package store

import (
	"database/sql"
	"time"

	"github.com/alexedwards/scs/postgresstore"
	"github.com/alexedwards/scs/v2"
)

const sessionsSchemaPostgres = `
CREATE TABLE IF NOT EXISTS sessions (
  token TEXT PRIMARY KEY,
  data BYTEA NOT NULL,
  expiry TIMESTAMPTZ NOT NULL
);
CREATE INDEX IF NOT EXISTS sessions_expiry_idx ON sessions (expiry);
`

// applySessionsSchema creates the scs sessions table if missing.
func applySessionsSchema(db *sql.DB) error {
	return applySchema(db, sessionsSchemaPostgres)
}

type sessionStopper interface {
	StopCleanup()
}

// SessionStore wraps scs Postgres session persistence and cleanup.
type SessionStore struct {
	store   scs.Store
	stopper sessionStopper
}

// NewSessionStore starts a postgresstore with the given cleanup interval.
func NewSessionStore(db *sql.DB, cleanupInterval time.Duration) *SessionStore {
	ps := postgresstore.NewWithCleanupInterval(db, cleanupInterval)
	return &SessionStore{store: ps, stopper: ps}
}

// Store returns the scs.Store implementation.
func (s *SessionStore) Store() scs.Store {
	return s.store
}

// Close stops background session cleanup.
func (s *SessionStore) Close() {
	if s == nil || s.stopper == nil {
		return
	}
	s.stopper.StopCleanup()
	s.stopper = nil
}