feat: initial version of pert simplifier

cmd/pertify/go.sum

@@ -12,5 +12,6 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/urfave/cli.v2 v2.0.0-20180128182452-d3ae77c26ac8 h1:Ggy3mWN4l3PUFPfSG0YB3n5fVYggzysUmiUQ89SnX6Y=
 gopkg.in/urfave/cli.v2 v2.0.0-20180128182452-d3ae77c26ac8/go.mod h1:cKXr3E0k4aosgycml1b5z33BVV6hai1Kh7uDgFOkbcs=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20190705120443-117fdf03f45f h1:nqBZgl3FUZD7Xe4yitNx/0mqkydzbl4Y89WSTjG6/ok=
 gopkg.in/yaml.v3 v3.0.0-20190705120443-117fdf03f45f/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

cmd/pertify/main.go

@@ -21,6 +21,7 @@ func main() {
 			&cli.BoolFlag{Name: "dot", Usage: "print 'dot' compatible output"},
 			&cli.BoolFlag{Name: "vertical", Usage: "displaying steps from top to bottom"},
 			&cli.BoolFlag{Name: "with-details", Usage: "Show pert numbers"},
+			&cli.BoolFlag{Name: "no-simplify", Usage: "Don't simplify the graph"},
 			&cli.BoolFlag{Name: "debug", Aliases: []string{"D"}, Usage: "verbose mode"},
 		},
 		Action: graph,
@@ -41,6 +42,9 @@ func graph(c *cli.Context) error {
 		return errors.Wrap(err, "failed to parse yaml file")
 	}
 
+	if c.Bool("no-simplify") {
+		config.Opts.NoSimplify = true
+	}
 	graph := graphman.FromPertConfig(config)
 	if c.Bool("debug") {
 		log.Println(graph)

graph.go

@@ -214,6 +214,16 @@ func (g *Graph) RemoveVertex(id string) bool {
 	return false
 }
 
+func (g *Graph) RemoveEdge(src, dst string) bool {
+	for k, v := range g.edges {
+		if v.src.id == src && v.dst.id == dst {
+			g.edges = append(g.edges[:k], g.edges[k+1:]...)
+			return true
+		}
+	}
+	return false
+}
+
 func (g Graph) GetVertex(id string) *Vertex {
 	for _, v := range g.vertices {
 		if v.id == id {
@@ -235,7 +245,7 @@ func (g *Graph) AddEdge(srcID, dstID string, attrs ...Attrs) *Edge {
 	dst := g.AddVertex(dstID)
 	edge := newEdge(src, dst, a)
 	src.successors = append(src.successors, edge)
-	dst.predecessors = append(src.predecessors, edge)
+	dst.predecessors = append(dst.predecessors, edge)
 	g.edges = append(g.edges, edge)
 	return edge
 }

pert_config.go

@@ -12,8 +12,18 @@ type PertAction struct {
 	DependsOn []string  `yaml:"depends_on"`
 }
 
+type PertState struct {
+	ID        string   `yaml:"id"`
+	Title     string   `yaml:"title"`
+	DependsOn []string `yaml:"depends_on"`
+}
+
 type PertConfig struct {
 	Actions []PertAction `yaml:"actions"`
+	States  []PertState  `yaml:"states"`
+	Opts    struct {
+		NoSimplify bool `yaml:"simplify"`
+	} `yaml:"opts"`
 }
 
 const (
@@ -27,6 +37,21 @@ func FromPertConfig(config PertConfig) *Graph {
 	graph.AddVertex(pertStartVertex)
 	graph.AddVertex(pertFinishVertex)
 
+	for _, state := range config.States {
+		attrs := Attrs{}
+		if state.Title != "" {
+			attrs.SetTitle(state.Title)
+		}
+		graph.AddVertex(state.ID, attrs)
+		for _, dependency := range state.DependsOn {
+			graph.AddEdge(
+				pertPostID(dependency),
+				state.ID,
+				Attrs{}.SetPertZeroTimeActivity(),
+			)
+		}
+	}
+
 	for _, action := range config.Actions {
 		attrs := Attrs{}
 		if action.Title != "" {
@@ -46,27 +71,30 @@ func FromPertConfig(config PertConfig) *Graph {
 		}
 
 		// relationships
-		postCurrent := fmt.Sprintf("post_%s", action.ID)
 		switch len(action.DependsOn) {
 		case 0: // no dependency, linking with Start
-			graph.AddEdge(pertStartVertex, postCurrent, attrs)
+			graph.AddEdge(
+				pertStartVertex,
+				pertPostID(action.ID),
+				attrs,
+			)
 		case 1: // only one dependency
 			dependency := action.DependsOn[0]
 			graph.AddEdge(
-				fmt.Sprintf("post_%s", dependency),
-				postCurrent,
+				pertPostID(dependency),
+				pertPreID(action.ID),
 				attrs,
 			)
 		default:
 			graph.AddEdge(
-				fmt.Sprintf("pre_%s", action.ID),
-				postCurrent,
+				pertPreID(action.ID),
+				pertPostID(action.ID),
 				attrs,
 			)
 			for _, dependency := range action.DependsOn {
 				graph.AddEdge(
-					fmt.Sprintf("post_%s", dependency),
-					fmt.Sprintf("pre_%s", action.ID),
+					pertPostID(dependency),
+					pertPreID(action.ID),
 					Attrs{}.SetPertZeroTimeActivity(),
 				)
 			}
@@ -75,28 +103,73 @@ func FromPertConfig(config PertConfig) *Graph {
 
 	// link ending vertices with finish
 	for _, vertex := range graph.SinkVertices() {
-		if vertex.ID() == pertFinishVertex {
+		if vertex.id == pertFinishVertex {
 			continue
 		}
 		graph.AddEdge(
-			vertex.ID(),
+			vertex.id,
 			pertFinishVertex,
 			Attrs{}.SetPertZeroTimeActivity(),
 		)
 	}
 
-	// optimize
-	// FIXME: TODO
-
 	// nice names
 	for _, vertex := range graph.Vertices() {
-		if vertex.ID() == pertStartVertex || vertex.ID() == pertFinishVertex {
+		if vertex.id == pertStartVertex || vertex.id == pertFinishVertex {
 			continue
 		}
 		if vertex.Attrs.GetTitle() == "" {
 			vertex.Attrs.SetPertUntitledState()
 		}
 	}
 
+	for _, vertex := range graph.Vertices() {
+		if vertex.Attrs.GetTitle() == "" {
+			vertex.Attrs.SetTitle(vertex.id)
+		}
+	}
+	if !config.Opts.NoSimplify { // simplify the graph
+		verticesToDelete := map[string]bool{} // creating a map so we can iterate over vertices while deleting some entries
+		for _, vertex := range graph.Vertices() {
+			if pertIsUntitledState(vertex) || true {
+				if vertex.OutDegree() == 1 { // remove dummy states with only one dummy successor
+					successor := vertex.SuccessorEdges()[0]
+					if pertIsZeroTimeActivity(successor) {
+						for _, predecessor := range vertex.PredecessorEdges() {
+							predecessor.dst = successor.dst
+						}
+						graph.RemoveEdge(vertex.id, successor.dst.id)
+						verticesToDelete[vertex.id] = true
+					}
+				}
+			}
+		}
+		for id := range verticesToDelete {
+			graph.RemoveVertex(id)
+		}
+	}
+
 	return graph
 }
+
+func pertPreID(id string) string  { return fmt.Sprintf("pre_%s", id) }
+func pertPostID(id string) string { return fmt.Sprintf("post_%s", id) }
+
+func pertIsZeroTimeActivity(edge *Edge) bool {
+	pert := edge.GetPert()
+	return pert != nil && pert.IsZeroTimeActivity
+}
+
+func pertIsUntitledState(vertex *Vertex) bool {
+	pert := vertex.GetPert()
+	return pert != nil && pert.IsUntitledState
+}
+
+func isMarkedAsDeleted(attrs Attrs) bool {
+	val, found := attrs["__deleted"].(bool)
+	return found && val
+}
+
+func markAsDeleted(attrs Attrs) {
+	attrs["__deleted"] = true
+}

viz/graphviz.go

@@ -30,16 +30,16 @@ func ToGraphviz(g *graphman.Graph, opts *Opts) (string, error) {
 	for _, vertex := range g.Vertices() {
 		if err := gv.AddNode(
 			"G",
-			vertex.ID(),
+			escape(vertex.ID()),
 			attrsFromVertex(vertex, opts),
 		); err != nil {
 			return "", err
 		}
 	}
 	for _, edge := range g.Edges() {
 		if err := gv.AddEdge(
-			edge.Src().ID(),
-			edge.Dst().ID(),
+			escape(edge.Src().ID()),
+			escape(edge.Dst().ID()),
 			true,
 			attrsFromEdge(edge, opts),
 		); err != nil {
@@ -65,6 +65,7 @@ func attrsFromVertex(vertex *graphman.Vertex, opts *Opts) map[string]string {
 		if pert.IsUntitledState {
 			attrs[string(graphviz.Label)] = " "
 			attrs[string(graphviz.Shape)] = "circle"
+			// attrs[string(graphviz.Style)] = "dashed"
 		}
 	}
 	attrsGeneric(vertex.Attrs, attrs, opts)