package tui

import (
	"strings"
	"unicode"
)

// Split text into words or newlines.
func splitText(s string) [][]rune {
	s = strings.TrimSpace(s)
	r := []rune(s)
	out := [][]rune{}

	nextWord := func() []rune {
		for i := range r {
			if unicode.IsSpace(r[i]) {
				ret := r[:i]
				r = r[i:]
				return ret
			}
		}
		ret := r
		r = r[:0]
		return ret
	}

	nextSpaces := func() []rune {
		for i := range r {
			if !unicode.IsSpace(r[i]) {
				ret := r[:i]
				r = r[i:]
				return ret
			}
		}
		// Code should never reach these lines.
		ret := r
		r = r[:0]
		return ret
	}

	for len(r) > 0 {
		word := nextWord()
		if len(word) != 0 {
			out = append(out, word)
		}

		if len(r) == 0 {
			break
		}

		spaces := nextSpaces()
		count := 0
		for _, x := range spaces {
			if x == '\n' {
				count++
			}
			if count > 1 {
				break
			}
		}

		if count > 1 {
			out = append(out, []rune{'\n'})
		}
	}

	return out
}