package update

import (
	domain "RenewCMS/internal/domain/update"
	"encoding/json"
	"errors"
	"fmt"
	"io/fs"
)

type FSRestartRequestStore struct {
	files domain.HelperFilesystem
	path  string
}

var _ domain.RestartRequestStore = &FSRestartRequestStore{}

func NewFSRestartRequestStore(files domain.HelperFilesystem, path string) *FSRestartRequestStore {
	return &FSRestartRequestStore{files: files, path: path}
}

func (s *FSRestartRequestStore) Write(request domain.RestartRequest) error {
	return writeJSONThroughTemporary(s.files, s.path, request, statusFilePermissions)
}

func (s *FSRestartRequestStore) Read() (domain.RestartRequest, error) {
	info, err := s.files.Lstat(s.path)
	if errors.Is(err, fs.ErrNotExist) {
		return domain.RestartRequest{}, domain.ErrNoRestartRequest
	}
	if err != nil {
		return domain.RestartRequest{}, err
	}
	if info.IsSymlink {
		return domain.RestartRequest{}, domain.SymlinkError{Path: s.path}
	}
	if !info.IsRegular {
		return domain.RestartRequest{}, fmt.Errorf("%s is not a regular file", s.path)
	}
	content, err := s.files.ReadFile(s.path)
	if err != nil {
		return domain.RestartRequest{}, err
	}
	var request domain.RestartRequest
	return request, json.Unmarshal(content, &request)
}

func (s *FSRestartRequestStore) Delete() error {
	return removeThrough(s.files, s.path)
}

func removeThrough(files domain.HelperFilesystem, path string) error {
	if err := files.Remove(path); err != nil && !errors.Is(err, fs.ErrNotExist) {
		return err
	}
	return nil
}

func writeJSONThroughTemporary(files domain.HelperFilesystem, path string, value any, mode uint32) error {
	content, err := json.Marshal(value)
	if err != nil {
		return err
	}
	return writeThroughTemporary(files, path, content, mode)
}

func writeThroughTemporary(files domain.HelperFilesystem, path string, content []byte, mode uint32) error {
	temporary := path + domain.ResultTempSuffix
	if _, err := files.Lstat(temporary); err == nil {
		if err := files.Remove(temporary); err != nil {
			return err
		}
	}
	if err := files.CreateExclusive(temporary, content, mode); err != nil {
		return err
	}
	if err := files.Rename(temporary, path); err != nil {
		_ = files.Remove(temporary)
		return err
	}
	return nil
}