import type { AdminStats, Course, CourseStatus, User } from './types'

const token = () => localStorage.getItem('xinghen_token')

async function request<T>(path: string, init: RequestInit = {}): Promise<T> {
  const headers = new Headers(init.headers)
  if (token()) headers.set('Authorization', `Bearer ${token()}`)
  const response = await fetch(`/api${path}`, { ...init, headers })
  if (!response.ok) {
    const body = await response.json().catch(() => ({ message: '请求失败，请稍后重试' }))
    if (response.status === 401) {
      localStorage.removeItem('xinghen_token')
      window.dispatchEvent(new Event('auth-expired'))
    }
    throw new Error(body.message || '请求失败，请稍后重试')
  }
  return response.json() as Promise<T>
}

export const api = {
  // 用户鉴权与信息
  register: (phone: string, password: string) =>
    request<{ token: string; user: User }>('/auth/register', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ phone, password })
    }),
  login: (phone: string, password: string) =>
    request<{ token: string; user: User }>('/auth/login', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ phone, password })
    }),
  logout: () => request<{ ok: boolean }>('/auth/logout', { method: 'POST' }),
  me: () => request<{ user: User }>('/me'),
  updateMe: (body: Pick<User, 'organization' | 'wechat' | 'contactName' | 'bio'>) =>
    request<{ user: User }>('/me', {
      method: 'PATCH',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body)
    }),
  changePassword: (currentPassword: string, newPassword: string) =>
    request<{ ok: boolean }>('/me/password', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ currentPassword, newPassword })
    }),

  // 普通用户课程操作
  listCourses: () => request<{ courses: Course[] }>('/courses'),
  createCourse: (body: Pick<Course, 'name' | 'category' | 'audience' | 'description'>) =>
    request<{ course: Course }>('/courses', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body)
    }),
  getCourse: (id: string) => request<{ course: Course }>(`/courses/${id}`),
  uploadAssets: (id: string, files: File[]) => {
    const form = new FormData()
    files.forEach((f) => form.append('assets', f))
    return request<{ course: Course }>(`/courses/${id}/assets`, { method: 'POST', body: form })
  },
  deleteAsset: (id: string, assetId: string) =>
    request<{ course: Course }>(`/courses/${id}/assets/${assetId}`, { method: 'DELETE' }),
  addInstructor: (
    id: string,
    data: { name: string; organization: string; introduction: string; image?: File }
  ) => {
    const f = new FormData()
    f.append('name', data.name)
    f.append('organization', data.organization)
    f.append('introduction', data.introduction)
    if (data.image) f.append('image', data.image)
    return request<{ course: Course }>(`/courses/${id}/instructors`, { method: 'POST', body: f })
  },
  deleteInstructor: (id: string, instructorId: string) =>
    request<{ course: Course }>(`/courses/${id}/instructors/${instructorId}`, { method: 'DELETE' }),
  submitCourse: (id: string) => request<{ course: Course }>(`/courses/${id}/submit`, { method: 'POST' }),

  // 管理员后台专区 API
  admin: {
    login: (phone: string, password: string) =>
      request<{ token: string; user: User }>('/admin/auth/login', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ phone, password })
      }),
    getStats: () => request<AdminStats>('/admin/stats'),
    listCourses: (params?: { status?: string; keyword?: string }) => {
      const q = new URLSearchParams()
      if (params?.status) q.set('status', params.status)
      if (params?.keyword) q.set('keyword', params.keyword)
      const qs = q.toString() ? `?${q.toString()}` : ''
      return request<{ courses: Course[]; total: number }>(`/admin/courses${qs}`)
    },
    getCourse: (id: string) => request<{ course: Course }>(`/admin/courses/${id}`),
    updateStatus: (id: string, status: CourseStatus) =>
      request<{ course: Course }>(`/admin/courses/${id}/status`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ status })
      }),
    uploadDeliverables: (id: string, files: File[]) => {
      const form = new FormData()
      files.forEach((f) => form.append('deliverables', f))
      return request<{ course: Course }>(`/admin/courses/${id}/deliverables`, { method: 'POST', body: form })
    },
    deleteDeliverable: (id: string, delivId: string) =>
      request<{ course: Course }>(`/admin/courses/${id}/deliverables/${delivId}`, { method: 'DELETE' }),
    completeCourse: (id: string, productionNotes: string) =>
      request<{ course: Course }>(`/admin/courses/${id}/complete`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ productionNotes })
      }),
    listUsers: (keyword?: string) => {
      const qs = keyword ? `?keyword=${encodeURIComponent(keyword)}` : ''
      return request<{ users: User[] }>(`/admin/users${qs}`)
    },
    updateUserRole: (id: string, role: 'USER' | 'ADMIN') =>
      request<{ user: User }>(`/admin/users/${id}/role`, {
        method: 'PATCH',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ role })
      })
  }
}