package flatfs_test

import (
	"io/ioutil"
	"os"
	"path/filepath"
	"testing"

	"github.com/jbenet/go-datastore"
	"github.com/jbenet/go-datastore/flatfs"
)

func tempdir(t testing.TB) (path string, cleanup func()) {
	path, err := ioutil.TempDir("", "test-datastore-flatfs-")
	if err != nil {
		t.Fatalf("cannot create temp directory: %v", err)
	}

	cleanup = func() {
		if err := os.RemoveAll(path); err != nil {
			t.Errorf("tempdir cleanup failed: %v", err)
		}
	}
	return path, cleanup
}

func TestBadPrefixLen(t *testing.T) {
	temp, cleanup := tempdir(t)
	defer cleanup()

	for i := 0; i > -3; i-- {
		_, err := flatfs.New(temp, 0)
		if g, e := err, flatfs.ErrBadPrefixLen; g != e {
			t.Errorf("expected ErrBadPrefixLen, got: %v", g)
		}
	}
}

func TestPutBadValueType(t *testing.T) {
	temp, cleanup := tempdir(t)
	defer cleanup()

	fs, err := flatfs.New(temp, 2)
	if err != nil {
		t.Fatalf("New fail: %v\n", err)
	}

	err = fs.Put(datastore.NewKey("quux"), 22)
	if g, e := err, datastore.ErrInvalidType; g != e {
		t.Fatalf("expected ErrInvalidType, got: %v\n", g)
	}
}

func TestPut(t *testing.T) {
	temp, cleanup := tempdir(t)
	defer cleanup()

	fs, err := flatfs.New(temp, 2)
	if err != nil {
		t.Fatalf("New fail: %v\n", err)
	}

	err = fs.Put(datastore.NewKey("quux"), []byte("foobar"))
	if err != nil {
		t.Fatalf("Put fail: %v\n", err)
	}
}

func TestGet(t *testing.T) {
	temp, cleanup := tempdir(t)
	defer cleanup()

	fs, err := flatfs.New(temp, 2)
	if err != nil {
		t.Fatalf("New fail: %v\n", err)
	}

	const input = "foobar"
	err = fs.Put(datastore.NewKey("quux"), []byte(input))
	if err != nil {
		t.Fatalf("Put fail: %v\n", err)
	}

	data, err := fs.Get(datastore.NewKey("quux"))
	if err != nil {
		t.Fatalf("Get failed: %v", err)
	}
	buf, ok := data.([]byte)
	if !ok {
		t.Fatalf("expected []byte from Get, got %T: %v", data, data)
	}
	if g, e := string(buf), input; g != e {
		t.Fatalf("Get gave wrong content: %q != %q", g, e)
	}
}

func TestPutOverwrite(t *testing.T) {
	temp, cleanup := tempdir(t)
	defer cleanup()

	fs, err := flatfs.New(temp, 2)
	if err != nil {
		t.Fatalf("New fail: %v\n", err)
	}

	const (
		loser  = "foobar"
		winner = "xyzzy"
	)
	err = fs.Put(datastore.NewKey("quux"), []byte(loser))
	if err != nil {
		t.Fatalf("Put fail: %v\n", err)
	}

	err = fs.Put(datastore.NewKey("quux"), []byte(winner))
	if err != nil {
		t.Fatalf("Put fail: %v\n", err)
	}

	data, err := fs.Get(datastore.NewKey("quux"))
	if err != nil {
		t.Fatalf("Get failed: %v", err)
	}
	if g, e := string(data.([]byte)), winner; g != e {
		t.Fatalf("Get gave wrong content: %q != %q", g, e)
	}
}

func TestGetNotFoundError(t *testing.T) {
	temp, cleanup := tempdir(t)
	defer cleanup()

	fs, err := flatfs.New(temp, 2)
	if err != nil {
		t.Fatalf("New fail: %v\n", err)
	}

	_, err = fs.Get(datastore.NewKey("quux"))
	if g, e := err, datastore.ErrNotFound; g != e {
		t.Fatalf("expected ErrNotFound, got: %v\n", g)
	}
}

func TestStorage(t *testing.T) {
	temp, cleanup := tempdir(t)
	defer cleanup()

	const prefixLen = 2
	const prefix = "2f71"
	const target = prefix + "/2f71757578.data"
	fs, err := flatfs.New(temp, prefixLen)
	if err != nil {
		t.Fatalf("New fail: %v\n", err)
	}

	err = fs.Put(datastore.NewKey("quux"), []byte("foobar"))
	if err != nil {
		t.Fatalf("Put fail: %v\n", err)
	}

	seen := false
	walk := func(absPath string, fi os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		path, err := filepath.Rel(temp, absPath)
		if err != nil {
			return err
		}
		switch path {
		case ".", "..":
			// ignore
		case prefix:
			if !fi.IsDir() {
				t.Errorf("prefix directory is not a file? %v", fi.Mode())
			}
			// we know it's there if we see the file, nothing more to
			// do here
		case target:
			seen = true
			if !fi.Mode().IsRegular() {
				t.Errorf("expected a regular file, mode: %04o", fi.Mode())
			}
			if g, e := fi.Mode()&os.ModePerm&0007, os.FileMode(0000); g != e {
				t.Errorf("file should not be world accessible: %04o", fi.Mode())
			}
		default:
			t.Errorf("saw unexpected directory entry: %q %v", path, fi.Mode())
		}
		return nil
	}
	if err := filepath.Walk(temp, walk); err != nil {
		t.Fatal("walk: %v", err)
	}
	if !seen {
		t.Error("did not see the data file")
	}
}