[#534] Initial implementation of unreachable federation targets retirement.

lib/pleroma/instances/instance.ex

@@ -0,0 +1,77 @@
+defmodule Pleroma.Instances.Instance do
+  @moduledoc "Instance."
+
+  alias Pleroma.Instances
+  alias Pleroma.Instances.Instance
+
+  use Ecto.Schema
+
+  import Ecto.{Query, Changeset}
+
+  alias Pleroma.Repo
+
+  schema "instances" do
+    field(:host, :string)
+    field(:unreachable_since, :naive_datetime)
+    field(:reachability_checked_at, :naive_datetime)
+
+    timestamps()
+  end
+
+  def update_changeset(struct, params \\ %{}) do
+    struct
+    |> cast(params, [:host, :unreachable_since, :reachability_checked_at])
+    |> unique_constraint(:host)
+  end
+
+  def reachable?(url) do
+    !Repo.one(
+      from(i in Instance,
+        where:
+          i.host == ^host(url) and i.unreachable_since <= ^Instances.reachability_time_threshold(),
+        select: true
+      )
+    )
+  end
+
+  def set_reachable(url) do
+    Repo.update_all(
+      from(i in Instance, where: i.host == ^host(url)),
+      set: [
+        unreachable_since: nil,
+        reachability_checked_at: DateTime.utc_now()
+      ]
+    )
+  end
+
+  def set_unreachable(url, unreachable_since \\ nil) do
+    unreachable_since = unreachable_since || DateTime.utc_now()
+    host = host(url)
+    existing_record = Repo.get_by(Instance, %{host: host})
+
+    changes = %{
+      unreachable_since: unreachable_since,
+      reachability_checked_at: NaiveDateTime.utc_now()
+    }
+
+    if existing_record do
+      update_changes =
+        if existing_record.unreachable_since &&
+             NaiveDateTime.compare(existing_record.unreachable_since, unreachable_since) != :gt,
+           do: Map.delete(changes, :unreachable_since),
+           else: changes
+
+      {:ok, _instance} = Repo.update(update_changeset(existing_record, update_changes))
+    else
+      {:ok, _instance} = Repo.insert(update_changeset(%Instance{}, Map.put(changes, :host, host)))
+    end
+  end
+
+  defp host(url_or_host) do
+    if url_or_host =~ ~r/^http/i do
+      URI.parse(url_or_host).host
+    else
+      url_or_host
+    end
+  end
+end