import type { AxiosError, AxiosResponse } from 'axios'
import { isAxiosError } from 'axios'
import type { z } from 'zod'
import type { RequestError } from './errors'

type SafeIssue = {
  code: string
  message: string
  path: string
}

export type SafeApiDiagnostic = {
  code?: string
  httpStatus?: number
  issues?: SafeIssue[]
  method?: string
  path?: string
  type: 'AxiosError' | 'Response' | 'ValidationError'
}

export type SafeApiErrorReport = {
  diagnostic?: SafeApiDiagnostic
  requestType: RequestError['type']
}

/**
 * 网络诊断只能描述请求形态，不得复制请求/响应 body、headers 或完整 URL。
 * 这些字段可能包含手机号、userId、sessionId、签名和其它业务数据。
 */
export function safeRequestPath(input?: string): string | undefined {
  if (!input) return undefined
  try {
    return new URL(input, 'https://xuqm.invalid').pathname
  } catch {
    return input.split(/[?#]/, 1)[0]
  }
}

function requestShape(response: AxiosResponse<unknown>) {
  return {
    httpStatus: response.status,
    method: response.config.method?.toUpperCase(),
    path: safeRequestPath(response.config.url),
  }
}

export function createResponseDiagnostic(response: AxiosResponse<unknown>): SafeApiDiagnostic {
  return { type: 'Response', ...requestShape(response) }
}

export function createValidationDiagnostic(
  response: AxiosResponse<unknown>,
  issues: z.ZodIssue[],
): SafeApiDiagnostic {
  return {
    type: 'ValidationError',
    ...requestShape(response),
    issues: issues.map(issue => ({
      code: issue.code,
      message: issue.message,
      path: issue.path.join('.'),
    })),
  }
}

export function createAxiosDiagnostic(error: AxiosError): SafeApiDiagnostic {
  return {
    type: 'AxiosError',
    code: error.code,
    httpStatus: error.response?.status,
    method: error.config?.method?.toUpperCase(),
    path: safeRequestPath(error.config?.url),
  }
}

/**
 * 非 axios 异常只允许记录构造名与截断消息。
 * 不接触 cause、stack、config 或任何可能持有业务数据的对象。
 */
export function createUnexpectedDiagnostic(error: unknown): string {
  if (error instanceof Error) {
    return `${error.name}: ${error.message.slice(0, 200)}`
  }
  return typeof error
}

type ValidationCause = {
  issues: z.ZodIssue[]
  response: AxiosResponse<unknown>
}

function isValidationCause(value: unknown): value is ValidationCause {
  if (!value || typeof value !== 'object') return false
  const candidate = value as Partial<ValidationCause>
  return Array.isArray(candidate.issues) && Boolean(candidate.response?.config)
}

/**
 * 全局错误采集只接收不可逆的安全摘要，绝不暴露 RequestError.cause。
 * cause 可能持有 Axios config、headers、请求体和完整响应，只能留在调用现场。
 */
export function createSafeApiErrorReport(error: RequestError): SafeApiErrorReport {
  const cause = error.cause
  const diagnostic = isValidationCause(cause)
    ? createValidationDiagnostic(cause.response, cause.issues)
    : isAxiosError(cause)
      ? createAxiosDiagnostic(cause)
      : undefined
  return { diagnostic, requestType: error.type }
}