package fs

import (
	"io/ioutil"
	"testing"
	"os"
	"github.com/dotcloud/docker/fake"
)



func TestLayersInit(t *testing.T) {
	store := tempStore(t)
	defer os.RemoveAll(store.Root)
	// Root should exist
	if _, err := os.Stat(store.Root); err != nil {
		t.Fatal(err)
	}
	// List() should be empty
	if l := store.List(); len(l) != 0 {
		t.Fatalf("List() should return %d, not %d", 0, len(l))
	}
}

func TestAddLayer(t *testing.T) {
	store := tempStore(t)
	defer os.RemoveAll(store.Root)
	layer, err := store.AddLayer("foo", testArchive(t), os.Stderr, Uncompressed)
	if err != nil {
		t.Fatal(err)
	}
	// Layer path should exist
	if _, err := os.Stat(layer); err != nil {
		t.Fatal(err)
	}
	// List() should return 1 layer
	if l := store.List(); len(l) != 1 {
		t.Fatalf("List() should return %d elements, not %d", 1, len(l))
	}
	// Get("foo") should return the correct layer
	if foo := store.Get("foo"); foo != layer {
		t.Fatalf("get(\"foo\") should return '%d', not '%d'", layer, foo)
	}
}

func TestAddLayerDuplicate(t *testing.T) {
	store := tempStore(t)
	defer os.RemoveAll(store.Root)
	if _, err := store.AddLayer("foobar123", testArchive(t), os.Stderr, Uncompressed); err != nil {
		t.Fatal(err)
	}
	if _, err := store.AddLayer("foobar123", testArchive(t), os.Stderr, Uncompressed); err == nil {
		t.Fatalf("Creating duplicate layer should fail")
	}
}


/*
 * HELPER FUNCTIONS
 */

func tempStore(t *testing.T) *LayerStore {
	tmp, err := ioutil.TempDir("", "docker-fs-layerstore-")
	if err != nil {
		t.Fatal(err)
	}
	store, err := NewLayerStore(tmp)
	if err != nil {
		t.Fatal(err)
	}
	return store
}

func testArchive(t *testing.T) Archive {
	archive, err := fake.FakeTar()
	if err != nil {
		t.Fatal(err)
	}
	return archive
}