Add functions to obtain ICE candidates (#26)

Author: LVala

lib/ex_ice/ice_agent.ex

@@ -40,7 +40,7 @@ defmodule ExICE.ICEAgent do
            gathering_state_change()
            | connection_state_change()
            | {:data, binary()}
-           | {:new_candidate, binary()}}
+           | {:new_candidate, String.t()}}
 
   @typedoc """
   ICE Agent configuration options.
@@ -119,6 +119,25 @@ defmodule ExICE.ICEAgent do
     GenServer.call(ice_agent, :get_local_credentials)
   end
 
+  @doc """
+  Gets all local candidates that have already been gathered.
+  """
+  @spec get_local_candidates(pid()) :: [String.t()]
+  def get_local_candidates(ice_agent) do
+    GenServer.call(ice_agent, :get_local_candidates)
+  end
+
+  @doc """
+  Gets all remote candidates.
+
+  This includes candidates supplied by `add_remote_candidate/2` and candidates
+  discovered during ICE connection establishment process (so called `prflx` candidates).
+  """
+  @spec get_remote_candidates(pid()) :: [String.t()]
+  def get_remote_candidates(ice_agent) do
+    GenServer.call(ice_agent, :get_remote_candidates)
+  end
+
   @doc """
   Sets remote credentials.
 
@@ -256,6 +275,18 @@ defmodule ExICE.ICEAgent do
     {:reply, {:ok, local_ufrag, local_pwd}, state}
   end
 
+  @impl true
+  def handle_call(:get_local_candidates, _from, state) do
+    candidates = ICEAgent.Impl.get_local_candidates(state.ice_agent)
+    {:reply, candidates, state}
+  end
+
+  @impl true
+  def handle_call(:get_remote_candidates, _from, state) do
+    candidates = ICEAgent.Impl.get_remote_candidates(state.ice_agent)
+    {:reply, candidates, state}
+  end
+
   @impl true
   def handle_call(:get_stats, _from, state) do
     stats = ICEAgent.Impl.get_stats(state.ice_agent)

lib/ex_ice/ice_agent/impl.ex

@@ -127,6 +127,16 @@ defmodule ExICE.ICEAgent.Impl do
     {ice_agent.local_ufrag, ice_agent.local_pwd}
   end
 
+  @spec get_local_candidates(t()) :: [binary()]
+  def get_local_candidates(ice_agent) do
+    Enum.map(ice_agent.local_cands, &Candidate.marshal/1)
+  end
+
+  @spec get_remote_candidates(t()) :: [binary()]
+  def get_remote_candidates(ice_agent) do
+    Enum.map(ice_agent.remote_cands, &Candidate.marshal/1)
+  end
+
   @spec get_stats(t()) :: map()
   def get_stats(ice_agent) do
     %{