// Package inflation contains the background worker that refreshes
// the price_snapshots table used by the dashboard charts.
package inflation

import (
	"context"
	"log"
	"time"

	"github.com/yourname/deflated/internal/db"
)

// StartRefreshWorker runs in a goroutine and refreshes price snapshots
// every interval. Call this from main() after connecting to the database.
//
// Example:
//
//	go inflation.StartRefreshWorker(ctx, queries, 1*time.Hour)
func StartRefreshWorker(ctx context.Context, q *db.Queries, interval time.Duration) {
	// Run once immediately on startup so the charts aren't empty
	runRefresh(ctx, q)

	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			runRefresh(ctx, q)
		case <-ctx.Done():
			log.Println("inflation refresh worker stopped")
			return
		}
	}
}

func runRefresh(ctx context.Context, q *db.Queries) {
	start := time.Now()
	if err := q.RefreshPriceSnapshots(ctx); err != nil {
		log.Printf("error refreshing price snapshots: %v", err)
		return
	}
	log.Printf("price snapshots refreshed in %s", time.Since(start).Round(time.Millisecond))
}