Fetches a collection by name.

Returns {:ok, collection} or {:error, {:unknown_collection, name}}.

Gets an existing collection by name or creates a new one.

If a description is provided and the collection already exists, the description is updated only if the existing one is nil or empty.

Examples

{:ok, collection} = Collection.get_or_create("products", MyRepo)
{:ok, collection} = Collection.get_or_create("default", MyRepo)
{:ok, collection} = Collection.get_or_create("docs", MyRepo, "Official documentation")

Extracts collection names from search/ask opts.

Looks for :collections (list) or :collection (single name). Returns [nil] if neither is set.

Resolves a single collection name to its ID.

Returns {:ok, nil} when name is nil (unscoped) or, in non-strict mode, when the collection doesn't exist. With strict? set, an unknown name returns {:error, {:unknown_collection, name}}.

Resolves a list of collection names to their IDs.

Returns {:ok, nil} for unscoped queries (when collections is [nil]), otherwise {:ok, ids}. Unknown names are dropped, so the list can be empty — callers must treat an empty list as "match nothing", never as "no filter". With strict: true, the first unknown name returns {:error, {:unknown_collection, name}} instead.