From 0281a9c3d07033bb17b8d655f73e55d8a73b3420 Mon Sep 17 00:00:00 2001
From: Nick O'Leary <nick.oleary@gmail.com>
Date: Tue, 13 Aug 2019 20:42:54 +0100
Subject: [PATCH] Add initial core:layout-flow action

---
 .../editor-client/src/js/ui/view-tools.js     | 164 ++++++++++++++++++
 1 file changed, 164 insertions(+)

diff --git a/packages/node_modules/@node-red/editor-client/src/js/ui/view-tools.js b/packages/node_modules/@node-red/editor-client/src/js/ui/view-tools.js
index 0814892be..66af9c083 100644
--- a/packages/node_modules/@node-red/editor-client/src/js/ui/view-tools.js
+++ b/packages/node_modules/@node-red/editor-client/src/js/ui/view-tools.js
@@ -108,6 +108,168 @@ RED.view.tools = (function() {
         }
     }
 
+    function layoutFlow() {
+
+        var selection = RED.view.selection();
+        if (!selection.nodes || selection.nodes.length !== 1) {
+            RED.notify("Select exactly one node");
+            return;
+        }
+        var ns = RED.nodes.getAllFlowNodes(selection.nodes[0]);
+
+        // Find Input node
+
+        var nodes = {};
+        var minRank = 0;
+        var stack = [];
+        var candidateInputs = {};
+        var candidateOutputs = {};
+        ns.forEach(function(n) {
+            candidateInputs[n.id] = n;
+            candidateOutputs[n.id] = n;
+            nodes[n.id] = {
+                n:n,
+                i:[],
+                o:[],
+                d:-1, // depth from start
+                r:-1, // rank order at that depth
+                downstream: 0
+            }
+        });
+        RED.nodes.eachLink(function(link) {
+            if (nodes[link.source.id] || nodes[link.target.id]) {
+                nodes[link.source.id].o.push(link.target.id);
+                nodes[link.target.id].i.push(link.source.id);
+                delete candidateInputs[link.target.id]
+                delete candidateOutputs[link.source.id]
+            }
+        })
+
+        var inputs = Object.keys(candidateInputs);
+        var outputs = Object.keys(candidateOutputs);
+
+        if (inputs.length > 1) {
+            RED.notify("Multiple start points - bailing")
+            return;
+        }
+
+       if (outputs.length === 0) {
+           RED.notify("No outputs - is this a big loop? Bailing");
+           return;
+       }
+
+        function applyDepth(id,d) {
+            if (nodes[id].d < d) {
+                nodes[id].d = d;
+                nodes[id].o.forEach(function(nid) {
+                    applyDepth(nid,d+1);
+                })
+            }
+        }
+        applyDepth(inputs[0],0)
+
+        function calculateDownstream(id,downstream) {
+            nodes[id].downstream += downstream;
+            nodes[id].i.forEach(function(nid) {
+                calculateDownstream(nid, nodes[id].downstream+1);
+            })
+        }
+        outputs.forEach(function(id) {
+            calculateDownstream(id, 0)
+        })
+
+        var ranks = {};
+        function rankNodes(node) {
+            if (node.r === -1) {
+                ranks[node.d] = ranks[node.d] || [];
+                node.r = ranks[node.d].length;
+                ranks[node.d].push(node);
+                node.o.sort(function(a,b) {
+                    return nodes[b].downstream - nodes[a].downstream
+                })
+                node.o.forEach(function(nid) {
+                    rankNodes(nodes[nid])
+                })
+            }
+        }
+        rankNodes(nodes[inputs[0]]);
+        function shuffleRanks(node) {
+            var pushed = false;
+            if (node.o.length > 1) {
+                var outputs = node.o.slice(0);
+                outputs.sort(function(a,b) {
+                    if (nodes[a].d === nodes[b].d) {
+                        return nodes[a].r - nodes[b].r;
+                    } else {
+                        return nodes[b].d - nodes[a].d;
+                    }
+                })
+                // outputs.forEach(function(o,i) { console.log(" ",i," + "+nodes[o].n.type," d:",nodes[o].d," r:",nodes[o].r)});
+                var rank = nodes[outputs[0]].r;
+                var depth = nodes[outputs[0]].d;
+                for (var i=1;i<outputs.length;i++) {
+                    // console.log(outputs[i]);
+                    var n = nodes[outputs[i]];
+                    if (n.d !== depth && n.r === rank) {
+                        // need to move n down one.
+                        var r = n.r;
+                        ns.forEach(function(_n) {
+                            var nn = nodes[_n.id];
+                            if (nn.d >= n.d && nn.d < depth && nn.r >= r) {
+                                pushed = true;
+                                nn.r++;
+                            }
+                        })
+                    }
+                    depth = n.d;
+                    rank = n.r;
+                }
+            }
+            node.o.forEach(function(n) {
+                pushed = pushed || shuffleRanks(nodes[n])
+            })
+            return pushed;
+        }
+        var shuffle = function() {
+            if (shuffleRanks(nodes[inputs[0]])) {
+                shuffle();
+            }
+        }
+        shuffle();
+
+
+        var x = nodes[inputs[0]].n.x;
+        var y = nodes[inputs[0]].n.y;
+        var changedNodes = [];
+        ns.forEach(function(n) {
+            var d = nodes[n.id].d;
+            var r = nodes[n.id].r;
+
+            changedNodes.push({
+                n:n,
+                ox: n.x,
+                oy: n.y,
+                moved: n.moved
+            });
+
+            n.x = x + d*200;
+            n.y = y + r*50;
+            n.dirty = true;
+            // n.dirtyStatus = true;
+            // n.status = {
+            //     text:"d"+d+" : r"+r+" : ds"+nodes[n.id].downstream
+            // }
+        });
+
+        if (changedNodes.length > 0) {
+            RED.history.push({t:"move",nodes:changedNodes,dirty:RED.nodes.dirty()});
+            RED.nodes.dirty(true);
+            RED.view.redraw(true);
+        }
+
+    }
+
+
     return {
         init: function() {
             RED.actions.add("core:align-selection-to-grid", alignToGrid);
@@ -121,6 +283,8 @@ RED.view.tools = (function() {
             RED.actions.add("core:step-selection-right", function() { moveSelection(RED.view.gridSize(),0);});
             RED.actions.add("core:step-selection-down", function() { moveSelection(0,RED.view.gridSize());});
             RED.actions.add("core:step-selection-left", function() { moveSelection(-RED.view.gridSize(),0);});
+
+            RED.actions.add("core:layout-flow", function() { layoutFlow() })
         },
         /**
          * Aligns all selected nodes to the current grid