const Tesseract = require('tesseract.js');
const path = require('path');
const logger = require('./logger');

// 彩票类型识别规则 (模块级别常量，避免每次调用时重建)
const LOTTERY_PATTERNS = {
  ssq: { name: '双色球', type: 'welfare', pattern: /双\s*色\s*球|SSQ/i, price: 2 },
  fc3d: { name: '福彩3D', type: 'welfare', pattern: /福\s*彩\s*3D|3D/i, price: 2 },
  qlc: { name: '七乐彩', type: 'welfare', pattern: /七\s*乐\s*彩/i, price: 2 },
  dlt: { name: '大乐透', type: 'sports', pattern: /大\s*乐\s*透|超级\s*大\s*乐\s*透/i, price: 2 },
  pl3: { name: '排列3', type: 'sports', pattern: /排列\s*3|排列\s*三/i, price: 2 },
  pl5: { name: '排列5', type: 'sports', pattern: /排列\s*5|排列\s*五/i, price: 2 },
  qxc: { name: '七星彩', type: 'sports', pattern: /七\s*星\s*彩/i, price: 2 },
};

// 简单的内存任务队列 (有界队列防止内存溢出)
const MAX_QUEUE_SIZE = 100;
const taskQueue = [];
const processingTasks = new Set();
const completedTasks = new Map(); // taskId -> result
const TASK_TIMEOUT = 5 * 60 * 1000; // 5分钟超时

// OCR处理函数
async function processOCR(task) {
  const { taskId, imagePath } = task;

  try {
    logger.info(`OCR任务开始: ${taskId}`);
    const text = await parseWithLocalTesseract(imagePath);
    const result = parseTicketText(text);

    completedTasks.set(taskId, { success: true, data: result });
    // 5分钟后清理已完成的任务 (只设置一次)
    setTimeout(() => {
      completedTasks.delete(taskId);
      logger.debug(`OCR任务已清理: ${taskId}`);
    }, 5 * 60 * 1000);
    logger.info(`OCR任务完成: ${taskId}`);
  } catch (err) {
    logger.error(`OCR任务失败: ${taskId}`, { error: err.message });
    completedTasks.set(taskId, { success: false, error: err.message });
    setTimeout(() => {
      completedTasks.delete(taskId);
    }, 5 * 60 * 1000);
  } finally {
    processingTasks.delete(taskId);
    processNextTask();
  }
}

// 处理下一个任务
function processNextTask() {
  if (processingTasks.size >= 2) return; // 最多同时处理2个

  const nextTask = taskQueue.shift();
  if (nextTask) {
    processingTasks.add(nextTask.taskId);
    processOCR(nextTask);
  }
}

// 提交OCR任务 (同步返回taskId)
function submitOCRTask(imagePath) {
  if (taskQueue.length >= MAX_QUEUE_SIZE) {
    throw new Error('任务队列已满，请稍后再试');
  }

  const taskId = `ocr_${Date.now()}_${Math.random().toString(36).slice(2)}`;
  taskQueue.push({ taskId, imagePath, submittedAt: Date.now() });
  logger.info(`OCR任务已提交: ${taskId}, 队列长度: ${taskQueue.length}`);

  processNextTask();

  return taskId;
}

// 查询任务状态
function getOCRTaskStatus(taskId) {
  if (completedTasks.has(taskId)) {
    return { completed: true, ...completedTasks.get(taskId) };
  }

  // 检查是否超时 - O(n) scan (可接受，队列通常很小)
  const task = taskQueue.find(t => t.taskId === taskId);
  if (task && Date.now() - task.submittedAt > TASK_TIMEOUT) {
    return { completed: true, success: false, error: '任务处理超时' };
  }

  if (processingTasks.has(taskId)) {
    return { completed: false, processing: true };
  }

  return { completed: false };
}

// 使用本地tesseract.js-core进行OCR识别
async function parseWithLocalTesseract(imagePath) {
  const corePath = path.join(__dirname, '../node_modules/tesseract.js-core');

  const { data } = await Tesseract.recognize(imagePath, 'chi_sim+eng', {
    corePath: corePath,
    logger: m => logger.debug(`OCR: ${m.status} ${m.progress || ''}`)
  });

  return data.text;
}

// 解析彩票图片 (改为异步提交)
function parseTicketImage(imagePath) {
  const taskId = submitOCRTask(imagePath);
  return { taskId, status: 'pending' };
}

// 查询OCR结果 (轮询)
function getOCRResult(taskId) {
  return getOCRTaskStatus(taskId);
}

// 解析彩票文本
function parseTicketText(text) {
  const result = {
    type: null,
    game: null,
    issue: null,
    numbers: [],
    bet_count: 1,
    multiple: 1,
    is_additional: false,
    cost: 0,
    raw_text: text
  };

  // 识别彩票类型 (使用模块级别的 LOTTERY_PATTERNS)
  for (const [key, lottery] of Object.entries(LOTTERY_PATTERNS)) {
    if (lottery.pattern.test(text)) {
      result.type = lottery.type;
      result.game = lottery.name;
      break;
    }
  }

  // 提取期号
  const issueMatch = text.match(/期\s*号\s*[:：]\s*(\d{5,})/);
  if (issueMatch) {
    result.issue = issueMatch[1];
  } else {
    const issueMatch2 = text.match(/第?\s*(\d{5,})\s*期/);
    if (issueMatch2) {
      result.issue = issueMatch2[1];
    }
  }

  // 提取注数
  const betMatch = text.match(/(\d+)\s*注/);
  if (betMatch) {
    result.bet_count = parseInt(betMatch[1]);
  }

  // 提取倍数
  const multipleMatch = text.match(/(\d+)\s*倍/);
  if (multipleMatch) {
    result.multiple = parseInt(multipleMatch[1]);
  }

  // 检测是否追加
  result.is_additional = /追加|追加投注/.test(text);

  // 提取金额
  const costMatch = text.match(/金额\s*[:：]\s*(\d+(?:[.,]\d+)?)\s*元|合计[：:]\s*(\d+(?:\.\d+)?)\s*元|(\d+(?:\.\d+)?)\s*元/);
  if (costMatch) {
    const costStr = (costMatch[1] || costMatch[2] || costMatch[3]).replace(',', '.');
    result.cost = parseFloat(costStr);
  }

  // 提取号码
  result.numbers = extractNumbers(text, result.game);

  if (result.numbers.length > 0) {
    result.bet_count = result.numbers.length;
  }

  if (!result.cost && result.game && result.numbers.length > 0) {
    const lottery = Object.values(LOTTERY_PATTERNS).find(l => l.name === result.game);
    if (lottery) {
      let basePrice = lottery.price * result.bet_count * result.multiple;
      if (result.is_additional) basePrice += result.bet_count * result.multiple;
      result.cost = basePrice;
    }
  }

  return result;
}

// 提取号码
function extractNumbers(text, game) {
  const numbers = [];

  let cleanText = text
    .replace(/[oO]/g, '0')
    .replace(/[D]/g, '0')
    .replace(/[lI|]/g, '1')
    .replace(/[S$§]/g, '5')
    .replace(/[@®»«]/g, '')
    .replace(/[:：]/g, ' ')
    .replace(/[g]/g, '9');

  cleanText = cleanText.replace(/\b(\d{6,})\b/g, (match) => {
    return match.match(/.{1,2}/g).join(' ');
  });
  cleanText = cleanText.replace(/\b(\d{4})\b/g, (match) => {
    return match.slice(0, 2) + ' ' + match.slice(2);
  });

  cleanText = cleanText.split('\n')
    .filter(line => !line.includes('开奖') && !line.includes('号码'))
    .join('\n');

  if (game === '双色球') {
    const patterns = [
      /(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})[-+](\d{2})/g,
      /(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s*[+|]\s*(\d{2})/g,
    ];

    for (const pattern of patterns) {
      const matches = cleanText.matchAll(pattern);
      for (const match of matches) {
        numbers.push({
          red: [match[1], match[2], match[3], match[4], match[5], match[6]],
          blue: match[7]
        });
      }
      if (numbers.length > 0) break;
    }
  } else if (game === '大乐透') {
    const patterns = [
      /(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})[-+](\d{2})\s+(\d{2})/g,
      /(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s+(\d{2})\s*[+|]\s*(\d{2})\s+(\d{2})/g,
      /(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})[-+](\d{2})(\d{2})/g,
      /(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})[+|](\d{2})(\d{2})/g,
    ];

    for (const pattern of patterns) {
      const matches = cleanText.matchAll(pattern);
      for (const match of matches) {
        numbers.push({
          front: [match[1], match[2], match[3], match[4], match[5]],
          back: [match[6], match[7]]
        });
      }
      if (numbers.length > 0) break;
    }
  } else if (game === '福彩3D' || game === '排列3') {
    const matches = cleanText.matchAll(/[^\d](\d)\s*(\d)\s*(\d)[^\d]/g);
    for (const match of matches) {
      numbers.push([match[1], match[2], match[3]]);
    }
  }

  return numbers;
}

module.exports = { parseTicketImage, parseTicketText, getOCRResult };