import { DraftMark } from './NavigationGuard.jsx';
import { useEffect, useId, useRef } from 'react';

export function Tabs({ tabs, active, onChange }) {
  const id = useId();
  const listRef = useRef(null);
  const tabRefs = useRef({});
  useEffect(() => {
    const panel = listRef.current?.nextElementSibling;
    if (!panel) return;
    panel.id = `${id}-panel`;
    panel.setAttribute('role', 'tabpanel');
    panel.setAttribute('aria-labelledby', `${id}-${active}`);
  }, [active, id]);
  function onKeyDown(event, index) {
    const delta = event.key === 'ArrowRight' ? 1 : event.key === 'ArrowLeft' ? -1 : 0;
    const next = event.key === 'Home' ? 0 : event.key === 'End' ? tabs.length - 1 : delta ? (index + delta + tabs.length) % tabs.length : null;
    if (next === null) return;
    event.preventDefault();
    onChange(tabs[next].key);
    tabRefs.current[tabs[next].key]?.focus();
  }
  return (
    <div className="tabs" role="tablist" ref={listRef}>
      {tabs.map((tab, index) => (
        <button
          key={tab.key}
          type="button"
          id={`${id}-${tab.key}`}
          ref={(node) => { tabRefs.current[tab.key] = node; }}
          role="tab"
          aria-selected={active === tab.key}
          aria-controls={`${id}-panel`}
          tabIndex={active === tab.key ? 0 : -1}
          onKeyDown={(event) => onKeyDown(event, index)}
          className={`tab-item ${active === tab.key ? 'active' : ''} ${tab.dirty ? 'tab-dirty' : ''}`}
          onClick={() => onChange(tab.key)}
        >
          {tab.label}
          {/* count=0 SI se muestra (badge "0") -- solo se omite si la pestaña ni siquiera manda
              la prop (undefined), para pestañas que no tienen numero que mostrar (Info/Gantt). */}
          {tab.count !== undefined && <span className="tab-badge">{tab.count}</span>}
          {/* Pestaña con cambios sin guardar (borrador pendiente). */}
          {tab.dirty && <DraftMark />}
        </button>
      ))}
    </div>
  );
}