package cache

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"git.nakama.town/fmartingr/gotoolkit/model"
)

var _ model.Cache = (*FileCache)(nil)

type FileCache struct {
	path string
}

func (c *FileCache) Get(key string) (result any, err error) {
	path := filepath.Join(c.path, key)

	contents, err := os.ReadFile(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) || errors.Is(err, os.ErrPermission) {
			return result, model.ErrCacheKeyDontExist
		}
		return
	}

	return contents, nil
}

func (c *FileCache) GetWithExpiry(key string, expiration time.Duration) (result any, err error) {
	path := filepath.Join(c.path, key)
	info, err := os.Stat(path)
	if err != nil {
		return result, model.ErrCacheKeyDontExist
	}

	if info.ModTime().Add(expiration).Before(time.Now()) {
		c.Delete(key)
		return result, model.ErrCacheKeyDontExist
	}

	return c.Get(key)
}

func (c *FileCache) Set(key string, value any) error {
	path := filepath.Join(c.path, key)

	if err := os.WriteFile(path, value.([]byte), 0766); err != nil {
		return fmt.Errorf("error writting cache file: %s", err)
	}

	return nil
}

func (c *FileCache) Delete(key string) error {
	path := filepath.Join(c.path, key)
	return os.Remove(path)
}

func NewFileCache(folderName string) (*FileCache, error) {
	userCacheDir, err := os.UserCacheDir()
	if err != nil {
		return nil, fmt.Errorf("Could not retrieve user cache directory: %w", err)
	}
	path := filepath.Join(userCacheDir, folderName)

	if err := os.MkdirAll(path, 0755); err != nil {
		return nil, fmt.Errorf("couldn't create cache directory: %w", err)
	}

	return &FileCache{
		path: path,
	}, nil
}