package envfile

import (
	"strings"
	"testing"
)

func TestSetPreservesDocumentAndUpdatesLastDuplicate(t *testing.T) {
	doc, err := Parse([]byte("# title\nA=one\nA=two\nB=3\n"))
	if err != nil {
		t.Fatal(err)
	}
	if err := doc.Set("A", "hello world"); err != nil {
		t.Fatal(err)
	}
	got := string(doc.Render())
	want := "# title\nA=one\nA=hello world\nB=3\n"
	if got != want {
		t.Fatalf("got %q want %q", got, want)
	}
}

func TestImportMissingCopiesComments(t *testing.T) {
	current, _ := Parse([]byte("A=1\n"))
	example, _ := Parse([]byte("# Alpha\nA=1\n\n# Beta help\nB=2\n"))
	missing, err := current.ImportMissing(example, "# imported")
	if err != nil {
		t.Fatal(err)
	}
	if len(missing) != 1 || missing[0] != "B" {
		t.Fatalf("unexpected missing: %#v", missing)
	}
	got := string(current.Render())
	if !strings.Contains(got, "# Beta help\nB=2") {
		t.Fatalf("comments/value not imported: %q", got)
	}
}

func TestEncodeDecode(t *testing.T) {
	values := []string{"plain", "contains # hash", "line1\nline2", " leading"}
	for _, value := range values {
		if got := DecodeValue(EncodeValue(value)); got != value {
			t.Fatalf("roundtrip %q -> %q", value, got)
		}
	}
}