package chat

import (
	"encoding/json"
	"log/slog"
	"os"
	"path/filepath"
	"sync"

	"github.com/ayn2op/discordo/internal/consts"
)

const maxFavoriteEmoji = 10

type emojiFavorites struct {
	Favorites []string `json:"favorites"`
	mu        sync.RWMutex
}

var emojiFavoritesPath = filepath.Join(consts.CacheDir(), "emoji_favorites.json")

func loadEmojiFavorites() *emojiFavorites {
	ef := &emojiFavorites{}
	data, err := os.ReadFile(emojiFavoritesPath)
	if err != nil {
		return ef
	}
	if err := json.Unmarshal(data, ef); err != nil {
		slog.Warn("failed to parse emoji favorites", "err", err)
		return &emojiFavorites{}
	}
	return ef
}

func (ef *emojiFavorites) save() {
	ef.mu.RLock()
	defer ef.mu.RUnlock()
	atomicSaveJSON(emojiFavoritesPath, ef)
}

func (ef *emojiFavorites) toggle(emoji string) {
	ef.mu.Lock()
	for i, e := range ef.Favorites {
		if e == emoji {
			ef.Favorites = append(ef.Favorites[:i], ef.Favorites[i+1:]...)
			ef.mu.Unlock()
			ef.save()
			return
		}
	}
	if len(ef.Favorites) >= maxFavoriteEmoji {
		ef.mu.Unlock()
		return
	}
	ef.Favorites = append(ef.Favorites, emoji)
	ef.mu.Unlock()
	ef.save()
}

func (ef *emojiFavorites) list() []string {
	ef.mu.RLock()
	defer ef.mu.RUnlock()
	out := make([]string, len(ef.Favorites))
	copy(out, ef.Favorites)
	return out
}