-- +goose Up
-- Special pages: a page's kind says what it shows instead of posts. The
-- first special kind is a gallery of the library's images; the images a
-- gallery leaves out are rows here, so a deleted file drops out by itself.
ALTER TABLE pages ADD COLUMN kind text NOT NULL DEFAULT 'posts'
    CHECK (kind IN ('posts', 'gallery'));

CREATE TABLE page_hidden_files (
    page_id bigint NOT NULL REFERENCES pages(id) ON DELETE CASCADE,
    file_id uuid   NOT NULL REFERENCES files(id) ON DELETE CASCADE,
    PRIMARY KEY (page_id, file_id)
);

-- +goose Down
DROP TABLE page_hidden_files;
ALTER TABLE pages DROP COLUMN kind;