From 108e90b18edcfb57b9839e7c5d6d444a63ae2069 Mon Sep 17 00:00:00 2001
From: Ivan Tashkinov <ivantashkinov@gmail.com>
Date: Sun, 31 Jan 2021 22:03:59 +0300
Subject: [PATCH] [#3213] Explicitly defined PKs in hashtags_objects and
 data_migration_failed_ids. Added "pleroma.database rollback" task to revert a
 single migration.

---
 lib/mix/tasks/pleroma/database.ex             | 24 +++++++++++++++++++
 ...20201221203824_create_hashtags_objects.exs |  4 ++--
 ...gration_create_populate_hashtags_table.exs |  4 +++-
 ...72254_create_data_migration_failed_ids.exs |  4 ++--
 4 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/lib/mix/tasks/pleroma/database.ex b/lib/mix/tasks/pleroma/database.ex
index 4ddace9c9..30c0d2bf1 100644
--- a/lib/mix/tasks/pleroma/database.ex
+++ b/lib/mix/tasks/pleroma/database.ex
@@ -20,6 +20,30 @@ defmodule Mix.Tasks.Pleroma.Database do
   @shortdoc "A collection of database related tasks"
   @moduledoc File.read!("docs/administration/CLI_tasks/database.md")
 
+  # Rolls back a specific migration (leaving subsequent migrations applied)
+  # Based on https://stackoverflow.com/a/53825840
+  def run(["rollback", version]) do
+    start_pleroma()
+
+    version = String.to_integer(version)
+    re = ~r/^#{version}_.*\.exs/
+    path = Application.app_dir(:pleroma, Path.join(["priv", "repo", "migrations"]))
+
+    result =
+      with {:find, "" <> file} <- {:find, Enum.find(File.ls!(path), &String.match?(&1, re))},
+           {:compile, [{mod, _} | _]} <- {:compile, Code.compile_file(Path.join(path, file))},
+           {:rollback, :ok} <- {:rollback, Ecto.Migrator.down(Repo, version, mod)} do
+        {:ok, "Reversed migration: #{file}"}
+      else
+        {:find, _} -> {:error, "No migration found with version prefix: #{version}"}
+        {:compile, e} -> {:error, "Problem compiling migration module: #{inspect(e)}"}
+        {:rollback, e} -> {:error, "Problem reversing migration: #{inspect(e)}"}
+        e -> {:error, "Something unexpected happened: #{inspect(e)}"}
+      end
+
+    IO.inspect(result)
+  end
+
   def run(["remove_embedded_objects" | args]) do
     {options, [], []} =
       OptionParser.parse(
diff --git a/priv/repo/migrations/20201221203824_create_hashtags_objects.exs b/priv/repo/migrations/20201221203824_create_hashtags_objects.exs
index 214ea81c3..efd60369d 100644
--- a/priv/repo/migrations/20201221203824_create_hashtags_objects.exs
+++ b/priv/repo/migrations/20201221203824_create_hashtags_objects.exs
@@ -3,8 +3,8 @@ defmodule Pleroma.Repo.Migrations.CreateHashtagsObjects do
 
   def change do
     create_if_not_exists table(:hashtags_objects, primary_key: false) do
-      add(:hashtag_id, references(:hashtags), null: false)
-      add(:object_id, references(:objects), null: false)
+      add(:hashtag_id, references(:hashtags), null: false, primary_key: true)
+      add(:object_id, references(:objects), null: false, primary_key: true)
     end
 
     create_if_not_exists(unique_index(:hashtags_objects, [:hashtag_id, :object_id]))
diff --git a/priv/repo/migrations/20210106183301_data_migration_create_populate_hashtags_table.exs b/priv/repo/migrations/20210106183301_data_migration_create_populate_hashtags_table.exs
index 2a965f075..cf3cf26a0 100644
--- a/priv/repo/migrations/20210106183301_data_migration_create_populate_hashtags_table.exs
+++ b/priv/repo/migrations/20210106183301_data_migration_create_populate_hashtags_table.exs
@@ -10,5 +10,7 @@ def up do
     )
   end
 
-  def down, do: :ok
+  def down do
+    execute("DELETE FROM data_migrations WHERE name = 'populate_hashtags_table';")
+  end
 end
diff --git a/priv/repo/migrations/20210111172254_create_data_migration_failed_ids.exs b/priv/repo/migrations/20210111172254_create_data_migration_failed_ids.exs
index ba0be98af..18afa74ac 100644
--- a/priv/repo/migrations/20210111172254_create_data_migration_failed_ids.exs
+++ b/priv/repo/migrations/20210111172254_create_data_migration_failed_ids.exs
@@ -3,8 +3,8 @@ defmodule Pleroma.Repo.Migrations.CreateDataMigrationFailedIds do
 
   def change do
     create_if_not_exists table(:data_migration_failed_ids, primary_key: false) do
-      add(:data_migration_id, references(:data_migrations), null: false)
-      add(:record_id, :bigint, null: false)
+      add(:data_migration_id, references(:data_migrations), null: false, primary_key: true)
+      add(:record_id, :bigint, null: false, primary_key: true)
     end
 
     create_if_not_exists(