import Taro from '@tarojs/taro'
import { frontendPreviewProfile, isFrontendPreview } from './frontendPreview'
import { createResourceCache } from '../utils/resourceCache'
import { getAvatarDemoProfile, isAvatarDemo, saveAvatarDemoImage, updateAvatarDemoProfile } from './avatarDemo'

export const BASE_URL = typeof API_BASE_URL === 'undefined' ? 'http://127.0.0.1:8080' : API_BASE_URL
const profileCache = createResourceCache<UserProfile>(30000)
const profileListeners = new Set<(profile: UserProfile | null) => void>()
export const getToken = (): string => Taro.getStorageSync('token') || ''
const profileKey = () => isFrontendPreview() ? 'preview' : isAvatarDemo() ? 'avatar-demo' : `user:${Taro.getStorageSync('token') || ''}`
const cloneProfile = (profile: UserProfile): UserProfile => JSON.parse(JSON.stringify(profile))
export class AuthenticationError extends Error {
  constructor(message = '请先登录') { super(message); this.name = 'AuthenticationError' }
}
export function subscribeProfile(listener: (profile: UserProfile | null) => void) {
  profileListeners.add(listener)
  return () => { profileListeners.delete(listener) }
}
function publishProfile(profile: UserProfile | null) {
  profileListeners.forEach(listener => listener(profile ? cloneProfile(profile) : null))
}
export function clearLogin() {
  Taro.removeStorageSync('token')
  profileCache.clear()
  publishProfile(null)
}
function normalizeProfile(profile: UserProfile): UserProfile {
  return { ...profile, nickname: profile.nickname || '', birthday: profile.birthday || '',
    birthHour: profile.birthHour || '', province: profile.province || '', city: profile.city || '',
    district: profile.district || '', gender: profile.gender || '未知', avatarUrl: profile.avatarUrl || '' }
}
function storeProfile(profile: UserProfile, key = profileKey()) {
  if (key !== profileKey()) throw new AuthenticationError('登录状态已变更，请重新打开页面')
  const data = normalizeProfile(profile)
  profileCache.seed(key, cloneProfile(data))
  publishProfile(data)
  return data
}
export function acceptLoginSession(session: LoginSession) {
  if (!session.token || !session.user) throw new Error('登录响应不完整，请重试')
  Taro.setStorageSync('token', session.token)
  return storeProfile(session.user)
}
export function getCachedProfile(): UserProfile | null {
  const profile = profileCache.peek(profileKey())
  return profile ? cloneProfile(profile) : null
}

type ApiResult<T> = {
  code: number
  message: string
  data: T
}

type RequestOptions = Omit<Taro.request.Option, 'url'>

function unwrap<T>(status: number, body: ApiResult<T>, token: string, protectedRequest: boolean): T {
  const expired = status === 401 || status === 403
    || (body?.code !== 0 && /请先登录|登录状态.*过期|重新登录/.test(body?.message || ''))
  if (expired && protectedRequest) {
    if (token === getToken()) clearLogin()
    throw new AuthenticationError('登录状态已失效，请重新登录')
  }
  if (status < 200 || status >= 300 || !body || body.code !== 0) {
    throw new Error(body?.message && typeof body.message === 'string' ? body.message : `请求失败（${status || '网络异常'}），请稍后重试`)
  }
  if (protectedRequest && token !== getToken()) throw new AuthenticationError('登录状态已变更，请重新打开页面')
  return body.data
}

export async function request<T>(url: string, options: RequestOptions = {}): Promise<T> {
  if (isAvatarDemo()) {
    if (url === '/api/user/profile' && (!options.method || options.method === 'GET')) return getAvatarDemoProfile() as T
    if (url === '/api/user/profile' && options.method === 'PUT') return updateAvatarDemoProfile(options.data as Partial<UserProfile>) as T
    throw new Error('已登录演示仅支持本地资料与头像，不请求真实后端')
  }
  if (isFrontendPreview()) {
    if (url === '/api/user/profile' && (!options.method || options.method === 'GET')) {
      return { ...frontendPreviewProfile, elementReport: { ...frontendPreviewProfile.elementReport, scores: [] } } as T
    }
    throw new Error('纯前端预览暂不请求后端或保存修改')
  }
  const token = Taro.getStorageSync('token')
  const protectedRequest = !/^\/api\/(auth|content)\//.test(url)
  if (protectedRequest && !token) throw new AuthenticationError()
  const headers = {
    'content-type': 'application/json',
    ...(token ? { Authorization: `Bearer ${token}` } : {}),
    ...(options.header || {})
  }
  const res = await Taro.request<ApiResult<T>>({
    url: `${BASE_URL}${url}`,
    ...options,
    timeout: options.timeout || 15000,
    credentials: 'omit',
    header: headers
  })
  return unwrap(res.statusCode, res.data, token, protectedRequest)
}

export function resolveAssetUrl(url?: string) {
  if (!url) return ''
  if (url.startsWith('cos://')) return '' // Only the backend may resolve private object references.
  return /^(https?:\/\/|wxfile:\/\/|blob:|data:image\/)/.test(url)
    ? url
    : `${BASE_URL}${url.startsWith('/') ? url : `/${url}`}`
}

async function uploadAvatar(filePath: string): Promise<UserProfile> {
  if (isAvatarDemo()) return storeProfile(saveAvatarDemoImage(filePath))
  if (isFrontendPreview()) throw new Error('纯前端预览暂不上传头像或保存修改')
  const token = Taro.getStorageSync('token')
  if (!token) throw new AuthenticationError()
  const key = profileKey()
  const response = await Taro.uploadFile({
    url: `${BASE_URL}/api/user/avatar`,
    filePath,
    name: 'file',
    timeout: 45000,
    withCredentials: false,
    header: token ? { Authorization: `Bearer ${token}` } : {}
  })
  let result: ApiResult<UserProfile>
  try {
    result = JSON.parse(response.data) as ApiResult<UserProfile>
  } catch (error) {
    if (response.statusCode === 401 || response.statusCode === 403) unwrap(response.statusCode, null, token, true)
    throw new Error('头像上传失败')
  }
  const profile = unwrap(response.statusCode, result, token, true)
  return storeProfile(profile, key)
}

export type LoginSession = { token: string; user: UserProfile }
export type WxLoginResponse = { sessionKey: string; phoneBound: boolean; token?: string; user?: UserProfile }

export const api = {
  wxLogin: (code: string) => request<WxLoginResponse>('/api/auth/wx-login', {
    method: 'POST',
    data: { code }
  }),
  sendSms: (phone: string) => request<{ mockCode?: string }>('/api/auth/sms', {
    method: 'POST',
    data: { phone }
  }),
  bindPhone: (sessionKey: string, phone: string, captcha: string) => request<LoginSession>('/api/auth/bind-phone', {
    method: 'POST',
    data: { sessionKey, phone, captcha }
  }),
  profile: (force = false) => profileCache.load(profileKey(), () => request<UserProfile>('/api/user/profile').then(normalizeProfile), force).then(data => {
    publishProfile(data)
    return cloneProfile(data)
  }),
  updateProfile: async (data: Partial<UserProfile>) => {
    const key = profileKey()
    const profile = await request<UserProfile>('/api/user/profile', { method: 'PUT', data })
    return storeProfile(profile, key)
  },
  uploadAvatar,
  exchangeStatus: () => request<{ points: number; available: boolean; message: string }>('/api/points/exchange-status'),
  agreement: (type: string) => request<{ title: string; body: string }>(`/api/content/agreement/${type}`),
  follow: () => request<Record<string, string>>('/api/content/follow'),
  homeOverview: () => request<HomeOverview>('/api/home/overview'),
  tiangong: () => request<TiangongItem[]>('/api/tiangong/items'),
  tiangongDetail: (id: string) => request<TiangongDetail>(`/api/tiangong/items/${id}`),
  dailyHome: () => request<DailyHome>('/api/daily/home'),
  pinDailyCard: (cardId: string) => request<{ pinnedCardId: string | null }>(`/api/daily/cards/${cardId}/pin`, {
    method: 'POST'
  })
}

export type ElementScore = {
  name: string
  color: string
  value: number
}

export type UserProfile = {
  id: number
  avatarUrl?: string
  nickname: string
  phone?: string
  gender: string
  birthday: string
  birthHour: string
  province: string
  city: string
  district: string
  points?: number
  remainingEdits: number
  elementReport: {
    scores: ElementScore[]
    favorable: string
    unfavorable: string
    dayMaster: string
  }
}

export type CalendarDay = {
  day: number
  weekName: string
  label: string
}

export type LuckyPanel = {
  title: string
  value: string
  accent: string
}

export type FortuneCard = {
  id: string
  title: string
  category: string
  categoryIcon: string
  verdict: string
  avoid: string
  summary: string
  detail: string
  color: string
  gradient: string
  mascot: string
}

export type LifeTip = {
  id: string
  title: string
  icon: string
  content: string
  color: string
  mark: string
}

export type DailyHome = {
  date: string
  lunarDate: string
  weekName: string
  fortuneLevel: string
  greeting: string
  dailySummary: string
  calendarDays: CalendarDay[]
  luckyPanels: LuckyPanel[]
  cards: FortuneCard[]
  lifeTips: LifeTip[]
  pinnedCardId?: string | null
}

export type DayFortune = {
  label: '昨日' | '今日' | '明日'
  date: string
  weekName: string
  lunarDate: string
  status: string
}

export type LuckyColor = {
  name: string
  value: string
}

export type DimensionItem = {
  id: string
  title: string
  icon: string
  headline: string
  detail: string
  suitable: boolean
}

export type HomeOverview = {
  days: DayFortune[]
  activeDay: '昨日' | '今日' | '明日'
  summary: string
  overallIndex: number
  luckyColors: LuckyColor[]
  luckyNumbers: string[]
  luckyDirection: string
  luckyHours: Array<{ branch: string; time: string }>
  dimensions: DimensionItem[]
}

export type TiangongItem = {
  id: string
  name: string
  imageUrl: string
  unlocked: boolean
}

export type TiangongDetail = {
  id: string
  name: string
  title: string
  imageUrl: string
  introduction: string
  blessing: string
}