import type { RequestDetail, RequestErrorDomain, RequestSchedulingFailure } from '@/api/dashboard'

export interface RequestFailureNotice {
  title: string
  message: string
  meta: string[]
  isSchedulingFailure: boolean
}

function nonEmptyString(value: string | null | undefined): string | null {
  const trimmed = value?.trim()
  return trimmed ? trimmed : null
}

function normalizeErrorDomain(domain: RequestErrorDomain | null | undefined): RequestErrorDomain | null {
  if (!nonEmptyString(domain?.message)) return null
  return domain ?? null
}

function formatHttpStatus(statusCode: number | null | undefined): string | null {
  return typeof statusCode === 'number' ? `HTTP ${statusCode}` : null
}

function uniqueMeta(values: Array<string | null | undefined>): string[] {
  return Array.from(new Set(values.map(value => value?.trim()).filter((value): value is string => Boolean(value))))
}

function schedulingFailureMessage(
  failure: RequestSchedulingFailure,
  fallbackDomain: RequestErrorDomain | null,
  fallbackErrorMessage: string | null,
): string | null {
  return nonEmptyString(failure.message)
    ?? nonEmptyString(fallbackDomain?.message)
    ?? fallbackErrorMessage
    ?? nonEmptyString(failure.reason_label)
    ?? nonEmptyString(failure.reason)
}

export function resolveRequestFailureNotice(detail: RequestDetail | null | undefined): RequestFailureNotice | null {
  if (!detail) return null

  const fallbackDomain = normalizeErrorDomain(detail.failure_summary)
    ?? normalizeErrorDomain(detail.client_error)
    ?? normalizeErrorDomain(detail.upstream_error)
    ?? normalizeErrorDomain(detail.request_error)
  const fallbackErrorMessage = nonEmptyString(detail.error_message ?? null)
  const schedulingFailure = detail.scheduling_failure ?? null

  if (schedulingFailure) {
    const message = schedulingFailureMessage(schedulingFailure, fallbackDomain, fallbackErrorMessage)
    if (message) {
      return {
        title: nonEmptyString(schedulingFailure.title) ?? '本地调度失败',
        message,
        isSchedulingFailure: true,
        meta: uniqueMeta([
          nonEmptyString(schedulingFailure.reason_summary),
          nonEmptyString(schedulingFailure.reason_label),
          nonEmptyString(schedulingFailure.reason),
          formatHttpStatus(schedulingFailure.status_code ?? detail.status_code),
          schedulingFailure.no_upstream_attempt ? '未进入上游执行' : null,
        ]),
      }
    }
  }

  const domain = fallbackDomain
  const message = nonEmptyString(domain?.message) ?? fallbackErrorMessage
  if (!message) return null

  return {
    title: '执行失败原因',
    message,
    isSchedulingFailure: false,
    meta: uniqueMeta([
      formatHttpStatus(domain?.status_code ?? detail.status_code),
      nonEmptyString(domain?.type),
      nonEmptyString(domain?.source),
    ]),
  }
}