package stario

import (
	"strings"
	"testing"
)

func benchmarkRawRedrawAppend(b *testing.B, current []rune, next rune, mask string) {
	b.Run("legacy", func(b *testing.B) {
		ioBuf := make([]rune, len(current)+1)
		copy(ioBuf, current)
		ioBuf[len(current)] = next
		b.ReportAllocs()
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			echo := renderRawEcho(ioBuf, mask)
			_ = stringDisplayWidth(echo)
		}
	})

	b.Run("fast", func(b *testing.B) {
		maskWidth := stringDisplayWidth(mask)
		b.ReportAllocs()
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			_, _, ok := rawEchoRenderUnit(next, mask, maskWidth)
			if !ok {
				b.Fatal("fast path rejected append rune")
			}
		}
	})
}

func benchmarkRawRedrawBackspace(b *testing.B, current []rune, mask string) {
	if len(current) == 0 {
		b.Fatal("backspace benchmark requires non-empty input")
	}
	last := current[len(current)-1]
	trimmed := current[:len(current)-1]

	b.Run("legacy", func(b *testing.B) {
		b.ReportAllocs()
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			echo := renderRawEcho(trimmed, mask)
			_ = stringDisplayWidth(echo)
		}
	})

	b.Run("fast", func(b *testing.B) {
		maskWidth := stringDisplayWidth(mask)
		b.ReportAllocs()
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			_, _, ok := rawEchoRenderUnit(last, mask, maskWidth)
			if !ok {
				b.Fatal("fast path rejected backspace rune")
			}
		}
	})
}

func BenchmarkRawRedrawAppendPlainLong(b *testing.B) {
	current := []rune(strings.Repeat("a", 4096))
	benchmarkRawRedrawAppend(b, current, 'b', "")
}

func BenchmarkRawRedrawAppendMaskLong(b *testing.B) {
	current := []rune(strings.Repeat("a", 4096))
	benchmarkRawRedrawAppend(b, current, 'b', "[]")
}

func BenchmarkRawRedrawBackspacePlainLong(b *testing.B) {
	current := []rune(strings.Repeat("a", 4096))
	benchmarkRawRedrawBackspace(b, current, "")
}

func BenchmarkRawRedrawBackspaceMaskLong(b *testing.B) {
	current := []rune(strings.Repeat("a", 4096))
	benchmarkRawRedrawBackspace(b, current, "[]")
}