App({
  globalData: {
    currentPersonId: null,
    persons: [],
    dataMap: {}
  },

  onLaunch() {
    // 清除旧版存储，避免残留
    wx.removeStorageSync("health_data")
    var data = wx.getStorageSync("health_data_v2")
    if (data) {
      this.globalData.persons = data.persons || []
      this.globalData.dataMap = data.dataMap || {}
      this.globalData.currentPersonId = data.currentPersonId || (this.globalData.persons[0] && this.globalData.persons[0].id) || null
    }
    // 无存储或 persons 为空时，由首页弹窗引导创建首个用户
  },

  _defaultItems() {
    return ["血红蛋白", "尿素", "肌酐", "尿酸", "血钾", "血钙", "血磷", "β2微球蛋白", "体重"]
  },

  saveData() {
    wx.setStorageSync("health_data_v2", {
      persons: this.globalData.persons,
      dataMap: this.globalData.dataMap,
      currentPersonId: this.globalData.currentPersonId
    })
  },

  getCurrentData() {
    var id = this.globalData.currentPersonId
    if (!id || !this.globalData.dataMap[id]) return { items: [], records: [] }
    return this.globalData.dataMap[id]
  },

  getCurrentPerson() {
    var id = this.globalData.currentPersonId
    var persons = this.globalData.persons
    for (var i = 0; i < persons.length; i++) {
      if (persons[i].id === id) return persons[i]
    }
    return null
  },

  switchPerson(id) {
    if (!this.globalData.dataMap[id]) return false
    this.globalData.currentPersonId = id
    this.saveData()
    return true
  },

  addPerson(name) {
    var id = Date.now().toString(36) + Math.random().toString(36).slice(2, 6)
    this.globalData.persons.push({ id: id, name: name })
    // 新用户默认有一份默认项目列表
    this.globalData.dataMap[id] = {
      items: this._defaultItems(),
      records: []
    }
    this.saveData()
    return id
  },

  removePerson(id) {
    var persons = this.globalData.persons
    if (persons.findIndex(function(p){return p.id===id}) < 0) return false
    this.globalData.persons = persons.filter(function (p) { return p.id !== id })
    delete this.globalData.dataMap[id]
    if (this.globalData.currentPersonId === id) {
      this.globalData.currentPersonId = this.globalData.persons.length > 0 ? this.globalData.persons[0].id : null
    }
    this.saveData()
    return true
  },

  renamePerson(id, newName) {
    var persons = this.globalData.persons
    for (var i = 0; i < persons.length; i++) {
      if (persons[i].id === id) {
        persons[i].name = newName
        this.saveData()
        return true
      }
    }
    return false
  },

  addRecord(record) {
    var data = this.getCurrentData()
    data.records.push({
      id: Date.now().toString(36) + Math.random().toString(36).slice(2, 6),
      item: record.item,
      date: record.date,
      value: parseFloat(record.value)
    })
    this.saveData()
  },

  deleteRecord(id) {
    var data = this.getCurrentData()
    data.records = data.records.filter(function (r) { return r.id !== id })
    this.saveData()
  },

  addItem(name) {
    var data = this.getCurrentData()
    if (data.items.indexOf(name) === -1) {
      data.items.push(name)
      this.saveData()
    }
  },

  removeItem(name) {
    var data = this.getCurrentData()
    data.items = data.items.filter(function (i) { return i !== name })
    data.records = data.records.filter(function (r) { return r.item !== name })
    this.saveData()
  }
})