From e4f0688a02335e8b8d9ff7f47db4fc2aa7646b9b Mon Sep 17 00:00:00 2001
From: Steve-Mcl <sdmclaughlin@gmail.com>
Date: Thu, 24 Feb 2022 19:46:21 +0000
Subject: [PATCH] dynamic link target 1st draft

---
 .../@node-red/nodes/core/common/60-link.html  |  31 ++-
 .../@node-red/nodes/core/common/60-link.js    | 198 ++++++++++++++++--
 .../nodes/locales/en-US/messages.json         |   4 +
 3 files changed, 209 insertions(+), 24 deletions(-)

diff --git a/packages/node_modules/@node-red/nodes/core/common/60-link.html b/packages/node_modules/@node-red/nodes/core/common/60-link.html
index f3fabba59..77d69f02f 100644
--- a/packages/node_modules/@node-red/nodes/core/common/60-link.html
+++ b/packages/node_modules/@node-red/nodes/core/common/60-link.html
@@ -32,8 +32,17 @@
         <label for="node-input-timeout"><span data-i18n="exec.label.timeout"></span></label>
         <input type="text" id="node-input-timeout" placeholder="30" style="width: 70px; margin-right: 5px;"><span data-i18n="inject.seconds"></span>
     </div>
-    <div style="position:relative; height: 30px; text-align: right;"><div style="display:inline-block"><input type="text" id="node-input-link-target-filter"></div></div>
-    <div class="form-row node-input-link-row"></div>
+    <div class="form-row">
+        <label for="node-input-linkType" data-i18n="link.linkCallType"></label>
+        <select id="node-input-linkType" style="width: 70%">
+            <option value="static" data-i18n="link.staticLinkCall"></option>
+            <option value="dynamic" data-i18n="link.dynamicLinkCall"></option>
+        </select>
+    </div>
+    <div class="link-call-target-tree" style="position:relative; height: 30px; text-align: right;">
+        <div style="display:inline-block"><input type="text" id="node-input-link-target-filter"></div>
+    </div>
+    <div class="form-row node-input-link-row link-call-target-tree"></div>
 </script>
 
 <script type="text/javascript">
@@ -259,6 +268,7 @@
         defaults: {
             name: {value:""},
             links: { value: [], type:"link in[]"},
+            linkType: {value:"static"},
             timeout: { value: "30", validate:RED.validators.number(true) }
         },
         inputs: 1,
@@ -271,7 +281,9 @@
             if (this.name) {
                 return this.name;
             }
-            if (this.links.length > 0) {
+            if (this.linkType === "dynamic") {
+                return this._("link.dynamicLinkLabel");
+            } else if (this.links.length > 0) {
                 var targetNode = RED.nodes.node(this.links[0]);
                 return targetNode && (targetNode.name || this._("link.linkCall"));
             }
@@ -281,6 +293,19 @@
             return this.name?"node_label_italic":"";
         },
         oneditprepare: function() {
+            console.log("link call oneditprepare")
+            const updateVisibility = function() {
+                const static = $('#node-input-linkType').val() !== "dynamic";
+                if(static) {
+                    $("div.link-call-target-tree").show();
+                } else {
+                    $("div.link-call-target-tree").hide();
+                }
+            }
+            $("#node-input-linkType").on("change",function(d){
+                updateVisibility();
+            });
+            updateVisibility();
             onEditPrepare(this,"link in");
         },
         oneditsave: function() {
diff --git a/packages/node_modules/@node-red/nodes/core/common/60-link.js b/packages/node_modules/@node-red/nodes/core/common/60-link.js
index 53404e446..a3fe82de7 100644
--- a/packages/node_modules/@node-red/nodes/core/common/60-link.js
+++ b/packages/node_modules/@node-red/nodes/core/common/60-link.js
@@ -16,8 +16,107 @@
 
 module.exports = function(RED) {
     "use strict";
-
     const crypto = require("crypto");
+    const targetCache = (function() {
+        const name2id = {};
+        let id2target = {};
+        return {
+            /** @type {((node: Node, [flowName]: string) => string) & ((nodeName: string, flowName: string) => string))} */
+            generateLookupName(node, flowName) {
+                if(!flowName) {
+                    flowName = node._flow.flow.label
+                }
+                if(node instanceof LinkInNode) {
+                    return `${flowName}/${node.name}`;
+                }
+                return `${flowName}/${node}`;
+            },
+            add(node) {
+                const id = node.id;
+                const nodeName = node.name;
+                if(!nodeName){ return null;} //node must be named
+                const flowName = node._flow.flow.label;
+                const lookupName = targetCache.generateLookupName(nodeName, flowName);
+                console.log(`Adding node '${lookupName}' (${id}) to cache`)
+                if(name2id[lookupName] && name2id[lookupName].id !== id) {
+                    //TODO: reassignment? duplate lookupName?  throw error or warning?
+                    console.warn(`💣 '${lookupName}' is already assigned to node with ID: ${name2id[lookupName]} `)
+                }
+                
+                name2id[lookupName] = id;
+                id2target[id] = {
+                    lookupName,
+                    nodeName,
+                    flowName,
+                    id
+                }
+                return id2target[id];
+            },
+            remove(node) {
+                if(node.name) console.log(`Removing node '${targetCache.generateLookupName(node)}' (${node.id})`)
+                const target = id2target[node.id];
+                targetCache._removeById(node.id);
+                if(target) {
+                    targetCache._removeById(target.id);
+                    targetCache._removeByName(target.lookupName);
+                }
+            },
+            getTarget(lookupName) {
+                const id = name2id[lookupName];
+                const target = id2target[id];
+                return target;
+            },
+            verify(cachedTarget, targetNode, nodeName, flowName) {
+                cachedTarget = cachedTarget || {};
+                targetNode = targetNode || {};
+                const _lookupName = targetCache.generateLookupName(nodeName, flowName);
+                const cachedId = name2id[_lookupName];
+   
+                const idOK = cachedTarget.id === targetNode.id && cachedId === targetNode.id;
+                const nodeNameOK = nodeName === cachedTarget.nodeName && cachedTarget.nodeName == targetNode.name;
+                const flowNameOK = flowName === cachedTarget.flowName && cachedTarget.flowName == targetNode._flow.flow.label;
+                const lookupNameOK = _lookupName === cachedTarget.lookupName;
+                if(idOK && nodeNameOK && flowNameOK && lookupNameOK) {
+                    return true;
+                }
+                console.warn(`verify(cachedTarget, targetNode, nodeName, flowName) failed: `, {cachedTarget, targetNode, nodeName, flowName})
+                console.warn(`> idOK:${idOK}, nodeNameOK:${nodeNameOK}, flowNameOK:${flowNameOK}, lookupNameOK:${lookupNameOK}`)
+                targetCache._removeById(targetNode.id);
+                targetCache._removeById(cachedId);
+                targetCache._removeByName(_lookupName);
+                targetCache._removeByName(cachedTarget.lookupName);
+                return false;
+            },
+            _removeById(id) {
+                if(!id) {
+                    return;
+                }
+                const target = id2target[id];
+                if(target && target.lookupName) {
+                    delete name2id[target.lookupName];
+                }
+                delete id2target[id];
+            },
+            _removeByName(lookupName) {
+                if(!lookupName) {
+                    return;
+                }
+                var id = name2id[lookupName];
+                var target = id2target[id];
+                if(id) {
+                    delete id2target[id];
+                }
+                if(target && target.lookupName) {
+                    delete name2id[target.lookupName];
+                }
+                delete name2id[lookupName];
+            },
+            clear() {
+                name2id = {};
+                id2target = {};
+            }
+        }
+    })();
 
     function LinkInNode(n) {
         RED.nodes.createNode(this,n);
@@ -27,12 +126,27 @@ module.exports = function(RED) {
             msg._event = n.event;
             node.receive(msg);
         }
+        //update target cache for link calls
+        function updateCache(o) {
+            console.log(node.id, node.name, o.config.rev, o)
+            const changed = o.diff.changed.includes(node.id);
+            const added = o.diff.added.includes(node.id);
+            if(changed) {
+                targetCache.remove(node);
+            }
+            if((changed || added) && node.name) {
+                targetCache.add(node);
+            }
+        }
+
+        RED.events.on("flows:started", updateCache);
         RED.events.on(event,handler);
         this.on("input", function(msg, send, done) {
             send(msg);
             done();
         });
         this.on("close",function() {
+            targetCache.remove(node);
             RED.events.removeListener(event,handler);
         });
     }
@@ -74,31 +188,73 @@ module.exports = function(RED) {
     function LinkCallNode(n) {
         RED.nodes.createNode(this,n);
         const node = this;
-        const target = n.links[0];
+        const staticTarget = n.links[0];
+        const linkType = n.linkType;
         const messageEvents = {};
-        let timeout = parseFloat(n.timeout || "30")*1000;
+
+        let timeout = parseFloat(n.timeout || "30") * 1000;
         if (isNaN(timeout)) {
             timeout = 30000;
         }
-
-        this.on("input", function(msg, send, done) {
-            msg._linkSource = msg._linkSource || [];
-            const messageEvent = {
-                id: crypto.randomBytes(14).toString('hex'),
-                node: node.id,
+        function findNode(target) {
+            let foundNode = null;
+            switch (typeof target) {
+                case "string":
+                    const nameParts = target.split("/");
+                    switch (nameParts.length) {
+                        case 1:
+                            target = { nodeName: nameParts[0], flowName: node._flow.flow.label }
+                            break;
+                        case 2:
+                            target = { nodeName: nameParts[1], flowName: nameParts[0] }
+                            break;
+                        default:
+                            target = { nodeName: target, flowName: node._flow.flow.label }
+                    }
+                case "object":
+                    break;
+                default:
+                    throw new Error("Invalid target");
             }
-            messageEvents[messageEvent.id] = {
-                msg: RED.util.cloneMessage(msg),
-                send,
-                done,
-                ts: setTimeout(function() {
-                    timeoutMessage(messageEvent.id)
-                }, timeout )
-            };
-            msg._linkSource.push(messageEvent);
-            var targetNode = RED.nodes.getNode(target);
-            if (targetNode) {
-                targetNode.receive(msg);
+            if(!target.nodeName || typeof target.nodeName !== "string") {
+                throw new Error("Link call target name invalid")
+            }
+            if(!target.flowName || typeof target.flowName !== "string") {
+                throw new Error("Link call target flow name invalid")
+            }
+            const lookupName = targetCache.generateLookupName(target.nodeName, target.flowName);
+            //const targetNode = targetCache.getNode(lookupName);
+            const cachedTarget = targetCache.getTarget(lookupName);
+            if (cachedTarget) {
+                foundNode = RED.nodes.getNode(cachedTarget.id);
+                if (targetCache.verify(cachedTarget, foundNode, target.nodeName, target.flowName)) {
+                    return foundNode;
+                }
+            }
+            throw new Error(`Link in node not found: ${lookupName}`);
+        }
+        this.on("input", function(msg, send, done) {
+            try {
+                let targetNode = linkType == "dynamic" ? findNode(msg.target) : RED.nodes.getNode(staticTarget);
+                if (targetNode && targetNode instanceof LinkInNode) {
+                    msg._linkSource = msg._linkSource || [];
+                    const messageEvent = {
+                        id: crypto.randomBytes(14).toString('hex'),
+                        node: node.id,
+                    }        
+                    messageEvents[messageEvent.id] = {
+                        msg: RED.util.cloneMessage(msg),
+                        send,
+                        done,
+                        ts: setTimeout(function() {
+                            timeoutMessage(messageEvent.id)
+                        }, timeout )
+                    };
+                    msg._linkSource.push(messageEvent);
+                    targetNode.receive(msg);
+                }  
+            } catch (error) {
+                node.error(error, msg);
             }
         });
 
diff --git a/packages/node_modules/@node-red/nodes/locales/en-US/messages.json b/packages/node_modules/@node-red/nodes/locales/en-US/messages.json
index ecc5d905c..ec09e01b1 100755
--- a/packages/node_modules/@node-red/nodes/locales/en-US/messages.json
+++ b/packages/node_modules/@node-red/nodes/locales/en-US/messages.json
@@ -170,6 +170,10 @@
         "outMode": "Mode",
         "sendToAll": "Send to all connected link nodes",
         "returnToCaller": "Return to calling link node",
+        "linkCallType": "Link Type",
+        "staticLinkCall": "Fixed target",
+        "dynamicLinkCall": "Dynamic target (msg.target)",
+        "dynamicLinkLabel": "Dynamic",
         "error": {
             "missingReturn": "Missing return node information"
         }