From f0549c2df8860aee6887b8c9426701ddb5d67cb2 Mon Sep 17 00:00:00 2001
From: Holger Hans Peter Freyther <holger@moiji-mobile.com>
Date: Wed, 28 May 2014 18:21:14 +0200
Subject: [PATCH] command: Be able to parse a MGCP Command

The Command and Response code could and should share parts. Start
with slowly aligning the APIs and begin being able to parse a
command from a string.
---
 callagent/MGCPCommands.st | 70 +++++++++++++++++++++++++++++++--------
 callagent/MGCPParser.st   |  6 +++-
 callagent/Tests.st        | 34 ++++++++++++++-----
 3 files changed, 87 insertions(+), 23 deletions(-)

diff --git a/callagent/MGCPCommands.st b/callagent/MGCPCommands.st
index 91c9fe7..1e316f0 100644
--- a/callagent/MGCPCommands.st
+++ b/callagent/MGCPCommands.st
@@ -16,27 +16,45 @@
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 "
 
-Object subclass: MGCPCommand [
+Object subclass: MGCPCommandBase [
     | transaction endp params sdp |
     <comment: 'I am a command send to a MGCP gateway. I know my timeout
     and such. Each MGCPGateWay can have a MGCPCommand subclass to specify
     certain things. E.g. the endpoint numbering is different'>
     <category: 'OsmoMGCP-callagent'>
 
-    MGCPCommand class >> create: anEndpoint callId: aCallId [
-        ^ (self new)
-	    endpoint: anEndpoint;
-            parameterAdd: 'C: ', aCallId asString;
+    MGCPCommandBase class >> fromDict: nodes [
+        | verb |
+        verb := nodes first.
+        self allSubclassesDo: [:each |
+            each verb = verb
+                ifTrue: [^each parseFromDict: nodes]].
+        ^self error: 'Unknown command verb "%1"' % {verb}.
+    ]
+
+    MGCPCommandBase class >> parseFromDict: nodes [
+        ^self new
+            transactionId: nodes third;
+            endpoint: (nodes at: 5);
+            addParametersInternal: (nodes at: 9);
+            sdp: (nodes at: 10);
             yourself
     ]
 
-    MGCPCommand class >> create: anEndpoint [
+    MGCPCommandBase class >> create: anEndpoint callId: aCallId [
+        ^ (self new)
+	    endpoint: anEndpoint;
+            addParameter: 'C' with: aCallId asString;
+            yourself
+    ]
+
+    MGCPCommandBase class >> create: anEndpoint [
         ^ (self new)
 	    endpoint: anEndpoint;
             yourself
     ]
 
-    MGCPCommand class >> verb [
+    MGCPCommandBase class >> verb [
         <category: 'verb'>
         ^ self subclassResponsibility
     ]
@@ -53,7 +71,29 @@ Object subclass: MGCPCommand [
 
     parameterAdd: aParam [
 	<category: 'private'>
-        self params add: aParam.
+        ^self error: 'This is deprecated. Use >>#addParameter:with:'
+    ]
+
+    addParameter: aKey with: aValue [
+        ^self params add: aKey->aValue.
+    ]
+
+    addParametersInternal: anArray [
+        <category: 'private'>
+        "TODO: Share code with MGCPResponse"
+        anArray do: [:each |
+            self addParameter: each first first asString with: each first fourth].
+    ]
+
+    parameterAt: aKey [
+        ^self parameterAt: aKey ifAbsent: [^self error: 'Parameter not found'].
+    ]
+
+    parameterAt: aKey ifAbsent: aBlock [
+        self params do: [:each |
+            each key = aKey
+                ifTrue: [^each value]].
+        ^aBlock value.
     ]
 
     params [
@@ -85,7 +125,9 @@ Object subclass: MGCPCommand [
         "write the parameters"
         self params do: [:each |
             out
-                nextPutAll: each;
+                nextPutAll: each key;
+                nextPutAll: ': ';
+                nextPutAll: each value;
                 cr; nl.
         ].
 
@@ -100,7 +142,7 @@ Object subclass: MGCPCommand [
     ]
 ]
 
-MGCPCommand subclass: MGCPCRCXCommand [
+MGCPCommandBase subclass: MGCPCRCXCommand [
     <comment: 'I represent a CRCX message'>
     <category: 'OsmoMGCP-Callagent'>
 
@@ -118,7 +160,7 @@ MGCPCommand subclass: MGCPCRCXCommand [
     ]
 ]
 
-MGCPCommand subclass: MGCPMDCXCommand [
+MGCPCommandBase subclass: MGCPMDCXCommand [
     <comment: 'I represent a MDCX message'>
     <category: 'OsmoMGCP-Callagent'>
 
@@ -135,7 +177,7 @@ MGCPCommand subclass: MGCPMDCXCommand [
     ]
 ]
 
-MGCPCommand subclass: MGCPDLCXCommand [
+MGCPCommandBase subclass: MGCPDLCXCommand [
     <comment: 'I represent a DLCX message'>
     <category: 'OsmoMGCP-Callagent'>
 
@@ -150,7 +192,7 @@ MGCPCommand subclass: MGCPDLCXCommand [
     ]
 ]
 
-MGCPCommand subclass: MGCPAUEPComamnd [
+MGCPCommandBase subclass: MGCPAUEPComamnd [
     <comment: 'I represent an AUEP message'>
     <category: 'OsmoMGCP-Callagent'>
 
@@ -165,7 +207,7 @@ MGCPCommand subclass: MGCPAUEPComamnd [
     ]
 ]
 
-MGCPCommand subclass: MGCPOsmoRSIPCommand [
+MGCPCommandBase subclass: MGCPOsmoRSIPCommand [
     <comment: 'I represent an Osmocom Extension to MGCP to reset remote
     mediagateways. The spec is working the other way around.'>
     <category: 'OsmoMGCP-Callagent'>
diff --git a/callagent/MGCPParser.st b/callagent/MGCPParser.st
index a052f55..f05041e 100644
--- a/callagent/MGCPParser.st
+++ b/callagent/MGCPParser.st
@@ -27,11 +27,15 @@ MGCPGrammar subclass: MGCPParser [
 
     MGCPCommand [
         <category: 'extract'>
-        ^ super MGCPCommand => [:nodes | nil]
+        ^ super MGCPCommand => [:nodes | MGCPCommandBase fromDict: nodes]
     ]
 
     MGCPResponse [
         <category: 'extract'>
         ^ super MGCPResponse => [:nodes | MGCPResponse fromDict: nodes]
     ]
+
+    endpointName [
+        ^super endpointName flatten
+    ]
 ]
diff --git a/callagent/Tests.st b/callagent/Tests.st
index d9ce38b..4ec2175 100644
--- a/callagent/Tests.st
+++ b/callagent/Tests.st
@@ -78,8 +78,8 @@ TestCase subclass: MGCPCommandTest [
         trans := MGCPTransaction on: self endpoint of: self callagent.
         trans transactionId: '808080'.
         crcx := (MGCPCRCXCommand createCRCX: self endpoint callId: '4a84ad5d25f')
-                    parameterAdd: 'L: p:20, a:GSM-EFR, nt:IN';
-                    parameterAdd: 'M: recvonly';
+                    addParameter: 'L' with: 'p:20, a:GSM-EFR, nt:IN';
+                    addParameter: 'M' with: 'recvonly';
                     yourself.
         trans command: crcx.
 
@@ -130,8 +130,8 @@ TestCase subclass: MGCPCommandTest [
         trans := MGCPTransaction on: self endpoint of: self callagent.
         trans transactionId: '808080'.
         mdcx := (MGCPMDCXCommand createMDCX: self endpoint callId: '4a84ad5d25f')
-                    parameterAdd: 'L: p:20, a:GSM-EFR, nt:IN';
-                    parameterAdd: 'M: recvonly';
+                    addParameter: 'L' with: 'p:20, a:GSM-EFR, nt:IN';
+                    addParameter: 'M' with: 'recvonly';
                     sdp: self exampleSDP;
                     yourself.
         trans command: mdcx.
@@ -224,8 +224,8 @@ TestCase subclass: MGCPTransactionTest [
 
         trans := MGCPShortTransaction on: self endpoint of: self timeoutCallagent.
         crcx := (MGCPCRCXCommand createCRCX: self endpoint callId: '4a84ad5d25f')
-                    parameterAdd: 'L: p:20, a:GSM-EFR, nt:IN';
-                    parameterAdd: 'M: recvonly';
+                    addParameter: 'L' with: 'p:20, a:GSM-EFR, nt:IN';
+                    addParameter: 'M' with: 'recvonly';
                     yourself.
         trans command: crcx.
 
@@ -248,8 +248,8 @@ TestCase subclass: MGCPTransactionTest [
 
         trans := MGCPShortTransaction on: self endpoint of: self dropAgent.
         crcx := (MGCPCRCXCommand createCRCX: self endpoint callId: '4a84ad5d25f')
-                    parameterAdd: 'L: p:20, a:GSM-EFR, nt:IN';
-                    parameterAdd: 'M: recvonly';
+                    addParameter: 'L' with: 'p:20, a:GSM-EFR, nt:IN';
+                    addParameter: 'M' with: 'recvonly';
                     yourself.
         trans command: crcx.
 
@@ -352,10 +352,28 @@ TestCase subclass: MGCPEndpointAllocTest [
 PP.PPCompositeParserTest subclass: MGCPParserTest [
     <category: 'OsmoMGCP-Callagent-Tests'>
 
+    MGCPParserTest class >> crcxMessage [
+        ^String streamContents: [:stream |
+            stream
+                nextPutAll: 'CRCX 1 14@mgw MGCP 1.0'; cr; nl;
+                nextPutAll: 'C: 4a84ad5d25f'; cr; nl;
+                nextPutAll: 'L: p:20, a:GSM-EFR, nt:IN'; cr; nl;
+                nextPutAll: 'M: recvonly'; cr; nl]
+    ]
+
     parserClass [
         ^MGCPParser
     ]
 
+    testParseCRCX [
+        | crcx |
+        crcx := self parse: self class crcxMessage.
+
+        self assert: crcx class verb equals: 'CRCX'.
+        self assert: (crcx parameterAt: 'M') equals: 'recvonly'.
+        self assert: crcx asDatagram equals: self class crcxMessage.
+    ]
+
     testRespParse [
         | nl res sdp |
         nl := Character cr asString, Character nl asString.