'use client';

import * as React from 'react';
import { Search } from 'lucide-react';
import * as DialogPrimitive from '@radix-ui/react-dialog';
import { useRouter } from '@/i18n/navigation';
import { cn } from '@/lib/utils';
import { isItemActive, type NavGroup, type ShellVariant } from './nav-config';

/**
 * Palette de commandes (⌘K / Ctrl+K).
 *
 * Implementee sur Radix Dialog pour heriter du focus trap et de la fermeture
 * par Escape, avec une navigation clavier explicite (fleches, Entree).
 */
interface CommandMenuProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  groups: NavGroup[];
  pathname: string;
  variant: ShellVariant;
  labels: {
    title: string;
    placeholder: string;
    noResults: string;
  };
}

/** Normalise pour une recherche insensible a la casse et aux accents. */
function normalize(value: string): string {
  return value
    .toLowerCase()
    .normalize('NFD')
    .replace(/[\u0300-\u036f]/g, '');
}

export function CommandMenu({
  open,
  onOpenChange,
  groups,
  pathname,
  variant,
  labels,
}: CommandMenuProps) {
  const router = useRouter();
  const [query, setQuery] = React.useState('');
  const [highlight, setHighlight] = React.useState(0);
  const listRef = React.useRef<HTMLDivElement>(null);

  const entries = React.useMemo(
    () =>
      groups.flatMap(group =>
        group.items.map(item => ({ ...item, groupLabel: group.label }))
      ),
    [groups]
  );

  const results = React.useMemo(() => {
    const q = normalize(query.trim());
    if (!q) return entries;
    return entries.filter(
      e => normalize(e.label).includes(q) || normalize(e.groupLabel).includes(q)
    );
  }, [entries, query]);

  // Reinitialise a chaque ouverture, et borne l'index quand la liste retrecit.
  React.useEffect(() => {
    if (open) {
      setQuery('');
      setHighlight(0);
    }
  }, [open]);

  React.useEffect(() => {
    setHighlight(h => Math.min(h, Math.max(0, results.length - 1)));
  }, [results.length]);

  const select = React.useCallback(
    (href: string) => {
      onOpenChange(false);
      router.push(href);
    },
    [onOpenChange, router]
  );

  const onKeyDown = (event: React.KeyboardEvent) => {
    if (event.key === 'ArrowDown') {
      event.preventDefault();
      setHighlight(h => (results.length ? (h + 1) % results.length : 0));
    } else if (event.key === 'ArrowUp') {
      event.preventDefault();
      setHighlight(h => (results.length ? (h - 1 + results.length) % results.length : 0));
    } else if (event.key === 'Enter') {
      event.preventDefault();
      const target = results[highlight];
      if (target) select(target.href);
    }
  };

  // Maintient l'element surligne visible lors de la navigation au clavier.
  React.useEffect(() => {
    listRef.current
      ?.querySelector<HTMLElement>(`[data-index="${highlight}"]`)
      ?.scrollIntoView({ block: 'nearest' });
  }, [highlight]);

  return (
    <DialogPrimitive.Root open={open} onOpenChange={onOpenChange}>
      <DialogPrimitive.Portal>
        <DialogPrimitive.Overlay className="fixed inset-0 z-50 bg-brand-navy/40 data-[state=open]:animate-in data-[state=open]:fade-in-0 data-[state=closed]:animate-out data-[state=closed]:fade-out-0" />
        <DialogPrimitive.Content
          onKeyDown={onKeyDown}
          className={cn(
            'fixed left-1/2 top-24 z-50 w-[calc(100%-2rem)] max-w-lg -translate-x-1/2',
            'overflow-hidden rounded-lg border border-border bg-white shadow-lg',
            'data-[state=open]:animate-in data-[state=open]:fade-in-0 data-[state=open]:zoom-in-95',
            'data-[state=closed]:animate-out data-[state=closed]:fade-out-0'
          )}
        >
          <DialogPrimitive.Title className="sr-only">{labels.title}</DialogPrimitive.Title>

          <div className="flex items-center gap-2 border-b border-border px-3">
            <Search className="size-4 shrink-0 text-neutral-400" aria-hidden="true" />
            <input
              autoFocus
              value={query}
              onChange={e => setQuery(e.target.value)}
              placeholder={labels.placeholder}
              aria-label={labels.title}
              aria-controls="command-menu-list"
              aria-activedescendant={
                results[highlight] ? `command-item-${highlight}` : undefined
              }
              className="h-11 w-full bg-transparent font-body text-body-sm text-brand-navy outline-none placeholder:text-neutral-400"
            />
          </div>

          <div
            id="command-menu-list"
            ref={listRef}
            role="listbox"
            aria-label={labels.title}
            className="max-h-72 overflow-y-auto p-1"
          >
            {results.length === 0 ? (
              <p className="px-3 py-6 text-center text-body-sm text-neutral-500">
                {labels.noResults}
              </p>
            ) : (
              results.map((item, index) => {
                const Icon = item.icon;
                const active = isItemActive(item.href, pathname, variant);
                return (
                  <button
                    key={item.key}
                    id={`command-item-${index}`}
                    data-index={index}
                    role="option"
                    aria-selected={index === highlight}
                    type="button"
                    onMouseMove={() => setHighlight(index)}
                    onClick={() => select(item.href)}
                    className={cn(
                      'flex w-full items-center gap-3 rounded-md px-3 py-2 text-left text-body-sm transition-colors',
                      index === highlight ? 'bg-neutral-100 text-brand-navy' : 'text-neutral-700'
                    )}
                  >
                    <Icon className="size-4 shrink-0 text-neutral-400" aria-hidden="true" />
                    <span className="flex-1 truncate">{item.label}</span>
                    <span className="shrink-0 text-body-xs text-neutral-400">
                      {item.groupLabel}
                    </span>
                    {active && (
                      <span className="size-1.5 shrink-0 rounded-full bg-brand-blue" />
                    )}
                  </button>
                );
              })
            )}
          </div>
        </DialogPrimitive.Content>
      </DialogPrimitive.Portal>
    </DialogPrimitive.Root>
  );
}

/** Ouvre la palette sur ⌘K / Ctrl+K. */
export function useCommandMenuShortcut(onOpen: () => void) {
  React.useEffect(() => {
    const handler = (event: KeyboardEvent) => {
      if (event.key.toLowerCase() === 'k' && (event.metaKey || event.ctrlKey)) {
        event.preventDefault();
        onOpen();
      }
    };
    document.addEventListener('keydown', handler);
    return () => document.removeEventListener('keydown', handler);
  }, [onOpen]);
}