// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

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

	"fuchsia.googlesource.com/jiri"
	"fuchsia.googlesource.com/jiri/gitutil"
	"fuchsia.googlesource.com/jiri/jiritest"
	"fuchsia.googlesource.com/jiri/project"
	"fuchsia.googlesource.com/jiri/tool"
)

func checkReadme(t *testing.T, jirix *jiri.X, project, message string) {
	if _, err := os.Stat(project); err != nil {
		t.Fatalf("%v", err)
	}
	readmeFile := filepath.Join(project, "README")
	data, err := ioutil.ReadFile(readmeFile)
	if err != nil {
		t.Fatalf("%v", err)
	}
	if got, want := data, []byte(message); bytes.Compare(got, want) != 0 {
		t.Fatalf("unexpected content %v:\ngot\n%s\nwant\n%s\n", project, got, want)
	}
}

func localProjectName(i int) string {
	return "test-local-project-" + fmt.Sprintf("%d", i+1)
}

func remoteProjectName(i int) string {
	return "test-remote-project-" + fmt.Sprintf("%d", i+1)
}

func writeReadme(t *testing.T, jirix *jiri.X, projectDir, message string) {
	path, perm := filepath.Join(projectDir, "README"), os.FileMode(0644)
	if err := ioutil.WriteFile(path, []byte(message), perm); err != nil {
		t.Fatalf("%s", err)
	}
	cwd, err := os.Getwd()
	if err != nil {
		t.Fatalf("%s", err)
	}
	defer os.Chdir(cwd)
	if err := os.Chdir(projectDir); err != nil {
		t.Fatalf("%s", err)
	}
	if err := gitutil.New(jirix, gitutil.UserNameOpt("John Doe"), gitutil.UserEmailOpt("john.doe@example.com")).CommitFile(path, "creating README"); err != nil {
		t.Fatalf("%s", err)
	}
}

// TestSnapshot tests creating and checking out a snapshot.
func TestSnapshot(t *testing.T) {
	fake, cleanup := jiritest.NewFakeJiriRoot(t)
	defer cleanup()

	// Setup the initial remote and local projects.
	numProjects, remoteProjects := 2, []string{}
	for i := 0; i < numProjects; i++ {
		if err := fake.CreateRemoteProject(remoteProjectName(i)); err != nil {
			t.Fatalf("%v", err)
		}
		if err := fake.AddProject(project.Project{
			Name:   remoteProjectName(i),
			Path:   localProjectName(i),
			Remote: fake.Projects[remoteProjectName(i)],
		}); err != nil {
			t.Fatalf("%v", err)
		}
	}

	// Create initial commits in the remote projects and use UpdateUniverse()
	// to mirror them locally.
	for i := 0; i < numProjects; i++ {
		writeReadme(t, fake.X, fake.Projects[remoteProjectName(i)], "revision 1")
	}
	if err := project.UpdateUniverse(fake.X, true, false, false, false, false, true /*run-hooks*/, project.DefaultHookTimeout); err != nil {
		t.Fatalf("%v", err)
	}

	// Create a snapshot.
	var stdout bytes.Buffer
	fake.X.Context = tool.NewContext(tool.ContextOpts{Stdout: &stdout, Env: fake.X.Context.Env()})

	tmpfile, err := ioutil.TempFile("", "jiri-snapshot-")
	if err != nil {
		t.Fatal(err)
	}
	defer os.Remove(tmpfile.Name())

	if err := runSnapshot(fake.X, []string{tmpfile.Name()}); err != nil {
		t.Fatalf("%v", err)
	}

	// Remove the local project repositories.
	for i, _ := range remoteProjects {
		localProject := filepath.Join(fake.X.Root, localProjectName(i))
		if err := os.RemoveAll(localProject); err != nil {
			t.Fatalf("%v", err)
		}
	}

	// Check that invoking the UpdateUniverse() with the snapshot restores the
	// local repositories.
	snapshotFile := tmpfile.Name()
	localX := fake.X.Clone(tool.ContextOpts{
		Manifest: &snapshotFile,
	})
	if err := project.UpdateUniverse(localX, true, false, false, false, false, true /*run-hooks*/, project.DefaultHookTimeout); err != nil {
		t.Fatalf("%v", err)
	}
	for i, _ := range remoteProjects {
		localProject := filepath.Join(fake.X.Root, localProjectName(i))
		checkReadme(t, fake.X, localProject, "revision 1")
	}
}