package parse

import "strings"

// Chunk splits text on double-newlines and builds chunks of at most maxRunes.
// A single paragraph longer than maxRunes is kept as its own chunk.
func Chunk(text string, maxRunes int) []string {
	paragraphs := strings.Split(text, "\n\n")
	var chunks []string
	var cur strings.Builder

	for _, p := range paragraphs {
		p = strings.TrimSpace(p)
		if p == "" {
			continue
		}
		pLen := len([]rune(p))
		if cur.Len() > 0 && len([]rune(cur.String()))+2+pLen > maxRunes {
			chunks = append(chunks, cur.String())
			cur.Reset()
		}
		if cur.Len() > 0 {
			cur.WriteString("\n\n")
		}
		cur.WriteString(p)
	}
	if cur.Len() > 0 {
		chunks = append(chunks, cur.String())
	}
	return chunks
}