From c0754f895b2eed0c36978eb16118711490c33885 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20=C5=9Aled=C5=BA?= <michalsledz34@gmail.com>
Date: Thu, 1 Feb 2024 11:16:06 +0100
Subject: [PATCH] Add `ICECandidate.to_json/1` and `ICECandidate.from_json/1`
 (#62)

---
 examples/echo/example.exs           | 19 ++-----------------
 examples/save_to_file/example.exs   | 18 ++----------------
 examples/send_from_file/example.exs | 19 ++-----------------
 lib/ex_webrtc/ice_candidate.ex      | 25 +++++++++++++++++++++++++
 4 files changed, 31 insertions(+), 50 deletions(-)

diff --git a/examples/echo/example.exs b/examples/echo/example.exs
index ceb24c7b..dedf913c 100644
--- a/examples/echo/example.exs
+++ b/examples/echo/example.exs
@@ -127,16 +127,8 @@ defmodule Peer do
 
   defp handle_ws_message(%{"type" => "ice", "data" => data}, state) do
     Logger.info("Received remote ICE candidate: #{inspect(data)}")
-
-    candidate = %ICECandidate{
-      candidate: data["candidate"],
-      sdp_mid: data["sdpMid"],
-      sdp_m_line_index: data["sdpMLineIndex"],
-      username_fragment: data["usernameFragment"]
-    }
-
+    candidate = ICECandidate.from_json(data)
     :ok = PeerConnection.add_ice_candidate(state.peer_connection, candidate)
-
     state
   end
 
@@ -146,14 +138,7 @@ defmodule Peer do
   end
 
   defp handle_webrtc_message({:ice_candidate, candidate}, state) do
-    candidate = %{
-      "candidate" => candidate.candidate,
-      "sdpMid" => candidate.sdp_mid,
-      "sdpMLineIndex" => candidate.sdp_m_line_index,
-      "usernameFragment" => candidate.username_fragment
-    }
-
-    msg = %{"type" => "ice", "data" => candidate}
+    msg = %{"type" => "ice", "data" => ICECandidate.to_json(candidate))
     :gun.ws_send(state.conn, state.stream, {:text, Jason.encode!(msg)})
     state
   end
diff --git a/examples/save_to_file/example.exs b/examples/save_to_file/example.exs
index 92e2b1ae..78bcd973 100644
--- a/examples/save_to_file/example.exs
+++ b/examples/save_to_file/example.exs
@@ -122,14 +122,7 @@ defmodule Peer do
 
   defp handle_ws_message(%{"type" => "ice", "data" => data}, state) do
     Logger.info("Received remote ICE candidate: #{inspect(data)}")
-
-    candidate = %ICECandidate{
-      candidate: data["candidate"],
-      sdp_mid: data["sdpMid"],
-      sdp_m_line_index: data["sdpMLineIndex"],
-      username_fragment: data["usernameFragment"]
-    }
-
+    candidate = ICECandidate.from_json(data)
     :ok = PeerConnection.add_ice_candidate(state.peer_connection, candidate)
   end
 
@@ -146,14 +139,7 @@ defmodule Peer do
   end
 
   defp handle_webrtc_message({:ice_candidate, candidate}, state) do
-    candidate = %{
-      "candidate" => candidate.candidate,
-      "sdpMid" => candidate.sdp_mid,
-      "sdpMLineIndex" => candidate.sdp_m_line_index,
-      "usernameFragment" => candidate.username_fragment
-    }
-
-    msg = %{"type" => "ice", "data" => candidate}
+    msg = %{"type" => "ice", "data" => ICECandidate.to_json(candidate)}
     :gun.ws_send(state.conn, state.stream, {:text, Jason.encode!(msg)})
     state
   end
diff --git a/examples/send_from_file/example.exs b/examples/send_from_file/example.exs
index da124bdf..db62e117 100644
--- a/examples/send_from_file/example.exs
+++ b/examples/send_from_file/example.exs
@@ -219,16 +219,8 @@ defmodule Peer do
 
   defp handle_ws_message(%{"type" => "ice", "data" => data}, state) do
     Logger.info("Received remote ICE candidate: #{inspect(data)}")
-
-    candidate = %ICECandidate{
-      candidate: data["candidate"],
-      sdp_mid: data["sdpMid"],
-      sdp_m_line_index: data["sdpMLineIndex"],
-      username_fragment: data["usernameFragment"]
-    }
-
+    candidate = ICECandidate.from_json(data)
     :ok = PeerConnection.add_ice_candidate(state.peer_connection, candidate)
-
     state
   end
 
@@ -238,14 +230,7 @@ defmodule Peer do
   end
 
   defp handle_webrtc_message({:ice_candidate, candidate}, state) do
-    candidate = %{
-      "candidate" => candidate.candidate,
-      "sdpMid" => candidate.sdp_mid,
-      "sdpMLineIndex" => candidate.sdp_m_line_index,
-      "usernameFragment" => candidate.username_fragment
-    }
-
-    msg = %{"type" => "ice", "data" => candidate}
+    msg = %{"type" => "ice", "data" => ICECandidate.to_json(candidate)}
     :gun.ws_send(state.conn, state.stream, {:text, Jason.encode!(msg)})
     state
   end
diff --git a/lib/ex_webrtc/ice_candidate.ex b/lib/ex_webrtc/ice_candidate.ex
index 47c2facd..068ba118 100644
--- a/lib/ex_webrtc/ice_candidate.ex
+++ b/lib/ex_webrtc/ice_candidate.ex
@@ -11,4 +11,29 @@ defmodule ExWebRTC.ICECandidate do
         }
 
   defstruct [:candidate, :username_fragment, :sdp_mid, :sdp_m_line_index]
+
+  @spec to_json(t()) :: %{String.t() => String.t()}
+  def to_json(%__MODULE__{} = c) do
+    %{
+      "candidate" => c.candidate,
+      "sdpMid" => c.sdp_mid,
+      "sdpMLineIndex" => c.sdp_m_line_index,
+      "usernameFragment" => c.username_fragment
+    }
+  end
+
+  @spec from_json(%{String.t() => String.t()}) :: t()
+  def from_json(%{
+        "candidate" => c,
+        "sdpMid" => mid,
+        "sdpMLineIndex" => mline_idx,
+        "usernameFragment" => ufrag
+      }) do
+    %__MODULE__{
+      candidate: c,
+      sdp_mid: mid,
+      sdp_m_line_index: mline_idx,
+      username_fragment: ufrag
+    }
+  end
 end