-- 0007_backfill_mai_projects.sql
-- One-time backfill: for every row in mai.projects that has not already been
-- promoted into projax (no item_links row with ref_type='mai-project' yet),
-- create a projax-native item under the heuristic-chosen area, link it back
-- to mai.projects via item_links, and (if the source row has a repo) record a
-- gitea-repo pointer.
--
-- Idempotent — re-running adds nothing because the existence guard checks the
-- item_links pointer.

CREATE OR REPLACE FUNCTION projax.guess_parent_area(p_slug text, p_repo text)
RETURNS uuid
LANGUAGE sql
STABLE
AS $$
  -- Pull the seven seeded areas once; choose by heuristic.
  WITH area AS (
    SELECT slug, id FROM projax.items WHERE parent_id IS NULL
  )
  SELECT id FROM area WHERE slug = (
    CASE
      WHEN p_slug = 'mhealth'                                          THEN 'health'
      WHEN p_slug IN ('msports', 'manjin')                             THEN 'sports'
      WHEN p_slug IN ('kanzlai', 'hlckm', 'work', 'mworkrepo', 'paliad')
        OR (p_repo IS NOT NULL AND p_repo LIKE 'HL/%')                 THEN 'work'
      WHEN p_slug = 'mhome'                                            THEN 'home'
      ELSE 'dev'
    END
  );
$$;

DO $backfill$
DECLARE
  rec       record;
  parent_id uuid;
  new_id    uuid;
  proj_status text;
BEGIN
  FOR rec IN
    SELECT p.id, p.name, p.repo, p.path, p.memory_group, p.status, p.goal, p.metadata
    FROM mai.projects p
    WHERE NOT EXISTS (
      SELECT 1 FROM projax.item_links l
      WHERE l.ref_type = 'mai-project' AND l.ref_id = p.id
    )
  LOOP
    parent_id := projax.guess_parent_area(rec.id, rec.repo);

    proj_status := CASE rec.status
      WHEN 'active'   THEN 'active'
      WHEN 'sleeping' THEN 'archived'
      WHEN 'archived' THEN 'archived'
      WHEN 'done'     THEN 'done'
      ELSE 'active'
    END;

    INSERT INTO projax.items
      (kind, title, slug, parent_id, content_md, metadata, status, management, tags)
    VALUES (
      ARRAY['project']::text[],
      rec.name,
      rec.id,
      parent_id,
      COALESCE(rec.goal, ''),
      jsonb_build_object(
        'repo',         COALESCE(rec.repo, ''),
        'path',         COALESCE(rec.path, ''),
        'memory_group', COALESCE(rec.memory_group, '')
      ) || COALESCE(rec.metadata, '{}'::jsonb),
      proj_status,
      ARRAY['mai']::text[],
      '{}'::text[]
    )
    RETURNING id INTO new_id;

    INSERT INTO projax.item_links (item_id, ref_type, ref_id, rel)
      VALUES (new_id, 'mai-project', rec.id, 'derived-from')
      ON CONFLICT (item_id, ref_type, ref_id, rel) DO NOTHING;

    IF rec.repo IS NOT NULL AND rec.repo <> '' THEN
      INSERT INTO projax.item_links (item_id, ref_type, ref_id, rel, metadata)
        VALUES (
          new_id,
          CASE WHEN rec.repo LIKE 'github.com/%' THEN 'github-repo' ELSE 'gitea-repo' END,
          rec.repo,
          'source',
          '{}'::jsonb
        )
        ON CONFLICT (item_id, ref_type, ref_id, rel) DO NOTHING;
    END IF;
  END LOOP;
END
$backfill$;

-- Any item linked back to mai.projects must carry 'mai' in management, even
-- if it was promoted before Phase 1.5 (when the column didn't exist).
UPDATE projax.items
   SET management = array_append(management, 'mai')
 WHERE NOT ('mai' = ANY(management))
   AND id IN (SELECT item_id FROM projax.item_links WHERE ref_type = 'mai-project');