package gitops

import (
	"context"
	"crypto/aes"
	"crypto/cipher"
	"crypto/hmac"
	"crypto/rand"
	"crypto/sha256"
	"database/sql"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"sort"
	"strings"
	"sync"
	"time"

	"git.send.nrw/sendnrw/dockwatch/internal/nodes"
	"git.send.nrw/sendnrw/dockwatch/internal/stacks"
)

var stackNameRx = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$`)

type Source struct {
	ID          int64  `json:"id"`
	NodeID      *int64 `json:"node_id,omitempty"`
	StackName   string `json:"stack_name"`
	RepoURL     string `json:"repo_url"`
	Branch      string `json:"branch"`
	Workdir     string `json:"workdir"`
	ComposeFile string `json:"compose_file"`
	AutoDeploy  bool   `json:"auto_deploy"`
	LastCommit  string `json:"last_commit"`
	LastSyncAt  *int64 `json:"last_sync_at,omitempty"`
	LastError   string `json:"last_error"`
	CreatedAt   int64  `json:"created_at"`
	UpdatedAt   int64  `json:"updated_at"`
}
type Input struct {
	NodeID      *int64 `json:"node_id"`
	StackName   string `json:"stack_name"`
	RepoURL     string `json:"repo_url"`
	Branch      string `json:"branch"`
	Workdir     string `json:"workdir"`
	ComposeFile string `json:"compose_file"`
	AutoDeploy  bool   `json:"auto_deploy"`
}
type Service struct {
	db     *sql.DB
	key    []byte
	stacks *stacks.Service
	nodes  *nodes.Manager
	locks  sync.Map
}

func New(db *sql.DB, key []byte, ss *stacks.Service, nm *nodes.Manager) *Service {
	return &Service{db: db, key: key, stacks: ss, nodes: nm}
}
func normalize(in *Input) error {
	in.StackName = strings.TrimSpace(in.StackName)
	in.RepoURL = strings.TrimSpace(in.RepoURL)
	in.Branch = strings.TrimSpace(in.Branch)
	in.Workdir = filepath.Clean(strings.TrimSpace(in.Workdir))
	in.ComposeFile = filepath.Clean(strings.TrimSpace(in.ComposeFile))
	if in.StackName == "" || in.RepoURL == "" {
		return errors.New("stack_name and repo_url required")
	}
	if !stackNameRx.MatchString(in.StackName) || strings.ContainsAny(in.RepoURL, "\r\n") || strings.HasPrefix(in.RepoURL, "-") {
		return errors.New("invalid stack name or repository URL")
	}
	if len(in.RepoURL) > 4096 || len(in.Branch) > 255 || strings.ContainsAny(in.Branch, "\r\n") {
		return errors.New("git source fields too long")
	}
	if in.Branch == "" {
		in.Branch = "main"
	}
	if in.Workdir == "." || in.Workdir == "" {
		in.Workdir = "."
	}
	if strings.HasPrefix(in.Workdir, "..") || filepath.IsAbs(in.Workdir) {
		return errors.New("invalid workdir")
	}
	if in.ComposeFile == "." || in.ComposeFile == "" {
		in.ComposeFile = "compose.yaml"
	}
	if strings.HasPrefix(in.ComposeFile, "..") || filepath.IsAbs(in.ComposeFile) {
		return errors.New("invalid compose_file")
	}
	return nil
}
func (s *Service) List(ctx context.Context) ([]Source, error) {
	rows, e := s.db.QueryContext(ctx, `SELECT id,node_id,stack_name,repo_url,branch,workdir,compose_file,auto_deploy,last_commit,last_sync_at,last_error,created_at,updated_at FROM git_sources ORDER BY stack_name`)
	if e != nil {
		return nil, e
	}
	defer rows.Close()
	out := []Source{}
	for rows.Next() {
		var x Source
		var sync, node sql.NullInt64
		if e := rows.Scan(&x.ID, &node, &x.StackName, &x.RepoURL, &x.Branch, &x.Workdir, &x.ComposeFile, &x.AutoDeploy, &x.LastCommit, &sync, &x.LastError, &x.CreatedAt, &x.UpdatedAt); e != nil {
			return nil, e
		}
		if node.Valid {
			v := node.Int64
			x.NodeID = &v
		}
		if sync.Valid {
			v := sync.Int64
			x.LastSyncAt = &v
		}
		out = append(out, x)
	}
	return out, rows.Err()
}
func (s *Service) Get(ctx context.Context, id int64) (Source, error) {
	var x Source
	var sync, node sql.NullInt64
	e := s.db.QueryRowContext(ctx, `SELECT id,node_id,stack_name,repo_url,branch,workdir,compose_file,auto_deploy,last_commit,last_sync_at,last_error,created_at,updated_at FROM git_sources WHERE id=?`, id).Scan(&x.ID, &node, &x.StackName, &x.RepoURL, &x.Branch, &x.Workdir, &x.ComposeFile, &x.AutoDeploy, &x.LastCommit, &sync, &x.LastError, &x.CreatedAt, &x.UpdatedAt)
	if node.Valid {
		v := node.Int64
		x.NodeID = &v
	}
	if sync.Valid {
		v := sync.Int64
		x.LastSyncAt = &v
	}
	return x, e
}
func (s *Service) Create(ctx context.Context, in Input) (Source, string, error) {
	if e := normalize(&in); e != nil {
		return Source{}, "", e
	}
	secret := make([]byte, 32)
	if _, e := rand.Read(secret); e != nil {
		return Source{}, "", e
	}
	sec := hex.EncodeToString(secret)
	enc, e := s.encrypt([]byte(sec))
	if e != nil {
		return Source{}, "", e
	}
	now := time.Now().Unix()
	r, e := s.db.ExecContext(ctx, `INSERT INTO git_sources(node_id,stack_name,repo_url,branch,workdir,compose_file,auto_deploy,webhook_secret_enc,last_commit,last_error,created_at,updated_at) VALUES(?,?,?,?,?,?,?,?,'','',?,?)`, in.NodeID, in.StackName, in.RepoURL, in.Branch, in.Workdir, in.ComposeFile, in.AutoDeploy, enc, now, now)
	if e != nil {
		return Source{}, "", e
	}
	id, _ := r.LastInsertId()
	x, e := s.Get(ctx, id)
	return x, sec, e
}
func (s *Service) Update(ctx context.Context, id int64, in Input) (Source, error) {
	if e := normalize(&in); e != nil {
		return Source{}, e
	}
	now := time.Now().Unix()
	r, e := s.db.ExecContext(ctx, `UPDATE git_sources SET node_id=?,stack_name=?,repo_url=?,branch=?,workdir=?,compose_file=?,auto_deploy=?,updated_at=? WHERE id=?`, in.NodeID, in.StackName, in.RepoURL, in.Branch, in.Workdir, in.ComposeFile, in.AutoDeploy, now, id)
	if e != nil {
		return Source{}, e
	}
	n, _ := r.RowsAffected()
	if n == 0 {
		return Source{}, sql.ErrNoRows
	}
	return s.Get(ctx, id)
}
func (s *Service) Delete(ctx context.Context, id int64) error {
	_, e := s.db.ExecContext(ctx, `DELETE FROM git_sources WHERE id=?`, id)
	return e
}
func (s *Service) RotateSecret(ctx context.Context, id int64) (string, error) {
	secret := make([]byte, 32)
	if _, e := rand.Read(secret); e != nil {
		return "", e
	}
	sec := hex.EncodeToString(secret)
	enc, e := s.encrypt([]byte(sec))
	if e != nil {
		return "", e
	}
	_, e = s.db.ExecContext(ctx, `UPDATE git_sources SET webhook_secret_enc=?,updated_at=? WHERE id=?`, enc, time.Now().Unix(), id)
	return sec, e
}
func (s *Service) VerifyWebhook(ctx context.Context, id int64, body []byte, signature, token string) error {
	var enc []byte
	if e := s.db.QueryRowContext(ctx, `SELECT webhook_secret_enc FROM git_sources WHERE id=?`, id).Scan(&enc); e != nil {
		return e
	}
	plain, e := s.decrypt(enc)
	if e != nil {
		return e
	}
	secret := string(plain)
	if token != "" && hmac.Equal([]byte(token), []byte(secret)) {
		return nil
	}
	signature = strings.TrimPrefix(signature, "sha256=")
	if signature != "" {
		mac := hmac.New(sha256.New, []byte(secret))
		_, _ = mac.Write(body)
		want := hex.EncodeToString(mac.Sum(nil))
		if hmac.Equal([]byte(strings.ToLower(signature)), []byte(want)) {
			return nil
		}
	}
	return errors.New("invalid webhook signature")
}
func (s *Service) lockFor(id int64) *sync.Mutex {
	v, _ := s.locks.LoadOrStore(id, &sync.Mutex{})
	return v.(*sync.Mutex)
}

func (s *Service) Sync(ctx context.Context, id int64) (Source, error) {
	mu := s.lockFor(id)
	mu.Lock()
	defer mu.Unlock()
	x, e := s.Get(ctx, id)
	if e != nil {
		return x, e
	}
	in := Input{NodeID: x.NodeID, StackName: x.StackName, RepoURL: x.RepoURL, Branch: x.Branch, Workdir: x.Workdir, ComposeFile: x.ComposeFile, AutoDeploy: x.AutoDeploy}
	var commit string
	if x.NodeID != nil {
		if s.nodes == nil {
			return s.syncFailed(ctx, x, errors.New("node manager unavailable"))
		}
		b, _, err := s.nodes.Do(ctx, *x.NodeID, "POST", "/agent/v1/git/sync", in)
		if err != nil {
			return s.syncFailed(ctx, x, err)
		}
		var resp struct {
			Commit string `json:"commit"`
		}
		if err = json.Unmarshal(b, &resp); err != nil {
			return s.syncFailed(ctx, x, err)
		}
		commit = resp.Commit
	} else {
		commit, e = s.SyncTransient(ctx, in)
		if e != nil {
			return s.syncFailed(ctx, x, e)
		}
	}
	now := time.Now().Unix()
	_, _ = s.db.ExecContext(ctx, `UPDATE git_sources SET last_commit=?,last_sync_at=?,last_error='',updated_at=? WHERE id=?`, commit, now, now, id)
	return s.Get(ctx, id)
}

// SyncTransient performs a Git-backed stack synchronization on the current
// Docker environment. Agents expose this operation to the master without
// persisting Git source metadata locally.
func (s *Service) SyncTransient(ctx context.Context, in Input) (string, error) {
	if e := normalize(&in); e != nil {
		return "", e
	}
	tmp, e := os.MkdirTemp("", "dockwatch-git-*")
	if e != nil {
		return "", e
	}
	defer os.RemoveAll(tmp)
	cloneDir := filepath.Join(tmp, "repo")
	cctx, cancel := context.WithTimeout(ctx, 3*time.Minute)
	defer cancel()
	cmd := exec.CommandContext(cctx, "git", "clone", "--depth", "1", "--branch", in.Branch, "--single-branch", in.RepoURL, cloneDir)
	out, e := cmd.CombinedOutput()
	if e != nil {
		return "", fmt.Errorf("git clone: %w: %s", e, strings.TrimSpace(string(out)))
	}
	commitRaw, e := exec.CommandContext(cctx, "git", "-C", cloneDir, "rev-parse", "HEAD").Output()
	if e != nil {
		return "", e
	}
	src := filepath.Join(cloneDir, in.Workdir)
	if fi, e := os.Stat(src); e != nil || !fi.IsDir() {
		return "", errors.New("git workdir not found")
	}
	if _, e := os.Stat(filepath.Join(src, in.ComposeFile)); e != nil {
		return "", fmt.Errorf("compose file not found: %s", in.ComposeFile)
	}
	dst := filepath.Join(s.stacks.Root(), in.StackName)
	stage := filepath.Join(tmp, "stage")
	if e := copyDir(src, stage); e != nil {
		return "", e
	}
	if filepath.Clean(in.ComposeFile) != "compose.yaml" {
		b, e := os.ReadFile(filepath.Join(stage, in.ComposeFile))
		if e != nil {
			return "", e
		}
		if e = os.WriteFile(filepath.Join(stage, "compose.yaml"), b, 0640); e != nil {
			return "", e
		}
	}
	if e := s.stacks.ValidateProject(ctx, in.StackName, stage, "compose.yaml"); e != nil {
		return "", e
	}
	if e := syncManagedTree(stage, dst); e != nil {
		return "", e
	}
	if in.AutoDeploy {
		if _, e = s.stacks.Action(ctx, in.StackName, "up"); e != nil {
			return "", e
		}
	}
	return strings.TrimSpace(string(commitRaw)), nil
}

func (s *Service) syncFailed(ctx context.Context, x Source, e error) (Source, error) {
	_, _ = s.db.ExecContext(ctx, `UPDATE git_sources SET last_error=?,updated_at=? WHERE id=?`, e.Error(), time.Now().Unix(), x.ID)
	x.LastError = e.Error()
	return x, e
}

const gitManifestPath = ".dockwatch/git-manifest.json"

type gitManifest struct {
	Files []string `json:"files"`
}

// syncManagedTree applies a Git checkout without treating the stack directory as
// disposable storage. Only files previously managed by Git and files present in
// the new checkout are changed. Unrelated files (for example bind-mount data)
// survive a sync. The touched files are snapshotted so a failed apply can be
// rolled back without copying or deleting the whole stack directory.
func syncManagedTree(stage, dst string) error {
	files, err := collectManagedFiles(stage)
	if err != nil {
		return err
	}
	if err := ensureSafeRoot(dst); err != nil {
		return err
	}
	old, err := readGitManifest(dst)
	if err != nil {
		return err
	}
	backup, err := os.MkdirTemp("", "dockwatch-git-rollback-*")
	if err != nil {
		return err
	}
	defer os.RemoveAll(backup)

	affected := map[string]struct{}{}
	for _, rel := range old {
		affected[rel] = struct{}{}
	}
	for _, rel := range files {
		affected[rel] = struct{}{}
	}
	manifestAbs := filepath.Join(dst, filepath.FromSlash(gitManifestPath))
	manifestBackup := filepath.Join(backup, "manifest.json")
	manifestExisted := false
	if info, err := os.Lstat(manifestAbs); err == nil {
		if !info.Mode().IsRegular() {
			return errors.New("Git manifest path is not a regular file")
		}
		if err := copyRegularFile(manifestAbs, manifestBackup, info.Mode().Perm()); err != nil {
			return err
		}
		manifestExisted = true
	} else if !os.IsNotExist(err) {
		return err
	}

	backedUp := map[string]bool{}
	for rel := range affected {
		target, err := safeManagedPath(dst, rel)
		if err != nil {
			return err
		}
		if err := ensureSafeParent(dst, filepath.Dir(target)); err != nil {
			return err
		}
		info, err := os.Lstat(target)
		if os.IsNotExist(err) {
			continue
		}
		if err != nil {
			return err
		}
		if info.Mode()&os.ModeSymlink != 0 {
			return fmt.Errorf("refusing to replace symlink in Git-managed path %q", rel)
		}
		if info.Mode().IsRegular() {
			bp := filepath.Join(backup, filepath.FromSlash(rel))
			if err := copyRegularFile(target, bp, info.Mode().Perm()); err != nil {
				return err
			}
			backedUp[rel] = true
		}
	}

	rollback := func() {
		for rel := range affected {
			target, err := safeManagedPath(dst, rel)
			if err != nil {
				continue
			}
			if info, err := os.Lstat(target); err == nil && info.Mode().IsRegular() {
				_ = os.Remove(target)
			}
			if backedUp[rel] {
				bp := filepath.Join(backup, filepath.FromSlash(rel))
				if info, err := os.Stat(bp); err == nil {
					_ = copyRegularFile(bp, target, info.Mode().Perm())
				}
			}
		}
		_ = os.Remove(manifestAbs)
		if manifestExisted {
			if info, err := os.Stat(manifestBackup); err == nil {
				_ = copyRegularFile(manifestBackup, manifestAbs, info.Mode().Perm())
			}
		}
	}

	newSet := make(map[string]struct{}, len(files))
	for _, rel := range files {
		newSet[rel] = struct{}{}
	}
	// Remove files that disappeared from Git, but never recursively remove a
	// directory. This deliberately leaves unrelated data untouched.
	for _, rel := range old {
		if _, ok := newSet[rel]; ok {
			continue
		}
		target, err := safeManagedPath(dst, rel)
		if err != nil {
			rollback()
			return err
		}
		if info, err := os.Lstat(target); err == nil {
			if info.Mode()&os.ModeSymlink != 0 || (!info.Mode().IsRegular() && !info.IsDir()) {
				rollback()
				return fmt.Errorf("refusing to remove non-regular Git-managed path %q", rel)
			}
			if info.Mode().IsRegular() {
				if err := os.Remove(target); err != nil {
					rollback()
					return err
				}
			}
		} else if !os.IsNotExist(err) {
			rollback()
			return err
		}
	}

	for _, rel := range files {
		source, err := safeManagedPath(stage, rel)
		if err != nil {
			rollback()
			return err
		}
		target, err := safeManagedPath(dst, rel)
		if err != nil {
			rollback()
			return err
		}
		if err := ensureSafeParent(dst, filepath.Dir(target)); err != nil {
			rollback()
			return err
		}
		if info, err := os.Lstat(target); err == nil && info.IsDir() {
			// A file replacing a directory is safe only when that directory is
			// empty. os.Remove intentionally refuses non-empty directories.
			if err := os.Remove(target); err != nil {
				rollback()
				return fmt.Errorf("Git file %q conflicts with existing directory containing unmanaged data: %w", rel, err)
			}
		} else if err == nil && info.Mode()&os.ModeSymlink != 0 {
			rollback()
			return fmt.Errorf("refusing to replace symlink in Git-managed path %q", rel)
		} else if err != nil && !os.IsNotExist(err) {
			rollback()
			return err
		}
		info, err := os.Stat(source)
		if err != nil {
			rollback()
			return err
		}
		if err := copyRegularFile(source, target, info.Mode().Perm()); err != nil {
			rollback()
			return err
		}
	}

	if err := writeGitManifest(dst, files); err != nil {
		rollback()
		return err
	}
	return nil
}

func collectManagedFiles(root string) ([]string, error) {
	out := []string{}
	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if path == root {
			return nil
		}
		rel, err := filepath.Rel(root, path)
		if err != nil {
			return err
		}
		rel = filepath.ToSlash(rel)
		if rel == gitManifestPath {
			return nil
		}
		if info.Mode()&os.ModeSymlink != 0 {
			return fmt.Errorf("Git stack contains unsupported symlink %q", rel)
		}
		if info.IsDir() {
			return nil
		}
		if info.Mode().IsRegular() {
			out = append(out, rel)
		}
		return nil
	})
	if err != nil {
		return nil, err
	}
	sort.Strings(out)
	return out, nil
}

func readGitManifest(dst string) ([]string, error) {
	path := filepath.Join(dst, filepath.FromSlash(gitManifestPath))
	if err := ensureSafeParent(dst, filepath.Dir(path)); err != nil {
		return nil, err
	}
	b, err := os.ReadFile(path)
	if os.IsNotExist(err) {
		return []string{}, nil
	}
	if err != nil {
		return nil, err
	}
	var m gitManifest
	if err := json.Unmarshal(b, &m); err != nil {
		return nil, fmt.Errorf("invalid Git-managed file manifest: %w", err)
	}
	out := make([]string, 0, len(m.Files))
	seen := map[string]bool{}
	for _, rel := range m.Files {
		rel = filepath.ToSlash(filepath.Clean(filepath.FromSlash(rel)))
		if rel == "." || rel == gitManifestPath || strings.HasPrefix(rel, "../") || filepath.IsAbs(filepath.FromSlash(rel)) || seen[rel] {
			continue
		}
		seen[rel] = true
		out = append(out, rel)
	}
	return out, nil
}

func writeGitManifest(dst string, files []string) error {
	path := filepath.Join(dst, filepath.FromSlash(gitManifestPath))
	if err := ensureSafeParent(dst, filepath.Dir(path)); err != nil {
		return err
	}
	b, err := json.MarshalIndent(gitManifest{Files: files}, "", "  ")
	if err != nil {
		return err
	}
	f, err := os.CreateTemp(filepath.Dir(path), ".dockwatch-git-manifest-*")
	if err != nil {
		return err
	}
	tmp := f.Name()
	defer os.Remove(tmp)
	if err := f.Chmod(0640); err != nil {
		_ = f.Close()
		return err
	}
	if _, err := f.Write(append(b, '\n')); err != nil {
		_ = f.Close()
		return err
	}
	if err := f.Sync(); err != nil {
		_ = f.Close()
		return err
	}
	if err := f.Close(); err != nil {
		return err
	}
	return os.Rename(tmp, path)
}

func safeManagedPath(root, rel string) (string, error) {
	rel = filepath.Clean(filepath.FromSlash(rel))
	if rel == "." || filepath.IsAbs(rel) || rel == ".." || strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
		return "", errors.New("invalid Git-managed path")
	}
	return filepath.Join(root, rel), nil
}

func ensureSafeRoot(root string) error {
	info, err := os.Lstat(root)
	if os.IsNotExist(err) {
		return os.MkdirAll(root, 0750)
	}
	if err != nil {
		return err
	}
	if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() {
		return errors.New("Git stack destination must be a real directory")
	}
	return nil
}

func ensureSafeParent(root, parent string) error {
	rel, err := filepath.Rel(root, parent)
	if err != nil || rel == ".." || strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
		return errors.New("path escapes stack root")
	}
	cur := root
	if err := ensureSafeRoot(root); err != nil {
		return err
	}
	if rel == "." {
		return nil
	}
	for _, part := range strings.Split(rel, string(os.PathSeparator)) {
		cur = filepath.Join(cur, part)
		info, err := os.Lstat(cur)
		if os.IsNotExist(err) {
			if err := os.Mkdir(cur, 0750); err != nil && !os.IsExist(err) {
				return err
			}
			continue
		}
		if err != nil {
			return err
		}
		if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() {
			return fmt.Errorf("unsafe parent path %q", cur)
		}
	}
	return nil
}

func copyRegularFile(src, dst string, mode os.FileMode) error {
	if err := os.MkdirAll(filepath.Dir(dst), 0750); err != nil {
		return err
	}
	in, err := os.Open(src)
	if err != nil {
		return err
	}
	tmp, err := os.CreateTemp(filepath.Dir(dst), ".dockwatch-git-write-*")
	if err != nil {
		_ = in.Close()
		return err
	}
	tmpName := tmp.Name()
	defer os.Remove(tmpName)
	if err := tmp.Chmod(mode); err != nil {
		_ = in.Close()
		_ = tmp.Close()
		return err
	}
	_, copyErr := io.Copy(tmp, in)
	inErr := in.Close()
	if copyErr == nil {
		copyErr = tmp.Sync()
	}
	outErr := tmp.Close()
	if copyErr != nil {
		return copyErr
	}
	if inErr != nil {
		return inErr
	}
	if outErr != nil {
		return outErr
	}
	return os.Rename(tmpName, dst)
}

func copyDir(src, dst string) error {
	return filepath.Walk(src, func(path string, info os.FileInfo, e error) error {
		if e != nil {
			return e
		}
		rel, e := filepath.Rel(src, path)
		if e != nil {
			return e
		}
		if rel == ".git" || strings.HasPrefix(rel, ".git"+string(os.PathSeparator)) {
			if info.IsDir() {
				return filepath.SkipDir
			}
			return nil
		}
		target := filepath.Join(dst, rel)
		if info.IsDir() {
			return os.MkdirAll(target, info.Mode().Perm())
		}
		if !info.Mode().IsRegular() {
			return nil
		}
		if e := os.MkdirAll(filepath.Dir(target), 0750); e != nil {
			return e
		}
		in, e := os.Open(path)
		if e != nil {
			return e
		}
		out, e := os.OpenFile(target, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, info.Mode().Perm())
		if e != nil {
			_ = in.Close()
			return e
		}
		_, copyErr := io.Copy(out, in)
		inErr := in.Close()
		outErr := out.Close()
		if copyErr != nil {
			return copyErr
		}
		if inErr != nil {
			return inErr
		}
		return outErr
	})
}
func (s *Service) encrypt(p []byte) ([]byte, error) {
	b, e := aes.NewCipher(s.key)
	if e != nil {
		return nil, e
	}
	g, e := cipher.NewGCM(b)
	if e != nil {
		return nil, e
	}
	nonce := make([]byte, g.NonceSize())
	if _, e = rand.Read(nonce); e != nil {
		return nil, e
	}
	return g.Seal(nonce, nonce, p, nil), nil
}
func (s *Service) decrypt(v []byte) ([]byte, error) {
	b, e := aes.NewCipher(s.key)
	if e != nil {
		return nil, e
	}
	g, e := cipher.NewGCM(b)
	if e != nil {
		return nil, e
	}
	if len(v) < g.NonceSize() {
		return nil, errors.New("invalid encrypted secret")
	}
	return g.Open(nil, v[:g.NonceSize()], v[g.NonceSize():], nil)
}