CSV source adapter

1"use client";
2 
3import * as React from "react";
4 
5import type { Source, SourceAnchor } from "@/lib/document-source";
6import type {
7  CsvCellAddress,
8  CsvViewerHandle,
9} from "@/components/ui/csv-viewer";
10 
11export interface SourceTarget {
12  scrollTo?: (source: Source, options: { behavior: ScrollBehavior }) => void;
13}
14 
15/** Spreadsheet column letter → 0-based index ("A" → 0, "C" → 2, "AA" → 26). */
16export function columnLetterToIndex(letter: string): number | null {
17  if (!/^[A-Za-z]+$/.test(letter)) return null;
18  let n = 0;
19  for (const ch of letter.toUpperCase()) {
20    n = n * 26 + (ch.charCodeAt(0) - 64);
21    if (!Number.isSafeInteger(n)) return null;
22  }
23  return n - 1;
24}
25 
26/**
27 * A `csv_cell` anchor → 0-based data coordinates. `row` is the 1-based data
28 * row (the header is not a data row); `column` is a letter.
29 */
30export function csvAnchorToTarget(anchor: SourceAnchor): CsvCellAddress | null {
31  if (anchor.kind === "csv_cell") {
32    const columnIndex = columnLetterToIndex(anchor.column);
33    if (
34      columnIndex == null ||
35      !Number.isInteger(anchor.row) ||
36      anchor.row < 1
37    ) {
38      return null;
39    }
40    return {
41      rowIndex: anchor.row - 1,
42      columnIndex,
43    };
44  }
45  return null;
46}
47 
48/** A stable source target over a `CsvViewer` ref. */
49export function useCsvSourceTarget(
50  viewerRef: React.RefObject<CsvViewerHandle | null>,
51): SourceTarget {
52  return React.useMemo<SourceTarget>(
53    () => ({
54      scrollTo: (source: Source, options) => {
55        const target = csvAnchorToTarget(source.anchor);
56        if (target) viewerRef.current?.scrollToCell(target, options);
57      },
58    }),
59    [viewerRef],
60  );
61}
62 
63/**
64 * The `activeCell` prop for `CsvViewer` derived from a source.
65 */
66export function sourceToCsvCell(
67  source: Source | undefined,
68): CsvCellAddress | null {
69  return source ? csvAnchorToTarget(source.anchor) : null;
70}