From c5e0821a12cd26cafa0101be43dc4d0df8cd7e15 Mon Sep 17 00:00:00 2001
From: Maksim Pechnikov <parallel588@gmail.com>
Date: Fri, 16 Oct 2020 22:33:47 +0300
Subject: [PATCH] added `users_tags` table

---
 lib/pleroma/tag.ex                                 |  1 +
 lib/pleroma/user.ex                                |  2 +-
 .../repo/migrations/20201012093959_create_tags.exs |  3 +-
 .../migrations/20201014064744_create_user_tag.exs  | 74 ++++++++++++++++++++++
 4 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 priv/repo/migrations/20201014064744_create_user_tag.exs

diff --git a/lib/pleroma/tag.ex b/lib/pleroma/tag.ex
index 16d0b0eda..5185a907b 100644
--- a/lib/pleroma/tag.ex
+++ b/lib/pleroma/tag.ex
@@ -14,6 +14,7 @@ defmodule Pleroma.Tag do
 
   schema "tags" do
     field(:name, :string)
+    many_to_many(:users, Pleroma.User, join_through: "users_tags", on_replace: :delete)
 
     timestamps()
   end
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index c1aa0f716..e4cb8e5c1 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -101,7 +101,6 @@ defmodule Pleroma.User do
     field(:following_address, :string)
     field(:search_rank, :float, virtual: true)
     field(:search_type, :integer, virtual: true)
-    field(:tags, {:array, :string}, default: [])
     field(:last_refreshed_at, :naive_datetime_usec)
     field(:last_digest_emailed_at, :naive_datetime)
     field(:banner, :map, default: %{})
@@ -161,6 +160,7 @@ defmodule Pleroma.User do
 
     has_many(:outgoing_relationships, UserRelationship, foreign_key: :source_id)
     has_many(:incoming_relationships, UserRelationship, foreign_key: :target_id)
+    many_to_many(:tags, Pleroma.Tag, join_through: "users_tags", on_replace: :delete)
 
     for {relationship_type,
          [
diff --git a/priv/repo/migrations/20201012093959_create_tags.exs b/priv/repo/migrations/20201012093959_create_tags.exs
index 54bf8a2ce..66e26f9a2 100644
--- a/priv/repo/migrations/20201012093959_create_tags.exs
+++ b/priv/repo/migrations/20201012093959_create_tags.exs
@@ -15,12 +15,13 @@ defmodule Pleroma.Repo.Migrations.CreateTags do
 
   def down do
     drop_if_exists(table(:tags))
+    drop_if_exists(unique_index(:tags, :name))
   end
 
   defp collect_user_tags_query do
     """
     INSERT INTO tags(name, inserted_at, updated_at)
-    SELECT DISTINCT unnest(tags), now(), now() from users
+    SELECT DISTINCT TRIM(unnest(tags)), now(), now() from users
     ON CONFLICT DO NOTHING
     """
   end
diff --git a/priv/repo/migrations/20201014064744_create_user_tag.exs b/priv/repo/migrations/20201014064744_create_user_tag.exs
new file mode 100644
index 000000000..d68b3a1cd
--- /dev/null
+++ b/priv/repo/migrations/20201014064744_create_user_tag.exs
@@ -0,0 +1,74 @@
+defmodule Pleroma.Repo.Migrations.CreateUserTag do
+  use Ecto.Migration
+
+  def up do
+    create_if_not_exists table(:users_tags, primary_key: false) do
+      add(:tag_id, references(:tags, on_delete: :delete_all))
+      add(:user_id, references(:users, type: :uuid, on_delete: :delete_all))
+    end
+
+    create_if_not_exists(index(:users_tags, [:tag_id]))
+    create_if_not_exists(index(:users_tags, [:user_id]))
+    create_if_not_exists(unique_index(:users_tags, [:user_id, :tag_id]))
+
+    flush()
+
+    execute(import_user_tags())
+
+    alter table(:users) do
+      remove_if_exists(:tags, {:array, :string})
+    end
+
+    drop_if_exists(index(:users, [:tags]))
+  end
+
+  def down do
+    alter table(:users) do
+      add_if_not_exists(:tags, {:array, :string}, default: [], null: false)
+    end
+
+    create_if_not_exists(index(:users, [:tags], using: :gin))
+
+    flush()
+
+    execute(restore_tags_column())
+
+    drop_if_exists(table(:users_tags))
+    drop_if_exists(index(:users_tags, [:tag_id]))
+    drop_if_exists(index(:users_tags, [:user_id]))
+
+    drop_if_exists(
+      unique_index(:users_tags, [:user_id, :tag_id], name: :user_id_tag_id_unique_index)
+    )
+  end
+
+  defp import_user_tags do
+    """
+    INSERT INTO users_tags(user_id, tag_id)
+    SELECT user_tags.user_id, tags.id
+     FROM (
+     SELECT  DISTINCT TRIM(unnest(tags)) as "tag", id as "user_id"
+       FROM users ) as "user_tags"
+     INNER JOIN tags as tags on tags.name = user_tags."tag"
+     ON CONFLICT DO NOTHING
+    """
+  end
+
+  defp restore_tags_column do
+    """
+    UPDATE
+      users
+    SET
+      tags = tags_query.tags_array,
+      updated_at = now()
+    FROM (
+      SELECT user_id, array_agg(tags.name) as tags_array
+      FROM users_tags
+        INNER JOIN users ON users.id = user_id
+        INNER JOIN tags ON tags.id = tag_id
+      GROUP BY user_id
+    ) as tags_query
+    WHERE tags_query.user_id = users.id
+    """
+  end
+end