import type { Human } from '@/api/types';
import { getInitials } from '@/lib/utils';

export const REMOVED_MEMBER_LABEL = 'Removed member';
export const REMOVED_MEMBER_INITIALS = '–';

export interface HumanDisplay {
  /** True when the human was found in the provided list. */
  exists: boolean;
  /** Short name for inline text (e.g. message sender). */
  displayName: string;
  /** Full email or fallback label for tooltips. */
  email: string;
  /** Initials for avatar fallback. */
  initials: string;
}

/**
 * Resolve a human's display info by id, falling back consistently when the
 * human has been removed from the network. Member content (particles, reactions,
 * etc.) is retained after removal, so every render path needs a graceful fallback
 * instead of leaking raw ids into the UI.
 */
export function resolveHumanDisplay(
  humanId: string | null | undefined,
  humans: Human[] | undefined,
): HumanDisplay {
  const human = humanId ? humans?.find((h) => h.id === humanId) : undefined;
  if (!human) {
    return {
      exists: false,
      displayName: REMOVED_MEMBER_LABEL,
      email: REMOVED_MEMBER_LABEL,
      initials: REMOVED_MEMBER_INITIALS,
    };
  }
  return {
    exists: true,
    displayName: human.email_prefix,
    email: human.email,
    initials: getInitials(human.email),
  };
}