import {
  createProfile,
  deleteProfile as deleteProfileRequest,
  getApiErrorMessage,
  getProfileDefaults,
  listProfiles
} from '../../utils/api'
import { addMinutes, formatUpdatedAt } from '../../utils/time'
import type { StudentDraft, StudentProfile, StudentProfileDefaults, Term } from '../../utils/types'

const grades = ['艺术类', '幼儿园', '一年级', '二年级', '三年级', '四年级', '五年级', '六年级']
const subjects = ['美术', '书法', '音乐', '舞蹈', '语文', '数学', '英语']
const terms: Term[] = ['春', '暑', '秋', '寒']
const years = Array.from({ length: 5 }, (_, index) => new Date().getFullYear() - 1 + index)
const initialDefaults: StudentProfileDefaults = {
  grade: '艺术类',
  subject: '美术',
  lessonDurationMinutes: 60
}

type InputEvent = { detail: { value: string } }
type PickerEvent = { detail: { value: string | number } }

function getCurrentTerm(): Term {
  const month = new Date().getMonth() + 1
  if (month >= 6 && month <= 8) return '暑'
  if (month >= 9 && month <= 12) return '秋'
  if (month <= 2) return '寒'
  return '春'
}

function buildDraft(defaults: StudentProfileDefaults = initialDefaults): StudentDraft {
  const startTime = '18:00'
  return {
    name: '',
    grade: defaults.grade,
    subject: defaults.subject,
    academicYear: new Date().getFullYear(),
    term: getCurrentTerm(),
    guardianTitle: '',
    startTime,
    endTime: addMinutes(startTime, defaults.lessonDurationMinutes)
  }
}

function filterProfiles(
  profiles: StudentProfile[],
  query: string,
  filterGrade: string,
  filterSubject: string
): StudentProfile[] {
  const keyword = query.trim().toLocaleLowerCase()
  return profiles.filter((profile) => {
    const searchable = [profile.name, profile.grade, profile.subject, profile.guardianTitle]
      .join(' ')
      .toLocaleLowerCase()
    const matchesKeyword = !keyword || searchable.includes(keyword)
    const matchesGrade = !filterGrade || profile.grade === filterGrade
    const matchesSubject = !filterSubject || profile.subject === filterSubject
    return matchesKeyword && matchesGrade && matchesSubject
  })
}

function getLastUpdatedText(profiles: StudentProfile[]): string {
  if (!profiles.length) return '--'
  const latest = Math.max(...profiles.map((profile) => profile.updatedAt))
  return formatUpdatedAt(latest)
}

Page({
  data: {
    profiles: [] as StudentProfile[],
    filteredProfiles: [] as StudentProfile[],
    query: '',
    filterVisible: false,
    filterGrade: '',
    filterSubject: '',
    grades,
    subjects,
    terms,
    years,
    sheetVisible: false,
    draft: buildDraft(),
    guardianAuto: true,
    refreshDraftFromDefaults: false,
    lastUpdatedText: '--',
    loading: false,
    saving: false,
    deletingId: '',
    errorMessage: ''
  },

  onShow() {
    this.getTabBar()?.setData({ selected: 1 })
    void this.refreshProfiles()
    if (this.data.sheetVisible && this.data.refreshDraftFromDefaults) {
      void this.refreshDraftDefaults()
    }
  },

  async refreshProfiles(showSuccess = false) {
    this.setData({ loading: true, errorMessage: '' })
    try {
      const profiles = await listProfiles()
      const filteredProfiles = filterProfiles(
        profiles,
        this.data.query,
        this.data.filterGrade,
        this.data.filterSubject
      )
      this.setData({
        profiles,
        filteredProfiles,
        lastUpdatedText: getLastUpdatedText(profiles)
      })
      if (showSuccess) wx.showToast({ title: '档案已刷新', icon: 'success' })
    } catch (error) {
      this.setData({ errorMessage: getApiErrorMessage(error) })
    } finally {
      this.setData({ loading: false })
    }
  },

  onRefresh() {
    void this.refreshProfiles(true)
  },

  retryLoad() {
    void this.refreshProfiles()
  },

  onSearch(event: InputEvent) {
    const query = event.detail.value
    this.setData({
      query,
      filteredProfiles: filterProfiles(
        this.data.profiles,
        query,
        this.data.filterGrade,
        this.data.filterSubject
      )
    })
  },

  toggleFilter() {
    this.setData({ filterVisible: !this.data.filterVisible })
  },

  selectFilter(event: WechatMiniprogram.TouchEvent) {
    const { type, value } = event.currentTarget.dataset as { type: 'grade' | 'subject'; value: string }
    const filterGrade = type === 'grade' ? (value === 'all' ? '' : value) : this.data.filterGrade
    const filterSubject = type === 'subject' ? (value === 'all' ? '' : value) : this.data.filterSubject
    this.setData({
      filterGrade,
      filterSubject,
      filteredProfiles: filterProfiles(this.data.profiles, this.data.query, filterGrade, filterSubject)
    })
  },

  clearFilters() {
    this.setData({
      query: '',
      filterGrade: '',
      filterSubject: '',
      filteredProfiles: this.data.profiles
    })
  },

  async openCreate() {
    this.setData({
      sheetVisible: true,
      guardianAuto: true,
      draft: buildDraft()
    })
    await this.refreshDraftDefaults()
  },

  async refreshDraftDefaults() {
    try {
      const defaults = await getProfileDefaults()
      if (!this.data.sheetVisible) return
      this.setData({
        'draft.grade': defaults.grade,
        'draft.subject': defaults.subject,
        'draft.endTime': addMinutes(this.data.draft.startTime, defaults.lessonDurationMinutes),
        refreshDraftFromDefaults: false
      })
    } catch (error) {
      this.setData({ refreshDraftFromDefaults: false })
      wx.showToast({ title: getApiErrorMessage(error), icon: 'none' })
    }
  },

  closeCreate() {
    this.setData({ sheetVisible: false })
  },

  noop() {},

  goDefaults() {
    this.setData({ refreshDraftFromDefaults: true })
    wx.navigateTo({ url: '/pages/defaults/index' })
  },

  onNameInput(event: InputEvent) {
    const name = event.detail.value
    const nextData: Record<string, unknown> = { 'draft.name': name }
    if (this.data.guardianAuto || !this.data.draft.guardianTitle) {
      nextData['draft.guardianTitle'] = name ? `${name}妈妈` : ''
      nextData.guardianAuto = true
    }
    this.setData(nextData)
  },

  onGuardianInput(event: InputEvent) {
    this.setData({
      'draft.guardianTitle': event.detail.value,
      guardianAuto: false
    })
  },

  onGradeChange(event: PickerEvent) {
    this.setData({ 'draft.grade': grades[Number(event.detail.value)] })
  },

  onSubjectChange(event: PickerEvent) {
    this.setData({ 'draft.subject': subjects[Number(event.detail.value)] })
  },

  onYearChange(event: PickerEvent) {
    this.setData({ 'draft.academicYear': years[Number(event.detail.value)] })
  },

  onTermChange(event: PickerEvent) {
    this.setData({ 'draft.term': terms[Number(event.detail.value)] })
  },

  onStartTimeChange(event: InputEvent) {
    const startTime = event.detail.value
    this.setData({ 'draft.startTime': startTime })
    void getProfileDefaults()
      .then((defaults) => {
        this.setData({ 'draft.endTime': addMinutes(startTime, defaults.lessonDurationMinutes) })
      })
      .catch(() => {
        this.setData({ 'draft.endTime': addMinutes(startTime, initialDefaults.lessonDurationMinutes) })
      })
  },

  onEndTimeChange(event: InputEvent) {
    this.setData({ 'draft.endTime': event.detail.value })
  },

  async saveStudent() {
    const draft = this.data.draft
    if (!draft.name.trim()) {
      wx.showToast({ title: '请填写学生姓名', icon: 'none' })
      return
    }

    this.setData({ saving: true })
    try {
      const profile = await createProfile({
        ...draft,
        name: draft.name.trim(),
        guardianTitle: draft.guardianTitle.trim() || `${draft.name.trim()}妈妈`
      })
      const profiles = [profile, ...this.data.profiles]
      this.setData({
        sheetVisible: false,
        profiles,
        filteredProfiles: filterProfiles(profiles, this.data.query, this.data.filterGrade, this.data.filterSubject),
        lastUpdatedText: formatUpdatedAt(profile.updatedAt),
        errorMessage: ''
      })
      wx.showToast({ title: '学生档案已保存', icon: 'success' })
    } catch (error) {
      wx.showToast({ title: getApiErrorMessage(error), icon: 'none' })
    } finally {
      this.setData({ saving: false })
    }
  },

  deleteProfile(event: WechatMiniprogram.TouchEvent) {
    const { id } = event.currentTarget.dataset as { id: string }
    const profile = this.data.profiles.find((item) => item.id === id)
    if (!profile) return

    wx.showModal({
      title: '删除学生档案',
      content: `确认删除“${profile.name}”吗？`,
      confirmColor: '#D14343',
      success: async (result) => {
        if (!result.confirm) return
        this.setData({ deletingId: id })
        try {
          await deleteProfileRequest(id)
          const profiles = this.data.profiles.filter((item) => item.id !== id)
          this.setData({
            profiles,
            filteredProfiles: filterProfiles(profiles, this.data.query, this.data.filterGrade, this.data.filterSubject),
            lastUpdatedText: getLastUpdatedText(profiles),
            errorMessage: ''
          })
          wx.showToast({ title: '已删除', icon: 'success' })
        } catch (error) {
          wx.showToast({ title: getApiErrorMessage(error), icon: 'none' })
        } finally {
          this.setData({ deletingId: '' })
        }
      }
    })
  }
})