package sessions

import (
	"errors"
	"fmt"
	"time"
)

type Session struct {
	Id          string
	Description string
	CreatedAt   time.Time

	// Should be set to a zero time if the session is still active
	EndedAt time.Time
}

func (s *Session) ExistsFor() time.Duration {
	return time.Now().Sub(s.CreatedAt)
}

var (
	ErrUnknownSession = errors.New("unknown session")
)

type Storage interface {
	// List all sessions.
	GetAllSessions() ([]Session, error)

	// List all active sessions.
	GetActiveSessions() ([]Session, error)

	// List all past sessions.
	GetPastSessions() ([]Session, error)

	// Start a new session.
	StartSession(description string, createdAt time.Time) (Session, error)

	// End an old session.
	// Should update a session's [EndedAt] property.
	// Should return [ErrUnknownSession] if the session couldn't be found.
	EndSession(id string, endedAt time.Time) error

	// Delete a session.
	// Should return [ErrUnknownSession] if the session couldn't be found.
	DeleteSession(id string) error

	fmt.Stringer
}