package storage

import (
	"os"
	"path/filepath"
	"testing"
)

func TestMultiUsesUniqueVirtualRootNames(t *testing.T) {
	a := t.TempDir()
	b := t.TempDir()
	m := NewMulti([]string{a, b})
	if len(m.Names) != 2 || m.Names[0] == m.Names[1] {
		t.Fatalf("names=%v", m.Names)
	}
	if _, _, ok := m.FindRoot(m.Names[0]); !ok {
		t.Fatal("first root not addressable")
	}
	if _, _, ok := m.FindRoot(m.Names[1]); !ok {
		t.Fatal("second root not addressable")
	}
}

func TestMultiRenameCannotCrossRoots(t *testing.T) {
	a := t.TempDir()
	b := t.TempDir()
	if err := os.WriteFile(filepath.Join(a, "src.txt"), []byte("src"), 0o644); err != nil {
		t.Fatal(err)
	}
	m := NewMulti([]string{a, b})
	err := m.Rename(m.Names[0]+"/src.txt", m.Names[1]+"/dst.txt")
	if err == nil {
		t.Fatal("expected cross-root rename to fail")
	}
	if _, err := os.Stat(filepath.Join(a, "src.txt")); err != nil {
		t.Fatalf("source disappeared: %v", err)
	}
	if _, err := os.Stat(filepath.Join(b, "dst.txt")); !os.IsNotExist(err) {
		t.Fatalf("destination unexpectedly created: %v", err)
	}
}

func TestMultiRemoveCannotRemoveVirtualRoot(t *testing.T) {
	m := NewMulti([]string{t.TempDir()})
	if err := m.Remove(""); err == nil {
		t.Fatal("expected virtual root removal to fail")
	}
}

func TestLocalCreateExclusiveRejectsExistingFile(t *testing.T) {
	root := t.TempDir()
	st := Local{Root: root}
	if err := os.WriteFile(filepath.Join(root, "x.txt"), []byte("old"), 0o644); err != nil {
		t.Fatal(err)
	}
	f, err := st.CreateExclusive("x.txt")
	if !os.IsExist(err) || f != nil {
		t.Fatalf("expected EEXIST, file=%v err=%v", f, err)
	}
	got, err := os.ReadFile(filepath.Join(root, "x.txt"))
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != "old" {
		t.Fatalf("existing file changed: %q", got)
	}
}

func TestLocalCreateExclusiveCreatesMissingFile(t *testing.T) {
	st := Local{Root: t.TempDir()}
	f, err := st.CreateExclusive("nested/x.txt")
	if err != nil {
		t.Fatal(err)
	}
	if _, err := f.WriteString("new"); err != nil {
		f.Close()
		t.Fatal(err)
	}
	if err := f.Close(); err != nil {
		t.Fatal(err)
	}
	got, err := os.ReadFile(filepath.Join(st.Root, "nested", "x.txt"))
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != "new" {
		t.Fatalf("unexpected content: %q", got)
	}
}