package diffx

import (
	"strings"
	"testing"
)

func TestUnifiedEmptyWhenEqual(t *testing.T) {
	if got := Unified("a.txt", "a.txt", "mesmo", "mesmo"); got != "" {
		t.Fatalf("esperava diff vazio, veio %q", got)
	}
}

func TestUnifiedCreateLooksLikeGit(t *testing.T) {
	got := Unified("(sem conteúdo)", "nota.md", "", "# Ola\n\nlinha\n")
	for _, want := range []string{"--- (sem conteúdo)", "+++ nota.md", "@@", "+# Ola", "+linha"} {
		if !strings.Contains(got, want) {
			t.Errorf("diff deveria conter %q; diff:\n%s", want, got)
		}
	}
	if strings.Contains(got, "-linha") {
		t.Errorf("não deveria haver remoção em criação pura:\n%s", got)
	}
}

func TestUnifiedEditHasAddAndRemove(t *testing.T) {
	before := "alpha\nbravo\ncharlie\n"
	after := "alpha\nBRAVO change\ncharlie\ndelta\n"
	got := Unified("n", "n", before, after)
	added, removed := Stats(got)
	if removed != 1 {
		t.Errorf("esperava 1 remoção, obtive %d (diff:\n%s)", removed, got)
	}
	if added != 2 {
		t.Errorf("esperava 2 adições, obtive %d (diff:\n%s)", added, got)
	}
}

func TestStatsIgnoresFileHeaders(t *testing.T) {
	added, removed := Stats("--- a\n+++ b\n@@ -1 +1 @@\n+x\n")
	if added != 1 || removed != 0 {
		t.Fatalf("added=%d removed=%d, esperava 1/0", added, removed)
	}
}