move last post to agent, update poll interval

diff --git a/lib/notifier/application.ex b/lib/notifier/application.ex
index f59a548f9ffd12e3bd500b85e86336c8f2af7f5d..7314521ac24e62e864faeef961e27e96e8287890 100644 (file)
--- a/lib/notifier/application.ex
+++ b/lib/notifier/application.ex
@@ -38,6 +38,7 @@ defmodule Notifier.Application do
          server_name_indication: ~c"#{sni}",
          depth: 99
        ]},
+      FBGraph.LastPost,
       {FBGraph.Supervisor,
        ids: fb_ids, notifier: Proton, http: HTTPPool, from: username, notify: [notify]}
     ]

diff --git a/lib/notifier/fb_graph/last_post.ex b/lib/notifier/fb_graph/last_post.ex
new file mode 100644 (file)
index 0000000..c062c7c
--- /dev/null
+++ b/lib/notifier/fb_graph/last_post.ex
@@ -0,0 +1,17 @@
+defmodule Notifier.FBGraph.LastPost do
+  use Agent
+
+  def start_link(_) do
+    Agent.start_link(fn -> %{} end, name: __MODULE__)
+  end
+
+  def set(id, post) do
+    Agent.update(__MODULE__, fn state ->
+      Map.put(state, id, post)
+    end)
+  end
+
+  def get(id) do
+    Agent.get(__MODULE__, fn state -> Map.get(state, id, %{id: nil}) end)
+  end
+end

diff --git a/lib/notifier/fb_graph/worker.ex b/lib/notifier/fb_graph/worker.ex
index 0cbad3058743260367aa511f4390010e6abac89b..d1886dd10a4d203973342270537df1de13c761f9 100644 (file)
--- a/lib/notifier/fb_graph/worker.ex
+++ b/lib/notifier/fb_graph/worker.ex
@@ -2,6 +2,7 @@ defmodule Notifier.FBGraph.Worker do
   use GenServer
   require Logger
 
+  alias Notifier.FBGraph.LastPost
   alias Notifier.SMTP
 
   @graph_url "https://www.facebook.com/api/graphql"
@@ -27,34 +28,43 @@ defmodule Notifier.FBGraph.Worker do
        notifier: notifier,
        from: from,
        http: http,
-       notify: notify,
-       last_post: %{id: nil}
+       notify: notify
      }, {:continue, :get_latest_post}}
   end
 
   def handle_continue(:get_latest_post, %{http: http, id: id} = state) do
-    last_post =
-      :post
-      |> Finch.build(@graph_url, headers(), body(id))
-      |> Finch.request(http)
-      |> handle_response()
-      |> handle_post()
-      |> maybe_notify(state)
-
-    poll_interval = 60_000 * (15..25 |> Enum.random())
+    :post
+    |> Finch.build(@graph_url, headers(), body(id))
+    |> Finch.request(http)
+    |> handle_response()
+    |> handle_post()
+    |> maybe_notify(state)
+    |> set_last_post(state)
+
+    poll_interval = 60_000 * (5..10 |> Enum.random())
     Logger.info("Will poll #{state.name} again in #{poll_interval}ms")
     Process.send_after(self(), :get_posts, poll_interval)
-    {:noreply, %{state | last_post: last_post}}
+    {:noreply, state}
   end
 
   def handle_info(:get_posts, state), do: {:noreply, state, {:continue, :get_latest_post}}
 
-  defp maybe_notify({:error, _}, %{last_post: last_post}), do: last_post
+  defp set_last_post(nil, _), do: :noop
 
-  defp maybe_notify(%{id: id}, %{last_post: %{id: id} = last_post}),
-    do: last_post
+  defp set_last_post(post, %{id: id}) do
+    LastPost.set(id, post)
+  end
+
+  defp maybe_notify({:error, _}, _), do: nil
+
+  defp maybe_notify(%{id: id} = post, %{id: fb_id} = state) do
+    case LastPost.get(fb_id) do
+      %{id: ^id} -> post
+      _old_post -> notify(post, state)
+    end
+  end
 
-  defp maybe_notify(
+  defp notify(
          %{message: message, images: images} = post,
          %{notifier: notifier, from: from, notify: notify, name: name}
        ) do
@@ -107,6 +117,16 @@ defmodule Notifier.FBGraph.Worker do
     error
   end
 
+  defp handle_post([res | _]) do
+    Logger.error("FB Graph returned error: #{inspect(res)}")
+    {:error, :no_data}
+  end
+
+  defp handle_post(res) do
+    Logger.error("Unhandled result: #{inspect(res)}")
+    {:error, :no_data}
+  end
+
   defp handle_response({:ok, %Finch.Response{status: 200, body: body}}) do
     body
     |> String.split("\r\n")