package storage

import (
	"encoding/json"
	"os"

	"github.com/disgoorg/snowflake/v2"
)

func NewChannelStorage(filename string) (*ChannelStorage, error) {
	storage := &ChannelStorage{
		filename: filename,
		Channels: make(map[snowflake.ID]bool),
	}

	if err := storage.Load(); err != nil && !os.IsNotExist(err) {
		return nil, err
	}

	return storage, nil
}

func (s *ChannelStorage) Load() error {
	s.mutex.Lock()
	defer s.mutex.Unlock()

	data, err := os.ReadFile(s.filename)
	if err != nil {
		return err
	}

	return json.Unmarshal(data, s)
}

func (s *ChannelStorage) Save() error {
	s.mutex.Lock()
	defer s.mutex.Unlock()

	data, err := json.MarshalIndent(s, "", "  ")
	if err != nil {
		return err
	}

	return os.WriteFile(s.filename, data, 0644)
}

func (s *ChannelStorage) AddChannel(channelID snowflake.ID) error {
	s.mutex.Lock()
	s.Channels[channelID] = true
	s.mutex.Unlock()

	return s.Save()
}

func (s *ChannelStorage) RemoveChannel(channelID snowflake.ID) error {
	s.mutex.Lock()
	delete(s.Channels, channelID)
	s.mutex.Unlock()

	return s.Save()
}

func (s *ChannelStorage) IsRegistered(channelID snowflake.ID) bool {
	s.mutex.RLock()
	defer s.mutex.RUnlock()

	return s.Channels[channelID]
}

func (s *ChannelStorage) GetAll() []snowflake.ID {
	s.mutex.RLock()
	defer s.mutex.RUnlock()

	channels := make([]snowflake.ID, 0, len(s.Channels))
	for channelID := range s.Channels {
		channels = append(channels, channelID)
	}

	return channels
}