package gc

import (
	"os"
	"sort"
	"time"

	"github.com/rs/zerolog/log"
)

type GC interface {
	List() ([]os.FileInfo, error)
	Delete(id string) error
}

func Start(g GC, maxSize int, interval time.Duration) {
	ticker := time.NewTicker(interval)
	for {
		<-ticker.C
		log.Debug().Msg("running GC")
		infos, err := g.List()
		if err != nil {
			log.Err(err).Msg("could not run GC")
			continue
		}

		var size int
		for _, info := range infos {
			size += int(info.Size())
		}

		if size < maxSize {
			continue
		}

		sort.Sort(sorter(infos))
		for size > maxSize {
			fi := infos[0]
			log.Debug().Msgf("deleting file %s", fi.Name())
			if err := g.Delete(fi.Name()); err != nil {
				log.Err(err).Msgf("could not delete file %s", fi.Name())
				break
			}
			size -= int(fi.Size())
			infos = infos[1:]
		}
		log.Debug().Msg("finished GC")
	}
}