package git

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"

	"git.ar21.de/yolokube/grafana-backuper/pkg/grafana"
	"github.com/ProtonMail/go-crypto/openpgp"
	"github.com/go-git/go-billy/v5"
	"github.com/go-git/go-billy/v5/memfs"
	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/object"
	"github.com/go-git/go-git/v5/plumbing/transport/http"
	"github.com/go-git/go-git/v5/storage/memory"
)

var (
	fs     billy.Filesystem
	storer *memory.Storage
)

type Payload struct {
	Author        *object.Signature
	Committer     *object.Signature
	Content       []byte
	Dashboard     grafana.FoundBoard
	DashboardInfo grafana.BoardProperties
	Directory     string
	KeyFile       string
	Repository    *git.Repository
	Version       grafana.DashboardVersion
}

func NewPayload(keyFile string) *Payload {
	fs = memfs.New()
	storer = memory.NewStorage()

	return &Payload{
		Author:        nil,
		Committer:     nil,
		Content:       []byte{},
		Dashboard:     grafana.FoundBoard{},
		DashboardInfo: grafana.BoardProperties{},
		Directory:     "",
		KeyFile:       keyFile,
		Repository:    nil,
		Version:       grafana.DashboardVersion{},
	}
}

func (p *Payload) AddAuthor(name, email string) {
	p.Author = &object.Signature{
		Name:  name,
		Email: email,
		When:  time.Now(),
	}
}

func (p *Payload) UpdateAuthor(timestamp time.Time) {
	p.Author.When = timestamp
}

func (p *Payload) AddCommitter(name, email string) {
	p.Committer = &object.Signature{
		Name:  name,
		Email: email,
		When:  time.Now(),
	}
}

func (p *Payload) UpdateCommitter() {
	p.Committer.When = time.Now()
}

func (p *Payload) UpdateContent(content []byte) {
	p.Content = content
}

func (p *Payload) UpdateDashboard(dashboard grafana.FoundBoard) {
	p.Dashboard = dashboard
}

func (p *Payload) UpdateDashboardInfo(dashboardInfo grafana.BoardProperties) {
	p.DashboardInfo = dashboardInfo
}

func (p *Payload) UpdateVersion(version grafana.DashboardVersion) {
	p.Version = version
}

func (p *Payload) GetRepo(repoURL, user, password string) (err error) {
	p.Repository, err = git.Clone(
		storer,
		fs,
		&git.CloneOptions{
			Auth:     genAuth(user, password),
			URL:      repoURL,
			Progress: os.Stdout,
		},
	)

	p.Directory = filepath.Base(repoURL)

	return
}

func (p *Payload) IsVersionCommitted(branch string) bool {
	refName := plumbing.NewBranchReferenceName(branch)
	ref, err := p.Repository.Reference(refName, false)
	if err != nil {
		return false
	}

	commitIter, err := p.Repository.Log(&git.LogOptions{From: ref.Hash()})
	if err != nil {
		return false
	}

	err = commitIter.ForEach(func(commit *object.Commit) error {
		if strings.Contains(commit.Message, fmt.Sprintf("Update %s", p.Version.DashboardUID)) && strings.Contains(commit.Message, fmt.Sprintf("version %d", p.Version.ID)) {
			return fmt.Errorf("version already committed")
		}
		return nil
	})

	return err != nil
}

func genAuth(user, password string) *http.BasicAuth {
	return &http.BasicAuth{
		Username: user,
		Password: password,
	}
}

func commitDashboard(repo *git.Repository, content []byte, commitMsg, dashboardTitle, folderTitle, gitRepoDirectory, keyFile string, author, committer *object.Signature) (err error) {
	var (
		file     billy.File
		signer   *openpgp.Entity
		worktree *git.Worktree
	)

	if strings.TrimSpace(keyFile) != "" {
		signer, err = getSigner(keyFile)
		if err != nil {
			return
		}
	}

	worktree, err = repo.Worktree()
	if err != nil {
		return
	}

	if err = fs.MkdirAll(folderTitle, 0755); err != nil {
		return
	}

	filePath := filepath.Join(folderTitle, fmt.Sprintf("%s.json", dashboardTitle))
	if file, err = fs.Create(filePath); err != nil {
		return
	}

	if _, err = file.Write(content); err != nil {
		return
	}

	if err = file.Close(); err != nil {
		return
	}

	if _, err = worktree.Add(filePath); err != nil {
		return
	}

	_, err = worktree.Commit(
		commitMsg,
		&git.CommitOptions{
			Author:    author,
			Committer: committer,
			SignKey:   signer,
		},
	)

	return
}

func (p *Payload) CreateCommit() error {
	var commitmsg string

	if p.Version.Message != "" {
		commitmsg = fmt.Sprintf(
			"%s: Update %s to version %d => %s",
			p.Dashboard.Title,
			p.Version.DashboardUID,
			p.Version.ID,
			p.Version.Message,
		)
	} else {
		commitmsg = fmt.Sprintf(
			"%s: Update %s to version %d",
			p.Dashboard.Title,
			p.Version.DashboardUID,
			p.Version.ID,
		)
	}

	p.UpdateAuthor(p.Version.Created)
	p.UpdateCommitter()

	return commitDashboard(
		p.Repository,
		p.Content,
		commitmsg,
		p.Dashboard.Title,
		p.DashboardInfo.FolderTitle,
		p.Directory,
		p.KeyFile,
		p.Author,
		p.Committer,
	)
}

func (p *Payload) PushToRemote(user, password string) error {
	origin, err := p.Repository.Remote("origin")
	if err != nil {
		return err
	}

	return origin.Push(
		&git.PushOptions{
			Auth:     genAuth(user, password),
			Progress: os.Stdout,
		},
	)
}