// package session manages Yggdrasil session lifecycle.

package session

import (
	"context"
	"log"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"

	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/database"
)

// StartCleanupWorker launches a background goroutine that deletes expired
// yggdrasil_sessions every interval. It stops when the context is cancelled.
func StartCleanupWorker(db *database.DB, interval time.Duration) context.CancelFunc {
	ctx, cancel := context.WithCancel(context.Background())

	go func() {
		log.Printf("Session cleanup worker started (interval: %v)", interval)
		ticker := time.NewTicker(interval)
		defer ticker.Stop()

		// Run once on start.
		cleanup(db)

		for {
			select {
			case <-ticker.C:
				cleanup(db)
			case <-ctx.Done():
				log.Println("Session cleanup worker stopped")
				return
			}
		}
	}()

	return cancel
}

func cleanup(db *database.DB) {
	if db == nil {
		return
	}
	pool := db.Pool()
	if pool == nil {
		return
	}
	tag, err := pool.Exec(context.Background(),
		`DELETE FROM yggdrasil_sessions WHERE expires_at < NOW()`)
	if err != nil {
		log.Printf("Session cleanup error: %v", err)
		return
	}
	if tag.RowsAffected() > 0 {
		log.Printf("Session cleanup: removed %d expired sessions", tag.RowsAffected())
	}
}

// CountActive returns the number of non-expired sessions.
func CountActive(pool *pgxpool.Pool) (int, error) {
	var count int
	err := pool.QueryRow(context.Background(),
		`SELECT COUNT(*) FROM yggdrasil_sessions WHERE expires_at > NOW()`,
	).Scan(&count)
	return count, err
}