import { DocumentBlock } from '../types/block';

/**
 * recomputeNumbering: 动态单遍重算整个文档块树的章节多级编号及图表题注
 * - 标题层级栈：1 -> 1.1 -> 1.1.1
 * - 图表计数器：表 1-1、图 1-1
 */
export function recomputeNumbering(root: DocumentBlock): DocumentBlock {
  const chapterStack: number[] = [0, 0, 0, 0, 0, 0];
  let currentTopChapter = 1;
  let tableCounter = 1;
  let figureCounter = 1;

  function traverse(block: DocumentBlock) {
    if (block.type === 'heading') {
      const level = Math.max(1, Math.min(6, block.level || 1));
      chapterStack[level - 1] += 1;
      for (let i = level; i < chapterStack.length; i++) {
        chapterStack[i] = 0;
      }
      const numStr = chapterStack.slice(0, level).join('.');
      block.numbering = numStr;

      if (level === 1) {
        currentTopChapter = chapterStack[0];
        tableCounter = 1;
        figureCounter = 1;
      }
    } else if (block.type === 'table') {
      block.numbering = `表 ${currentTopChapter}-${tableCounter++}`;
    } else if (block.type === 'mermaid') {
      block.numbering = `图 ${currentTopChapter}-${figureCounter++}`;
    }

    if (block.children && block.children.length > 0) {
      for (const child of block.children) {
        traverse(child);
      }
    }
  }

  if (root.children) {
    for (const child of root.children) {
      traverse(child);
    }
  }

  return root;
}