-- Persian normalization fn (idempotent via OR REPLACE).
CREATE OR REPLACE FUNCTION teknav_norm_fa(t text)
RETURNS text LANGUAGE sql IMMUTABLE PARALLEL SAFE AS $$
  SELECT regexp_replace(
    translate(
      coalesce(t, ''),
      E'يكأإآٱ‌ـًٌٍَُِّْ،؛؟',
      E'یکاااا                ,;?'
    ),
    '\s+', ' ', 'g'
  );
$$;

-- Trigram support for autocomplete / fuzzy matching.
CREATE EXTENSION IF NOT EXISTS pg_trgm;

-- Weighted tsvector computed column (A=title, B=subtitle+summary, C=content).
ALTER TABLE "Article"
  ADD COLUMN IF NOT EXISTS "search_tsv" tsvector
  GENERATED ALWAYS AS (
    setweight(to_tsvector('simple', teknav_norm_fa("title")),                    'A') ||
    setweight(to_tsvector('simple', teknav_norm_fa(coalesce("subtitle", ''))),  'B') ||
    setweight(to_tsvector('simple', teknav_norm_fa("summary")),                 'B') ||
    setweight(to_tsvector('simple', teknav_norm_fa("content")),                 'C')
  ) STORED;

-- GIN index for full-text search.
CREATE INDEX IF NOT EXISTS "Article_search_tsv_idx" ON "Article" USING GIN ("search_tsv");

-- Trigram index for title autocomplete.
CREATE INDEX IF NOT EXISTS "Article_title_trgm_idx" ON "Article" USING GIN ("title" gin_trgm_ops);