#!/usr/bin/env node

/**
 * 工作周报管理工具
 * 用于管理个人工作周报，包括制定计划、记录工作、查询周报等
 */

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

// 数据文件路径
const DATA_DIR = path.join(__dirname, '..', 'data');
const DATA_FILE = path.join(DATA_DIR, 'weekly-reports.json');

// 确保数据目录存在
if (!fs.existsSync(DATA_DIR)) {
  fs.mkdirSync(DATA_DIR, { recursive: true });
}

/**
 * 生成 UUID
 */
function generateUUID() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    const r = Math.random() * 16 | 0;
    const v = c === 'x' ? r : (r & 0x3 | 0x8);
    return v.toString(16);
  });
}

/**
 * 获取本地日期字符串 YYYY-MM-DD
 */
function toLocalDateString(date) {
  const year = date.getFullYear();
  const month = String(date.getMonth() + 1).padStart(2, '0');
  const day = String(date.getDate()).padStart(2, '0');
  return `${year}-${month}-${day}`;
}

/**
 * 获取当前日期字符串
 */
function getCurrentDateStr() {
  const now = new Date();
  return now.toISOString().split('T')[0];
}

/**
 * 获取当前时间 ISO 字符串
 */
function getCurrentISO() {
  return new Date().toISOString();
}

/**
 * 判断是否为法定工作日（周一至周五）
 */
function isWorkday(dateStr) {
  const date = new Date(dateStr);
  const day = date.getDay();
  return day >= 1 && day <= 5;
}

/**
 * 获取日期所在周的第一天（周一）
 */
function getWeekStartDate(dateStr) {
  const date = new Date(dateStr);
  const day = date.getDay();
  // 计算到周一的天数
  const diff = day === 0 ? -6 : 1 - day;
  const monday = new Date(date);
  monday.setDate(date.getDate() + diff);
  return toLocalDateString(monday);
}

/**
 * 获取日期所在周的周五
 */
function getWeekEndDate(weekStartDate) {
  const monday = new Date(weekStartDate);
  const friday = new Date(monday);
  friday.setDate(monday.getDate() + 4);
  return toLocalDateString(friday);
}

/**
 * 获取 ISO 周编号 (YYYY-Www)
 * 遵循 ISO 8601 标准：每周从周一开始，第一个包含1月4日的周是W1
 */
function getWeekNumber(dateStr) {
  const date = new Date(dateStr);
  const MS_PER_DAY = 24 * 60 * 60 * 1000;
  
  // 找到该日期所在周的周四（ISO 8601 以包含1月4日的周为W1）
  const thursday = new Date(date);
  thursday.setDate(date.getDate() + (4 - (date.getDay() === 0 ? 7 : date.getDay())));
  
  // 计算该年的1月1日是周几
  const yearStart = new Date(thursday.getFullYear(), 0, 1);
  const jan1Day = yearStart.getDay(); // 0=Sun, 1=Mon, ..., 6=Sat
  
  // 计算这是该年的第几天（1月1日=1）
  const dayOfYear = Math.floor((thursday - yearStart) / MS_PER_DAY) + 1;
  
  // ISO 周号：(dayOfYear + 该年1月1日的星期几 - 1) / 7 向上取整
  // 如果1月1日是周四(day=4)，则 Jan1 就在 W01 中
  // 如果1月1日是周五/周六/周日，则需要调整（这些天属于上一年最后一周）
  const weekNum = Math.ceil((dayOfYear + (jan1Day === 0 ? 6 : jan1Day) - 1) / 7);
  
  // 处理年末/年初边界情况：
  // 如果计算的周号是0，说明属于上一年最后一周
  // 如果周号超过该年最大周数，说明属于下一年第一周
  let year = thursday.getFullYear();
  let finalWeek = weekNum;
  
  if (finalWeek === 0) {
    // 上一年最后一周
    year = year - 1;
    const prevJan1Day = new Date(year, 0, 1).getDay();
    finalWeek = prevJan1Day === 4 || (prevJan1Day === 3 && isLeapYear(year)) ? 53 : 52;
  } else {
    const maxWeeks = (jan1Day === 4 || (jan1Day === 3 && isLeapYear(thursday.getFullYear()))) ? 53 : 52;
    if (finalWeek > maxWeeks) {
      // 下一年第一周
      year = year + 1;
      finalWeek = 1;
    }
  }
  
  return `${year}-W${String(finalWeek).padStart(2, '0')}`;
}

function isLeapYear(year) {
  return (year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0);
}

/**
 * 获取当前工作周信息
 */
function getCurrentWeek() {
  const today = getCurrentDateStr();
  return getWeekInfo(today);
}

/**
 * 获取指定日期所在的工作周信息
 */
function getWeekInfo(dateStr) {
  const weekStart = getWeekStartDate(dateStr);
  const weekEnd = getWeekEndDate(weekStart);
  const weekNumber = getWeekNumber(dateStr);
  return {
    weekNumber,
    startDate: weekStart,
    endDate: weekEnd
  };
}

/**
 * 解析周标识为周编号
 */
function parseWeekIdentifier(identifier) {
  if (!identifier || identifier === '本周' || identifier === '当前周') {
    return getCurrentWeek().weekNumber;
  }
  if (identifier === '上周') {
    const today = new Date();
    today.setDate(today.getDate() - 7);
    return getWeekNumber(today.toISOString().split('T')[0]);
  }
  if (identifier === '上上周') {
    const today = new Date();
    today.setDate(today.getDate() - 14);
    return getWeekNumber(today.toISOString().split('T')[0]);
  }
  if (identifier === '下周') {
    const today = new Date();
    today.setDate(today.getDate() + 7);
    return getWeekNumber(today.toISOString().split('T')[0]);
  }
  // 假设是 YYYY-Www 格式
  if (/^\d{4}-W\d{2}$/.test(identifier)) {
    return identifier;
  }
  throw new Error(`无法解析周标识: ${identifier}`);
}

/**
 * 加载数据文件
 */
function loadData() {
  if (!fs.existsSync(DATA_FILE)) {
    const initial = {
      meta: {
        version: '1.0.0',
        createdAt: getCurrentISO(),
        updatedAt: getCurrentISO()
      },
      weeklyReports: {}
    };
    fs.writeFileSync(DATA_FILE, JSON.stringify(initial, null, 2), 'utf8');
    return initial;
  }
  const content = fs.readFileSync(DATA_FILE, 'utf8');
  return JSON.parse(content);
}

/**
 * 保存数据文件
 */
function saveData(data) {
  data.meta.updatedAt = getCurrentISO();
  fs.writeFileSync(DATA_FILE, JSON.stringify(data, null, 2), 'utf8');
}

/**
 * 从周编号反推该周的周一日期
 * 使用 ISO 8601 标准：每年第一个周四所在的周为第1周（W1从该周的周一开始）
 */
function getWeekStartFromWeekNumber(year, weekNum) {
  const MS_PER_DAY = 24 * 60 * 60 * 1000;

  // 找到该年1月4日（ISO 8601 定义：包含该年第一个周四的那一周是W1）
  const jan4 = new Date(year, 0, 4);
  const jan4Day = jan4.getDay(); // 0=Sun, 1=Mon, ..., 6=Sat

  // 找到W1的周一（ISO 8601：每年第一个包含1月4日的周是W1，该周的周一是W1起始）
  // jan4Day: 0=Sun, 1=Mon, ..., 6=Sat
  // 如果1月4日是周日，W1周一是Dec 29（上周一）
  // 如果1月4日是周一，W1周一是1月4日
  // 否则，W1周一是1月4日往前到周一的天数
  const daysToSubtract = (jan4Day === 0 ? 7 : jan4Day) - 1;
  const firstMonday = new Date(jan4.getTime() - daysToSubtract * MS_PER_DAY);

  // 计算目标周的周一
  const targetMonday = new Date(firstMonday.getTime() + (weekNum - 1) * 7 * MS_PER_DAY);
  return targetMonday;
}

/**
 * 获取或创建指定周的周报对象
 */
function getOrCreateWeeklyReport(weekNumber) {
  const data = loadData();
  if (!data.weeklyReports[weekNumber]) {
    const [yearStr, weekPart] = weekNumber.split('-W');
    const year = parseInt(yearStr, 10);
    const weekNum = parseInt(weekPart, 10);

    const targetMonday = getWeekStartFromWeekNumber(year, weekNum);
    const targetFriday = new Date(targetMonday);
    targetFriday.setDate(targetMonday.getDate() + 4);

    data.weeklyReports[weekNumber] = {
      weekNumber,
      weekStartDate: toLocalDateString(targetMonday),
      weekEndDate: toLocalDateString(targetFriday),
      plan: [],
      records: {},
      summary: ''
    };
  }
  return { data, report: data.weeklyReports[weekNumber] };
}

/**
 * 制定/更新周计划
 */
function planWeek(weekNumber, tasks, priority = 'medium', expectedDate = null) {
  const { data, report } = getOrCreateWeeklyReport(weekNumber);
  const now = getCurrentISO();

  for (const taskDesc of tasks) {
    const planItem = {
      id: generateUUID(),
      description: taskDesc,
      expectedDate: expectedDate,
      priority: priority,
      status: 'pending',
      createdAt: now,
      updatedAt: now
    };
    report.plan.push(planItem);
  }

  saveData(data);
  return report;
}

/**
 * 添加工作记录
 */
function addRecord(date, content, status, options = {}) {
  const { hours, planItemId } = options;

  if (!isWorkday(date)) {
    throw new Error(`${date} 不是法定工作日（周一至周五）`);
  }

  const weekInfo = getWeekInfo(date);
  const { data, report } = getOrCreateWeeklyReport(weekInfo.weekNumber);

  if (!report.records[date]) {
    report.records[date] = [];
  }

  const record = {
    id: generateUUID(),
    content,
    date,
    status,
    hours: hours || null,
    planItemId: planItemId || null,
    createdAt: getCurrentISO(),
    updatedAt: getCurrentISO()
  };

  report.records[date].push(record);

  // 如果有关联的计划项，自动更新其状态
  if (planItemId) {
    const planItem = report.plan.find(p => p.id === planItemId);
    if (planItem) {
      planItem.status = status === 'completed' ? 'completed' :
                        status === 'in-progress' ? 'in-progress' : planItem.status;
      planItem.updatedAt = getCurrentISO();
    }
  }

  saveData(data);
  return report;
}

/**
 * 获取未完成的工作项
 */
function getPendingItems(weekIdentifier) {
  const weekNumber = parseWeekIdentifier(weekIdentifier);
  const { data, report } = getOrCreateWeeklyReport(weekNumber);

  const pending = report.plan.filter(p => p.status === 'pending' || p.status === 'in-progress');

  // 按优先级排序
  const priorityOrder = { high: 0, medium: 1, low: 2 };
  pending.sort((a, b) => priorityOrder[a.priority] - priorityOrder[b.priority]);

  return pending;
}

/**
 * 查询周报
 */
function queryWeek(weekIdentifier, format = 'detail') {
  const weekNumber = parseWeekIdentifier(weekIdentifier);
  const { report } = getOrCreateWeeklyReport(weekNumber);

  if (format === 'summary') {
    return formatWeekSummary(report);
  }

  return report;
}

/**
 * 格式化周报摘要
 */
function formatWeekSummary(report) {
  const total = report.plan.length;
  const completed = report.plan.filter(p => p.status === 'completed').length;
  const pending = report.plan.filter(p => p.status === 'pending' || p.status === 'in-progress');

  let output = `周报摘要: ${report.weekNumber} (${report.weekStartDate} 至 ${report.weekEndDate})\n`;
  output += '================================================================\n\n';

  output += `计划完成率: ${completed}/${total}`;
  if (total > 0) {
    output += ` (${Math.round(completed / total * 100)}%)`;
  }
  output += '\n\n';

  if (report.plan.length > 0) {
    output += '计划项:\n';
    for (const item of report.plan) {
      const statusIcon = item.status === 'completed' ? '[√]' : '[ ]';
      const priorityTag = item.priority === 'high' ? '[高]' : item.priority === 'low' ? '[低]' : '[中]';
      output += `  ${statusIcon} ${priorityTag} ${item.description}`;
      if (item.expectedDate) {
        output += ` (预计: ${item.expectedDate})`;
      }
      output += '\n';
    }
    output += '\n';
  }

  if (Object.keys(report.records).length > 0) {
    output += '每日记录:\n';
    const sortedDates = Object.keys(report.records).sort();
    for (const date of sortedDates) {
      const records = report.records[date];
      const hours = records.reduce((sum, r) => sum + (r.hours || 0), 0);
      const content = records.map(r => r.content).join('; ');
      output += `  - ${date}: ${content}`;
      if (hours > 0) {
        output += ` (${hours}h)`;
      }
      output += '\n';
    }
    output += '\n';
  }

  if (pending.length > 0) {
    output += '未完成工作:\n';
    for (const item of pending) {
      output += `  - ${item.description}\n`;
    }
    output += '\n';
  }

  if (report.summary) {
    output += `总结: ${report.summary}\n`;
  }

  return output;
}

/**
 * 更新计划项状态
 */
function updatePlanItemStatus(weekNumber, planItemId, status) {
  const { data, report } = getOrCreateWeeklyReport(weekNumber);

  const planItem = report.plan.find(p => p.id === planItemId);
  if (!planItem) {
    throw new Error(`未找到计划项: ${planItemId}`);
  }

  planItem.status = status;
  planItem.updatedAt = getCurrentISO();

  saveData(data);
  return report;
}

/**
 * 延期计划项
 * 将计划项的预计完成日期延长到指定日期
 */
function extendPlanItem(weekNumber, planItemId, newExpectedDate, reason = '') {
  const { data, report } = getOrCreateWeeklyReport(weekNumber);

  const planItem = report.plan.find(p => p.id === planItemId);
  if (!planItem) {
    throw new Error(`未找到计划项: ${planItemId}`);
  }

  const oldDate = planItem.expectedDate;
  planItem.expectedDate = newExpectedDate;
  planItem.updatedAt = getCurrentISO();

  // 如果传入了延期原因，记录在 extendedReason 字段
  if (reason) {
    planItem.extendedReason = reason;
  }

  // 增加延期次数统计
  planItem.extendCount = (planItem.extendCount || 0) + 1;

  saveData(data);
  return { report, planItem, oldDate, newDate: newExpectedDate };
}

/**
 * 设置周报总结
 */
function setSummary(weekNumber, summary) {
  const { data, report } = getOrCreateWeeklyReport(weekNumber);
  report.summary = summary;
  saveData(data);
  return report;
}

/**
 * 删除计划项
 */
function removePlanItem(weekNumber, planItemId) {
  const { data, report } = getOrCreateWeeklyReport(weekNumber);
  const index = report.plan.findIndex(p => p.id === planItemId);
  if (index === -1) {
    throw new Error(`未找到计划项: ${planItemId}`);
  }
  report.plan.splice(index, 1);
  saveData(data);
  return report;
}

/**
 * 获取工作周的所有工作日
 */
function getWorkdays(weekNumber) {
  const { report } = getOrCreateWeeklyReport(weekNumber);
  const workdays = [];
  const current = new Date(report.weekStartDate);
  const end = new Date(report.weekEndDate);

  while (current <= end) {
    workdays.push(current.toISOString().split('T')[0]);
    current.setDate(current.getDate() + 1);
  }
  return workdays;
}

// === CLI 模式 ===
if (require.main === module) {
  const args = process.argv.slice(2);
  const command = args[0];

  // 已知的标志列表
  const FLAGS = ['--week', '--tasks', '--priority', '--date', '--content', '--status', '--hours', '--plan-item', '--format', '--expected-date'];

  function getArgValue(flag) {
    const index = args.indexOf(flag);
    if (index !== -1 && index + 1 < args.length) {
      const nextArg = args[index + 1];
      // 如果下一个参数也是标志，返回null
      if (FLAGS.includes(nextArg)) {
        return null;
      }
      return nextArg;
    }
    // 支持 --flag=value 格式
    const combined = args.find(arg => arg.startsWith(`${flag}=`));
    if (combined) {
      return combined.split('=')[1];
    }
    return null;
  }

  function getRemainingArgs(flag) {
    const index = args.indexOf(flag);
    if (index === -1) return [];

    const result = [];
    let i = index + 1;

    while (i < args.length) {
      const arg = args[i];
      // 如果遇到另一个标志，停止
      if (FLAGS.includes(arg)) {
        break;
      }
      result.push(arg);
      i++;
    }

    return result;
  }

  try {
    switch (command) {
      case 'plan': {
        const week = getArgValue('--week') || getCurrentWeek().weekNumber;
        const tasks = getRemainingArgs('--tasks');
        if (tasks.length === 0) {
          console.error('错误: 请提供任务列表 (--tasks "任务1" "任务2" ...)');
          process.exit(1);
        }
        const priority = getArgValue('--priority') || 'medium';
        const expectedDate = getArgValue('--expected-date');
        const report = planWeek(week, tasks, priority, expectedDate);
        console.log(`已在 ${report.weekNumber} 创建 ${tasks.length} 个计划项`);
        console.log('\n计划项:');
        report.plan.slice(-tasks.length).forEach((item, i) => {
          const dateStr = item.expectedDate ? ` [预计: ${item.expectedDate}]` : '';
          console.log(`  ${i + 1}. [${item.priority}] ${item.description}${dateStr} (${item.id})`);
        });
        break;
      }

      case 'record': {
        const date = getArgValue('--date') || getCurrentDateStr();
        const content = getArgValue('--content');
        if (!content) {
          console.error('错误: 请提供工作内容 (--content "内容")');
          process.exit(1);
        }
        const status = getArgValue('--status') || 'in-progress';
        const hours = getArgValue('--hours') ? parseFloat(getArgValue('--hours')) : null;
        const planItemId = getArgValue('--plan-item');
        const report = addRecord(date, content, status, { hours, planItemId });
        console.log(`已在 ${date} 添加工作记录`);
        console.log(`周 ${report.weekNumber} 当前共有 ${report.plan.length} 个计划项`);
        break;
      }

      case 'pending': {
        const week = getArgValue('--week') || getCurrentWeek().weekNumber;
        const pending = getPendingItems(week);
        const currentWeek = getCurrentWeek();
        console.log(`本周未完成的工作 (${week})\n`);
        console.log('========================================\n');

        if (pending.length === 0) {
          console.log('所有任务已完成！');
        } else {
          const high = pending.filter(p => p.priority === 'high');
          const medium = pending.filter(p => p.priority === 'medium');
          const low = pending.filter(p => p.priority === 'low');

          if (high.length > 0) {
            console.log('[高优先级]');
            high.forEach(p => console.log(`  - ${p.description}`));
            console.log();
          }
          if (medium.length > 0) {
            console.log('[中优先级]');
            medium.forEach(p => console.log(`  - ${p.description}`));
            console.log();
          }
          if (low.length > 0) {
            console.log('[低优先级]');
            low.forEach(p => console.log(`  - ${p.description}`));
            console.log();
          }
        }
        console.log(`共 ${pending.length} 项未完成任务`);
        break;
      }

      case 'query': {
        const week = getArgValue('--week') || '本周';
        const format = getArgValue('--format') || 'detail';
        const weekNumber = parseWeekIdentifier(week);
        const result = queryWeek(weekNumber, format);
        console.log(typeof result === 'string' ? result : JSON.stringify(result, null, 2));
        break;
      }

      case 'update-status': {
        const weekIdentifier = getArgValue('--week') || '本周';
        const planItemId = getArgValue('--plan-item');
        const status = getArgValue('--status');
        if (!planItemId || !status) {
          console.error('错误: 请提供计划项ID (--plan-item) 和状态 (--status)');
          process.exit(1);
        }
        const weekNumber = parseWeekIdentifier(weekIdentifier);
        const report = updatePlanItemStatus(weekNumber, planItemId, status);
        console.log(`已更新计划项 ${planItemId} 状态为 ${status}`);
        console.log(`周 ${report.weekNumber} 计划完成率: ${report.plan.filter(p => p.status === 'completed').length}/${report.plan.length}`);
        break;
      }

      case 'summary': {
        const weekIdentifier = getArgValue('--week') || '本周';
        const content = getArgValue('--content');
        if (!content) {
          console.error('错误: 请提供总结内容 (--content "内容")');
          process.exit(1);
        }
        const weekNumber = parseWeekIdentifier(weekIdentifier);
        const report = setSummary(weekNumber, content);
        console.log(`已在 ${weekNumber} 设置周报总结`);
        break;
      }

      case 'remove-plan': {
        const weekIdentifier = getArgValue('--week') || '本周';
        const planItemId = getArgValue('--plan-item');
        if (!planItemId) {
          console.error('错误: 请提供计划项ID (--plan-item)');
          process.exit(1);
        }
        const weekNumber = parseWeekIdentifier(weekIdentifier);
        const report = removePlanItem(weekNumber, planItemId);
        console.log(`已删除计划项 ${planItemId}`);
        console.log(`周 ${report.weekNumber} 剩余 ${report.plan.length} 个计划项`);
        break;
      }

      case 'extend-plan': {
        const weekIdentifier = getArgValue('--week') || '本周';
        const planItemId = getArgValue('--plan-item');
        const newDate = getArgValue('--new-date');
        const reason = getArgValue('--reason') || '';
        if (!planItemId || !newDate) {
          console.error('错误: 请提供计划项ID (--plan-item) 和新日期 (--new-date YYYY-MM-DD)');
          process.exit(1);
        }
        const weekNumber = parseWeekIdentifier(weekIdentifier);
        const result = extendPlanItem(weekNumber, planItemId, newDate, reason);
        const item = result.planItem;
        console.log(`已将计划项延期:`);
        console.log(`  任务: ${item.description}`);
        console.log(`  原定日期: ${result.oldDate || '未设置'}`);
        console.log(`  新日期: ${result.newDate}`);
        if (reason) console.log(`  延期原因: ${reason}`);
        console.log(`  延期次数: ${item.extendCount} 次`);
        break;
      }

      case 'week-info': {
        const date = getArgValue('--date') || getCurrentDateStr();
        const info = getWeekInfo(date);
        console.log(`日期 ${date} 所在工作周:`);
        console.log(`  周编号: ${info.weekNumber}`);
        console.log(`  周一: ${info.startDate}`);
        console.log(`  周五: ${info.endDate}`);
        break;
      }

      default:
        console.log('用法:');
        console.log('  node work-weekly-report.js plan --tasks "任务1" "任务2" [--week YYYY-Www] [--priority high|medium|low]');
        console.log('  node work-weekly-report.js record --content "内容" [--date YYYY-MM-DD] [--status completed|in-progress|blocked] [--hours N] [--plan-item UUID]');
        console.log('  node work-weekly-report.js pending [--week YYYY-Www]');
        console.log('  node work-weekly-report.js query [--week YYYY-Www] [--format detail|summary]');
        console.log('  node work-weekly-report.js update-status --plan-item UUID --status STATUS [--week YYYY-Www]');
        console.log('  node work-weekly-report.js summary --content "总结" [--week YYYY-Www]');
        console.log('  node work-weekly-report.js remove-plan --plan-item UUID [--week YYYY-Www]');
        console.log('  node work-weekly-report.js extend-plan --plan-item UUID --new-date YYYY-MM-DD [--week YYYY-Www] [--reason "原因"]');
        console.log('  node work-weekly-report.js week-info [--date YYYY-MM-DD]');
        console.log('\n周标识: YYYY-Www, 本周, 上周, 上上周, 下周');
    }
  } catch (error) {
    console.error('错误:', error.message);
    process.exit(1);
  }
}

// 导出模块
module.exports = {
  getCurrentWeek,
  getWeekInfo,
  planWeek,
  addRecord,
  getPendingItems,
  queryWeek,
  updatePlanItemStatus,
  setSummary,
  removePlanItem,
  extendPlanItem,
  getWorkdays,
  parseWeekIdentifier,
  isWorkday
};