From 467d7d5cbcd0d7bf06a6e4ea4fd872f594dd7763 Mon Sep 17 00:00:00 2001
From: Matt Ludwigs <mattludwigs@users.noreply.github.com>
Date: Wed, 15 Jul 2020 11:22:18 -0700
Subject: [PATCH] Add configuration for handlers

---
 .circleci/config.yml                          |  4 +--
 README.md                                     | 29 +++++++++++++++++++
 .../firmware_update_supervisor.ex             | 16 +++++++++-
 .../inclusions/inclusion_runner_supervisor.ex | 16 +++++++++-
 mix.exs                                       |  2 +-
 5 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index a8eed243..6ffbe857 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -43,7 +43,7 @@ jobs:
             - v1-mix-cache-{{ checksum "mix.lock" }}
       - run: mix deps.get
       - run: mix compile --warnings-as-errors
-      - run: mix test --include inclusion --include integration
+      - run: mix test --include inclusion --include integration --include firmware_update
       - run: mix format --check-formatted
       - run: mix docs
       - run: mix hex.build
@@ -72,7 +72,7 @@ jobs:
             - v1-mix-cache-{{ checksum "mix.lock" }}
       - run: mix deps.get
       - run: mix compile --warnings-as-errors
-      - run: mix test --include inclusion --include integration
+      - run: mix test --include inclusion --include integration --include firmware_update
       - run: mix format --check-formatted
       - run: MIX_ENV=docs mix docs
       - run: MIX_ENV=docs mix hex.build
diff --git a/README.md b/README.md
index 47cad2b4..7a81c500 100644
--- a/README.md
+++ b/README.md
@@ -149,6 +149,35 @@ config :grizzly,
 
 For more information see `Grizzly.Runtime` module
 
+## Handlers
+
+Grizzly manages the low level details of around things that require more than
+just sending one off commands like including/excluding a device and firmware
+updates.
+
+However, sometimes your higher level application will have some logic that you
+will want to preform during the process. So, there are handler behaviours for
+this types of processes. You can read more about those behaviours in their
+respective modules.
+
+You can provide the handler for any such process that accepts one either at
+runtime or through mix configuration options. The configuration option looks
+like:
+
+```elixir
+config :grizzly,
+  handlers: %{
+    firmware_update: MyFirmwareUpdateHandler,
+    inclusion: MyInclusionHandler
+  }
+```
+
+If you do not pass any handler at runtime or configure any for the process will
+send messages to the calling process.
+
+You can override the configured handlers at runtime by passing in the `:handler`
+option to these processes.
+
 ## Z-Wave Bridge Configuration
 
 Grizzly defers the low-level Z-Wave protocol handling to a combination of third
diff --git a/lib/grizzly/firmware_updates/firmware_update_supervisor.ex b/lib/grizzly/firmware_updates/firmware_update_supervisor.ex
index cf9c67c8..6952f884 100644
--- a/lib/grizzly/firmware_updates/firmware_update_supervisor.ex
+++ b/lib/grizzly/firmware_updates/firmware_update_supervisor.ex
@@ -11,7 +11,7 @@ defmodule Grizzly.FirmwareUpdates.FirmwareUpdateRunnerSupervisor do
 
   @spec start_runner([FirmwareUpdates.opt()]) :: DynamicSupervisor.on_start_child()
   def start_runner(opts \\ []) do
-    opts = Keyword.merge([handler: self()], opts)
+    opts = ensure_handler(opts)
     child_spec = FirmwareUpdateRunner.child_spec(opts)
     DynamicSupervisor.start_child(__MODULE__, child_spec)
   end
@@ -21,4 +21,18 @@ defmodule Grizzly.FirmwareUpdates.FirmwareUpdateRunnerSupervisor do
     # Only one firmware update runner can be running at a time
     DynamicSupervisor.init(strategy: :one_for_one, max_children: 1)
   end
+
+  defp ensure_handler(opts) do
+    Keyword.put_new_lazy(opts, :handler, &get_firmware_update_handler/0)
+  end
+
+  defp get_firmware_update_handler() do
+    case Application.get_env(:girzzly, :handlers) do
+      nil ->
+        self()
+
+      handlers ->
+        Map.get(handlers, :firmware_update, self())
+    end
+  end
 end
diff --git a/lib/grizzly/inclusions/inclusion_runner_supervisor.ex b/lib/grizzly/inclusions/inclusion_runner_supervisor.ex
index cc5575ed..76c42220 100644
--- a/lib/grizzly/inclusions/inclusion_runner_supervisor.ex
+++ b/lib/grizzly/inclusions/inclusion_runner_supervisor.ex
@@ -11,7 +11,7 @@ defmodule Grizzly.Inclusions.InclusionRunnerSupervisor do
 
   @spec start_runner([Inclusions.opt()]) :: DynamicSupervisor.on_start_child()
   def start_runner(opts \\ []) do
-    opts = Keyword.merge([handler: self()], opts)
+    opts = ensure_handler(opts)
     child_spec = InclusionRunner.child_spec(opts)
     DynamicSupervisor.start_child(__MODULE__, child_spec)
   end
@@ -21,4 +21,18 @@ defmodule Grizzly.Inclusions.InclusionRunnerSupervisor do
     # Only one inclusion runner can be running at a time
     DynamicSupervisor.init(strategy: :one_for_one, max_children: 1)
   end
+
+  defp ensure_handler(opts) do
+    Keyword.put_new_lazy(opts, :handler, &get_inclusion_handler/0)
+  end
+
+  defp get_inclusion_handler() do
+    case Application.get_env(:girzzly, :handlers) do
+      nil ->
+        self()
+
+      handlers ->
+        Map.get(handlers, :inclusion, self())
+    end
+  end
 end
diff --git a/mix.exs b/mix.exs
index 88a0d132..37f2ebd2 100644
--- a/mix.exs
+++ b/mix.exs
@@ -71,7 +71,7 @@ defmodule Grizzly.MixProject do
 
   defp aliases() do
     [
-      test: ["test --exclude integration --exclude inclusion"]
+      test: ["test --exclude integration --exclude inclusion --exclude firmware_update"]
     ]
   end
 end