// +build !openbsd
// +build !windows

package main

import (
	"context"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"testing"
	"time"

	"restic"
	"restic/repository"
	. "restic/test"
)

const (
	mountWait       = 20
	mountSleep      = 100 * time.Millisecond
	mountTestSubdir = "snapshots"
)

func snapshotsDirExists(t testing.TB, dir string) bool {
	f, err := os.Open(filepath.Join(dir, mountTestSubdir))
	if err != nil && os.IsNotExist(err) {
		return false
	}

	if err != nil {
		t.Error(err)
	}

	if err := f.Close(); err != nil {
		t.Error(err)
	}

	return true
}

// waitForMount blocks (max mountWait * mountSleep) until the subdir
// "snapshots" appears in the dir.
func waitForMount(t testing.TB, dir string) {
	for i := 0; i < mountWait; i++ {
		if snapshotsDirExists(t, dir) {
			t.Log("mounted directory is ready")
			return
		}

		time.Sleep(mountSleep)
	}

	t.Errorf("subdir %q of dir %s never appeared", mountTestSubdir, dir)
}

func testRunMount(t testing.TB, gopts GlobalOptions, dir string) {
	opts := MountOptions{}
	OK(t, runMount(opts, gopts, []string{dir}))
}

func testRunUmount(t testing.TB, gopts GlobalOptions, dir string) {
	var err error
	for i := 0; i < mountWait; i++ {
		if err = umount(dir); err == nil {
			t.Logf("directory %v umounted", dir)
			return
		}

		time.Sleep(mountSleep)
	}

	t.Errorf("unable to umount dir %v, last error was: %v", dir, err)
}

func listSnapshots(t testing.TB, dir string) []string {
	snapshotsDir, err := os.Open(filepath.Join(dir, "snapshots"))
	OK(t, err)
	names, err := snapshotsDir.Readdirnames(-1)
	OK(t, err)
	OK(t, snapshotsDir.Close())
	return names
}

func checkSnapshots(t testing.TB, global GlobalOptions, repo *repository.Repository, mountpoint, repodir string, snapshotIDs restic.IDs) {
	t.Logf("checking for %d snapshots: %v", len(snapshotIDs), snapshotIDs)

	go testRunMount(t, global, mountpoint)
	waitForMount(t, mountpoint)
	defer testRunUmount(t, global, mountpoint)

	if !snapshotsDirExists(t, mountpoint) {
		t.Fatal(`virtual directory "snapshots" doesn't exist`)
	}

	ids := listSnapshots(t, repodir)
	t.Logf("found %v snapshots in repo: %v", len(ids), ids)

	namesInSnapshots := listSnapshots(t, mountpoint)
	t.Logf("found %v snapshots in fuse mount: %v", len(namesInSnapshots), namesInSnapshots)
	Assert(t,
		len(namesInSnapshots) == len(snapshotIDs),
		"Invalid number of snapshots: expected %d, got %d", len(snapshotIDs), len(namesInSnapshots))

	namesMap := make(map[string]bool)
	for _, name := range namesInSnapshots {
		namesMap[name] = false
	}

	for _, id := range snapshotIDs {
		snapshot, err := restic.LoadSnapshot(context.TODO(), repo, id)
		OK(t, err)

		ts := snapshot.Time.Format(time.RFC3339)
		present, ok := namesMap[ts]
		if !ok {
			t.Errorf("Snapshot %v (%q) isn't present in fuse dir", id.Str(), ts)
		}

		for i := 1; present; i++ {
			ts = fmt.Sprintf("%s-%d", snapshot.Time.Format(time.RFC3339), i)
			present, ok = namesMap[ts]
			if !ok {
				t.Errorf("Snapshot %v (%q) isn't present in fuse dir", id.Str(), ts)
			}

			if !present {
				break
			}
		}

		namesMap[ts] = true
	}

	for name, present := range namesMap {
		Assert(t, present, "Directory %s is present in fuse dir but is not a snapshot", name)
	}
}

func TestMount(t *testing.T) {
	if !RunFuseTest {
		t.Skip("Skipping fuse tests")
	}

	withTestEnvironment(t, func(env *testEnvironment, gopts GlobalOptions) {
		mountpoint, err := ioutil.TempDir(TestTempDir, "restic-test-mount-")
		OK(t, err)

		testRunInit(t, gopts)

		repo, err := OpenRepository(gopts)
		OK(t, err)

		// We remove the mountpoint now to check that cmdMount creates it
		RemoveAll(t, mountpoint)

		checkSnapshots(t, gopts, repo, mountpoint, env.repo, []restic.ID{})

		SetupTarTestFixture(t, env.testdata, filepath.Join("testdata", "backup-data.tar.gz"))

		// first backup
		testRunBackup(t, []string{env.testdata}, BackupOptions{}, gopts)
		snapshotIDs := testRunList(t, "snapshots", gopts)
		Assert(t, len(snapshotIDs) == 1,
			"expected one snapshot, got %v", snapshotIDs)

		checkSnapshots(t, gopts, repo, mountpoint, env.repo, snapshotIDs)

		// second backup, implicit incremental
		testRunBackup(t, []string{env.testdata}, BackupOptions{}, gopts)
		snapshotIDs = testRunList(t, "snapshots", gopts)
		Assert(t, len(snapshotIDs) == 2,
			"expected two snapshots, got %v", snapshotIDs)

		checkSnapshots(t, gopts, repo, mountpoint, env.repo, snapshotIDs)

		// third backup, explicit incremental
		bopts := BackupOptions{Parent: snapshotIDs[0].String()}
		testRunBackup(t, []string{env.testdata}, bopts, gopts)
		snapshotIDs = testRunList(t, "snapshots", gopts)
		Assert(t, len(snapshotIDs) == 3,
			"expected three snapshots, got %v", snapshotIDs)

		checkSnapshots(t, gopts, repo, mountpoint, env.repo, snapshotIDs)
	})
}

func TestMountSameTimestamps(t *testing.T) {
	if !RunFuseTest {
		t.Skip("Skipping fuse tests")
	}

	withTestEnvironment(t, func(env *testEnvironment, gopts GlobalOptions) {
		SetupTarTestFixture(t, env.base, filepath.Join("testdata", "repo-same-timestamps.tar.gz"))

		repo, err := OpenRepository(gopts)
		OK(t, err)

		mountpoint, err := ioutil.TempDir(TestTempDir, "restic-test-mount-")
		OK(t, err)

		ids := []restic.ID{
			restic.TestParseID("280303689e5027328889a06d718b729e96a1ce6ae9ef8290bff550459ae611ee"),
			restic.TestParseID("75ad6cdc0868e082f2596d5ab8705e9f7d87316f5bf5690385eeff8dbe49d9f5"),
			restic.TestParseID("5fd0d8b2ef0fa5d23e58f1e460188abb0f525c0f0c4af8365a1280c807a80a1b"),
		}

		checkSnapshots(t, gopts, repo, mountpoint, env.repo, ids)
	})
}