1 files changed, 91 insertions, 0 deletions
diff --git a/lib/irc/plugin_supervisor.ex b/lib/irc/plugin_supervisor.ex
new file mode 100644
index 0000000..ca092dc
--- /dev/null
+++ b/lib/irc/plugin_supervisor.ex
@@ -0,0 +1,91 @@
+defmodule IRC.Plugin do
+  require Logger
+
+  defmodule Supervisor do
+    use DynamicSupervisor
+
+    def start_link() do
+      DynamicSupervisor.start_link(__MODULE__, [], name: __MODULE__)
+    end
+
+    def start_child(module, opts \\ []) do
+      IO.inspect(module)
+      spec = %{id: {IRC.Plugin,module}, start: {IRC.Plugin, :start_link, [module, opts]}, name: module, restart: :transient}
+      DynamicSupervisor.start_child(__MODULE__, spec)
+    end
+
+    @impl true
+    def init(_init_arg) do
+      DynamicSupervisor.init(
+        strategy: :one_for_one,
+        max_restarts: 10,
+        max_seconds: 1
+      )
+    end
+  end
+
+  def dets(), do: to_charlist(LSG.data_path("/plugins.dets"))
+
+  def setup() do
+    :dets.open_file(dets(), [])
+  end
+
+  def enabled() do
+    :dets.foldl(fn
+      {name, true, _}, acc -> [name | acc]
+      _, acc -> acc
+    end, [], dets())
+  end
+
+  def start_all() do
+    for mod <- enabled(), do: {mod, IRC.Plugin.Supervisor.start_child(mod)}
+  end
+
+  def declare(module) do
+    case get(module) do
+      :disabled -> :dets.insert(dets(), {module, true, nil})
+      _ -> nil
+    end
+  end
+
+  def start(module, opts \\ []) do
+    IRC.Plugin.Supervisor.start_child(module)
+  end
+
+  @doc "Enables a plugin"
+  def enable(name), do: switch(name, true)
+
+  @doc "Disables a plugin"
+  def disable(name), do: switch(name, false)
+
+  @doc "Enables or disables a plugin"
+  def switch(name, value) when is_boolean(value) do
+    last = case get(name) do
+      {:ok, last} -> last
+      _ -> nil
+    end
+    :dets.insert(dets(), {name, value, last})
+  end
+
+  @spec get(module()) :: {:ok, last_start :: nil | non_neg_integer()} | :disabled
+  def get(name) do
+    case :dets.lookup(dets(), name) do
+      [{name, enabled, last_start}] -> {:ok, enabled, last_start}
+      _ -> :disabled
+    end
+  end
+
+  def start_link(module, options \\ []) do
+    with {:disabled, {_, true, last}} <- {:disabled, get(module)},
+          {:throttled, false} <- {:throttled, false}
+    do
+      module.start_link()
+    else
+      {error, _} ->
+        Logger.info("Plugin: #{to_string(module)} ignored start: #{to_string(error)}")
+        :ignore
+    end
+  end
+
+end
+