CREATE EXTENSION IF NOT EXISTS pg_trgm;

ALTER TABLE posts
  ADD COLUMN IF NOT EXISTS search_text TEXT NOT NULL DEFAULT '';

ALTER TABLE pages
  ADD COLUMN IF NOT EXISTS search_text TEXT NOT NULL DEFAULT '';

CREATE OR REPLACE FUNCTION normalize_public_search_text(value TEXT)
RETURNS TEXT
LANGUAGE sql
IMMUTABLE
AS $$
  SELECT lower(trim(regexp_replace(
    regexp_replace(
      regexp_replace(coalesce(value, ''), E'!\\[[^]]*\\]\\([^)]*\\)', ' ', 'g'),
      E'/uploads/[^[:space:])"]+',
      ' ',
      'g'
    ),
    E'[[:space:]]+',
    ' ',
    'g'
  )))
$$;

CREATE OR REPLACE FUNCTION set_post_search_text()
RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
  NEW.search_text := normalize_public_search_text(concat_ws(E'\n', NEW.title, NEW.excerpt, NEW.content));
  RETURN NEW;
END;
$$;

CREATE OR REPLACE FUNCTION set_page_search_text()
RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
  NEW.search_text := normalize_public_search_text(concat_ws(E'\n', NEW.title, NEW.listing_section, NEW.listing_title, NEW.listing_description, NEW.content));
  RETURN NEW;
END;
$$;

DROP TRIGGER IF EXISTS posts_search_text_before_write ON posts;

CREATE TRIGGER posts_search_text_before_write
  BEFORE INSERT OR UPDATE OF title, excerpt, content
  ON posts
  FOR EACH ROW
  EXECUTE FUNCTION set_post_search_text();

DROP TRIGGER IF EXISTS pages_search_text_before_write ON pages;

CREATE TRIGGER pages_search_text_before_write
  BEFORE INSERT OR UPDATE OF title, listing_section, listing_title, listing_description, content
  ON pages
  FOR EACH ROW
  EXECUTE FUNCTION set_page_search_text();

UPDATE posts
SET search_text = normalize_public_search_text(concat_ws(E'\n', title, excerpt, content));

UPDATE pages
SET search_text = normalize_public_search_text(concat_ws(E'\n', title, listing_section, listing_title, listing_description, content));

CREATE INDEX IF NOT EXISTS posts_public_search_text_trgm_idx
  ON posts USING gin (search_text gin_trgm_ops)
  WHERE status = 'published';

CREATE INDEX IF NOT EXISTS pages_public_search_text_trgm_idx
  ON pages USING gin (search_text gin_trgm_ops)
  WHERE status = 'published' AND is_listed = true;

CREATE INDEX IF NOT EXISTS tags_name_trgm_idx
  ON tags USING gin ((lower(name)) gin_trgm_ops);

CREATE INDEX IF NOT EXISTS tags_slug_trgm_idx
  ON tags USING gin ((lower(slug)) gin_trgm_ops);