// 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 jiritest

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

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

// FakeJiriRoot sets up a fake root under a tmp directory.
type FakeJiriRoot struct {
	X        *jiri.X
	Projects map[string]string
	remote   string
}

const (
	ManifestFileName    = "public"
	ManifestProjectPath = "manifest"
)
const (
	defaultDataDir      = "data"
	ManifestProjectName = "manifest"
)

// NewFakeJiriRoot returns a new FakeJiriRoot and a cleanup closure.  The
// closure must be run to cleanup temporary directories and restore the original
// environment; typically it is run as a defer function.
func NewFakeJiriRoot(t *testing.T) (*FakeJiriRoot, func()) {
	jirix, cleanup := NewX(t)
	fake := &FakeJiriRoot{
		X:        jirix,
		Projects: map[string]string{},
	}

	// Create fake remote manifest projects.
	remoteDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatalf("TempDir() failed: %v", err)
	}
	fake.remote = remoteDir
	if err := fake.CreateRemoteProject(ManifestProjectPath); err != nil {
		t.Fatal(err)
	}
	// Create a fake manifest.
	manifestDir := filepath.Join(remoteDir, ManifestProjectPath)
	if err := os.MkdirAll(manifestDir, os.FileMode(0700)); err != nil {
		t.Fatal(err)
	}
	if err := fake.WriteRemoteManifest(&project.Manifest{}); err != nil {
		t.Fatal(err)
	}
	// Add the "manifest" project to the manifest.
	if err := fake.AddProject(project.Project{
		Name:   ManifestProjectName,
		Path:   ManifestProjectPath,
		Remote: fake.Projects[ManifestProjectName],
	}); err != nil {
		t.Fatal(err)
	}
	// Create a .jiri_manifest file which imports the manifest created above.
	if err := fake.WriteJiriManifest(&project.Manifest{
		Imports: []project.Import{
			project.Import{
				Manifest: ManifestFileName,
				Name:     ManifestProjectName,
				Remote:   filepath.Join(fake.remote, ManifestProjectPath),
			},
		},
	}); err != nil {
		t.Fatal(err)
	}

	// Update the contents of the fake instance based on  the information
	// recorded in the remote manifest.
	if err := fake.UpdateUniverse(false); err != nil {
		t.Fatal(err)
	}

	return fake, func() {
		cleanup()
		if err := os.RemoveAll(fake.remote); err != nil {
			t.Fatalf("RemoveAll(%q) failed: %v", fake.remote, err)
		}
	}
}

// AddProject adds the given project to a remote manifest.
func (fake FakeJiriRoot) AddProject(project project.Project) error {
	manifest, err := fake.ReadRemoteManifest()
	if err != nil {
		return err
	}
	manifest.Projects = append(manifest.Projects, project)
	if err := fake.WriteRemoteManifest(manifest); err != nil {
		return err
	}
	return nil
}

// AddHook adds the given hook to a remote manifest.
func (fake FakeJiriRoot) AddHook(hook project.Hook) error {
	manifest, err := fake.ReadRemoteManifest()
	if err != nil {
		return err
	}
	manifest.Hooks = append(manifest.Hooks, hook)
	if err := fake.WriteRemoteManifest(manifest); err != nil {
		return err
	}
	return nil
}

// DisableRemoteManifestPush disables pushes to the remote manifest
// repository.
func (fake FakeJiriRoot) DisableRemoteManifestPush() error {
	dir := gitutil.RootDirOpt(filepath.Join(fake.remote, ManifestProjectPath))
	if err := gitutil.New(fake.X, dir).CheckoutBranch("master"); err != nil {
		return err
	}
	return nil
}

// EnableRemoteManifestPush enables pushes to the remote manifest
// repository.
func (fake FakeJiriRoot) EnableRemoteManifestPush() error {
	dir := filepath.Join(fake.remote, ManifestProjectPath)
	scm := gitutil.New(fake.X, gitutil.RootDirOpt(dir))
	if ok, err := scm.BranchExists("non-master"); ok && err == nil {
		if err := scm.CreateBranch("non-master"); err != nil {
			return err
		}
	} else if err != nil {
		return err
	}
	if err := scm.CheckoutBranch("non-master"); err != nil {
		return err
	}
	return nil
}

// CreateRemoteProject creates a new remote project.
func (fake FakeJiriRoot) CreateRemoteProject(name string) error {
	projectDir := filepath.Join(fake.remote, name)
	if err := os.MkdirAll(projectDir, os.FileMode(0700)); err != nil {
		return err
	}
	if err := gitutil.New(fake.X).Init(projectDir); err != nil {
		return err
	}
	git := gitutil.New(fake.X, gitutil.RootDirOpt(projectDir))
	if err := git.Config("user.email", "john.doe@example.com"); err != nil {
		return err
	}
	if err := git.Config("user.name", "John Doe"); err != nil {
		return err
	}

	if err := git.CommitWithMessage("initial commit"); err != nil {
		return err
	}
	fake.Projects[name] = projectDir
	return nil
}

// ReadRemoteManifest read a manifest from the remote manifest project.
func (fake FakeJiriRoot) ReadRemoteManifest() (*project.Manifest, error) {
	path := filepath.Join(fake.remote, ManifestProjectPath, ManifestFileName)
	return project.ManifestFromFile(fake.X, path)
}

// UpdateUniverse synchronizes the content of the Vanadium fake based
// on the content of the remote manifest.
func (fake FakeJiriRoot) UpdateUniverse(gc bool) error {
	if err := project.UpdateUniverse(fake.X, gc, false, false, false, false, true /*run-hooks*/, project.DefaultHookTimeout); err != nil {
		return err
	}
	return nil
}

// ReadJiriManifest reads the .jiri_manifest manifest.
func (fake FakeJiriRoot) ReadJiriManifest() (*project.Manifest, error) {
	return project.ManifestFromFile(fake.X, fake.X.JiriManifestFile())
}

// WriteJiriManifest writes the given manifest to the .jiri_manifest file.
func (fake FakeJiriRoot) WriteJiriManifest(manifest *project.Manifest) error {
	return manifest.ToFile(fake.X, fake.X.JiriManifestFile())
}

// WriteRemoteManifest writes the given manifest to the remote
// manifest project.
func (fake FakeJiriRoot) WriteRemoteManifest(manifest *project.Manifest) error {
	dir := filepath.Join(fake.remote, ManifestProjectPath)
	path := filepath.Join(dir, ManifestFileName)
	return fake.writeManifest(manifest, dir, path)
}

func (fake FakeJiriRoot) writeManifest(manifest *project.Manifest, dir, path string) error {
	git := gitutil.New(fake.X, gitutil.UserNameOpt("John Doe"), gitutil.UserEmailOpt("john.doe@example.com"), gitutil.RootDirOpt(dir))
	if err := manifest.ToFile(fake.X, path); err != nil {
		return err
	}
	if err := git.Add(path); err != nil {
		return err
	}
	if err := git.Commit(); err != nil {
		return err
	}
	return nil
}