@@ -17,6 +17,39 @@
 	"gitlab.com/tozd/go/errors"
 )
 
+type Options struct {
+	Update    bool
+	Replace   bool
+	LowMemory bool
+	Logger    *log.Logger
+}
+
+var Job struct {
+	InProgress bool
+	StartedAt  time.Time
+	FinishedAt time.Time
+	NextRun    time.Time
+}
+
+func SetNextRun(nextRun time.Time) {
+	Job.NextRun = nextRun
+}
+
+func SetLastUpdated(last time.Time) {
+	Job.FinishedAt = last
+}
+
+func MarkIndexingStarted() {
+	Job.StartedAt = time.Now()
+	Job.InProgress = true
+}
+
+func MarkIndexingFinished(nextRun time.Time) {
+	Job.FinishedAt = time.Now()
+	Job.InProgress = false
+	Job.NextRun = nextRun
+}
+
 func createSourceImporter(
 	parent context.Context,
 	log *log.Logger,
@@ -203,3 +236,87 @@ }
 
 	return nil
 }
+
+func SetupIndex(ctx context.Context, cfg *config.Config, options *Options) errors.E {
+	var i uint
+	cfgEnabledSources := make([]string, len(cfg.Importer.Sources))
+	for key := range cfg.Importer.Sources {
+		cfgEnabledSources[i] = key
+		i++
+	}
+	slices.Sort(cfgEnabledSources)
+
+	read, write, exists, err := index.OpenOrCreate(
+		cfg.DataPath,
+		options.Replace,
+		&index.Options{
+			LowMemory: options.LowMemory,
+			Logger:    options.Logger.Named("index"),
+		},
+	)
+	if err != nil {
+		return errors.Wrap(err, "Failed to open or create index")
+	}
+
+	if !exists || options.Replace || options.Update {
+		options.Logger.Info(
+			"Starting build job",
+			"new",
+			!exists,
+			"replace",
+			options.Replace,
+			"update",
+			options.Update,
+		)
+		imp := New(cfg, options.Logger.Named("importer"), write)
+		err = imp.Start(
+			ctx,
+			options.Replace || options.Update,
+			nil,
+		)
+		if err != nil {
+			return errors.Wrap(err, "Failed to build index")
+		}
+		if options.Replace || options.Update {
+			return nil
+		}
+	} else {
+		indexedSources, err := read.GetEnabledSources()
+		if err != nil {
+			return errors.Wrap(err, "Failed to get enabled sources from index")
+		}
+		slices.Sort(indexedSources)
+		if !slices.Equal(cfgEnabledSources, indexedSources) {
+			newSources := slices.DeleteFunc(slices.Clone(cfgEnabledSources), func(s string) bool {
+				return slices.Contains(indexedSources, s)
+			})
+			retiredSources := slices.DeleteFunc(slices.Clone(indexedSources), func(s string) bool {
+				return slices.Contains(cfgEnabledSources, s)
+			})
+			if len(newSources) > 0 {
+				options.Logger.Info("adding new sources", "sources", newSources)
+				imp := New(cfg, options.Logger.Named("importer"), write)
+				err := imp.Start(
+					ctx,
+					false,
+					&newSources,
+				)
+				if err != nil {
+					return errors.Wrap(err, "Failed to update index with new sources")
+				}
+			}
+			if len(retiredSources) > 0 {
+				options.Logger.Info("removing retired sources", "sources", retiredSources)
+				for _, s := range retiredSources {
+					err := write.DeleteBySource(s)
+					if err != nil {
+						return errors.Wrapf(err, "Failed to remove retired source %s", s)
+					}
+				}
+			}
+		}
+	}
+	SetLastUpdated(read.LastUpdated())
+
+	return nil
+}