refactor(schema): invert relationship between items and recipes

Move item_id to recipes table and drop recipe_id from items
Update backend queries and admin UI to reflect the new domain model

backend/db/schema.sql

@@ -48,23 +48,11 @@ CREATE TABLE IF NOT EXISTS acquisition_methods (
   name text NOT NULL UNIQUE
 );
 
-CREATE TABLE IF NOT EXISTS recipes (
-  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
-  name text NOT NULL UNIQUE
-);
-
-CREATE TABLE IF NOT EXISTS recipe_acquisition_methods (
-  recipe_id integer NOT NULL REFERENCES recipes(id) ON DELETE CASCADE,
-  acquisition_method_id integer NOT NULL REFERENCES acquisition_methods(id),
-  PRIMARY KEY (recipe_id, acquisition_method_id)
-);
-
 CREATE TABLE IF NOT EXISTS items (
   id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
   name text NOT NULL UNIQUE,
   category_id integer NOT NULL REFERENCES item_categories(id),
   usage_id integer REFERENCES item_usages(id),
-  recipe_id integer REFERENCES recipes(id),
   dyeable boolean NOT NULL DEFAULT false,
   dual_dyeable boolean NOT NULL DEFAULT false,
   pattern_editable boolean NOT NULL DEFAULT false
@@ -72,6 +60,49 @@ CREATE TABLE IF NOT EXISTS items (
 
 ALTER TABLE items ALTER COLUMN usage_id DROP NOT NULL;
 
+CREATE TABLE IF NOT EXISTS recipes (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  item_id integer NOT NULL UNIQUE REFERENCES items(id)
+);
+
+ALTER TABLE recipes ADD COLUMN IF NOT EXISTS item_id integer REFERENCES items(id);
+
+DO $$
+BEGIN
+  IF EXISTS (
+    SELECT 1
+    FROM information_schema.columns
+    WHERE table_name = 'items'
+      AND column_name = 'recipe_id'
+  ) THEN
+    EXECUTE '
+      UPDATE recipes r
+      SET item_id = linked.item_id
+      FROM (
+        SELECT DISTINCT ON (recipe_id) recipe_id, id AS item_id
+        FROM items
+        WHERE recipe_id IS NOT NULL
+        ORDER BY recipe_id, id
+      ) linked
+      WHERE r.id = linked.recipe_id
+        AND r.item_id IS NULL
+    ';
+  END IF;
+END $$;
+
+DELETE FROM recipes WHERE item_id IS NULL;
+
+ALTER TABLE recipes ALTER COLUMN item_id SET NOT NULL;
+CREATE UNIQUE INDEX IF NOT EXISTS recipes_item_id_key ON recipes(item_id);
+ALTER TABLE recipes DROP COLUMN IF EXISTS name;
+ALTER TABLE items DROP COLUMN IF EXISTS recipe_id;
+
+CREATE TABLE IF NOT EXISTS recipe_acquisition_methods (
+  recipe_id integer NOT NULL REFERENCES recipes(id) ON DELETE CASCADE,
+  acquisition_method_id integer NOT NULL REFERENCES acquisition_methods(id),
+  PRIMARY KEY (recipe_id, acquisition_method_id)
+);
+
 DROP TABLE IF EXISTS item_item_tags;
 DROP TABLE IF EXISTS item_tags;