import crypto from 'crypto'

export type NotificationCenterDelivery = {
  id: string
  projectCode: string
  status: 'pending' | 'sending' | 'retrying' | 'sent' | 'unread' | 'read' | 'failed'
  recipientUserId: string
  title: string
  processQueryKey?: string | null
  lastErrorCode?: string | null
  lastErrorMessage?: string | null
  sentAt?: string | null
  readAt?: string | null
}

export class NotificationCenterError extends Error {
  constructor(message: string, public readonly deterministic = false) {
    super(message)
    this.name = 'NotificationCenterError'
  }
}

const config = () => ({
  baseUrl: String(process.env.YYD_NOTIFICATION_CENTER_URL || '').trim().replace(/\/$/, ''),
  projectCode: String(process.env.YYD_NOTIFICATION_CENTER_PROJECT_CODE || '').trim(),
  secret: String(process.env.YYD_NOTIFICATION_CENTER_PROJECT_SECRET || '').trim()
})

export const getNotificationCenterConfigStatus = () => {
  const value = config()
  const missing: string[] = []
  if (!value.baseUrl) missing.push('YYD_NOTIFICATION_CENTER_URL')
  if (!value.projectCode) missing.push('YYD_NOTIFICATION_CENTER_PROJECT_CODE')
  if (!value.secret) missing.push('YYD_NOTIFICATION_CENTER_PROJECT_SECRET')
  return { configured: missing.length === 0, missing }
}

const sha256 = (value: string) => crypto.createHash('sha256').update(value).digest('hex')

const signedHeaders = (method: string, path: string, body: string) => {
  const value = config()
  const timestamp = String(Math.floor(Date.now() / 1000))
  const nonce = crypto.randomBytes(18).toString('base64url')
  const canonical = [timestamp, nonce, method.toUpperCase(), path, sha256(body)].join('\n')
  const signature = crypto.createHmac('sha256', value.secret).update(canonical).digest('hex')
  return {
    'Content-Type': 'application/json',
    'x-yyd-project-code': value.projectCode,
    'x-yyd-timestamp': timestamp,
    'x-yyd-nonce': nonce,
    'x-yyd-signature': signature
  }
}

const request = async (path: string, method: 'GET' | 'POST', payload?: Record<string, unknown>) => {
  const value = config()
  const status = getNotificationCenterConfigStatus()
  if (!status.configured) throw new NotificationCenterError(`由壹点通知中心配置不完整: ${status.missing.join(', ')}`, true)
  const body = payload ? JSON.stringify(payload) : ''
  const controller = new AbortController()
  const timeout = setTimeout(() => controller.abort(), 8_000)
  let response: Response
  try {
    response = await fetch(`${value.baseUrl}${path}`, {
      method,
      headers: signedHeaders(method, path, body),
      body: body || undefined,
      signal: controller.signal
    })
  } catch (error: any) {
    if (error?.name === 'AbortError') throw new NotificationCenterError('由壹点通知中心请求超时')
    throw new NotificationCenterError(error?.message || '由壹点通知中心网络请求失败')
  } finally {
    clearTimeout(timeout)
  }
  const data = await response.json().catch(() => ({})) as Record<string, any>
  if (!response.ok) {
    throw new NotificationCenterError(
      `由壹点通知中心请求失败: ${data.error || response.status}`,
      response.status >= 400 && response.status < 500 && response.status !== 429
    )
  }
  return data as NotificationCenterDelivery
}

const buildActionUrl = (actionUrl: string) => {
  const publicBaseUrl = String(process.env.DINGTALK_PUBLIC_BASE_URL || '').trim().replace(/\/$/, '')
  const safePath = actionUrl.startsWith('/') && !actionUrl.startsWith('//') ? actionUrl : '/'
  return `${publicBaseUrl}/dingtalk-entry?redirect=${encodeURIComponent(safePath)}`
}

export const submitYouyidianNotification = (input: {
  idempotencyKey: string
  recipientUserId: string
  title: string
  content: string
  actionTitle?: string
  actionUrl: string
}) => request('/v1/notifications', 'POST', {
  idempotencyKey: input.idempotencyKey,
  recipientUserId: input.recipientUserId,
  title: input.title,
  content: input.content,
  actionTitle: input.actionTitle || '查看详情',
  actionUrl: buildActionUrl(input.actionUrl)
})

export const getYouyidianNotificationStatus = (id: string) => {
  const path = `/v1/notifications/${encodeURIComponent(id)}`
  return request(path, 'GET')
}