// A file's lines as the review store counts them (format §7.3, blobLines in
// src/main/reviews/store/anchors.ts): each LF ends a line, and a last line
// without LF counts. An editor instead counts the empty line after a final
// LF, which the viewer must neither show nor offer for comments.

/** Lines in `text` as the store counts them: 0 for an empty text. */
export function lineCount(text: string): number {
  let n = 0
  for (let i = text.indexOf('\n'); i >= 0; i = text.indexOf('\n', i + 1)) n++
  return text.length && !text.endsWith('\n') ? n + 1 : n
}

/**
 * The text an editor shows: without the line break that ends the last line
 * (LF or CRLF), so it has one line per store line. Line numbers and the
 * positions of every character stay those of `text`.
 */
export const viewText = (text: string): string => text.replace(/\r?\n$/, '')

/** A 1-based line range cut to lines 1..count, or null when none of it is a line. */
export function clampLines(range: readonly [number, number], count: number): [number, number] | null {
  const from = Math.max(1, range[0])
  const to = Math.min(count, range[1])
  return from <= to ? [from, to] : null
}