From 25eb62a8f9f713458a2a88928c9813c4b2bb9a6f Mon Sep 17 00:00:00 2001
From: Philippe PITTOLI <p.pittoli@unistra.fr>
Date: Mon, 3 Feb 2020 23:50:13 +0100
Subject: [PATCH] IPC::Message#from_json and #to_json

---
 src/ipc/connection.cr | 13 ++++---
 src/ipc/message.cr    | 91 +++++++++++++++++++++++++++----------------
 2 files changed, 66 insertions(+), 38 deletions(-)

diff --git a/src/ipc/connection.cr b/src/ipc/connection.cr
index c1da50d..fea663f 100644
--- a/src/ipc/connection.cr
+++ b/src/ipc/connection.cr
@@ -41,8 +41,11 @@ class IPC::Connection
 		@connection.fd
 	end
 
-	def send(type : UInt8, payload : Bytes)
-		message = LibIPC::Message.new type: LibIPC::MessageType::Data.to_u8, user_type: type, length: payload.bytesize, payload: payload.to_unsafe
+	def send(utype : UInt8, payload : Bytes)
+		message = LibIPC::Message.new type: LibIPC::MessageType::Data.to_u8,
+			user_type: utype,
+			length: payload.bytesize,
+			payload: payload.to_unsafe
 
 		r = LibIPC.ipc_write(self.pointer, pointerof(message))
 		if r.error_code != 0
@@ -51,12 +54,12 @@ class IPC::Connection
 		end
 	end
 
-	def send(type : UInt8, payload : String)
-		send(type, Bytes.new(payload.to_unsafe, payload.bytesize))
+	def send(utype : UInt8, payload : String)
+		send(utype, Bytes.new(payload.to_unsafe, payload.bytesize))
 	end
 
 	def send(message : IPC::Message)
-		send(message.type, message.payload)
+		send(message.utype, message.payload)
 	end
 
 	def read
diff --git a/src/ipc/message.cr b/src/ipc/message.cr
index 8b2fa79..0276e9f 100644
--- a/src/ipc/message.cr
+++ b/src/ipc/message.cr
@@ -1,7 +1,63 @@
 require "./lowlevel"
+require "json"
+
+# JSON is currently used for messages over websockets
+# At some point, this will be replaced by the CBOR format
 
 class IPC::Message
 
+	property mtype   : UInt8   # libipc message type
+	property utype   : UInt8   # libipc user message type
+	property payload : Bytes
+
+	struct JSONMessage
+		include JSON::Serializable
+
+		property mtype : UInt8 = 1  # libipc message type
+		property utype : UInt8      # libipc user message type
+		property payload : String
+
+		def initialize(@utype, @payload, @mtype = 1)
+		end
+	end
+
+	def self.from_json (str : String)
+		jsonmessage = JSONMessage.from_json str
+
+		IPC::Message.new jsonmessage.mtype, jsonmessage.utype, jsonmessage.payload
+	end
+
+	def to_json
+		JSONMessage.new(@utype, String.new(@payload), @mtype).to_json
+	end
+
+	def initialize(message : Pointer(LibIPC::Message))
+		if message.null?
+			@mtype = LibIPC::MessageType::Error.to_u8
+			@utype = 0
+			@payload = Bytes.new "".to_unsafe, 0
+		else
+			m = message.value
+			@mtype = m.type
+			@utype = m.user_type
+			@payload = Bytes.new m.payload, m.length
+		end
+	end
+
+	def initialize(message : LibIPC::Message)
+		initialize pointerof(message)
+	end
+
+	def initialize(mtype, utype, payload : Bytes)
+		@mtype = mtype.to_u8
+		@utype = utype
+		@payload = payload
+	end
+
+	def initialize(mtype, utype, payload : String)
+		initialize(mtype, utype, Bytes.new(payload.to_unsafe, payload.bytesize))
+	end
+
 	def self.to_packet (user_type : Int, message : String)
 		payload = Bytes.new (6 + message.to_slice.size)
 
@@ -16,43 +72,12 @@ class IPC::Message
 		return payload
 	end
 
-	getter mtype : UInt8   # libipc message type
-	property type : UInt8    # libipc user message type
-	property payload : Bytes
-
-	def initialize(message : Pointer(LibIPC::Message))
-		if message.null?
-			@mtype = LibIPC::MessageType::Error.to_u8
-			@type = 0
-			@payload = Bytes.new "".to_unsafe, 0
-		else
-			m = message.value
-			@mtype = m.type
-			@type = m.user_type
-			@payload = Bytes.new m.payload, m.length
-		end
-	end
-
-	def initialize(message : LibIPC::Message)
-		initialize pointerof(message)
-	end
-
-	def initialize(mtype, type, payload : Bytes)
-		@mtype = mtype.to_u8
-		@type = type
-		@payload = payload
-	end
-
-	def initialize(mtype, type, payload : String)
-		initialize(mtype, type, Bytes.new(payload.to_unsafe, payload.bytesize))
-	end
-
 	def to_packet
-		IPC::Message.to_packet @type, String.new(@payload)
+		IPC::Message.to_packet @utype, String.new(@payload)
 	end
 
 	def to_s
-		"(internal) type #{@mtype}, (user) type #{@type}, payload #{String.new @payload}"
+		"(internal) utype #{@mtype}, (user) utype #{@utype}, payload #{String.new @payload}"
 	end
 
 end