Function wrapRows

internal/tui/render.go:190–234

wrapRows mirrors bubbles/textarea.wrap()'s row count so the prompt's auto-grow stays in lock step with what the textarea renders: word-boundary aware with a hard-wrap fallback for over-wide words, plus the trailing cursor-anchor row when content exactly fills the width. Adapted from charmbracelet/bu

(s string, width int)

// cursor-anchor row when content exactly fills the width.
// Adapted from charmbracelet/bubbles v0.20 textarea.
//
// Caveat: width is summed per-rune (runewidth) rather than per grapheme cluster
// like bubbles' uniseg, so ASCII and CJK match exactly, but a multi-rune cluster
// (a ZWJ-family emoji, a keycap) can over-count, harmlessly over-growing the
// prompt by a row on emoji-heavy input. Not worth pulling in uniseg for that.
func wrapRows(s string, width int) int {
	if width <= 0 {
		return 1
	}
	row := 0
	var lineW, wordW, spaces, charW int
	var hadWord bool

	for _, r := range s {
		charW = 0
		if unicode.IsSpace(r) {
			spaces++
		} else {
			charW = runewidth.RuneWidth(r)
			wordW += charW
			hadWord = true
		}

		switch {
		case spaces > 0:
			if lineW+wordW+spaces > width {
				row++
				lineW = wordW + spaces
			} else {
				lineW += wordW + spaces
			}
			wordW, spaces = 0, 0
			hadWord = false
		case hadWord && wordW+charW > width:
			// Space-less word grew past the width; matches bubbles'
			// StringWidth(word)+lastCharLen check.
			if lineW > 0 {
				row++
			}
			lineW = wordW
			wordW = 0
			hadWord = false
		}
	}

	if lineW+wordW+spaces >= width {
		row++
	}