feat(reports): allow reports to hold multiple events

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

priv/repo/migrations/20230605143534_allow_multiple_events_to_be_reported.exs

@@ -0,0 +1,14 @@
+defmodule Mobilizon.Storage.Repo.Migrations.AllowMultipleEventsToBeReported do
+  use Ecto.Migration
+
+  def up do
+    create table(:reports_events, primary_key: false) do
+      add(:report_id, references(:reports, on_delete: :delete_all), null: false)
+      add(:event_id, references(:events, on_delete: :delete_all), null: false)
+    end
+  end
+
+  def down do
+    drop table(:reports_events)
+  end
+end

priv/repo/migrations/20230605153836_backfill_report_events_with_old_events.exs

@@ -0,0 +1,31 @@
+defmodule Mobilizon.Storage.Repo.Migrations.BackfillReportEventsWithOldEvents do
+  use Ecto.Migration
+
+  def up do
+    process_reports_with_events()
+  end
+
+  def down do
+    IO.puts("Doing nothing, migration can't be reverted")
+  end
+
+  defp process_reports_with_events do
+    %Postgrex.Result{rows: rows} =
+      Ecto.Adapters.SQL.query!(
+        Mobilizon.Storage.Repo,
+        "SELECT id, event_id FROM reports WHERE event_id IS NOT NULL"
+      )
+
+    Enum.map(rows, &migrate_event_row/1)
+  end
+
+  defp migrate_event_row([report_id, event_id]) when not is_nil(event_id) do
+    Ecto.Adapters.SQL.query!(
+      Mobilizon.Storage.Repo,
+      "INSERT INTO reports_events VALUES ($1, $2)",
+      [report_id, event_id]
+    )
+  end
+
+  defp migrate_event_row(_), do: :ok
+end

priv/repo/migrations/20230605154106_remove_obsolete_event_id_on_reports.exs

@@ -0,0 +1,15 @@
+defmodule Mobilizon.Storage.Repo.Migrations.RemoveObsoleteEventIdOnReports do
+  use Ecto.Migration
+
+  def up do
+    alter table(:reports) do
+      remove_if_exists :event_id, :integer
+    end
+  end
+
+  def down do
+    alter table(:reports) do
+      add(:event_id, references(:events, on_delete: :delete_all), null: true)
+    end
+  end
+end