package commands

import (
	"fmt"
	"os"
	"testing"

	"github.com/go-git/go-billy/v5"
	"github.com/go-git/go-billy/v5/memfs"
	"github.com/go-git/go-billy/v5/osfs"
	"github.com/go-git/go-git/v5"
	gitcfg "github.com/go-git/go-git/v5/config"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/cache"
	"github.com/go-git/go-git/v5/storage/filesystem"
	"github.com/go-git/go-git/v5/storage/memory"
	"gitlab.com/revalus/grm/config"
)

type TestDir struct {
	rootFS         billy.Filesystem
	baseRepository struct {
		fileSystem billy.Filesystem
		repo       *git.Repository
	}
}

func getTestDirForTests() TestDir {

	checkError := func(err error) {
		if err != nil {
			fmt.Printf("During preparing repositories, an error occurred: %v\n", err)
			os.Exit(4)
		}
	}

	baseTMPPath := fmt.Sprintf("%v/grmTest", os.TempDir())
	if _, ok := os.Stat(baseTMPPath); ok != nil {
		err := os.Mkdir(baseTMPPath, 0777)
		checkError(err)
	}

	tmpDir, err := os.MkdirTemp(baseTMPPath, "*")
	checkError(err)

	baseFileSystem := osfs.New(tmpDir)

	initRepositoryFileSystem, err := baseFileSystem.Chroot("worktree")
	checkError(err)

	directoryForGitMetadata, err := initRepositoryFileSystem.Chroot(".git")
	checkError(err)

	repository, err := git.Init(filesystem.NewStorage(directoryForGitMetadata, cache.NewObjectLRUDefault()), initRepositoryFileSystem)
	checkError(err)

	fileForFirstCommit, err := initRepositoryFileSystem.Create("TestFile.txt")
	checkError(err)

	_, err = fileForFirstCommit.Write([]byte("foo-conent"))
	checkError(err)

	repositoryWorkTree, err := repository.Worktree()
	checkError(err)

	repositoryWorkTree.Add(fileForFirstCommit.Name())
	_, err = repositoryWorkTree.Commit("First commit", &git.CommitOptions{})

	checkError(err)

	return TestDir{
		baseRepository: struct {
			fileSystem billy.Filesystem
			repo       *git.Repository
		}{
			fileSystem: initRepositoryFileSystem,
			repo:       repository,
		},
		rootFS: baseFileSystem,
	}

}

func unexpectedError(err error, t *testing.T) {
	if err != nil {
		t.Errorf("Unexpected error %v", err)
	}
}

func makeCommit(wk *git.Worktree, commitMessage string, fileName string) error {

	wk.Commit(commitMessage, &git.CommitOptions{})
	return nil
}

func TestIfBranchesAreEqual(t *testing.T) {
	tmpDirWithInitialRepository := getTestDirForTests()

	fakeLocalRepo, err := git.Clone(memory.NewStorage(), memfs.New(), &git.CloneOptions{
		URL: tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
	})
	unexpectedError(err, t)

	currentReference, err := fakeLocalRepo.Head()
	unexpectedError(err, t)

	remote, err := fakeLocalRepo.Remote("origin")
	unexpectedError(err, t)

	remoteRevision, err := fakeLocalRepo.ResolveRevision(plumbing.Revision(fmt.Sprintf("%v/%v", remote.Config().Name, currentReference.Name().Short())))
	unexpectedError(err, t)

	currentBranchCommit, err := fakeLocalRepo.CommitObject(currentReference.Hash())
	unexpectedError(err, t)

	remoteBranchCommit, err := fakeLocalRepo.CommitObject(*remoteRevision)
	unexpectedError(err, t)

	result := findNumberOfCommitDiffs(currentBranchCommit, remoteBranchCommit)
	if result != 0 {
		t.Errorf("Expected to get 0 changes, instead of this got %v", result)
	}
}

func TestIfCurrentBranchIsAbove(t *testing.T) {

	tmpDirWithInitialRepository := getTestDirForTests()
	tmpFileSystemForLocalRepository := memfs.New()
	fakeLocalRepo, err := git.Clone(memory.NewStorage(), tmpFileSystemForLocalRepository, &git.CloneOptions{
		URL: tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
	})
	unexpectedError(err, t)

	localWorktree, err := fakeLocalRepo.Worktree()
	unexpectedError(err, t)

	err = makeCommit(localWorktree, "commit 1", "Commit1")
	unexpectedError(err, t)

	localReference, err := fakeLocalRepo.Head()
	unexpectedError(err, t)

	remoteConnection, err := fakeLocalRepo.Remote("origin")
	unexpectedError(err, t)

	remoteRevision, err := fakeLocalRepo.ResolveRevision(plumbing.Revision(fmt.Sprintf("%v/%v", remoteConnection.Config().Name, localReference.Name().Short())))
	unexpectedError(err, t)

	currentBranchCommit, err := fakeLocalRepo.CommitObject(localReference.Hash())
	unexpectedError(err, t)

	remoteBranchCommit, err := fakeLocalRepo.CommitObject(*remoteRevision)
	unexpectedError(err, t)

	result := findNumberOfCommitDiffs(currentBranchCommit, remoteBranchCommit)
	if result != 1 {
		t.Errorf("Expected to get 1 changes, instead of this got %v", result)
	}

	for i := 1; i < 15; i++ {
		err = makeCommit(localWorktree, fmt.Sprintf("Commit +%v", i), fmt.Sprintf("Commit%v", i))
		unexpectedError(err, t)
	}

	localReference, err = fakeLocalRepo.Head()
	unexpectedError(err, t)

	currentBranchCommit, err = fakeLocalRepo.CommitObject(localReference.Hash())
	unexpectedError(err, t)

	result = findNumberOfCommitDiffs(currentBranchCommit, remoteBranchCommit)
	if result != 15 {
		t.Errorf("Expected to get 5 changes, instead of this got %v", result)
	}
}

func TestCommandRepositoryDoesNotExists(t *testing.T) {

	tmpDirWithInitialRepository := getTestDirForTests()

	fileSystemForLocalRepo, err := tmpDirWithInitialRepository.rootFS.Chroot("NotMatterValue")
	unexpectedError(err, t)

	directoryForLocalRepoMetadata, err := fileSystemForLocalRepo.Chroot(".git")
	unexpectedError(err, t)

	storageForTestRepo := filesystem.NewStorage(directoryForLocalRepoMetadata, cache.NewObjectLRUDefault())
	_, err = git.Clone(storageForTestRepo, fileSystemForLocalRepo, &git.CloneOptions{
		URL: tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
	})
	unexpectedError(err, t)

	sc := StatusChecker{
		workspace: tmpDirWithInitialRepository.rootFS.Root(),
	}

	repoCfg := config.RepositoryConfig{
		Name: "test",
		Src:  tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
		Dest: tmpDirWithInitialRepository.rootFS.Root(),
	}

	ch := make(chan CommandStatus)
	go sc.Command(repoCfg, ch)
	repoStatus := <-ch
	expectedMessage := "repository does not exist"

	if !repoStatus.Error {
		t.Errorf("Expected error")
	}
	if repoStatus.Changed {
		t.Errorf("Unexpected change value")
	}
	if repoStatus.Message != expectedMessage {
		t.Errorf("Expected to get \"%v\", instead of this got \"%v\"", expectedMessage, repoStatus.Message)
	}
}

func TestCommandRepositoryNoRemoteBranch(t *testing.T) {

	tmpDirWithInitialRepository := getTestDirForTests()
	dirNameForLocalRepository := "testRepo"
	fileSystemForLocalRepo, err := tmpDirWithInitialRepository.rootFS.Chroot(dirNameForLocalRepository)
	unexpectedError(err, t)

	directoryForLocalRepoMetadata, err := fileSystemForLocalRepo.Chroot(".git")
	unexpectedError(err, t)

	storageForTestRepo := filesystem.NewStorage(directoryForLocalRepoMetadata, cache.NewObjectLRUDefault())
	fakeLocalRepository, err := git.Clone(storageForTestRepo, fileSystemForLocalRepo, &git.CloneOptions{
		URL: tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
	})
	unexpectedError(err, t)

	err = fakeLocalRepository.DeleteRemote("origin")
	unexpectedError(err, t)

	sc := StatusChecker{
		workspace: tmpDirWithInitialRepository.rootFS.Root(),
	}

	repoCfg := config.RepositoryConfig{
		Name: "test",
		Src:  tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
		Dest: dirNameForLocalRepository,
	}

	ch := make(chan CommandStatus)
	go sc.Command(repoCfg, ch)
	repoStatus := <-ch
	expectedMessage := "cannot find remote branches"

	if !repoStatus.Error {
		t.Errorf("Expected error")
	}
	if repoStatus.Changed {
		t.Errorf("Unexpected change value")
	}

	if repoStatus.Message != expectedMessage {
		t.Errorf("Expected to get \"%v\", instead of this got \"%v\"", expectedMessage, repoStatus.Message)
	}
}

func TestCommandAllCorrect(t *testing.T) {

	tmpDirWithInitialRepository := getTestDirForTests()
	dirNameForLocalRepository := "testRepo"
	fileSystemForLocalRepo, err := tmpDirWithInitialRepository.rootFS.Chroot(dirNameForLocalRepository)
	unexpectedError(err, t)

	directoryForLocalRepoMetadata, err := fileSystemForLocalRepo.Chroot(".git")
	unexpectedError(err, t)

	storageForTestRepo := filesystem.NewStorage(directoryForLocalRepoMetadata, cache.NewObjectLRUDefault())
	fakeLocalRepository, err := git.Clone(storageForTestRepo, fileSystemForLocalRepo, &git.CloneOptions{
		URL: tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
	})
	unexpectedError(err, t)

	sc := StatusChecker{
		workspace: tmpDirWithInitialRepository.rootFS.Root(),
	}
	repoCfg := config.RepositoryConfig{
		Name: "test",
		Src:  tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
		Dest: dirNameForLocalRepository,
	}

	ch := make(chan CommandStatus)

	go sc.Command(repoCfg, ch)
	repoStatus := <-ch
	expectedMessage := "branch master - ( | origin | \u21910 \u21930 )"

	if repoStatus.Error {
		t.Errorf("Unexpected error")
		t.Errorf("Message %v", repoStatus.Message)
	}
	if repoStatus.Changed {
		t.Errorf("Expeected that changed will be true")
	}
	if repoStatus.Message != expectedMessage {
		t.Errorf("Expected to get \"%v\", instead of this got \"%v\"", expectedMessage, repoStatus.Message)
	}

	fakeLocalWorkTree, err := fakeLocalRepository.Worktree()
	unexpectedError(err, t)

	err = makeCommit(fakeLocalWorkTree, "commit 1", "Commit1")
	unexpectedError(err, t)

	go sc.Command(repoCfg, ch)
	repoStatus = <-ch
	expectedMessage = "branch master - ( | origin | \u21911 \u21930 )"

	if repoStatus.Message != expectedMessage {
		t.Errorf("Expected to get \"%v\", instead of this got \"%v\"", expectedMessage, repoStatus.Message)
	}
	if repoStatus.Error {
		t.Errorf("Unexpected error")
		t.Errorf("Message %v", repoStatus.Message)
	}
	if !repoStatus.Changed {
		t.Errorf("Expeected that changed will be true")
	}
	if repoStatus.Message != expectedMessage {
		t.Errorf("Expected to get \"%v\", instead of this got \"%v\"", expectedMessage, repoStatus.Message)
	}
}

func TestCommandMultiRemote(t *testing.T) {

	tmpDirWithInitialRepository := getTestDirForTests()
	dirNameForLocalRepository := "testRepo"
	fileSystemForLocalRepo, err := tmpDirWithInitialRepository.rootFS.Chroot(dirNameForLocalRepository)
	unexpectedError(err, t)

	directoryForLocalRepoMetadata, err := fileSystemForLocalRepo.Chroot(".git")
	unexpectedError(err, t)

	storageForTestRepo := filesystem.NewStorage(directoryForLocalRepoMetadata, cache.NewObjectLRUDefault())
	fakeLocalRepository, err := git.Clone(storageForTestRepo, fileSystemForLocalRepo, &git.CloneOptions{
		URL: tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
	})
	unexpectedError(err, t)

	fakeLocalRepository.CreateRemote(&gitcfg.RemoteConfig{
		Name: "subremote",
		URLs: []string{tmpDirWithInitialRepository.baseRepository.fileSystem.Root()},
	})

	fakeLocalRepository.Fetch(&git.FetchOptions{
		RemoteName: "subremote",
	})

	sc := StatusChecker{
		workspace: tmpDirWithInitialRepository.rootFS.Root(),
	}
	repoCfg := config.RepositoryConfig{
		Name: "test",
		Src:  tmpDirWithInitialRepository.baseRepository.fileSystem.Root(),
		Dest: dirNameForLocalRepository,
	}

	ch := make(chan CommandStatus)

	go sc.Command(repoCfg, ch)
	repoStatus := <-ch
	expectedMessage := "branch master - ( | origin | \u21910 \u21930 ) - ( | subremote | \u21910 \u21930 )"

	if repoStatus.Error {
		t.Errorf("Unexpected error")
		t.Errorf("Message %v", repoStatus.Message)
	}
	if repoStatus.Changed {
		t.Errorf("Expeected that changed will be true")
	}
	if repoStatus.Message != expectedMessage {
		t.Errorf("Expected to get \"%v\", instead of this got \"%v\"", expectedMessage, repoStatus.Message)
	}

	fakeLocalWorkTree, err := fakeLocalRepository.Worktree()
	unexpectedError(err, t)

	err = makeCommit(fakeLocalWorkTree, "commit 1", "Commit1")
	unexpectedError(err, t)

	go sc.Command(repoCfg, ch)
	repoStatus = <-ch
	expectedMessage = "branch master - ( | origin | \u21911 \u21930 ) - ( | subremote | \u21911 \u21930 )"

	if repoStatus.Error {
		t.Errorf("Unexpected error")
		t.Errorf("Message %v", repoStatus.Message)
	}
	if !repoStatus.Changed {
		t.Errorf("Expeected that changed will be true")
	}
	if repoStatus.Message != expectedMessage {
		t.Errorf("Expected to get \"%v\", instead of this got \"%v\"", expectedMessage, repoStatus.Message)
	}
}