package services

import (
	"os"
	"path/filepath"
	"strings"
	"time"
	"voicesnap/internal/userdict"

	"github.com/wailsapp/wails/v3/pkg/application"
)

// UserDictService exposes user dictionary management to the frontend.
type UserDictService struct {
	store *userdict.Store
	app   *application.App
	win   application.Window
}

func NewUserDictService(store *userdict.Store) *UserDictService {
	return &UserDictService{store: store}
}

// SetApp sets the Wails app and parent window used for native dialogs.
func (s *UserDictService) SetApp(app *application.App, win application.Window) {
	s.app = app
	s.win = win
}

// GetAll returns all replacement entries.
func (s *UserDictService) GetAll() []userdict.Entry {
	return s.store.GetAll()
}

// Add creates a replacement entry.
func (s *UserDictService) Add(from, to string) (userdict.Entry, error) {
	return s.store.Add(from, to)
}

// Update modifies an existing replacement entry.
func (s *UserDictService) Update(id int64, from, to string, enabled bool) (userdict.Entry, error) {
	return s.store.Update(id, from, to, enabled)
}

// Delete removes an entry by id.
func (s *UserDictService) Delete(id int64) {
	s.store.Delete(id)
}

// ClearAll removes all entries.
func (s *UserDictService) ClearAll() {
	s.store.ClearAll()
}

// ExportJSON returns the full userdict.json payload.
func (s *UserDictService) ExportJSON() string {
	return s.store.ExportJSON()
}

// ExportToFile asks the user where to save userdict.json, writes it, and returns the path.
func (s *UserDictService) ExportToFile() (string, error) {
	if s.app == nil {
		return "", os.ErrInvalid
	}

	home, _ := os.UserHomeDir()
	dialog := s.app.Dialog.SaveFile().
		SetMessage("导出用户词库").
		SetButtonText("导出").
		SetDirectory(filepath.Join(home, "Downloads")).
		SetFilename("userdict-"+time.Now().Format("20060102-1504")+".json").
		AddFilter("JSON Files", "*.json").
		CanCreateDirectories(true)

	if s.win != nil {
		dialog.AttachToWindow(s.win)
	}

	path, err := dialog.PromptForSingleSelection()
	if err != nil {
		return "", err
	}
	if path == "" {
		return "", nil
	}
	if strings.TrimSpace(filepath.Ext(path)) == "" {
		path += ".json"
	}

	if err := os.WriteFile(path, []byte(s.store.ExportJSON()), 0644); err != nil {
		return "", err
	}
	return path, nil
}

// ImportJSON replaces the dictionary from a JSON payload.
func (s *UserDictService) ImportJSON(content string) error {
	return s.store.ImportJSON(content)
}

// GetPath returns the local userdict.json path.
func (s *UserDictService) GetPath() string {
	return s.store.Path()
}