/** ANSI helpers for /bin/edit (preamble; no import in src). */

const EDIT_ANSI_RESET = '\x1b[0m'

/**
 * @param {Record<string, unknown>} [ctx]
 * @returns {import('stream').Writable | undefined}
 */
function bareEditResolveStdout(ctx) {
  if (!ctx || typeof ctx !== 'object') return globalThis.process?.stdout
  const c = /** @type {{ replStdout?: unknown, stdout?: unknown }} */ (ctx)
  const out = c.replStdout || c.stdout || globalThis.process?.stdout
  return /** @type {import('stream').Writable | undefined} */ (out)
}

/**
 * @param {Record<string, unknown>} [ctx]
 */
function bareEditUseColor(ctx) {
  const env =
    ctx && typeof ctx === 'object' && ctx.env && typeof ctx.env === 'object'
      ? /** @type {Record<string, string>} */ (ctx.env)
      : {}
  if (env.NO_COLOR != null && String(env.NO_COLOR) !== '') return false
  const out = bareEditResolveStdout(ctx)
  return Boolean(out && /** @type {{ isTTY?: boolean }} */ (out).isTTY)
}

/**
 * @param {'keyword'|'string'|'comment'|'number'|'status'|'inverse'|'dim'} cls
 * @param {boolean} on
 */
function bareEditSgr(cls, on) {
  if (!on) return ''
  switch (cls) {
    case 'keyword':
      return '\x1b[36m'
    case 'string':
      return '\x1b[32m'
    case 'comment':
      return '\x1b[90m'
    case 'number':
      return '\x1b[33m'
    case 'status':
      return '\x1b[44m\x1b[97m'
    case 'inverse':
      return '\x1b[7m'
    case 'dim':
      return '\x1b[2m'
    default:
      return ''
  }
}

/**
 * @param {string} fullLine
 * @param {Array<{ start: number, end: number, cls: string }>} spans offsets into fullLine
 * @param {number} visStart first column (0-based)
 * @param {number} maxLen max code units to show
 * @param {boolean} useColor
 */
function bareEditPaintLineWindow(fullLine, spans, visStart, maxLen, useColor) {
  const slice = fullLine.slice(visStart, visStart + maxLen)
  if (!useColor) return slice
  const n = slice.length
  const relSpans = spans
    .map((s) => ({
      start: Math.max(0, s.start - visStart),
      end: Math.min(n, s.end - visStart),
      cls: s.cls
    }))
    .filter((s) => s.end > 0 && s.start < n)
    .sort((a, b) => a.start - b.start)

  let out = ''
  let pos = 0
  for (const sp of relSpans) {
    if (sp.start > pos) out += slice.slice(pos, sp.start)
    out +=
      bareEditSgr(/** @type {'keyword'} */ (sp.cls), true) +
      slice.slice(sp.start, sp.end) +
      EDIT_ANSI_RESET
    pos = sp.end
  }
  if (pos < n) out += slice.slice(pos)
  return out
}

/**
 * Move cursor (1-based row/col, DEC origin). Clamp to sane bounds for escape parsing.
 * @param {number} row1
 * @param {number} col1
 */
function bareEditCup(row1, col1) {
  const r = Math.max(1, Math.min(Math.floor(row1), 9999))
  const c = Math.max(1, Math.min(Math.floor(col1), 9999))
  return '\x1b[' + r + ';' + c + 'H'
}