import React, { useState, useEffect, useRef, useLayoutEffect, useCallback, useMemo } from 'react';
import {
  ChevronRight,
  ChevronDown,
  Check,
  CheckSquare,
  X,
  Trash2,
  MoreHorizontal,
  Code,
  Heading1,
  Heading2,
  Heading3,
  ListTodo,
  Minus,
  MessageSquare,
  ExternalLink,
  Maximize2,
  Link as LinkIcon,
  FileText,
  Lock,
  AlertTriangle,
  Image as ImageIcon,
  Mic,
  AudioLines,
  FileOutput,
} from 'lucide-react';
import { DocumentBlock, BlockType } from '../../lib/types';
import { LinkModal } from './LinkModal';
import { CodeBlockEditor, resolveLanguageId, isUnambiguousLanguageShortcut } from './CodeBlockEditor';
import { ImagePicker } from './ImagePicker';
import { ImageBlock } from './ImageBlock';
import { AudioRecorderPicker } from './AudioRecorderPicker';
import { AudioBlock } from './AudioBlock';
import { DictationBlock } from './DictationBlock';
import { currentVoiceConfig } from '../../lib/voice';
import { LinkPreviewCard } from './LinkPreviewCard';
import { linkCardUrl, hidePreviewContent, useLinkPreviewsEnabled } from '../../lib/linkPreview';
import { mediaContent, parseMediaContent } from '../../lib/media';
import { renderInlineMarkdown } from '../../lib/markdown';
import { api } from '../../lib/api';
import { safeHref } from '../../lib/safeUrl';

export interface SlashCommand {
  type: BlockType | 'link' | 'dictation' | 'extract';
  label: string;
  desc: string;
  icon: React.ReactNode;
  /** Only offered in an empty bullet; the bullet turns into an inline picker first */
  media?: boolean;
  /** Further names that find the command (e.g. German ones) */
  aliases?: string[];
}

const SLASH_COMMANDS: SlashCommand[] = [
  { type: 'todo', label: '/todo', desc: 'Aufgabe mit Checkbox', icon: <ListTodo className="w-3.5 h-3.5" /> },
  { type: 'link', label: '/link', desc: 'Notiz oder Weblink', icon: <LinkIcon className="w-3.5 h-3.5" /> },
  { type: 'h1', label: '/h1', desc: 'Große Überschrift', icon: <Heading1 className="w-3.5 h-3.5" /> },
  { type: 'h2', label: '/h2', desc: 'Abschnitts-Überschrift', icon: <Heading2 className="w-3.5 h-3.5" /> },
  { type: 'h3', label: '/h3', desc: 'Unterabschnitt', icon: <Heading3 className="w-3.5 h-3.5" /> },
  { type: 'code', label: '/code', desc: 'Code-Block mit Syntax', icon: <Code className="w-3.5 h-3.5" /> },
  { type: 'callout', label: '/callout', desc: 'Hinweisbox', icon: <MessageSquare className="w-3.5 h-3.5" /> },
  { type: 'divider', label: '/divider', desc: 'Trennlinie', icon: <Minus className="w-3.5 h-3.5" /> },
  { type: 'extract', label: '/extract', desc: 'Ast als eigene Notiz', icon: <FileOutput className="w-3.5 h-3.5" />, aliases: ['notiz', 'auslagern'] },
  { type: 'image', label: '/image', desc: 'Bilder hochladen oder verlinken', icon: <ImageIcon className="w-3.5 h-3.5" />, media: true, aliases: ['bild', 'foto'] },
  { type: 'audio', label: '/audio', desc: 'Sprachnotiz oder Audiodatei', icon: <Mic className="w-3.5 h-3.5" />, media: true, aliases: ['sprachnotiz'] },
  { type: 'dictation', label: '/diktat', desc: 'Sprechen statt tippen', icon: <AudioLines className="w-3.5 h-3.5" />, media: true, aliases: ['dictate'] },
];

export interface OutlinerBlockProps {
  docId: string;
  block: DocumentBlock;
  index: number;
  isLast: boolean;
  maxAllowedLevel: number;
  hasChildren: boolean;
  isFocused: boolean;
  canEdit: boolean;
  levelOffset?: number;
  onZoomBlock?: (blockId: string) => void;
  /** Turns this bullet and its children into a note of its own */
  onExtractBlock?: (blockId: string) => void;
  onUpdateBlock: (updated: DocumentBlock, immediate?: boolean) => void;
  onCreateBlockBelow: (afterBlockId: string, newContent?: string) => void;
  onDeleteBlock: (blockId: string, deleteSubtree?: boolean) => void;
  onMergeWithPrevious?: (blockId: string, content: string) => boolean;
  onIndentBlock: (blockId: string, delta: 1 | -1) => void;
  onNavigateFocus: (blockId: string, direction: 'up' | 'down') => void;
  onFocusBlock?: (blockId: string) => void;
  onBlurBlock?: (blockId: string) => void;
  onOpenTask?: (taskId: string) => void;
  onTagClick?: (tag: string) => void;
  onWikiLinkClick?: (pageTitle: string) => void;
  onDragStartBlock?: (index: number) => void;
  onDragOverBlock?: (e: React.DragEvent, index: number) => void;
  onDropBlock?: (index: number) => void;
  isDragTarget?: boolean;
  isTargeted?: boolean;
  registerTextareaRef: (blockId: string, el: HTMLTextAreaElement | null) => void;
  onPasteMultiLines?: (blockId: string, textBefore: string, textAfter: string, rawLines: string[]) => void;
  lockedBy?: string; // someone else is editing this block
  canAppendBelow?: boolean; // the user may edit the note, so Enter in a locked block still adds one below
  onResolveConflict?: (blockId: string, accept: boolean) => void;
  onUndo?: () => void;
  onRedo?: () => void;
}

// Rendered markdown only drops syntax characters (**, `, [..](url) …), so its text is a subsequence of the raw
// text. Walking both strings in parallel maps a caret offset in the rendered text back to the raw text.
export function mapRenderedOffsetToRaw(raw: string, rendered: string, renderedOffset: number): number {
  let j = 0;
  for (let i = 0; i < renderedOffset && i < rendered.length; i++) {
    const idx = raw.indexOf(rendered[i], j);
    if (idx === -1) break;
    j = idx + 1;
  }
  return Math.min(j, raw.length);
}

export const OutlinerBlock: React.FC<OutlinerBlockProps> = ({
  docId,
  block,
  index,
  hasChildren,
  isFocused,
  canEdit,
  levelOffset = 0,
  onZoomBlock,
  onExtractBlock,
  onUpdateBlock,
  onCreateBlockBelow,
  onDeleteBlock,
  onMergeWithPrevious,
  onIndentBlock,
  onNavigateFocus,
  onFocusBlock,
  onBlurBlock,
  onOpenTask,
  onTagClick,
  onWikiLinkClick,
  onDragStartBlock,
  onDragOverBlock,
  onDropBlock,
  isDragTarget,
  isTargeted,
  registerTextareaRef,
  onPasteMultiLines,
  lockedBy,
  canAppendBelow,
  onResolveConflict,
  onUndo,
  onRedo,
}) => {
  const [localContent, setLocalContent] = useState<string>(block.content || '');
  const [isLocallyFocused, setIsLocallyFocused] = useState<boolean>(false);
  const activeFocus = isFocused || isLocallyFocused;
  // A block someone else is editing can still get the cursor (read-only), e.g. to press Enter at its end
  const canFocus = canEdit || (!!lockedBy && !!canAppendBelow);
  const [slashSearch, setSlashSearch] = useState<string | null>(null);
  // Inline picker an empty bullet turns into after /image (local only, nothing synced until done)
  const [mediaPicker, setMediaPicker] = useState<'image' | 'audio' | 'dictation' | null>(null);
  // Card above bullets whose entire content is a plain https address (lib/linkPreview.ts)
  const previewsOn = useLinkPreviewsEnabled();
  const previewUrl =
    previewsOn && !mediaPicker && ['bullet', 'text', 'paragraph', 'todo', 'h1', 'h2', 'h3'].includes(block.type || 'bullet')
      ? linkCardUrl(localContent)
      : null;
  const [slashIndex, setSlashIndex] = useState(0);
  const slashItemRefs = useRef<(HTMLButtonElement | null)[]>([]);
  const [showLinkModal, setShowLinkModal] = useState<boolean>(false);
  const [showTodoMenu, setShowTodoMenu] = useState<boolean>(false);

  const textareaRef = useRef<HTMLTextAreaElement | null>(null);
  const debounceTimerRef = useRef<number | null>(null);
  const latestBlockRef = useRef<DocumentBlock>(block);
  latestBlockRef.current = block;
  const localContentRef = useRef<string>(localContent);
  localContentRef.current = localContent;

  // Callback refs to avoid stale closures in setTimeout, debounce flush, and event listeners
  const onUpdateBlockRef = useRef(onUpdateBlock);
  onUpdateBlockRef.current = onUpdateBlock;
  const onCreateBlockBelowRef = useRef(onCreateBlockBelow);
  onCreateBlockBelowRef.current = onCreateBlockBelow;
  const onPasteMultiLinesRef = useRef(onPasteMultiLines);
  onPasteMultiLinesRef.current = onPasteMultiLines;
  const onDeleteBlockRef = useRef(onDeleteBlock);
  onDeleteBlockRef.current = onDeleteBlock;
  const onMergeWithPreviousRef = useRef(onMergeWithPrevious);
  onMergeWithPreviousRef.current = onMergeWithPrevious;
  const onIndentBlockRef = useRef(onIndentBlock);
  onIndentBlockRef.current = onIndentBlock;
  const onNavigateFocusRef = useRef(onNavigateFocus);
  onNavigateFocusRef.current = onNavigateFocus;
  const isPastingRef = useRef<boolean>(false);

  // Track if this input currently has actual focus in an active browser window
  const isFocusedRef = useRef<boolean>(false);

  const flushDebounce = useCallback(
    (contentToFlush: string, overrides?: Partial<DocumentBlock>) => {
      if (debounceTimerRef.current !== null) {
        window.clearTimeout(debounceTimerRef.current);
        debounceTimerRef.current = null;
      }
      const nextBlock: DocumentBlock = {
        ...latestBlockRef.current,
        content: contentToFlush,
        ...overrides,
      };
      onUpdateBlockRef.current(nextBlock, true);
    },
    []
  );

  // Right after undo/redo the focused field must show the engine's text, not keep its own
  const acceptRemoteUntilRef = useRef<number>(0);
  const onUndoRef = useRef(onUndo);
  onUndoRef.current = onUndo;
  const onRedoRef = useRef(onRedo);
  onRedoRef.current = onRedo;

  // Sync incoming remote changes ONLY when this textarea is NOT actively being edited
  // Condition: isFocusedRef.current === true && document.hasFocus()
  useEffect(() => {
    const isActivelyEditing =
      isFocusedRef.current === true &&
      typeof document !== 'undefined' &&
      document.hasFocus() &&
      textareaRef.current !== null &&
      document.activeElement === textareaRef.current;

    const acceptAfterUndo = Date.now() < acceptRemoteUntilRef.current;
    if ((!isActivelyEditing || acceptAfterUndo) && block.content !== localContentRef.current) {
      setLocalContent(block.content || '');
      localContentRef.current = block.content || '';
    }
  }, [block.content]);

  // Handle window blur / focus to instantly flush debounced input and clear zombie focus
  useEffect(() => {
    const handleWindowBlur = () => {
      if (debounceTimerRef.current !== null) {
        window.clearTimeout(debounceTimerRef.current);
        debounceTimerRef.current = null;
        flushDebounce(localContentRef.current);
      } else if (localContentRef.current !== latestBlockRef.current.content) {
        flushDebounce(localContentRef.current);
      }
      isFocusedRef.current = false;
    };

    const handleWindowFocus = () => {
      const isThisActive =
        textareaRef.current !== null &&
        document.activeElement === textareaRef.current &&
        document.hasFocus();
      isFocusedRef.current = isThisActive;
    };

    window.addEventListener('blur', handleWindowBlur);
    window.addEventListener('focus', handleWindowFocus);
    return () => {
      window.removeEventListener('blur', handleWindowBlur);
      window.removeEventListener('focus', handleWindowFocus);
    };
  }, [flushDebounce]);

  useEffect(() => {
    return () => {
      if (debounceTimerRef.current !== null) {
        window.clearTimeout(debounceTimerRef.current);
        debounceTimerRef.current = null;
      }
    };
  }, []);

  const renderedTextRef = useRef<HTMLSpanElement | null>(null);

  // Focus the textarea and place the caret where the user clicked in the rendered (markdown) text layer
  const focusAtPoint = (clientX: number, clientY: number) => {
    const ta = textareaRef.current;
    if (!ta) return;
    const raw = ta.value;
    let pos = raw.length;
    const span = renderedTextRef.current;
    const doc = document as any;
    let node: Node | null = null;
    let offset = 0;
    if (typeof doc.caretPositionFromPoint === 'function') {
      const p = doc.caretPositionFromPoint(clientX, clientY);
      if (p) {
        node = p.offsetNode;
        offset = p.offset;
      }
    } else if (typeof doc.caretRangeFromPoint === 'function') {
      const r = doc.caretRangeFromPoint(clientX, clientY);
      if (r) {
        node = r.startContainer;
        offset = r.startOffset;
      }
    }
    if (span && node && span.contains(node)) {
      const range = document.createRange();
      range.setStart(span, 0);
      range.setEnd(node, offset);
      pos = mapRenderedOffsetToRaw(raw, span.textContent || '', range.toString().length);
    }
    ta.focus();
    ta.setSelectionRange(pos, pos);
  };

  const adjustHeight = useCallback(() => {
    const el = textareaRef.current;
    if (!el) return;
    el.style.height = 'auto';
    el.style.height = `${Math.max(22, el.scrollHeight)}px`;
  }, []);

  useLayoutEffect(() => {
    adjustHeight();
  }, [localContent, block.type, block.level, activeFocus, adjustHeight]);

  // Turning the block into another type (slash menu, ``` or markdown shortcut) can swap the text field
  // for a new one (e.g. the code editor); the cursor must stay in the block so typing goes on there
  const refocusAfterTypeChangeRef = useRef(false);
  useLayoutEffect(() => {
    if (!refocusAfterTypeChangeRef.current) return;
    refocusAfterTypeChangeRef.current = false;
    const ta = textareaRef.current;
    if (ta && document.activeElement !== ta) {
      ta.focus();
      const end = ta.value.length;
      ta.setSelectionRange(end, end);
    }
  }, [block.type]);

  useEffect(() => {
    window.addEventListener('resize', adjustHeight);
    // The field can be measured while hidden (phone layout shows the editor only after selecting a note);
    // measure again whenever its width changes
    const el = textareaRef.current;
    let lastWidth = el?.clientWidth ?? 0;
    const observer =
      el && typeof ResizeObserver !== 'undefined'
        ? new ResizeObserver(() => {
            if (el.clientWidth !== lastWidth) {
              lastWidth = el.clientWidth;
              adjustHeight();
            }
          })
        : null;
    if (el) observer?.observe(el);
    return () => {
      window.removeEventListener('resize', adjustHeight);
      observer?.disconnect();
    };
  }, [adjustHeight, block.type]);

  const filteredSlashCommands = useMemo(() => {
    if (slashSearch === null) return [];
    const q = slashSearch.toLowerCase();
    const cmdQuery = q.startsWith('code ') ? 'code' : q;
    // Media only in an otherwise empty bullet
    const emptyBullet = localContent.replace(/(^|\s)\/(code\s+[a-z0-9_+#.-]*|[a-z0-9]*)$/i, '').trim() === '';
    return SLASH_COMMANDS.filter(
      (c) =>
        (!c.media || emptyBullet) &&
        (c.type !== 'dictation' || ['server', 'browser'].includes(currentVoiceConfig().mode)) &&
        // The bullet's text becomes the title of the new note
        (c.type !== 'extract' || (!emptyBullet && !!onExtractBlock)) &&
        (c.label.toLowerCase().includes(cmdQuery) ||
          c.desc.toLowerCase().includes(cmdQuery) ||
          (c.aliases || []).some((a) => a.includes(cmdQuery)))
    );
  }, [slashSearch, localContent, onExtractBlock]);

  useEffect(() => {
    if (slashSearch === null) return;
    slashItemRefs.current[slashIndex]?.scrollIntoView?.({ block: 'nearest', inline: 'nearest' });
  }, [slashIndex, slashSearch]);

  const applySlashCommand = (cmd: SlashCommand) => {
    setSlashSearch(null);
    const codeLangMatch = localContent.match(/(^|\s)\/code\s+([a-z0-9_+#.-]+)$/i);
    const clean = localContent.replace(/(^|\s)\/(code\s+[a-z0-9_+#.-]*|[a-z0-9]*)$/i, '').trim();
    if (cmd.type === 'link') {
      setLocalContent(clean);
      localContentRef.current = clean;
      setShowLinkModal(true);
      return;
    }
    if (cmd.type === 'extract') {
      setLocalContent(clean);
      localContentRef.current = clean;
      flushDebounce(clean);
      onExtractBlock?.(block.id);
      return;
    }
    if (cmd.media) {
      // The typed "/image" must not stay in the synced text; the block type changes only after the upload
      setLocalContent('');
      localContentRef.current = '';
      flushDebounce('');
      setMediaPicker(cmd.type as 'image' | 'audio' | 'dictation');
      return;
    }
    const langOverride =
      cmd.type === 'code' && codeLangMatch
        ? resolveLanguageId(codeLangMatch[2]) || codeLangMatch[2].toLowerCase()
        : undefined;
    setLocalContent(clean);
    localContentRef.current = clean;
    if (cmd.type !== block.type) refocusAfterTypeChangeRef.current = true;
    flushDebounce(clean, {
      type: cmd.type as BlockType, // media commands returned above
      ...(langOverride !== undefined ? { lang: langOverride } : {}),
      checked: cmd.type === 'todo' ? Boolean(block.checked) : false,
    });
  };

  const handleInsertLink = (linkMarkdown: string) => {
    setShowLinkModal(false);
    if (localContent.trim() === '') {
      const webMatch = linkMarkdown.match(/^\[.*\]\((https?:\/\/[^\s)]+)\)$/);
      if (webMatch) {
        const bareUrl = webMatch[1];
        setLocalContent(bareUrl);
        localContentRef.current = bareUrl;
        flushDebounce(bareUrl);
        return;
      }
    }
    const cursor = textareaRef.current?.selectionStart ?? localContent.length;
    const before = localContent.slice(0, cursor);
    const after = localContent.slice(cursor);
    const newContent = `${before}${before && !before.endsWith(' ') ? ' ' : ''}${linkMarkdown}${after && !after.startsWith(' ') ? ' ' : ''}${after}`.trim();
    setLocalContent(newContent);
    localContentRef.current = newContent;
    flushDebounce(newContent);
  };

  const handleContentChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
    if (!canEdit) return;
    let val = e.target.value;
    let typeOverride: BlockType | undefined;
    let checkedOverride: boolean | undefined;
    let langOverride: string | undefined;

    if (block.type !== 'code') {
      // Quick markdown shortcuts
      const fenceSpaceMatch = val.match(/^```([a-z0-9_+#.-]*)\s([\s\S]*)$/i);
      const fenceDirectMatch = val.match(/^```([a-z0-9_+#.-]+)$/i);
      const slashCodeSpaceMatch = val.match(/^\/code\s+([a-z0-9_+#.-]+)\s([\s\S]*)$/i);
      const slashCodeDirectMatch = val.match(/^\/code\s+([a-z0-9_+#.-]+)$/i);

      if (fenceSpaceMatch) {
        const rawLang = fenceSpaceMatch[1];
        val = fenceSpaceMatch[2];
        typeOverride = 'code';
        langOverride = rawLang ? resolveLanguageId(rawLang) || rawLang.toLowerCase() : '';
      } else if (fenceDirectMatch && isUnambiguousLanguageShortcut(fenceDirectMatch[1])) {
        val = '';
        typeOverride = 'code';
        langOverride = resolveLanguageId(fenceDirectMatch[1]) || fenceDirectMatch[1].toLowerCase();
      } else if (slashCodeSpaceMatch) {
        const rawLang = slashCodeSpaceMatch[1];
        val = slashCodeSpaceMatch[2];
        typeOverride = 'code';
        langOverride = resolveLanguageId(rawLang) || rawLang.toLowerCase();
      } else if (slashCodeDirectMatch && isUnambiguousLanguageShortcut(slashCodeDirectMatch[1])) {
        val = '';
        typeOverride = 'code';
        langOverride = resolveLanguageId(slashCodeDirectMatch[1]) || slashCodeDirectMatch[1].toLowerCase();
      } else if (val.startsWith('[] ') || val.startsWith('[ ] ')) {
        val = val.replace(/^\[\s?\]\s/, '');
        typeOverride = 'todo';
        checkedOverride = false;
      } else if (val.startsWith('[x] ') || val.startsWith('[X] ')) {
        val = val.replace(/^\[[xX]\]\s/, '');
        typeOverride = 'todo';
        checkedOverride = true;
      } else if (val.startsWith('# ') && block.type !== 'h1') {
        val = val.slice(2);
        typeOverride = 'h1';
      } else if (val.startsWith('## ') && block.type !== 'h2') {
        val = val.slice(3);
        typeOverride = 'h2';
      } else if (val.startsWith('### ') && block.type !== 'h3') {
        val = val.slice(4);
        typeOverride = 'h3';
      }

      // Check for slash command invocation
      const slashMatch = !typeOverride ? val.match(/(^|\s)\/(code\s+[a-z0-9_+#.-]*|[a-z0-9]*)$/i) : null;
      if (slashMatch) {
        setSlashSearch(slashMatch[2]);
        setSlashIndex(0);
      } else {
        setSlashSearch(null);
      }
    } else {
      setSlashSearch(null);
    }

    setLocalContent(val);
    localContentRef.current = val;

    if (debounceTimerRef.current !== null) {
      window.clearTimeout(debounceTimerRef.current);
    }

    if (typeOverride) {
      refocusAfterTypeChangeRef.current = true;
      flushDebounce(val, {
        type: typeOverride,
        ...(langOverride !== undefined ? { lang: langOverride } : {}),
        checked: checkedOverride ?? latestBlockRef.current.checked,
      });
      return;
    }

    debounceTimerRef.current = window.setTimeout(() => {
      debounceTimerRef.current = null;
      onUpdateBlockRef.current({
        ...latestBlockRef.current,
        content: val,
      });
    }, 150);
  };

  const handleFocus = () => {
    isFocusedRef.current = true;
    setIsLocallyFocused(true);
    onFocusBlock?.(block.id);
    setTimeout(adjustHeight, 0);
  };

  const handleBlur = () => {
    isFocusedRef.current = false;
    setIsLocallyFocused(false);
    onBlurBlock?.(block.id);
    if (isPastingRef.current) {
      isPastingRef.current = false;
      return;
    }
    if (debounceTimerRef.current !== null) {
      window.clearTimeout(debounceTimerRef.current);
      debounceTimerRef.current = null;
      flushDebounce(localContentRef.current);
    } else if (localContentRef.current !== latestBlockRef.current.content) {
      flushDebounce(localContentRef.current);
    }
  };

  const handlePaste = (e: React.ClipboardEvent<HTMLTextAreaElement>) => {
    if (!canEdit || block.type === 'code') return;
    const pastedText = e.clipboardData.getData('text');
    if (!pastedText || !pastedText.includes('\n')) return;

    e.preventDefault();
    const rawLines = pastedText.split(/\r?\n/);
    if (rawLines.length <= 1) return;

    const start = e.currentTarget.selectionStart ?? localContent.length;
    const end = e.currentTarget.selectionEnd ?? start;
    const textBefore = localContent.slice(0, start);
    const textAfter = localContent.slice(end);

    if (debounceTimerRef.current !== null) {
      window.clearTimeout(debounceTimerRef.current);
      debounceTimerRef.current = null;
    }

    isPastingRef.current = true;
    onPasteMultiLinesRef.current?.(block.id, textBefore, textAfter, rawLines);
  };

  // Ctrl/Cmd+Z undoes the user's own changes in the whole note (not the browser's per-field undo)
  const runHistory = (redo: boolean) => {
    if (debounceTimerRef.current !== null) {
      flushDebounce(localContentRef.current);
    }
    acceptRemoteUntilRef.current = Date.now() + 500;
    if (redo) onRedoRef.current?.();
    else onUndoRef.current?.();
  };

  useEffect(() => {
    const el = textareaRef.current;
    if (!el) return;
    // Mobile keyboards and the context menu undo via beforeinput instead of key events
    const onBeforeInput = (e: InputEvent) => {
      if (e.inputType === 'historyUndo' || e.inputType === 'historyRedo') {
        e.preventDefault();
        runHistory(e.inputType === 'historyRedo');
      }
    };
    el.addEventListener('beforeinput', onBeforeInput);
    return () => el.removeEventListener('beforeinput', onBeforeInput);
  });

  const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
    if ((e.ctrlKey || e.metaKey) && !e.altKey && ['z', 'y'].includes(e.key.toLowerCase())) {
      e.preventDefault();
      e.stopPropagation();
      runHistory(e.key.toLowerCase() === 'y' || e.shiftKey);
      return;
    }
    // Enter in a block someone else is editing cannot split it (read-only), so it adds a new block below
    // without touching the locked one. (Chromium does not move the caret with End in read-only fields.)
    if (lockedBy && canAppendBelow && e.key === 'Enter' && !e.shiftKey) {
      e.preventDefault();
      onCreateBlockBelowRef.current(block.id, '');
      return;
    }
    if (!canEdit) return;

    // Slash command navigation
    if (slashSearch !== null) {
      if (e.key === 'Escape') {
        e.preventDefault();
        setSlashSearch(null);
        return;
      }
      if (filteredSlashCommands.length > 0) {
        if (e.key === 'ArrowDown') {
          e.preventDefault();
          setSlashIndex((prev) => (prev + 1) % filteredSlashCommands.length);
          return;
        }
        if (e.key === 'ArrowUp') {
          e.preventDefault();
          setSlashIndex((prev) => (prev - 1 + filteredSlashCommands.length) % filteredSlashCommands.length);
          return;
        }
        if (e.key === 'Enter' || e.key === 'Tab') {
          e.preventDefault();
          const selected = filteredSlashCommands[slashIndex];
          if (selected) {
            applySlashCommand(selected);
          }
          return;
        }
      }
    }

    // 1. Tab / Shift+Tab -> Strict Indent / Outdent
    if (e.key === 'Tab') {
      e.preventDefault();
      e.stopPropagation();
      flushDebounce(localContent);
      onIndentBlockRef.current(block.id, e.shiftKey ? -1 : 1);
      return;
    }

    // 2. Enter (without Shift) -> If block is completely empty:
    //    - If level > minLevel, outdent (Shift+Tab behaviour)
    //    - Otherwise split paragraph at cursor and create new block below
    if (e.key === 'Enter' && !e.shiftKey && block.type !== 'code') {
      e.preventDefault();
      e.stopPropagation();
      setSlashSearch(null);

      const fenceMatch = localContent.match(/^```([a-z0-9_+#.-]*)$/i);
      if (fenceMatch) {
        const rawLang = fenceMatch[1];
        const resolvedLang = rawLang ? resolveLanguageId(rawLang) || rawLang.toLowerCase() : '';
        setLocalContent('');
        localContentRef.current = '';
        refocusAfterTypeChangeRef.current = true;
        flushDebounce('', {
          type: 'code',
          lang: resolvedLang,
          checked: false,
        });
        return;
      }

      const minLevel = levelOffset || 0;
      if (localContent === '') {
        if (Math.max(0, block.level || 0) > minLevel) {
          flushDebounce(localContent);
          onIndentBlockRef.current(block.id, -1);
          return;
        }
      }

      const start = e.currentTarget.selectionStart ?? localContent.length;
      const end = e.currentTarget.selectionEnd ?? start;
      let beforeText = localContent.slice(0, start);
      let afterText = localContent.slice(end);

      // Clean linebreaks at the split boundary if present
      if (beforeText.endsWith('\r\n')) {
        beforeText = beforeText.slice(0, -2);
      } else if (beforeText.endsWith('\n')) {
        beforeText = beforeText.slice(0, -1);
      }
      if (afterText.startsWith('\r\n')) {
        afterText = afterText.slice(2);
      } else if (afterText.startsWith('\n')) {
        afterText = afterText.slice(1);
      }

      setLocalContent(beforeText);
      localContentRef.current = beforeText;
      flushDebounce(beforeText);
      onCreateBlockBelowRef.current(block.id, afterText);
      return;
    }

    // 3. Backspace on empty block -> IMMEDIATELY DELETE THE BLOCK (regardless of level)!
    // Outdenting is strictly done via Shift+Tab.
    if (e.key === 'Backspace' && localContent === '') {
      e.preventDefault();
      e.stopPropagation();
      setSlashSearch(null);
      if (debounceTimerRef.current !== null) {
        window.clearTimeout(debounceTimerRef.current);
        debounceTimerRef.current = null;
      }
      onDeleteBlockRef.current(block.id);
      return;
    }

    // 3b. Backspace at the very start of a non-empty block -> append its text to the previous block
    if (
      e.key === 'Backspace' &&
      localContent !== '' &&
      block.type !== 'code' &&
      onMergeWithPreviousRef.current &&
      e.currentTarget.selectionStart === 0 &&
      e.currentTarget.selectionEnd === 0
    ) {
      if (onMergeWithPreviousRef.current(block.id, localContent)) {
        // Text lives in the previous block afterwards, so drop this block's pending save
        if (debounceTimerRef.current !== null) {
          window.clearTimeout(debounceTimerRef.current);
          debounceTimerRef.current = null;
        }
        e.preventDefault();
        e.stopPropagation();
        setSlashSearch(null);
      }
      return;
    }

    // 4. Arrow navigation between blocks
    if (e.key === 'ArrowUp' && !e.shiftKey && !e.altKey) {
      const el = textareaRef.current;
      if (el && el.selectionStart === 0 && el.selectionEnd === 0) {
        e.preventDefault();
        flushDebounce(localContent);
        onNavigateFocusRef.current(block.id, 'up');
      }
      return;
    }

    if (e.key === 'ArrowDown' && !e.shiftKey && !e.altKey) {
      const el = textareaRef.current;
      if (el && el.selectionStart === localContent.length && el.selectionEnd === localContent.length) {
        e.preventDefault();
        flushDebounce(localContent);
        onNavigateFocusRef.current(block.id, 'down');
      }
      return;
    }
  };

  const level = Math.max(0, block.level || 0);
  const visualLevel = Math.max(0, level - (levelOffset || 0));
  const isEmpty = (!localContent || localContent.trim() === '') && !hasChildren;

  // Parse rich tokens (WikiLinks [[Page]], Markdown Links [Title](url), raw URLs, and #Tags)
  const tokens = useMemo(() => {
    const parts = (localContent || '').split(
      /(\[\[.*?\]\]|\[.*?\]\(https?:\/\/.*?\)|\bhttps?:\/\/[^\s]+|#[a-zA-Z0-9äöüÄÖÜß_-]+)/g
    );
    return parts.filter(Boolean);
  }, [localContent]);

  // #Hashtags are rendered inline inside the text, so only links need the badge bar below
  const hasSpecialTokens = tokens.some(
    (t) =>
      (t.startsWith('[[') && t.endsWith(']]')) ||
      /^\[(.*?)\]\((https?:\/\/.*?)\)$/.test(t) ||
      (/^https?:\/\//.test(t) && t !== previewUrl)
  );

  return (
    <div
      className={`group relative flex items-start gap-1 py-1 px-0.5 sm:px-1.5 rounded-card transition-all duration-300 ${
        isDragTarget
          ? 'border-t-2 border-accent bg-accent/10'
          : isTargeted
          ? 'bg-panel-elevated'
          : ''
      } ${block.conflictOf ? 'border-l-2 border-status-warn bg-status-warn/5' : ''}`}
      style={{
        // Indent per level and room kept for text come from CSS (narrower on phones, see index.css);
        // deep rows get wider than the screen and the note scrolls sideways instead of squeezing them
        paddingLeft: `calc(var(--outline-indent) * ${visualLevel} + 4px)`,
        minWidth: `calc(var(--outline-indent) * ${visualLevel} + var(--outline-min-text))`,
      }}
      onDragOver={(e) => onDragOverBlock?.(e, index)}
      onDrop={() => onDropBlock?.(index)}
      onClick={(e) => {
        if ((e.target as HTMLElement).closest('button, a, input, select')) return;
        if (!activeFocus && canFocus && textareaRef.current) {
          textareaRef.current.focus();
          const len = textareaRef.current.value.length;
          textareaRef.current.setSelectionRange(len, len);
        }
      }}
    >
      {/* Bullet Controls: Collapse Toggle & Bullet (Drag-Handle & Zoom) / Checkbox */}
      <div className="flex items-center gap-0.5 pt-1 select-none shrink-0">
        {hasChildren ? (
          <button
            type="button"
            onClick={() =>
              flushDebounce(localContent, { collapsed: !block.collapsed })
            }
            className="p-0.5 text-muted hover:text-accent transition-[color,opacity] opacity-0 group-hover:opacity-100 focus-visible:opacity-100"
            title={block.collapsed ? 'Unterpunkte ausklappen' : 'Unterpunkte einklappen'}
          >
            {block.collapsed ? (
              <ChevronRight className="w-3.5 h-3.5" />
            ) : (
              <ChevronDown className="w-3.5 h-3.5 text-accent" />
            )}
          </button>
        ) : (
          <span className="w-3.5" />
        )}

        {/* Bullet handle for dragging and zoom focus */}
        <button
          type="button"
          draggable={canEdit}
          onDragStart={() => canEdit && onDragStartBlock?.(index)}
          onClick={() => onZoomBlock?.(block.id)}
          className={`w-4 h-4 flex items-center justify-center rounded-btn group/bullet transition-transform ${
            canEdit ? 'cursor-grab active:cursor-grabbing' : 'cursor-pointer'
          }`}
          title={
            canEdit
              ? 'Ziehen zum Verschieben • Klick: Ast hineinzoomen (Fokus-Modus)'
              : 'Klick: In diesen Ast hineinzoomen (Fokus-Modus)'
          }
        >
          <span
            className={`w-1.5 h-1.5 rounded-full transition-all duration-150 ${
              block.collapsed && hasChildren
                ? 'bg-accent ring-2 ring-accent/30'
                : activeFocus
                ? 'bg-main scale-125'
                : 'bg-faint group-hover/bullet:bg-accent group-hover/bullet:scale-125'
            } ${
              isEmpty
                ? 'opacity-0 group-hover:opacity-100 hover:opacity-100'
                : 'opacity-100'
            }`}
          />
        </button>

        {/* If To-Do block: checkbox alongside bullet */}
        {block.type === 'todo' && (
          <button
            type="button"
            disabled={!canEdit}
            onClick={() =>
              flushDebounce(localContent, { checked: !block.checked })
            }
            className={`w-4 h-4 checkbox-square flex items-center justify-center transition-colors border ${
              block.checked
                ? 'bg-status-ok border-status-ok text-on-accent'
                : 'border-strong hover:border-accent text-transparent'
            }`}
            title={block.checked ? 'Als offen markieren' : 'Als erledigt markieren'}
          >
            <Check className="w-3 h-3 stroke-[3]" />
          </button>
        )}
      </div>

      {/* Main Block Content */}
      <div className="flex-1 min-w-0 pr-1 relative min-h-[1.5rem]">
        {previewUrl && (
          <LinkPreviewCard
            url={previewUrl}
            canEdit={canEdit}
            onHide={(title) => {
              const content = hidePreviewContent(localContent, previewUrl, title);
              setLocalContent(content);
              localContentRef.current = content;
              flushDebounce(content);
            }}
          />
        )}
        {mediaPicker === 'image' ? (
          <ImagePicker
            docId={docId}
            onDone={(media) => {
              setMediaPicker(null);
              const content = mediaContent('image', media.id);
              setLocalContent(content);
              localContentRef.current = content;
              flushDebounce(content, { type: 'image' });
            }}
            onCancel={() => {
              setMediaPicker(null);
              requestAnimationFrame(() => textareaRef.current?.focus());
            }}
          />
        ) : mediaPicker === 'dictation' ? (
          <DictationBlock
            onDone={(text) => {
              setMediaPicker(null);
              setLocalContent(text);
              localContentRef.current = text;
              flushDebounce(text);
              requestAnimationFrame(() => {
                const ta = textareaRef.current;
                if (!ta) return;
                ta.focus();
                ta.setSelectionRange(ta.value.length, ta.value.length);
              });
            }}
            onCancel={() => {
              setMediaPicker(null);
              requestAnimationFrame(() => textareaRef.current?.focus());
            }}
          />
        ) : mediaPicker === 'audio' ? (
          <AudioRecorderPicker
            docId={docId}
            onDone={(media) => {
              setMediaPicker(null);
              const content = mediaContent('audio', media.id);
              setLocalContent(content);
              localContentRef.current = content;
              flushDebounce(content, { type: 'audio' });
            }}
            onCancel={() => {
              setMediaPicker(null);
              requestAnimationFrame(() => textareaRef.current?.focus());
            }}
          />
        ) : block.type === 'audio' ? (
          <AudioBlock
            content={localContent}
            canEdit={canEdit}
            onCaptionChange={(caption) => {
              const ref = parseMediaContent(localContent);
              if (!ref) return;
              const content = mediaContent('audio', ref.id, caption);
              setLocalContent(content);
              localContentRef.current = content;
              flushDebounce(content);
            }}
          />
        ) : block.type === 'image' ? (
          <ImageBlock
            content={localContent}
            canEdit={canEdit}
            onCaptionChange={(caption) => {
              const ref = parseMediaContent(localContent);
              if (!ref) return;
              const content = mediaContent('image', ref.id, caption);
              setLocalContent(content);
              localContentRef.current = content;
              flushDebounce(content);
            }}
          />
        ) : block.type === 'divider' ? (
          <div className="py-2">
            <hr className="border-t border-border" />
          </div>
        ) : block.type === 'code' ? (
          <CodeBlockEditor
            block={block}
            content={localContent}
            canEdit={canEdit}
            textareaRef={textareaRef}
            registerTextareaRef={registerTextareaRef}
            onChangeContent={(newContent) => {
              setLocalContent(newContent);
              localContentRef.current = newContent;
              flushDebounce(newContent);
            }}
            onChangeLang={(lang) => flushDebounce(localContent, { lang })}
            onConvertToText={() => flushDebounce(localContent, { type: 'bullet' })}
            handleFocus={handleFocus}
            handleBlur={handleBlur}
            handleContentChange={handleContentChange}
            handleKeyDown={handleKeyDown}
          />
        ) : block.type === 'callout' ? (
          <div className="bg-panel-elevated border-l-2 border-accent p-2 rounded-r-btn my-0.5">
            <textarea
              ref={(el) => {
                textareaRef.current = el;
                registerTextareaRef(block.id, el);
              }}
              rows={1}
              value={localContent}
              readOnly={!canEdit}
              onFocus={handleFocus}
              onBlur={handleBlur}
              onChange={handleContentChange}
              onKeyDown={handleKeyDown}
              className="w-full resize-none bg-transparent text-sm text-main border-0 focus:outline-none focus:ring-0 leading-relaxed italic"
            />
          </div>
        ) : (
          <div className="relative w-full min-h-[1.5rem]">
            {/* View Layer with Inline Markdown & Actions (3-dots or Erweitert Badge) directly behind text */}
            <div
              onClick={(e) => {
                if (!activeFocus && canFocus && textareaRef.current) {
                  // Keep the row's click handler from moving the caret back to the end
                  e.stopPropagation();
                  focusAtPoint(e.clientX, e.clientY);
                }
              }}
              className={`w-full min-h-[1.5rem] leading-relaxed whitespace-pre-wrap break-words [overflow-wrap:anywhere] ${
                activeFocus ? 'absolute inset-0 pointer-events-none' : 'relative cursor-text'
              } ${
                block.type === 'h1'
                  ? 'text-lg font-bold text-main tracking-tight'
                  : block.type === 'h2'
                  ? 'text-base font-semibold text-main'
                  : block.type === 'h3'
                  ? 'text-sm font-semibold text-main'
                  : block.type === 'todo' && block.checked
                  ? 'text-sm text-faint line-through'
                  : 'text-sm text-main'
              }`}
            >
              {/* When actively focused, ghost text is invisible so textarea renders text/caret directly */}
              <span ref={renderedTextRef} className={activeFocus ? 'invisible' : ''}>
                {localContent ? renderInlineMarkdown(localContent, { onTagClick }) : '\u200b'}
              </span>

              {/* Inline Badge and 3-Dots directly behind the text */}
              {block.type === 'todo' && (
                <span className="inline-flex items-center align-middle ml-1.5 gap-1 shrink-0 pointer-events-auto z-10 relative select-none">
                  {block.taskId && (
                    <button
                      type="button"
                      onMouseDown={(e) => e.stopPropagation()}
                      onClick={(e) => {
                        e.stopPropagation();
                        onOpenTask?.(block.taskId as string);
                      }}
                      className="badge-accent text-[9px] inline-flex items-center gap-0.5 px-1.5 py-0.2 rounded font-medium shrink-0 cursor-pointer hover:opacity-80"
                      title="Erweiterte Aufgabe öffnen"
                    >
                      <CheckSquare className="w-2.5 h-2.5" />
                      <span>Erweitert</span>
                    </button>
                  )}

                  {canEdit && (
                    <span className="relative inline-flex items-center">
                      <button
                        type="button"
                        onClick={(e) => {
                          e.stopPropagation();
                          setShowTodoMenu((prev) => !prev);
                        }}
                        className="p-0.5 text-faint hover:text-accent rounded-btn transition-colors cursor-pointer"
                        title="Aufgaben-Optionen"
                      >
                        <MoreHorizontal className="w-3.5 h-3.5" />
                      </button>
                      {showTodoMenu && (
                        <div
                          className="absolute left-0 top-full mt-1 bg-panel border border-border shadow-lg rounded-card p-1 z-30 w-52 text-xs"
                          onClick={(e) => e.stopPropagation()}
                        >
                          {!block.taskId ? (
                            <button
                              type="button"
                              onClick={async () => {
                                setShowTodoMenu(false);
                                try {
                                  const targetDocId = docId || block.documentId || block.docId || '';
                                  const thought = await api.createEnhancedTask(targetDocId, block.id, {
                                    content: localContent || 'Aufgabe',
                                    checked: Boolean(block.checked),
                                  });
                                  const updatedBlock: DocumentBlock = {
                                    ...latestBlockRef.current,
                                    content: localContent,
                                    taskId: thought.id,
                                    type: 'todo',
                                  };
                                  onUpdateBlockRef.current(updatedBlock, true);
                                  onOpenTask?.(thought.id);
                                } catch (err: any) {
                                  alert(err.message || 'Fehler beim Erstellen der erweiterten Aufgabe');
                                }
                              }}
                              className="w-full text-left px-2 py-1.5 rounded-btn hover:bg-panel-elevated hover:text-accent flex items-center gap-1.5 text-main font-medium cursor-pointer"
                            >
                              <CheckSquare className="w-3.5 h-3.5 text-accent" />
                              <span>In erweiterte Aufgabe umwandeln</span>
                            </button>
                          ) : (
                            <button
                              type="button"
                              onClick={async () => {
                                setShowTodoMenu(false);
                                try {
                                  if (block.taskId) {
                                    await api.unlinkEnhancedTask(block.taskId).catch(() => {});
                                  }
                                  const updatedBlock: DocumentBlock = {
                                    ...latestBlockRef.current,
                                    content: localContent,
                                    taskId: '',
                                    type: 'todo',
                                  };
                                  onUpdateBlockRef.current(updatedBlock, true);
                                } catch (err: any) {
                                  alert(err.message || 'Fehler beim Aufheben der Verknüpfung');
                                }
                              }}
                              className="w-full text-left px-2 py-1.5 rounded-btn hover:bg-panel-elevated hover:text-status-warn flex items-center gap-1.5 text-main font-medium cursor-pointer"
                            >
                              <X className="w-3.5 h-3.5 text-status-warn" />
                              <span>Verknüpfung aufheben</span>
                            </button>
                          )}
                        </div>
                      )}
                    </span>
                  )}
                </span>
              )}
            </div>

            <textarea
              ref={(el) => {
                textareaRef.current = el;
                registerTextareaRef(block.id, el);
              }}
              rows={1}
              value={localContent}
              readOnly={!canEdit}
              onFocus={handleFocus}
              onBlur={handleBlur}
              onChange={handleContentChange}
              onKeyDown={handleKeyDown}
              onPaste={handlePaste}
              className={`w-full min-h-[1.5rem] resize-none overflow-hidden bg-transparent border-0 focus:outline-none focus:ring-0 leading-relaxed whitespace-pre-wrap break-words [overflow-wrap:anywhere] ${
                activeFocus ? 'relative z-0 text-main' : 'absolute inset-0 text-transparent selection:text-transparent pointer-events-none'
              } ${
                block.type === 'h1'
                  ? 'text-lg font-bold text-main tracking-tight'
                  : block.type === 'h2'
                  ? 'text-base font-semibold text-main'
                  : block.type === 'h3'
                  ? 'text-sm font-semibold text-main'
                  : block.type === 'todo' && block.checked
                  ? 'text-sm text-faint line-through'
                  : 'text-sm text-main'
              }`}
            />
          </div>
        )}

        {/* Conflict copy: text that lost against someone else's change */}
        {block.conflictOf && (
          <div className="flex flex-wrap items-center gap-1.5 mt-1 text-[11px] text-status-warn select-none">
            <AlertTriangle className="w-3 h-3 shrink-0" />
            <span>
              {block.conflictOf === 'title' ? 'Konflikt beim Titel' : 'Konflikt'}
              {block.conflictAuthor ? ` – Version von ${block.conflictAuthor}` : ''}
            </span>
            {onResolveConflict && (
              <>
                <button
                  type="button"
                  onClick={() => onResolveConflict(block.id, true)}
                  className="px-1.5 py-0.5 rounded-btn border border-status-warn/40 hover:bg-status-warn/15 cursor-pointer"
                  title={block.conflictOf === 'title' ? 'Diesen Text als Titel übernehmen' : 'Diesen Text in den ursprünglichen Punkt übernehmen'}
                >
                  Übernehmen
                </button>
                <button
                  type="button"
                  onClick={() => onResolveConflict(block.id, false)}
                  className="px-1.5 py-0.5 rounded-btn border border-border text-muted hover:text-main hover:bg-panel cursor-pointer"
                  title="Diese Version verwerfen"
                >
                  Verwerfen
                </button>
              </>
            )}
          </div>
        )}

        {/* Rich Tokens Bar (Wiki-Links & #Tags) if present */}
        {hasSpecialTokens && !isFocused && (
          <div className="flex flex-wrap items-center gap-1 mt-0.5">
            {tokens.map((part, idx) => {
              if (part.startsWith('[[') && part.endsWith(']]')) {
                const page = part.slice(2, -2).trim();
                return (
                  <button
                    key={idx}
                    type="button"
                    onClick={() => onWikiLinkClick?.(page)}
                    className="inline-flex items-center gap-0.5 px-1.5 py-0.5 text-[10px] font-medium text-status-info bg-status-info/10 hover:bg-status-info/20 rounded-btn transition-colors"
                    title={`Notiz öffnen: ${page}`}
                  >
                    <FileText className="w-2.5 h-2.5 opacity-80" />
                    <span>{page}</span>
                  </button>
                );
              }
              const mdMatch = part.match(/^\[(.*?)\]\((https?:\/\/.*?)\)$/);
              if (mdMatch && safeHref(mdMatch[2])) {
                const label = mdMatch[1];
                const url = safeHref(mdMatch[2]) as string;
                return (
                  <a
                    key={idx}
                    href={url}
                    target="_blank"
                    rel="noopener noreferrer"
                    className="inline-flex items-center gap-0.5 px-1.5 py-0.5 text-[10px] font-medium text-status-ok bg-status-ok/10 hover:bg-status-ok/20 rounded-btn transition-colors"
                    title={url}
                  >
                    <ExternalLink className="w-2.5 h-2.5 opacity-80" />
                    <span>{label || url}</span>
                  </a>
                );
              }
              // The preview card above already shows this address
              if (/^https?:\/\//.test(part) && safeHref(part) && part !== previewUrl) {
                return (
                  <a
                    key={idx}
                    href={safeHref(part) as string}
                    target="_blank"
                    rel="noopener noreferrer"
                    className="inline-flex items-center gap-0.5 px-1.5 py-0.5 text-[10px] font-medium text-status-ok bg-status-ok/10 hover:bg-status-ok/20 rounded-btn transition-colors"
                    title={part}
                  >
                    <ExternalLink className="w-2.5 h-2.5 opacity-80" />
                    <span className="truncate max-w-[160px]">{part}</span>
                  </a>
                );
              }
              return null;
            })}
          </div>
        )}

        {/* Floating Slash Commands Menu */}
        {slashSearch !== null && canEdit && (
          <div className="absolute left-0 top-8 z-40 w-72 max-w-[calc(100vw-2rem)] panel-surface shadow-panel border border-border rounded-card p-1">
            <div className="px-2 py-1 text-[10px] font-bold uppercase tracking-wider text-faint border-b border-border mb-1">
              Befehl auswählen
            </div>
            <div className="max-h-48 overflow-y-auto space-y-0.5">
              {filteredSlashCommands.map((cmd, i) => (
                <button
                  key={cmd.type}
                  ref={(el) => {
                    slashItemRefs.current[i] = el;
                  }}
                  type="button"
                  onMouseDown={(e) => {
                    e.preventDefault();
                    applySlashCommand(cmd);
                  }}
                  className={`w-full text-left px-2 py-1 rounded-btn text-xs flex items-center justify-between transition-colors ${
                    i === slashIndex
                      ? 'bg-accent text-on-accent'
                      : 'text-main hover:bg-panel-elevated'
                  }`}
                >
                  <div className="flex items-center gap-1.5 shrink-0">
                    {cmd.icon}
                    <span className="font-semibold whitespace-nowrap">{cmd.label}</span>
                  </div>
                  <span className="ml-3 min-w-0 truncate text-right text-[10px] opacity-75">{cmd.desc}</span>
                </button>
              ))}
              {filteredSlashCommands.length === 0 && (
                <div className="p-2 text-center text-xs text-faint">
                  Kein Befehl gefunden
                </div>
              )}
            </div>
          </div>
        )}
      </div>

      {/* Branch into its own note (desktop; phones use /extract) */}
      {canEdit && onExtractBlock && localContent.trim() !== '' && !mediaPicker && (
        <button
          type="button"
          onClick={() => onExtractBlock(block.id)}
          className="hidden sm:block opacity-0 group-hover:opacity-100 focus:opacity-100 p-0.5 text-faint hover:text-accent rounded-btn transition-opacity shrink-0"
          title="In eigene Notiz umwandeln (mit allen Unterpunkten)"
        >
          <FileOutput className="w-3.5 h-3.5" />
        </button>
      )}

      {/* Zoom / Focus button on hover */}
      <button
        type="button"
        onClick={() => onZoomBlock?.(block.id)}
        // Phones zoom by tapping the bullet; the button would only take width from the text there
        className="hidden sm:block opacity-0 group-hover:opacity-100 focus:opacity-100 p-0.5 text-faint hover:text-accent rounded-btn transition-opacity shrink-0"
        title="In diesen Ast hineinzoomen (Fokus-Modus)"
      >
        <Maximize2 className="w-3.5 h-3.5" />
      </button>

      {/* Someone else is editing this block */}
      {lockedBy && (
        <span
          className="shrink-0 self-start mt-1 inline-flex items-center gap-1 px-1.5 py-0.5 rounded-btn text-[10px] text-muted bg-panel border border-border select-none"
          title={`${lockedBy} bearbeitet diesen Punkt gerade`}
        >
          <Lock className="w-2.5 h-2.5" />
          {lockedBy}
        </span>
      )}

      {/* Delete button on hover (Trash2 icon); on phones only in the row being edited */}
      {canEdit && (
        <button
          type="button"
          onClick={() => {
            if (hasChildren) {
              if (window.confirm('Bist du sicher? Alle Unterpunkte dieses Asts werden ebenfalls gelöscht.')) {
                onDeleteBlockRef.current(block.id, true);
              }
            } else {
              onDeleteBlockRef.current(block.id, false);
            }
          }}
          className={
            activeFocus
              ? 'opacity-0 group-hover:opacity-100 focus:opacity-100 p-0.5 text-faint hover:text-status-err rounded-btn transition-opacity shrink-0 cursor-pointer'
              : 'hidden sm:block opacity-0 group-hover:opacity-100 focus:opacity-100 p-0.5 text-faint hover:text-status-err rounded-btn transition-opacity shrink-0 cursor-pointer'
          }
          title="Block löschen"
        >
          <Trash2 className="w-3.5 h-3.5" />
        </button>
      )}

      {/* Link Insertion Modal */}
      {showLinkModal && (
        <LinkModal
          isOpen={showLinkModal}
          onClose={() => setShowLinkModal(false)}
          onInsertLink={handleInsertLink}
        />
      )}
    </div>
  );
};