export type FormFieldLabel = { key: string; label: string };

export type TemplateVars = {
  title: string;
  mobile?: string | null;
  formName?: string | null;
  formValues?: Record<string, unknown> | null;
};

/** counter یک‌واحد افزایش‌یافته از AutomationCursor است (از ۱ شروع می‌شود) */
export function pickRoundRobin(memberIds: string[], counter: number): string | null {
  const ids = [...new Set(memberIds.filter(Boolean))].sort();
  if (!ids.length) return null;
  const n = Math.max(1, Math.trunc(counter));
  return ids[(n - 1) % ids.length] ?? null;
}

/** جایگزینی {{title}}، {{mobile}}، {{form}} و {{field.<key>}} */
export function renderAutomationTemplate(text: string, vars: TemplateVars): string {
  return text.replace(/\{\{\s*([\w.\u0600-\u06FF-]+)\s*\}\}/g, (_m, name: string) => {
    if (name === 'title') return vars.title ?? '';
    if (name === 'mobile') return vars.mobile ?? '';
    if (name === 'form') return vars.formName ?? '';
    if (name.startsWith('field.')) {
      const v = vars.formValues?.[name.slice(6)];
      return v == null ? '' : String(v);
    }
    return '';
  });
}

export function formatFormAnswers(
  fields: FormFieldLabel[] | null | undefined,
  values: Record<string, unknown> | null | undefined,
): string {
  if (!values) return '';
  const lines: string[] = [];
  const seen = new Set<string>();
  for (const f of fields ?? []) {
    seen.add(f.key);
    const raw = values[f.key];
    const v = raw == null ? '' : String(raw).trim();
    if (v) lines.push(`${f.label}: ${v}`);
  }
  for (const [key, raw] of Object.entries(values)) {
    if (seen.has(key)) continue;
    const v = raw == null ? '' : String(raw).trim();
    if (v) lines.push(`${key}: ${v}`);
  }
  return lines.join('\n');
}