/**
 * 本地存储管理工具（含缓存层）
 */

// 内存缓存
const _cache = {
  persons: null,
  anniversaries: null
}

function _invalidate() {
  _cache.persons = null
  _cache.anniversaries = null
}

/**
 * 存储人员数据
 */
function savePersons(persons) {
  try {
    wx.setStorageSync('persons', persons)
    _cache.persons = persons
    return { success: true }
  } catch (e) {
    console.error('保存人员数据失败', e)
    return { success: false, error: e.message }
  }
}

/**
 * 获取人员数据
 */
function getPersons() {
  if (_cache.persons !== null) return _cache.persons
  try {
    _cache.persons = wx.getStorageSync('persons') || []
    return _cache.persons
  } catch (e) {
    console.error('获取人员数据失败', e)
    return []
  }
}

/**
 * 根据ID获取人员
 */
function getPersonById(id) {
  return getPersons().find(p => p.id === id) || null
}

/**
 * 添加人员
 */
function addPerson(person) {
  const persons = getPersons()
  const newPerson = {
    id: generateId(),
    ...person,
    createTime: new Date().getTime(),
    updateTime: new Date().getTime()
  }
  persons.push(newPerson)
  const result = savePersons(persons)
  return result.success ? newPerson : null
}

/**
 * 更新人员
 */
function updatePerson(id, updates) {
  const persons = getPersons()
  const index = persons.findIndex(p => p.id === id)
  if (index !== -1) {
    persons[index] = { ...persons[index], ...updates, updateTime: new Date().getTime() }
    return savePersons(persons).success
  }
  return false
}

/**
 * 删除人员
 */
function deletePerson(id) {
  const persons = getPersons()
  return savePersons(persons.filter(p => p.id !== id)).success
}

/**
 * 存储纪念日数据
 */
function saveAnniversaries(anniversaries) {
  try {
    wx.setStorageSync('anniversaries', anniversaries)
    _cache.anniversaries = anniversaries
    return { success: true }
  } catch (e) {
    console.error('保存纪念日数据失败', e)
    return { success: false, error: e.message }
  }
}

/**
 * 获取纪念日数据
 */
function getAnniversaries() {
  if (_cache.anniversaries !== null) return _cache.anniversaries
  try {
    _cache.anniversaries = wx.getStorageSync('anniversaries') || []
    return _cache.anniversaries
  } catch (e) {
    console.error('获取纪念日数据失败', e)
    return []
  }
}

/**
 * 根据人员ID获取纪念日
 */
function getAnniversariesByPersonId(personId) {
  return getAnniversaries().filter(a => a.personId === personId)
}

/**
 * 添加纪念日
 */
function addAnniversary(anniversary) {
  const anniversaries = getAnniversaries()
  const newAnniversary = {
    id: generateId(),
    ...anniversary,
    createTime: new Date().getTime(),
    updateTime: new Date().getTime()
  }
  anniversaries.push(newAnniversary)
  const result = saveAnniversaries(anniversaries)
  return result.success ? newAnniversary : null
}

/**
 * 更新纪念日
 */
function updateAnniversary(id, updates) {
  const anniversaries = getAnniversaries()
  const index = anniversaries.findIndex(a => a.id === id)
  if (index !== -1) {
    anniversaries[index] = { ...anniversaries[index], ...updates, updateTime: new Date().getTime() }
    return saveAnniversaries(anniversaries).success
  }
  return false
}

/**
 * 删除纪念日
 */
function deleteAnniversary(id) {
  const anniversaries = getAnniversaries()
  return saveAnniversaries(anniversaries.filter(a => a.id !== id)).success
}

/**
 * 原子性删除人员及其所有纪念日
 */
function deletePersonWithAnniversaries(personId) {
  try {
    const persons = getPersons().filter(p => p.id !== personId)
    const anniversaries = getAnniversaries().filter(a => a.personId !== personId)
    wx.setStorageSync('persons', persons)
    wx.setStorageSync('anniversaries', anniversaries)
    _cache.persons = persons
    _cache.anniversaries = anniversaries
    return true
  } catch (e) {
    console.error('删除人员及纪念日失败', e)
    _invalidate() // 缓存可能不一致，强制失效
    return false
  }
}

/**
 * 生成唯一ID
 */
function generateId() {
  return 'id_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9)
}

/**
 * 导出数据
 */
function exportData() {
  return {
    persons: getPersons(),
    anniversaries: getAnniversaries(),
    exportTime: new Date().getTime()
  }
}

/**
 * 验证人员数据结构
 */
function _validatePerson(p) {
  return p && typeof p === 'object' && typeof p.id === 'string' && typeof p.name === 'string'
}

/**
 * 验证纪念日数据结构
 */
function _validateAnniversary(a) {
  return a && typeof a === 'object' && typeof a.id === 'string' &&
    typeof a.personId === 'string' &&
    typeof a.solarMonth === 'number' && typeof a.solarDay === 'number'
}

/**
 * 导入数据（含验证）
 */
function importData(data) {
  try {
    if (!data || typeof data !== 'object') {
      return { success: false, error: '无效的数据格式' }
    }
    if (!Array.isArray(data.persons) || !Array.isArray(data.anniversaries)) {
      return { success: false, error: 'persons 和 anniversaries 必须是数组' }
    }
    if (!data.persons.every(_validatePerson)) {
      return { success: false, error: '人员数据格式不正确' }
    }
    if (!data.anniversaries.every(_validateAnniversary)) {
      return { success: false, error: '纪念日数据格式不正确' }
    }
    wx.setStorageSync('persons', data.persons)
    wx.setStorageSync('anniversaries', data.anniversaries)
    _cache.persons = data.persons
    _cache.anniversaries = data.anniversaries
    return { success: true }
  } catch (e) {
    console.error('导入数据失败', e)
    return { success: false, error: e.message }
  }
}

/**
 * 清空所有数据
 */
function clearAllData() {
  try {
    wx.clearStorageSync()
    _invalidate()
    return true
  } catch (e) {
    console.error('清空数据失败', e)
    return false
  }
}

module.exports = {
  // 人员相关
  savePersons,
  getPersons,
  getPersonById,
  addPerson,
  updatePerson,
  deletePerson,
  deletePersonWithAnniversaries,

  // 纪念日相关
  saveAnniversaries,
  getAnniversaries,
  getAnniversariesByPersonId,
  addAnniversary,
  updateAnniversary,
  deleteAnniversary,

  // 工具函数
  exportData,
  importData,
  clearAllData
}