package registry

import (
	"encoding/json"
	"fmt"
	"os"
	"path"
	"sync"
	"time"

	"git.wzray.com/homelab/mastermind/internal/types"
)

type FileStorage struct {
	filename   string
	lock       sync.Mutex
}

func NewFileStorage(filename string) *FileStorage {
	return &FileStorage{
		filename: filename,
	}
}

func (fs *FileStorage) EnsureExists() {
	dirname := path.Dir(fs.filename)
	if _, err := os.Stat(dirname); os.IsNotExist(err) {
		os.MkdirAll(dirname, 0755)
	}

	if _, err := os.Stat(fs.filename); os.IsNotExist(err) {
		fs.Save(&storedConfig{
			LastUpdate: time.Now().UnixMilli(),
			Nodes: make(map[string]types.Node),
		})
	}
}

func (fs *FileStorage) Save(cfg *storedConfig) error {
	fs.lock.Lock()
	defer fs.lock.Unlock()

	buf, err := json.Marshal(cfg)
	if err != nil {
		return fmt.Errorf("marshal registry: %w", err)
	}

	if err := os.WriteFile(fs.filename, buf, 0644); err != nil {
		return fmt.Errorf("write registry file: %w", err)
	}

	return nil
}

func (fs *FileStorage) Load(cfg *storedConfig) error {
	fs.lock.Lock()
	defer fs.lock.Unlock()

	data, err := os.ReadFile(fs.filename)
	if err != nil {
		return fmt.Errorf("read registry file: %w", err)
	}
	if err := json.Unmarshal(data, cfg); err != nil {
		return fmt.Errorf("unmarshal registry: %w", err)
	}

	return nil
}