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package editor

import (
	"strings"

	"github.com/charmbracelet/lipgloss"
)

// Span is a run of text with a single Lipgloss style.
type Span struct {
	Text  string
	Style lipgloss.Style
}

// renderSpans concatenates styled spans into a single string.
func renderSpans(spans []Span) string {
	var b strings.Builder
	for _, s := range spans {
		b.WriteString(s.Style.Render(s.Text))
	}
	return b.String()
}

// renderSpansCursor renders spans rune-by-rune, drawing the cursor cell at the
// given rune column with cursorStyle. A cursor at or past the end of the line
// is drawn as a styled space.
func renderSpansCursor(spans []Span, col int, cursorStyle lipgloss.Style) string {
	var b strings.Builder
	idx := 0
	for _, s := range spans {
		for _, r := range s.Text {
			if idx == col {
				b.WriteString(cursorStyle.Render(string(r)))
			} else {
				b.WriteString(s.Style.Render(string(r)))
			}
			idx++
		}
	}
	if col >= idx {
		b.WriteString(cursorStyle.Render(" "))
	}
	return b.String()
}