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import type { Editor } from "@tiptap/core";
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import { NodeSelection, TextSelection, type Transaction } from "@tiptap/pm/state";
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import { scheduleMovedTextblockSelectionFinalization } from "./moved-textblock-selection";
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import { findTopLevelBlockByBid, getTopLevelBlocks } from "./top-level-blocks";
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type MoveDirection = -1 | 1;
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export function canMoveTopLevelBlock(doc: Transaction["doc"], bid: string | null, direction: MoveDirection): boolean {
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  const blocks = getTopLevelBlocks(doc);
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  const block = blocks.find((candidate) => candidate.bid === bid) ?? null;
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  if (!block) return false;
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  const targetIndex = block.index + direction;
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  return targetIndex >= 0 && targetIndex < blocks.length;
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}
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export function applyMoveTopLevelBlock(tr: Transaction, bid: string | null, direction: MoveDirection): boolean {
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  const blocks = getTopLevelBlocks(tr.doc);
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  const source = blocks.find((candidate) => candidate.bid === bid) ?? null;
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  if (!source) return false;
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  const targetIndex = source.index + direction;
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  if (targetIndex < 0 || targetIndex >= blocks.length) return false;
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  const target = blocks[targetIndex];
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  if (!target) return false;
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  const sourceStart = source.pos;
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  const sourceEnd = sourceStart + source.node.nodeSize;
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  const insertAnchor = direction < 0 ? target.pos : target.pos + target.node.nodeSize;
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  tr.delete(sourceStart, sourceEnd);
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  const insertPos = tr.mapping.map(insertAnchor, direction < 0 ? -1 : 1);
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  tr.insert(insertPos, source.node);
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  tr.setSelection(NodeSelection.create(tr.doc, insertPos));
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  return true;
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}
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export function applyDeleteTopLevelBlock(tr: Transaction, bid: string | null): boolean {
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  const blocks = getTopLevelBlocks(tr.doc);
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  const block = blocks.find((candidate) => candidate.bid === bid) ?? null;
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  if (!block) return false;
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  if (blocks.length === 1) {
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    const paragraph = tr.doc.type.schema.nodes.paragraph;
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    if (!paragraph) return false;
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    tr.replaceWith(block.pos, block.pos + block.node.nodeSize, paragraph.create());
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    tr.setSelection(TextSelection.create(tr.doc, 1));
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    return true;
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  }
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  tr.delete(block.pos, block.pos + block.node.nodeSize);
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  const nextPos = Math.min(block.pos, tr.doc.content.size);
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  tr.setSelection(TextSelection.near(tr.doc.resolve(nextPos)));
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  return true;
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}
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export function moveTopLevelBlock(editor: Editor, bid: string | null, direction: MoveDirection): boolean {
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  const tr = editor.state.tr;
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  if (!applyMoveTopLevelBlock(tr, bid, direction)) return false;
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  editor.view.dispatch(tr);
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  editor.view.focus();
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  scheduleMovedTextblockSelectionFinalization(editor.view);
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  return true;
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}
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export function deleteTopLevelBlock(editor: Editor, bid: string | null): boolean {
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  const tr = editor.state.tr;
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  if (!applyDeleteTopLevelBlock(tr, bid)) return false;
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  editor.view.dispatch(tr);
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  editor.view.focus();
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  return true;
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}
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export function getCurrentTopLevelBlock(editor: Editor, bid: string | null) {
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  return findTopLevelBlockByBid(editor.state.doc, bid);
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}