feat: random sort option for front page (#2363)

* Add hook for random sorting

* Add random sorting to front page

* Add multiple tests for random sorting.

* Be extra sure that all recipes are returned.

* Too stable random. seed doesn't reach backend.

* add timestamp to useRecipeSearch

* Update randomization tests for timestamp seeding

* ruff cleanup

* pass timestamp separately in getAll

* remove debugging log items

* remove timestamp from address bar

* remove defaults from backend timestamps

* timestamp should be optional

* fix edge case: query without timestamp

* similar edge case: no timestamp in pagination

* ruff :/

* better edge case handling

* stabilize random search test w/more recipes

* better pagination seeding

* update pagination seed test

* remove redundant random/seed check

* Test for api routes to random sorting.

* please the typing gods

* hack to make query parameters throw correct exc

* ruff

* fix validator message typo

* black reformatting

---------

Co-authored-by: Hayden <64056131+hay-kot@users.noreply.github.com>

mealie/repos/repository_generic.py

@@ -1,12 +1,13 @@
 from __future__ import annotations
 
+import random
 from collections.abc import Iterable
 from math import ceil
 from typing import Any, Generic, TypeVar
 
 from fastapi import HTTPException
 from pydantic import UUID4, BaseModel
-from sqlalchemy import Select, delete, func, select
+from sqlalchemy import Select, case, delete, func, select
 from sqlalchemy.orm.session import Session
 from sqlalchemy.sql import sqltypes
 
@@ -378,4 +379,16 @@ class RepositoryGeneric(Generic[Schema, Model]):
 
                 query = query.order_by(order_attr)
 
+            elif pagination.order_by == "random":
+                # randomize outside of database, since not all db's can set random seeds
+                # this solution is db-independent & stable to paging
+                temp_query = query.with_only_columns(self.model.id)
+                allids = self.session.execute(temp_query).scalars().all()  # fast because id is indexed
+                order = list(range(len(allids)))
+                random.seed(pagination.pagination_seed)
+                random.shuffle(order)
+                random_dict = dict(zip(allids, order, strict=True))
+                case_stmt = case(random_dict, value=self.model.id)
+                query = query.order_by(case_stmt)
+
         return query.limit(pagination.per_page).offset((pagination.page - 1) * pagination.per_page), count, total_pages