// Package notes stores private server notes independently of the host cache.
package notes

import (
	"context"
	"crypto/sha256"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/netbox"
	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/storage"
)

type Note struct {
	Text, ETag string
	Host       netbox.HostEntry
}
type Service struct {
	Dir, Namespace string
	Client         *netbox.Client
}

func New(namespace string, client *netbox.Client) *Service {
	dir, err := os.UserConfigDir()
	if err != nil {
		dir = filepath.Join(os.Getenv("HOME"), ".config")
	}
	return &Service{Dir: filepath.Join(dir, "netssh", "notes"), Namespace: strings.TrimRight(namespace, "/"), Client: client}
}

func (s *Service) path(host netbox.HostEntry) string {
	key := fmt.Sprintf("%s\x00%s\x00%s", s.Namespace, host.Kind, strings.ToLower(host.Name))
	return filepath.Join(s.Dir, fmt.Sprintf("%x.txt", sha256.Sum256([]byte(key))))
}

func (s *Service) Read(ctx context.Context, host netbox.HostEntry, remote bool) (Note, error) {
	note := Note{Host: host}
	if remote {
		if s.Client == nil {
			return note, fmt.Errorf("NetBox is not configured")
		}
		if host.ID == 0 {
			resolved, err := s.Client.FindHost(ctx, host.Name, host.Kind)
			if err != nil {
				return note, err
			}
			note.Host = resolved
		}
		var err error
		note.Text, note.ETag, err = s.Client.GetComments(ctx, note.Host)
		return note, err
	}
	data, err := os.ReadFile(s.path(host))
	if os.IsNotExist(err) {
		return note, nil
	}
	note.Text = string(data)
	return note, err
}

func (s *Service) Write(ctx context.Context, note Note, remote bool) error {
	if remote {
		if s.Client == nil {
			return fmt.Errorf("NetBox is not configured")
		}
		return s.Client.SetComments(ctx, note.Host, note.Text, note.ETag)
	}
	return storage.WriteFile(s.path(note.Host), []byte(note.Text), 0o600)
}