Rename 'MapDS' to 'JsonDS'; Added some docs

internal/datastore/json_datastore/partition_key_ranges.go

@@ -0,0 +1,49 @@
+package jsondatastore
+
+import (
+	"fmt"
+
+	"github.com/google/uuid"
+	"github.com/pikami/cosmium/internal/datastore"
+	"github.com/pikami/cosmium/internal/resourceid"
+)
+
+// I have no idea what this is tbh
+func (r *JsonDataStore) GetPartitionKeyRanges(databaseId string, collectionId string) ([]datastore.PartitionKeyRange, datastore.DataStoreStatus) {
+	r.storeState.RLock()
+	defer r.storeState.RUnlock()
+
+	databaseRid := databaseId
+	collectionRid := collectionId
+	var timestamp int64 = 0
+
+	if database, ok := r.storeState.Databases[databaseId]; !ok {
+		databaseRid = database.ResourceID
+	}
+
+	if collection, ok := r.storeState.Collections[databaseId][collectionId]; !ok {
+		collectionRid = collection.ResourceID
+		timestamp = collection.TimeStamp
+	}
+
+	pkrResourceId := resourceid.NewCombined(collectionRid, resourceid.New(resourceid.ResourceTypePartitionKeyRange))
+	pkrSelf := fmt.Sprintf("dbs/%s/colls/%s/pkranges/%s/", databaseRid, collectionRid, pkrResourceId)
+	etag := fmt.Sprintf("\"%s\"", uuid.New())
+
+	return []datastore.PartitionKeyRange{
+		{
+			ResourceID:         pkrResourceId,
+			ID:                 "0",
+			Etag:               etag,
+			MinInclusive:       "",
+			MaxExclusive:       "FF",
+			RidPrefix:          0,
+			Self:               pkrSelf,
+			ThroughputFraction: 1,
+			Status:             "online",
+			Parents:            []interface{}{},
+			TimeStamp:          timestamp,
+			Lsn:                17,
+		},
+	}, datastore.StatusOk
+}