golang: Split things into packages

This makes this logically more separate! :) As an aside...

I really hate the way golang does dependencies and packages. Yes, some
people insist on nesting their code deep into a $GOPATH, which is fine
if you're a google dev and are forced to work this way, but annoying for
the rest of the world. Your code shouldn't need a git commit to switch
to a a different vcs host! Gah I hate this so much.

pgraph/autoedge.go

@@ -0,0 +1,104 @@
+// Mgmt
+// Copyright (C) 2013-2016+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+// Package pgraph represents the internal "pointer graph" that we use.
+package pgraph
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/purpleidea/mgmt/global"
+	"github.com/purpleidea/mgmt/resources"
+)
+
+// add edges to the vertex in a graph based on if it matches a uuid list
+func (g *Graph) addEdgesByMatchingUUIDS(v *Vertex, uuids []resources.ResUUID) []bool {
+	// search for edges and see what matches!
+	var result []bool
+
+	// loop through each uuid, and see if it matches any vertex
+	for _, uuid := range uuids {
+		var found = false
+		// uuid is a ResUUID object
+		for _, vv := range g.GetVertices() { // search
+			if v == vv { // skip self
+				continue
+			}
+			if global.DEBUG {
+				log.Printf("Compile: AutoEdge: Match: %v[%v] with UUID: %v[%v]", vv.Kind(), vv.GetName(), uuid.Kind(), uuid.GetName())
+			}
+			// we must match to an effective UUID for the resource,
+			// that is to say, the name value of a res is a helpful
+			// handle, but it is not necessarily a unique identity!
+			// remember, resources can return multiple UUID's each!
+			if resources.UUIDExistsInUUIDs(uuid, vv.GetUUIDs()) {
+				// add edge from: vv -> v
+				if uuid.Reversed() {
+					txt := fmt.Sprintf("AutoEdge: %v[%v] -> %v[%v]", vv.Kind(), vv.GetName(), v.Kind(), v.GetName())
+					log.Printf("Compile: Adding %v", txt)
+					g.AddEdge(vv, v, NewEdge(txt))
+				} else { // edges go the "normal" way, eg: pkg resource
+					txt := fmt.Sprintf("AutoEdge: %v[%v] -> %v[%v]", v.Kind(), v.GetName(), vv.Kind(), vv.GetName())
+					log.Printf("Compile: Adding %v", txt)
+					g.AddEdge(v, vv, NewEdge(txt))
+				}
+				found = true
+				break
+			}
+		}
+		result = append(result, found)
+	}
+	return result
+}
+
+// AutoEdges adds the automatic edges to the graph.
+func (g *Graph) AutoEdges() {
+	log.Println("Compile: Adding AutoEdges...")
+	for _, v := range g.GetVertices() { // for each vertexes autoedges
+		if !v.Meta().AutoEdge { // is the metaparam true?
+			continue
+		}
+		autoEdgeObj := v.AutoEdges()
+		if autoEdgeObj == nil {
+			log.Printf("%v[%v]: Config: No auto edges were found!", v.Kind(), v.GetName())
+			continue // next vertex
+		}
+
+		for { // while the autoEdgeObj has more uuids to add...
+			uuids := autoEdgeObj.Next() // get some!
+			if uuids == nil {
+				log.Printf("%v[%v]: Config: The auto edge list is empty!", v.Kind(), v.GetName())
+				break // inner loop
+			}
+			if global.DEBUG {
+				log.Println("Compile: AutoEdge: UUIDS:")
+				for i, u := range uuids {
+					log.Printf("Compile: AutoEdge: UUID%d: %v", i, u)
+				}
+			}
+
+			// match and add edges
+			result := g.addEdgesByMatchingUUIDS(v, uuids)
+
+			// report back, and find out if we should continue
+			if !autoEdgeObj.Test(result) {
+				break
+			}
+		}
+	}
+}