// 日期工具函数

// 格式化日期
export function formatDate(date, format = 'YYYY-MM-DD') {
  if (!date) return ''
  
  const d = new Date(date)
  const year = d.getFullYear()
  const month = String(d.getMonth() + 1).padStart(2, '0')
  const day = String(d.getDate()).padStart(2, '0')
  const hour = String(d.getHours()).padStart(2, '0')
  const minute = String(d.getMinutes()).padStart(2, '0')
  const second = String(d.getSeconds()).padStart(2, '0')
  
  return format
    .replace('YYYY', year)
    .replace('MM', month)
    .replace('DD', day)
    .replace('HH', hour)
    .replace('mm', minute)
    .replace('ss', second)
}

// 格式化日期为中国格式 (例如: 2025年1月1日 13:40 星期三)
export function formatChineseDate(date) {
  if (!date) return ''
  
  const d = new Date(date)
  const year = d.getFullYear()
  const month = d.getMonth() + 1
  const day = d.getDate()
  const hour = String(d.getHours()).padStart(2, '0')
  const minute = String(d.getMinutes()).padStart(2, '0')
  
  const weekdays = ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六']
  const weekday = weekdays[d.getDay()]
  
  return `${year}年${month}月${day}日 ${hour}:${minute} ${weekday}`
}

// 获取周的开始日期
export function getWeekStart(date = new Date()) {
  const d = new Date(date)
  const day = d.getDay()
  const diff = d.getDate() - day + (day === 0 ? -6 : 1) // 周一
  return new Date(d.setDate(diff))
}

// 获取月的开始日期
export function getMonthStart(date = new Date()) {
  const d = new Date(date)
  return new Date(d.getFullYear(), d.getMonth(), 1)
}

// 获取月的结束日期
export function getMonthEnd(date = new Date()) {
  const d = new Date(date)
  return new Date(d.getFullYear(), d.getMonth() + 1, 0)
}