package app

import (
	"context"
	"log"
	"os"
	"path/filepath"
	"sync"

	"fast_reader/internal/reader"
	"fast_reader/internal/settings"
	"fast_reader/internal/storage"
)

type App struct {
	ctx          context.Context
	mu           sync.RWMutex
	settings     settings.Settings
	settingsPath string
}

func NewApp() *App {
	return &App{
		settings: settings.Default(),
	}
}

func (a *App) Startup(ctx context.Context) {
	a.ctx = ctx

	configDir, err := os.UserConfigDir()
	if err != nil {
		log.Printf("Could not locate user config directory: %v", err)
		return
	}

	a.mu.Lock()
	defer a.mu.Unlock()

	a.settingsPath = filepath.Join(
		configDir,
		"fast_reader",
		"settings.json",
	)

	var saved settings.Settings

	err = storage.Load(a.settingsPath, &saved)

	if err != nil {
		if !os.IsNotExist(err) {
			log.Printf("Could not load settings: %v", err)
		}

		a.settings = settings.Default()
		return
	}

	a.settings = saved.Normalize()

	log.Println("Settings loaded successfully")
}

// PrepareText converts pasted text into a sequence of words
// ready for RSVP playback.
func (a *App) PrepareText(text string) []reader.Word {
	return reader.Tokenize(text)
}

// GetVersion returns the application version.
func (a *App) GetVersion() string {
	return "0.1.0"
}

// GetSettings returns the current application settings.
func (a *App) GetSettings() settings.Settings {
	a.mu.RLock()
	defer a.mu.RUnlock()

	return a.settings
}

// SaveSettings validates and persists application settings.
func (a *App) SaveSettings(input settings.Settings) error {
	normalized := input.Normalize()

	a.mu.Lock()
	defer a.mu.Unlock()

	if a.settingsPath == "" {
		configDir, err := os.UserConfigDir()
		if err != nil {
			return err
		}

		a.settingsPath = filepath.Join(
			configDir,
			"fast_reader",
			"settings.json",
		)
	}

	if err := storage.Save(a.settingsPath, normalized); err != nil {
		return err
	}

	a.settings = normalized

	return nil
}

// ResetSettings restores and persists the default settings.
func (a *App) ResetSettings() (settings.Settings, error) {
	defaults := settings.Default()

	if err := a.SaveSettings(defaults); err != nil {
		return settings.Settings{}, err
	}

	return defaults, nil
}