lemmy/migrations/2023-07-26-000217_create_controversial_indexes/down.sql

-- Update comment_aggregates_score trigger function to exclude controversy_rank update
create or replace function comment_aggregates_score()
returns trigger language plpgsql
as $$
begin
  IF (TG_OP = 'INSERT') THEN
    update comment_aggregates ca
    set score = score + NEW.score,
    upvotes = case when NEW.score = 1 then upvotes + 1 else upvotes end,
    downvotes = case when NEW.score = -1 then downvotes + 1 else downvotes end
    where ca.comment_id = NEW.comment_id;

  ELSIF (TG_OP = 'DELETE') THEN
    -- Join to comment because that comment may not exist anymore
    update comment_aggregates ca
    set score = score - OLD.score,
    upvotes = case when OLD.score = 1 then upvotes - 1 else upvotes end,
    downvotes = case when OLD.score = -1 then downvotes - 1 else downvotes end
    from comment c
    where ca.comment_id = c.id
    and ca.comment_id = OLD.comment_id;

  END IF;
  return null;
end $$;

-- Update post_aggregates_score trigger function to exclude controversy_rank update
create or replace function post_aggregates_score()
returns trigger language plpgsql
as $$
begin
  IF (TG_OP = 'INSERT') THEN
    update post_aggregates pa
    set score = score + NEW.score,
    upvotes = case when NEW.score = 1 then upvotes + 1 else upvotes end,
    downvotes = case when NEW.score = -1 then downvotes + 1 else downvotes end
    where pa.post_id = NEW.post_id;

  ELSIF (TG_OP = 'DELETE') THEN
    -- Join to post because that post may not exist anymore
    update post_aggregates pa
    set score = score - OLD.score,
    upvotes = case when OLD.score = 1 then upvotes - 1 else upvotes end,
    downvotes = case when OLD.score = -1 then downvotes - 1 else downvotes end
    from post p
    where pa.post_id = p.id
    and pa.post_id = OLD.post_id;
  END IF;
  return null;
end $$;

-- Drop the indexes
drop index if exists idx_post_aggregates_featured_local_controversy;
drop index if exists idx_post_aggregates_featured_community_controversy;
drop index if exists idx_comment_aggregates_controversy;

-- Remove the added columns from the tables
alter table post_aggregates drop column controversy_rank;
alter table comment_aggregates drop column controversy_rank;

-- Remove function
drop function controversy_rank(numeric, numeric);