpose: '首图决定点击率，展示产品使用状态+核心卖点',
        layout_description: `上60%：猫咪佩戴${productColor}${productName}的居家场景。下40%：浅色Banner展示3个核心卖点。`,
        ai_prompt: `Professional Amazon main image, 1:1 square format. A beautiful cat wearing a ${productColor} soft cone collar in a cozy modern home interior. Natural soft lighting, warm atmosphere. Bottom section shows a light blue rounded banner with "DESIGNED FOR COMFORTABLE RECOVERY" text and three small product detail images highlighting key features. Clean, professional pet product photography style. --ar 1:1`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      },
      {
        id: 'Main_02',
        type: 'Product Detail + Craftsmanship',
        purpose: '展示产品结构和工艺细节',
        layout_description: `产品平铺俯视图，配合2-3个细节放大框展示材质和工艺`,
        ai_prompt: `Professional product flat lay image, 1:1 square format. ${productColor} soft cone collar displayed from above on white background. Two circular detail callouts showing: 1) waterproof PU outer layer texture, 2) soft cotton inner lining. Clean product photography, even lighting, high detail. Brand logo "TOUCHDOG®" visible on right petal. --ar 1:1`,
        logo_placement: { position: 'none', type: 'none', color: 'red' }
      },
      {
        id: 'Main_03',
        type: 'Function Demonstration',
        purpose: '展示可调节绑带等功能特性',
        layout_description: `主场景展示佩戴状态，配合细节图展示调节功能`,
        ai_prompt: `Professional Amazon feature demonstration image, 1:1 square format. Main image shows cat wearing ${productColor} cone, looking comfortable. Detail callouts show: adjustable velcro strap being secured, snug fit around neck. Text overlay "ADJUSTABLE STRAP FOR A SECURE FIT". Light blue background with paw print decorations. --ar 1:1`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      },
      {
        id: 'Main_04',
        type: 'Use Cases Grid',
        purpose: '展示4种适用场景',
        layout_description: `四宫格布局，展示术后护理、滴药、剪指甲、梳毛四个场景`,
        ai_prompt: `Professional Amazon use case image, 1:1 square format. Four-panel grid showing: 1) cat resting after surgery wearing cone, 2) owner applying eye drops to cat, 3) owner trimming cat's nails, 4) cat being groomed. Each panel labeled: "POSTOPERATIVE CARE", "EYE MEDICATION", "NAIL TRIMMING", "GROOMING". Light blue header banner "APPLICABLE SCENARIOS". --ar 1:1`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      },
      {
        id: 'Main_05',
        type: 'Size & Specifications',
        purpose: '展示尺寸规格信息',
        layout_description: `产品尺寸标注图配合尺码对照表`,
        ai_prompt: `Professional Amazon size guide image, 1:1 square format. ${productColor} cone collar with dimension annotations showing depth measurement (${sku.specs.depth_cm}cm). Clean size chart showing XS to XL with neck circumference ranges. Professional infographic style, clear readable text. Light background. --ar 1:1`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      },
      {
        id: 'Main_06',
        type: 'Brand & Benefits Summary',
        purpose: '强化品牌认知和卖点汇总',
        layout_description: `品牌Logo突出展示，配合核心卖点图标`,
        ai_prompt: `Professional Amazon brand summary image, 1:1 square format. Touchdog brand logo prominently displayed. Key benefit icons with text: "65g Ultra Light", "Waterproof PU", "Breathable Cotton", "Adjustable Fit", "Foldable Design". Cat wearing ${productColor} cone as background element. Premium brand aesthetic. --ar 1:1`,
        logo_placement: { position: 'center', type: 'combined', color: 'red' }
      },
      {
        id: 'APlus_01',
        type: 'Brand Banner',
        purpose: '品牌形象首图',
        layout_description: `品牌名+产品名+生活场景大图`,
        ai_prompt: `Professional Amazon A+ banner image, 970x600px landscape. Beautiful cat wearing ${productColor} Touchdog soft cone collar in warm modern home interior. Large "TOUCHDOG" brand text and "CAT SOFT CONE COLLAR" product name overlaid. Lifestyle photography, natural lighting, cozy atmosphere. --ar 3:2`,
        logo_placement: { position: 'top-left', type: 'combined', color: 'red' }
      },
      {
        id: 'APlus_02',
        type: 'Competitor Comparison',
        purpose: '竞品对比展示优势',
        layout_description: `左侧我们的产品（彩色+优点），右侧传统产品（灰色+缺点）`,
        ai_prompt: `Professional Amazon A+ comparison image, 970x600px landscape. Left side (colored): Touchdog ${productColor} soft cone with green checkmark, labeled "OUR" with benefits "CLOUD-LIGHT COMFORT", "WIDER & CLEARER", "FOLDABLE & PORTABLE". Right side (grayscale): Generic plastic cone with red X, labeled "OTHER" with drawbacks "HEAVY & BULKY", "BLOCKS VISION & MOVEMENT", "HARD TO STORE". Center shows cat wearing our product. Warm beige background with paw prints. --ar 3:2`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' },
        is_comparison: true
      },
      {
        id: 'APlus_03',
        type: 'Benefits Grid',
        purpose: '核心卖点展示',
        layout_description: `三宫格展示3个核心卖点`,
        ai_prompt: `Professional Amazon A+ benefits image, 970x600px landscape. Three-panel layout showing key features: 1) "STURDY AND BREATHABLE" with fabric texture close-up, 2) "EASY TO CLEAN" with dimension annotation ${sku.specs.depth_cm}cm, 3) "REINFORCED STITCHING" with stitching detail. Header "ENGINEERED FOR UNCOMPROMISED COMFORT". Warm beige background. --ar 3:2`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      },
      {
        id: 'APlus_04',
        type: 'Features Grid',
        purpose: '功能场景展示',
        layout_description: `四宫格展示功能：易清洁、不影响进食、可翻折、360°舒适`,
        ai_prompt: `Professional Amazon A+ features image, 970x600px landscape. Four vertical panels: 1) "HYGIENIC & EASY TO CLEAN" showing water-resistant surface, 2) "UNRESTRICTED EATING/DRINKING" showing cat eating while wearing cone, 3) "REVERSIBLE WEAR" showing flip-over design, 4) "360° COMFORT" showing cat sleeping peacefully. Warm beige background, consistent styling. --ar 3:2`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      },
      {
        id: 'APlus_05',
        type: 'Material & Craftsmanship',
        purpose: '材质工艺展示',
        layout_description: `材质剖面和工艺细节展示`,
        ai_prompt: `Professional Amazon A+ material image, 970x600px landscape. Close-up details of ${productColor} cone showing: waterproof PU outer layer with water droplets, soft cotton inner lining texture, reinforced stitching seams, embroidered TOUCHDOG logo. Technical infographic style with material callouts. Light background. --ar 3:2`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      },
      {
        id: 'APlus_06',
        type: 'Size Guide',
        purpose: '尺寸选择指南',
        layout_description: `完整尺码表+测量指南`,
        ai_prompt: `Professional Amazon A+ size guide image, 970x600px landscape. Comprehensive size chart showing all sizes (XS-XL) with neck circumference and depth measurements in both cm and inches. Illustration showing how to measure pet's neck. Clear, readable table format. Helpful sizing tips. Professional infographic design. --ar 3:2`,
        logo_placement: { position: 'bottom-right', type: 'combined', color: 'red' }
      }
    ]
  };
}

/**
 * 主入口：生成图片规划
 * @param {object} sku - SKU数据
 * @param {object} options - 选项
 * @returns {Promise<object>} 图片规划
 */
async function planImages(sku, options = {}) {
  try {
    // 尝试调用LLM生成计划
    const plan = await generateImagePlan(sku, options);
    console.log('Brain generated plan successfully');
    return plan;
  } catch (error) {
    console.error('Brain failed, using default plan:', error.message);
    // 失败时使用默认计划
    return generateDefaultPlan(sku);
  }
}

module.exports = {
  planImages,
  generateImagePlan,
  generateDefaultPlan,
  validatePlan
};