import type { ApiFieldErrors } from '@/api/errorDetails'

export interface ApiEnvelope<T> {
  code: string
  message: string
  data: T
  requestId: string | null
  traceId: string | null
  timestamp: string
}

export type { ApiFieldErrors } from '@/api/errorDetails'

export class ApiError extends Error {
  constructor(
    message: string,
    readonly code = 'NETWORK_ERROR',
    readonly status?: number,
    readonly fieldErrors?: ApiFieldErrors,
    readonly traceId?: string | null,
    readonly requestId?: string | null,
  ) {
    super(message)
    this.name = 'ApiError'
  }
}

export function isApiEnvelope(value: unknown): value is ApiEnvelope<unknown> {
  if (!value || typeof value !== 'object') return false
  const record = value as Record<string, unknown>
  return typeof record.code === 'string' && typeof record.message === 'string' && 'data' in record
}

// Security failures have no business data, unlike successful API responses.
export function isApiFailure(value: unknown): value is Omit<ApiEnvelope<never>, 'data'> {
  if (!value || typeof value !== 'object') return false
  const record = value as Record<string, unknown>
  return typeof record.code === 'string' && record.code !== '200'
    && typeof record.message === 'string'
    && (record.requestId == null || typeof record.requestId === 'string')
    && (record.traceId == null || typeof record.traceId === 'string')
}