// Package files implements sessions saved into filesystem persistently encoded using gob
package files

import (
	"fmt"
	"os"
	"sync"
	"time"
)

const (
	sessDir string = "go-session"
	sessExt string = "gsd"
)

func init() {

}

// ProviderFiles implement filesystem session provider
type ProviderFiles struct {
	sessPath string
	lock     sync.Mutex
}

func (pder *ProviderFiles) ckdirpath(sid string) string {
	return fmt.Sprintf("%s/%s/%s.%s", pder.sessPath, sessDir, sid, sessExt)
}

func (pder *ProviderFiles) updateAtime(sid string) (err error) {
	return
}
func (pder *ProviderFiles) getAtime(sid string) (atime *time.Time, err error) {
	return
}

// SetParams for files session provider set base path in filesystem for save sessions
func (pder *ProviderFiles) SetParams(p any) (err error) {
	if p != nil {
		if s, ok := p.(string); ok {
			pder.sessPath = s
			return
		}
		return fmt.Errorf("parameter for files session provider is not string")
	}
	return fmt.Errorf("parameter for files session provider must not be nil")
}

// Init create session file if not exists and retturn *Session
func (pder *ProviderFiles) Init(sid string) (err error) {
	pder.lock.Lock()
	defer pder.lock.Unlock()
	var fd *os.File
	ckf := pder.ckdirpath(sid)
	if fd, err = os.Create(ckf); err != nil {
		return fmt.Errorf("create session file: %s failed with err: %w", ckf, err)
	}
	return fd.Close()
}