import { FieldPath, FieldValues, UseFormReturn } from "react-hook-form"

export interface TabDefinition<T extends FieldValues = FieldValues> {
  /** Unique tab identifier, used as ProgressTabs value */
  id: string
  /** i18n key for the tab label (used when `label` is not provided) */
  labelKey: string
  /** Raw label string (overrides `labelKey`) */
  label?: string
  /** Fields validated when navigating forward from this tab. If omitted, full form validation is used. */
  validationFields?: FieldPath<T>[]
  /** Predicate to conditionally show/hide this tab at runtime */
  isVisible?: (form: UseFormReturn<T>) => boolean
}

/**
 * Helper to declare tab metadata on a component with type safety.
 *
 * Usage:
 * ```ts
 * const MyTab = () => { ... }
 * MyTab._tabMeta = defineTabMeta<MyFormSchema>({
 *   id: "details",
 *   labelKey: "products.create.tabs.details",
 *   validationFields: ["title", "handle"],
 * })
 * ```
 */
export const defineTabMeta = <T extends FieldValues = FieldValues>(
  meta: TabDefinition<T>
): TabDefinition<T> => {
  if (process.env.NODE_ENV !== "production") {
    if (!meta.id) {
      console.warn("[TabbedForm] Tab meta is missing required 'id' field")
    }
    if (!meta.labelKey && !meta.label) {
      console.warn(
        `[TabbedForm] Tab "${meta.id}" has neither 'labelKey' nor 'label' — the tab header will be empty`
      )
    }
  }
  return meta
}