-- One row per distinct work, shared by every bookmark that tracks it
-- (ADR-0003). Keyed (site, series_id), the pair a bookmark key decomposes
-- into. title/series_url/cover are written once, at creation, and never
-- again: client-supplied values are ignored once the row exists and the
-- poller is the only party that may change them. kind and the latest-chapter
-- fields are last-write-wins like the bookmark's own fields.
CREATE TABLE series (
  site               text NOT NULL,
  series_id          text NOT NULL,
  title              text NOT NULL DEFAULT '',
  series_url         text NOT NULL DEFAULT '',
  cover              text NOT NULL DEFAULT '',
  kind               text NOT NULL DEFAULT 'manga',
  latest_chapter     text NOT NULL DEFAULT '',
  latest_chapter_num double precision,
  -- When the server last polled this series, unix ms; 0 means never, and sorts
  -- first so a new bookmark is picked up on the next tick with no special case.
  latest_checked_at  bigint NOT NULL DEFAULT 0,
  PRIMARY KEY (site, series_id)
);

-- Backfill from today's rows. The bookmark key's uniqueness makes
-- (site, series_id) unique in practice; DISTINCT is belt and braces.
INSERT INTO series (site, series_id, title, series_url, cover, kind,
                    latest_chapter, latest_chapter_num, latest_checked_at)
SELECT DISTINCT site, series_id, title, series_url, cover, kind,
                latest_chapter, latest_chapter_num, latest_checked_at
FROM bookmarks;

-- The bookmark keeps only what differs between readers (ADR-0003): progress,
-- favourite, lifecycle bucket. The dropped columns now live on series.
ALTER TABLE bookmarks
  DROP COLUMN title,
  DROP COLUMN series_url,
  DROP COLUMN cover,
  DROP COLUMN kind,
  DROP COLUMN latest_chapter,
  DROP COLUMN latest_chapter_num,
  DROP COLUMN latest_checked_at;

-- A bookmark may not point at a series that does not exist. No cascade: a
-- series outlives its last bookmark, and deleting one is not a store operation.
ALTER TABLE bookmarks
  ADD CONSTRAINT bookmarks_series_fk
  FOREIGN KEY (site, series_id) REFERENCES series (site, series_id);