1 files changed, 55 insertions, 0 deletions
diff --git a/backend/gen.go b/backend/gen.go
new file mode 100644
index 0000000..6e95aeb
--- /dev/null
+++ b/backend/gen.go
@@ -0,0 +1,55 @@
+package backend
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+)
+
+// genForestTree generates a forest representation of the tree with the given index
+func GenForestTree(database *sql.DB, index int64) string {
+	db = database
+	rootNodeID := getRootNodeID(index)
+	return genForestTreeNode(rootNodeID)
+}
+
+// genForestTreeNodes returns a sub-representation of a given node in forest format
+func genForestTreeNode(nodeID int64) string {
+	var returnString string
+
+	// get the subnode ids
+	var subnode [4]int64
+
+	query := fmt.Sprintf("SELECT subnode[1], subnode[2], subnode[3], subnode[4] FROM nodes WHERE node_id=%d", nodeID)
+	err := db.QueryRow(query).Scan(&subnode[0], &subnode[1], &subnode[2], &subnode[3])
+	if err != nil {
+		log.Fatalf("[ E ] updateTotalMassNode query: %v\n\t\t\t query: %s\n", err, query)
+	}
+
+	returnString += "["
+
+	// iterate over all subnodes updating their total masses
+	for _, subnodeID := range subnode {
+		if subnodeID != 0 {
+			centerOfMass := getCenterOfMass(nodeID)
+			mass := getNodeTotalMass(nodeID)
+			returnString += fmt.Sprintf("%.0f %.0f %.0f", centerOfMass.X, centerOfMass.Y, mass)
+			returnString += genForestTreeNode(subnodeID)
+		} else {
+			if getStarID(nodeID) != 0 {
+				coords := getStarCoordinates(nodeID)
+				starID := getStarID(nodeID)
+				mass := getStarMass(starID)
+				returnString += fmt.Sprintf("[%.0f %.0f %.0f]", coords.X, coords.Y, mass)
+			} else {
+				returnString += fmt.Sprintf("[0 0]")
+			}
+			// break, this stops a star from being counted multiple (4) times
+			break
+		}
+	}
+
+	returnString += "]"
+
+	return returnString
+}