/**
 * A single match returned by `git grep`.
 */
export interface GrepMatch {
  /** Path of the matching file relative to the repository root. */
  file: string

  /** One-based line number of the match within the file. */
  line: number

  /** Content of the matching line. */
  text: string
}

/**
 * Regular expression that splits a `git grep -nz` record into file, line number, and content.
 * The `-z` flag separates the three fields with NUL bytes so paths containing colons are unambiguous.
 * The trailing `\r?` strips the carriage return that git grep emits for source files with CRLF endings.
 *
 * @const {RegExp}
 * @default /^([^\0]+)\0(\d+)\0(.*)\r?$/
 */
const grepRecordRegex = /^([^\0]+)\0(\d+)\0(.*)\r?$/

/**
 * Parses raw `git grep -nz` output into a typed list of matches.
 *
 * @param raw The raw stdout produced by `git grep -nz`.
 * @returns The parsed match list.
 */
export function parseGrepOutput(raw: string): GrepMatch[] {
  const tokens = raw.split("\0")
  const matches: GrepMatch[] = []

  for (let i = 0; i + 2 < tokens.length; i += 3) {
    const file = tokens[i]
    const lineStr = tokens[i + 1]
    const text = tokens[i + 2]

    // Skip empty filenames or invalid line numbers
    if (file.length === 0) continue
    const line = Number(lineStr)
    if (Number.isNaN(line)) continue

    matches.push({ file, line, text })
  }

  return matches
}

/**
 * A single match returned by `git grep`.
 */
export interface GrepMatch {
  /** Path of the matching file relative to the repository root. */
  file: string

  /** One-based line number of the match within the file. */
  line: number

  /** Content of the matching line. */
  text: string
}

/**
 * Regular expression that splits a `git grep -nz` record into file, line number, and content.
 * The `-z` flag separates the three fields with NUL bytes so paths containing colons are unambiguous.
 * The trailing `\r?` strips the carriage return that git grep emits for source files with CRLF endings.
 *
 * @const {RegExp}
 * @default /^([^\0]+)\0(\d+)\0(.*)\r?$/
 */
const grepRecordRegex = /^([^\0]+)\0(\d+)\0(.*)\r?$/

/**
 * Parses raw `git grep -nz` output into a typed list of matches.
 *
 * @param raw The raw stdout produced by `git grep -nz`.
 * @returns The parsed match list.
 */
export function parseGrepOutput(raw: string): GrepMatch[] {
  const tokens = raw.split("\0")
  const matches: GrepMatch[] = []

  for (let i = 0; i + 2 < tokens.length; i += 3) {
    const file = tokens[i]
    const lineStr = tokens[i + 1]
    const text = tokens[i + 2]

    // Skip empty filenames or invalid line numbers
    if (file.length === 0) continue
    const line = Number(lineStr)
    if (Number.isNaN(line)) continue

    matches.push({ file, line, text })
  }

  return matches
}