-- A grab may target a whole season: one season-pack torrent satisfies every
-- episode in it (DESIGN.md §13 phase 6). SQLite cannot alter a CHECK, so the
-- table is rebuilt.
CREATE TABLE grabs_new (
    id          INTEGER PRIMARY KEY,
    release_id  INTEGER NOT NULL REFERENCES releases (id),
    target_kind TEXT NOT NULL CHECK (target_kind IN ('movie', 'episode', 'season')),
    target_id   INTEGER NOT NULL,
    infohash    TEXT NOT NULL UNIQUE,
    state       TEXT NOT NULL DEFAULT 'sent'
                CHECK (state IN ('sent', 'downloaded', 'imported', 'failed')),
    grabbed_at  TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
    imported_at TEXT
) STRICT;

INSERT INTO grabs_new (id, release_id, target_kind, target_id, infohash, state, grabbed_at, imported_at)
SELECT id, release_id, target_kind, target_id, infohash, state, grabbed_at, imported_at FROM grabs;

DROP TABLE grabs;
ALTER TABLE grabs_new RENAME TO grabs;

CREATE INDEX grabs_state ON grabs (state);
CREATE INDEX grabs_target ON grabs (target_kind, target_id);