From f7afaac0ef10d228d6ecf5ed5e47b4ea7a9bab0e Mon Sep 17 00:00:00 2001
From: Xie Yuheng <xyheme@gmail.com>
Date: Sun, 30 Jul 2023 18:52:08 +0800
Subject: [PATCH] `connect` should not reconnect

---
 src/lang/graph/cleanUpWires.ts | 13 ++++++++-----
 src/lang/graph/connect.ts      |  8 ++++++++
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/lang/graph/cleanUpWires.ts b/src/lang/graph/cleanUpWires.ts
index 3fde1175..3ed3b820 100644
--- a/src/lang/graph/cleanUpWires.ts
+++ b/src/lang/graph/cleanUpWires.ts
@@ -1,18 +1,21 @@
 import { Net } from "./Net"
 import { connect } from "./connect"
-import { removeEdge } from "./removeEdge"
+import { disconnect } from "./disconnect"
 import { removeNode } from "./removeNode"
 
 export function cleanUpWires(net: Net): void {
   for (const wire of net.wires) {
     if (wire.start.connection && wire.end.connection) {
-      removeEdge(net, wire.start.connection.edge)
-      removeEdge(net, wire.end.connection.edge)
-
       removeNode(net, wire.start.node)
       removeNode(net, wire.end.node)
 
-      connect(net, wire.start.connection.port, wire.end.connection.port)
+      const start = wire.start.connection.port
+      const end = wire.end.connection.port
+
+      disconnect(net, wire.start.connection.edge)
+      disconnect(net, wire.end.connection.edge)
+
+      connect(net, start, end)
     }
   }
 
diff --git a/src/lang/graph/connect.ts b/src/lang/graph/connect.ts
index be99e64c..e60124d4 100644
--- a/src/lang/graph/connect.ts
+++ b/src/lang/graph/connect.ts
@@ -4,6 +4,14 @@ import { lookupRuleByPorts } from "../mod/lookupRuleByPorts"
 export function connect(net: Net, start: Port, end: Port): void {
   const rule = lookupRuleByPorts(net.mod, start, end)
 
+  if (start.connection !== undefined) {
+    throw new Error(`[connect] The start port is already connected`)
+  }
+
+  if (end.connection !== undefined) {
+    throw new Error(`[connect] The end port is already connected`)
+  }
+
   if (rule !== undefined) {
     const edge = { start, end, rule }
     start.connection = { edge, port: end }