Init basic structs

core/graph-basic.go

@@ -0,0 +1,111 @@
+package core
+
+import (
+	"fmt"
+)
+
+func isMultiple(m map[string][]string, id string) bool {
+	list, ok := m[id]
+	return ok && len(list) > 1;
+}
+
+type Set map[string]struct{}
+
+func (s *Set) Add(key string) {
+	(*s)[key] = struct{}{}
+}
+
+func (s *Set) Has(key string) bool {
+	_, ok := (*s)[key]
+	return ok
+}
+
+type relationMap map[string][]string
+type nodesMap map[string]NodeInput
+
+type GraphBasic struct {
+	list []NodeInput
+	nodesMap nodesMap
+	incomesByNodeIdMap relationMap
+	outcomesByNodeIdMap relationMap
+	loopsByNodeIdMap relationMap
+}
+
+func NewGraphBasic(list []NodeInput) (*GraphBasic, error) {
+	g := &GraphBasic{
+		list: list,
+		nodesMap: make(nodesMap),
+		incomesByNodeIdMap: make(relationMap),
+		outcomesByNodeIdMap: make(relationMap),
+		loopsByNodeIdMap: make(relationMap),
+	}
+	for _, node := range g.list {
+		if _, ok := g.nodesMap[node.Id]; ok {
+			return nil, fmt.Errorf("Duplicate node id `%s`", node.Id)
+		}
+		g.nodesMap[node.Id] = node
+	}
+}
+
+func (g *GraphBasic) detectIncomesAndOutcomes() (err error) {
+	totalSet := make(Set)
+	for _, node := range g.list {
+		if totalSet.Has(node.Id) {
+			continue
+		}
+		branchSet :=  make(Set)
+		_ , err = g.traverseVertically(node, &branchSet, &totalSet)
+		if err != nil {
+			return
+		}
+	}
+}
+
+func (g *GraphBasic) traverseVertically(node NodeInput, branchSet *Set, totalSet *Set) (*Set, error) {
+	if branchSet.Has(node.Id) {
+		return nil, fmt.Errorf("Duplicate incomes for node id `%s`", node.Id)
+	}
+	branchSet.Add(node.Id)
+	totalSet.Add(node.Id)
+	for _, outcomeId := range node.Next {
+		// skip loops which are already detected
+		if g.IsLoopEdge(node.Id, outcomeId) {
+			continue
+		}
+		// detect loops
+		if branchSet.Has(outcomeId) {
+			addUniqueRelation(g.loopsByNodeIdMap, node.Id, outcomeId)
+		}
+		// @TODO check if addUniqueRelation works
+	}
+}
+
+func (g *GraphBasic) IsLoopEdge(nodeId string, outcomeId string) bool {
+	loops, ok := g.loopsByNodeIdMap[nodeId]
+	if !ok {
+		return false
+	}
+	for _, id := range loops {
+		if id == outcomeId {
+			return true
+		}
+	}
+	return false
+}
+
+func addUniqueRelation(rm relationMap, key, value string) {
+	relations, ok := rm[key]
+	if !ok {
+		rm[key] = []string{value}
+	}
+	isUnique := true
+	for _, v := range relations {
+		if v == value {
+			isUnique = false
+			break
+		}
+	}
+	if isUnique {
+		rm[key] = append(relations, value)
+	}
+}