export interface InstitutionListParams {
  token: string
  search?: string
  type?: string
  province?: string
  city?: string
  page?: number
}

export interface InstitutionListItem {
  id: number
  code: string
  name: string
  type: string
  level: string
  province: string
  city: string
  bannerUrl: string
  createdAt: string
  updatedAt: string
}

export interface InstitutionListResult {
  institutions: InstitutionListItem[]
  total: number
}

export interface InstitutionPayload {
  code?: string
  name?: string
  type?: string
  level?: string
  province?: string
  city?: string
  banner_url?: string
}

export interface CreateInstitutionPayload extends InstitutionPayload {
  code: string
  name: string
}

export interface InstitutionMutationParams {
  token: string
  payload: InstitutionPayload
}

export interface UpdateInstitutionParams extends InstitutionMutationParams {
  id: number
}

export interface DisableInstitutionParams {
  token: string
  id: number
}

export interface UploadInstitutionBannerParams {
  token: string
  id: number
  file: File
}

export interface UploadInstitutionBannerResult {
  message: string
  bannerUrl: string
  raw: unknown
}

export interface ImportInstitutionsParams {
  token: string
  file: File
}

export interface ExportInstitutionsParams extends InstitutionListParams {}

function createAuthorization(token: string) {
  return /^Bearer\s+/i.test(token) ? token : `Bearer ${token}`
}

function parseResponseText(text: string): unknown {
  if (!text) {
    return null
  }

  try {
    return JSON.parse(text)
  } catch {
    return null
  }
}

function getMessageFromResponse(data: unknown): string {
  if (!data || typeof data !== 'object') {
    return ''
  }

  const record = data as Record<string, unknown>
  const message = record.message || record.msg || record.detail
  if (typeof message === 'string') {
    return message
  }

  return getMessageFromResponse(record.data)
}

function getString(record: Record<string, unknown>, key: string): string {
  const value = record[key]
  if (typeof value === 'string') {
    return value
  }
  if (typeof value === 'number') {
    return String(value)
  }

  return ''
}

function getBannerUrlFromResponse(data: unknown): string {
  if (!data || typeof data !== 'object') {
    return ''
  }

  const record = data as Record<string, unknown>
  const bannerUrl = record.banner_url || record.bannerUrl
  if (typeof bannerUrl === 'string') {
    return bannerUrl
  }

  const nested = record.data || record.result || record.payload
  if (nested && typeof nested === 'object') {
    return getBannerUrlFromResponse(nested)
  }

  return ''
}

function getInstitutionIdFromResponse(data: unknown): number {
  if (!data || typeof data !== 'object') {
    return 0
  }

  const record = data as Record<string, unknown>
  const id = record.id || record.institution_id || record.institutionId
  if (typeof id === 'number' && Number.isFinite(id)) {
    return id
  }
  if (typeof id === 'string' && Number.isFinite(Number(id))) {
    return Number(id)
  }

  const nested = record.data || record.result || record.payload || record.institution
  if (nested && typeof nested === 'object') {
    return getInstitutionIdFromResponse(nested)
  }

  return 0
}

function normalizeInstitution(item: unknown): InstitutionListItem {
  const record = item && typeof item === 'object' ? (item as Record<string, unknown>) : {}
  const id = record.id

  return {
    id: typeof id === 'number' ? id : Number(id) || 0,
    code: getString(record, 'code'),
    name: getString(record, 'name'),
    type: getString(record, 'type'),
    level: getString(record, 'level'),
    province: getString(record, 'province'),
    city: getString(record, 'city'),
    bannerUrl: getString(record, 'banner_url'),
    createdAt: getString(record, 'created_at'),
    updatedAt: getString(record, 'updated_at')
  }
}

function getTotal(data: unknown, fallback: number): number {
  if (!data || typeof data !== 'object') {
    return fallback
  }

  const record = data as Record<string, unknown>
  const total = record.count || record.total
  if (typeof total === 'number') {
    return total
  }
  if (typeof total === 'string' && Number.isFinite(Number(total))) {
    return Number(total)
  }

  return fallback
}

function getResults(data: unknown): unknown[] {
  if (Array.isArray(data)) {
    return data
  }
  if (!data || typeof data !== 'object') {
    return []
  }

  const record = data as Record<string, unknown>
  if (Array.isArray(record.results)) {
    return record.results
  }
  if (Array.isArray(record.data)) {
    return record.data
  }
  if (record.data && typeof record.data === 'object') {
    return getResults(record.data)
  }

  return []
}

function createInstitutionQuery(params: Partial<InstitutionListParams>) {
  const query = new URLSearchParams()
  if (params.search?.trim()) {
    query.set('search', params.search.trim())
  }
  if (params.type) {
    query.set('type', params.type)
  }
  if (params.province?.trim()) {
    query.set('province', params.province.trim())
  }
  if (params.city?.trim()) {
    query.set('city', params.city.trim())
  }
  if (params.page) {
    query.set('page', String(params.page))
  }

  return query
}

async function parseMutationResponse(response: Response, fallbackMessage: string): Promise<unknown> {
  const text = await response.text()
  const data = parseResponseText(text)

  if (!response.ok) {
    const message = getMessageFromResponse(data) || fallbackMessage
    throw new Error(message)
  }

  return data
}

function getFilenameFromDisposition(disposition: string | null, fallback: string) {
  if (!disposition) {
    return fallback
  }

  const utf8Match = disposition.match(/filename\*=UTF-8''([^;]+)/i)
  if (utf8Match?.[1]) {
    return decodeURIComponent(utf8Match[1])
  }

  const filenameMatch = disposition.match(/filename="?([^"]+)"?/i)
  return filenameMatch?.[1] || fallback
}

async function downloadResponse(response: Response, fallbackFilename: string, fallbackMessage: string) {
  if (!response.ok) {
    const text = await response.text()
    const data = parseResponseText(text)
    const message = getMessageFromResponse(data) || fallbackMessage
    throw new Error(message)
  }

  const blob = await response.blob()
  const url = URL.createObjectURL(blob)
  const link = document.createElement('a')
  link.href = url
  link.download = getFilenameFromDisposition(response.headers.get('content-disposition'), fallbackFilename)
  document.body.appendChild(link)
  link.click()
  link.remove()
  URL.revokeObjectURL(url)
}

export async function fetchInstitutions(params: InstitutionListParams): Promise<InstitutionListResult> {
  const query = createInstitutionQuery(params)
  const url = `/server/api/cms/institutions/${query.toString() ? `?${query.toString()}` : ''}`
  const response = await fetch(url, {
    method: 'GET',
    headers: {
      Accept: 'application/json',
      Authorization: createAuthorization(params.token)
    }
  })
  const text = await response.text()
  const data = parseResponseText(text)

  if (!response.ok) {
    const message = getMessageFromResponse(data) || '获取医院列表失败'
    throw new Error(message)
  }

  const results = getResults(data)

  return {
    institutions: results.map(normalizeInstitution),
    total: getTotal(data, results.length)
  }
}

export async function createInstitution(params: InstitutionMutationParams): Promise<InstitutionListItem> {
  const response = await fetch('/server/api/cms/institutions/', {
    method: 'POST',
    headers: {
      Accept: 'application/json',
      Authorization: createAuthorization(params.token),
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(params.payload)
  })

  const data = await parseMutationResponse(response, '新增机构失败')
  const normalized = normalizeInstitution(data)
  const id = normalized.id || getInstitutionIdFromResponse(data)

  return {
    ...normalized,
    id
  }
}

export async function updateInstitution(params: UpdateInstitutionParams): Promise<unknown> {
  const response = await fetch(`/server/api/cms/institutions/${params.id}/update/`, {
    method: 'POST',
    headers: {
      Accept: 'application/json',
      Authorization: createAuthorization(params.token),
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(params.payload)
  })

  return parseMutationResponse(response, '编辑机构失败')
}

export async function disableInstitution(params: DisableInstitutionParams): Promise<unknown> {
  const response = await fetch(`/server/api/cms/institutions/${params.id}/disable/`, {
    method: 'POST',
    headers: {
      Accept: 'application/json',
      Authorization: createAuthorization(params.token)
    }
  })

  return parseMutationResponse(response, '停用机构失败')
}

export async function uploadInstitutionBanner(params: UploadInstitutionBannerParams): Promise<UploadInstitutionBannerResult> {
  const formData = new FormData()
  formData.append('file', params.file)

  const response = await fetch(`/server/api/cms/institutions/${params.id}/banner/`, {
    method: 'POST',
    headers: {
      Accept: 'application/json',
      Authorization: createAuthorization(params.token)
    },
    body: formData
  })
  const data = await parseMutationResponse(response, '上传机构背景图失败')

  return {
    message: getMessageFromResponse(data),
    bannerUrl: getBannerUrlFromResponse(data),
    raw: data
  }
}

export async function importInstitutions(params: ImportInstitutionsParams): Promise<unknown> {
  const formData = new FormData()
  formData.append('file', params.file)

  const response = await fetch('/server/api/cms/institutions/import/', {
    method: 'POST',
    headers: {
      Accept: 'application/json',
      Authorization: createAuthorization(params.token)
    },
    body: formData
  })

  return parseMutationResponse(response, '导入机构失败')
}

export async function exportInstitutions(params: ExportInstitutionsParams): Promise<void> {
  const query = createInstitutionQuery(params)
  const url = `/server/api/cms/institutions/export/${query.toString() ? `?${query.toString()}` : ''}`
  const response = await fetch(url, {
    method: 'GET',
    headers: {
      Authorization: createAuthorization(params.token)
    }
  })

  await downloadResponse(response, 'institutions.xlsx', '导出机构失败')
}

export async function downloadInstitutionImportTemplate(token: string): Promise<void> {
  const response = await fetch('/server/api/cms/institutions/import-template/', {
    method: 'GET',
    headers: {
      Authorization: createAuthorization(token)
    }
  })

  await downloadResponse(response, 'institutions-import-template.xlsx', '下载导入模板失败')
}